CN102388119A - Method for producing biomass charcoal and device for producing biomass charcoal to be used therefor - Google Patents

Abstract

A method for producing biochar, comprising carbonizing biomass to generate biochar and tar-containing waste gas, and contacting at least a part of the tar in the exhausted gas with the biomass and/or the biochar , to produce biocoke in which tar adheres and precipitates as carbonized products.

Description

Method for manufacturing biochar and apparatus for manufacturing biochar used therein

technical field

The present invention relates to a method for producing biocoke by carbonizing biomass and a production device for biocoke used therein.

Background technique

From the viewpoint of preventing global warming, reducing the emission of carbon dioxide is an urgent issue. The following technological developments have been carried out as methods for reducing carbon dioxide emissions.

·Reduce carbon input.

·Recover the output carbon dioxide.

·Replace existing coal/petroleum with carbon-free carbon sources.

Biomass is known as a carbon-free carbon source. Examples of biomass include wood waste generated from dismantling of buildings and households, wood-based waste generated from wood processing, pruning waste such as forests, and agricultural waste. As the method of disposal and utilization thereof, landfill, storage, incineration, fuel, etc. are mainly used. In addition, biofuel crops for the purpose of fuel utilization are also known.

On the other hand, in the iron and steel industry, especially the ironmaking process is a process of reducing iron ore using coal as a reducing material. In addition, in the steelmaking process, heat required for refining is supplied from coal or the like. Therefore, in the steel industry, carbon sources must be used. On the other hand, biomass is composed of carbon, oxygen, and hydrogen, but biomass itself has a high moisture content and low calorific value (for example, 15% by mass of moisture, 16.2MJ/kg-dry basis), and is directly used in iron and steel processing Not efficient in terms of efficiency. Therefore, there is a method in which biomass is dry-distilled, subjected to dehydration, decarbonation, and other treatments to remove moisture and increase the calorific value, and use it in iron and steel processing. Dry distillation causes dehydration and degassing (decarbonation, demethanation, tar generation, etc.), and carbon components in biomass are generated as gas and tar components, so there is little carbon component (biomass char) remaining as solid. As a substitute for coal in iron and steel processing, it is necessary to produce biocoke at a high yield in order to effectively utilize the carbon component remaining as a solid after such dry distillation as biocoke.

There is also known a technique of thermally decomposing such biomass to produce combustible gas and carbonized product (biomass char) and reuse them.

Patent Document 1 discloses a method of producing carbonized products with high calorific value by circulating and absorbing volatile matter generated during heating to carbonized products obtained by heating and carbonizing biomass.

Patent Document 2 discloses a treatment method for organic matter as follows: thermally decompose the organic matter without supply of combustion air to generate amorphous carbon, and decompose the undecomposed organic matter containing flammable gas and gaseous tar. The treatment gas is passed through the amorphous carbon at a temperature of 800 to 1000° C. under atmospheric pressure, and the tar is almost completely thermally decomposed to obtain a treatment gas from which the tar has been removed.

Patent Document 3 discloses a thermal decomposition treatment apparatus for waste that thermally decomposes waste charged into a shaft furnace by contact with heating gas blown from a gas injection nozzle, and is separated into charred and thermally decomposed waste in the furnace. gas.

Patent Document 4 discloses a charcoal manufacturing apparatus that fills the furnace body of a box furnace with charcoal raw materials, heats, dries, carbonizes, and carbonizes to produce charcoal.

The following carbonization furnace is disclosed in Patent Document 5, which includes: a box-shaped furnace body with a raw material inlet and a charcoal discharge port; a carbonization chamber with a square cross section in the body; Combustion chamber in which combustible gas produced by heating wood materials burns in the upper space; tuyere for blowing air into the combustion chamber; unit for adjusting the amount of air blown in from the tuyere; and a side or side of the carbonization chamber Thermally conductive walls on the bottom.

Patent Document 6 discloses a wood carbonization method in which wood is heated at 300 to 1000° C. with an oxygen concentration of 10% or less using a rotary kiln or a rotary dryer, and the gas generated by heating is mixed with the above-mentioned rotary kiln or the above-mentioned Combustion in a combustor connected to a rotary dryer.

Patent Document 1: Japanese Patent Laid-Open No. 2003-213273

Patent Document 2: Patent No. 3781379

Patent Document 3: Japanese Patent Laid-Open No. 2001-131557

Patent Document 4: Japanese Patent Application Laid-Open No. 03-122191

Patent Document 5: Japanese Patent Laid-Open No. 2007-146016

Patent Document 6: Japanese Patent Laid-Open No. 2002-241762

Contents of the invention

When biocoke is produced by the method described in Patent Document 1, the yield of biocoke increases only by the amount of adhering tar or the like. However, it is considered that the surface of the carbonized product obtained by the method of absorbing liquid volatile matter is sticky and difficult to handle. Usually, tar obtained by pyrolyzing biomass is a liquid obtained by pyrolysis, but the calorific value of carbonized biomass is about 30MJ/kg, while tar is at most about 10MJ/kg, which is less than half of heavy oil. In addition, when biomass is thermally decomposed to obtain carbonized products, a large amount of oxygen in the biomass is detached from the biomass as tar components and volatiles, so the oxygen content in the carbonized products is less than 10% by mass. Oxygen content in Oxygen sometimes exceeds 20% by mass and becomes close to 40% by mass. Tar with a high oxygen content and high reactivity also has high pyrophoric properties and has problems in terms of safety.

As described above, tar components have a higher oxygen content, lower calorific value, higher viscosity, higher reactivity, and lower stability than carbonized products. Therefore, if they adhere to the biocoke, the quality of the biocoke will deteriorate.

In Patent Document 2, the object is to increase the yield of combustible gas by decomposing tar irrespective of water vapor reforming when generating amorphous carbon and combustible gas. From the viewpoint of production of carbonized products, the yield of carbonized products decreases due to gasification or tarification of carbon components in the raw material. As described in Patent Document 2, when tar is thermally decomposed at a temperature close to 1000° C., almost all of it is converted into gas, and the yield of charred products obtained from tar is several mass % at most.

In Patent Document 3, a carbonized product is produced by carbonizing biomass or the like in a shaft furnace. Usually, it is carried out by feeding an oxygen-free high-temperature gas from the lower part of the furnace to heat the contents, but due to the thermal decomposition caused by this dry distillation, gas, tar, etc. are generated in addition to carbonized products. These gases and tars can also be effectively utilized. Therefore, from the viewpoint of producing carbonized products, the yield of carbonized products decreases due to gasification or tarification of carbon components in raw materials.

The conventional technologies described in Patent Documents 4 to 6 have the following problems (a) to (d).

(a) Both the batch method and the rotary method are methods of carbonizing biomass only by controlling heating temperature, environmental conditions, and the like. The yield of carbonized biomass (biomass char) is about 25% by mass in the batch system and about 20% by mass in the rotary system, and it is difficult to further increase the yield of biochar.

(b) When the generated gas and tar are combusted and used as a heat source for dry distillation of biomass, the gas and tar components cannot be recovered as biomass charcoal. The tar produced is expected to be actively transformed into biochar.

(c) In the batch method of Patent Documents 4 and 5, since it is not a continuous process, it takes more than 5 hours for carbonization, which is uneconomical.

(d) In addition to light gases, wood vinegar and heavy hydrocarbon (tar) components are produced in the biomass pyrolysis product, and air ratio, temperature, etc. must be controlled in order to completely burn the tar components. In addition, in order to separately utilize the dry distillation product without performing the combustion treatment, it is necessary to perform exhaust gas treatment such as tar removal.

The object of the present invention is to solve such problems of the prior art, and provide a method for producing biocoke and a production device for producing biocoke used in the method, when using a shaft furnace to carbonize biomass to produce biocoke , the yield of biochar can be increased, and the quality of biochar is less reduced.

(1) A method for producing biochar, wherein,

Carbonize biomass to form biochar,

discharging exhaust gas containing tar generated during said carbonization,

contacting at least a portion of said tar in said exhaust gas with said biomass and/or said biochar,

At least a portion of the tar contacted with the biomass and/or the biochar is converted to char.

(2) The method for producing biochar as described in (1), wherein,

Biomass input from the top or side upper part of the shaft furnace,

Hot air is blown from the bottom of the shaft furnace or a position lower than the discharge position of the exhaust gas, that is, a side lower part,

charring the biomass in the shaft furnace to form biochar,

discharging waste gas containing tar produced during said carbonization from the top or side upper part of said shaft furnace,

blowing at least a portion of the tar in the exhaust gas into the shaft furnace to contact the biomass and/or the biochar,

Converting at least a portion of the tar in contact with the biomass and/or the biochar to char.

(3) The method for producing biochar as described in (2), wherein,

At least a part of the tar in the exhaust gas is blown into the shaft furnace together with the hot air.

(4) The method for producing biochar as described in (2) or (3), wherein,

Cooling gas is supplied from the bottom or side lower part of the shaft furnace.

(5) The method for producing biochar as described in (4), wherein,

The cooling gas recycles the waste gas.

(6) The method for producing biochar as described in (4) or (5), wherein,

A part of the tar is supplied into the furnace together with the cooling gas.

(7) The method for producing biocoke according to any one of (2) to (6), wherein,

The tar is separated from the exhaust gas, and the separated tar is blown into a shaft furnace.

(8) The method for producing biocoke according to any one of (2) to (7), wherein,

The exhaust gas is burned with an air ratio of less than 1, and blown into the shaft furnace as hot air.

(9) The method for producing biocoke according to any one of (2) to (8), wherein,

The carbonization temperature of the biochar is 300-700°C.

(10) The method for producing biocoke according to any one of (2) to (9), wherein,

The temperature of the waste gas is 50-300°C.

(11) The method for producing biochar according to any one of (2) to (10), wherein,

The hot air is anaerobic or hypoxic, and the temperature is 400-1200°C.

(12) The method for producing biochar as described in (1), wherein,

The carbonization of the biomass is carried out by feeding biomass into the shaft furnace from the top or side upper part of the shaft furnace and blowing hot air from the bottom or side lower part of the shaft furnace,

The discharge of the waste gas is carried out by discharging the waste gas containing the tar generated during the carbonization from the top or side upper part of the shaft furnace,

Contacting at least a part of the tar is performed by blowing at least a part of the tar in the exhaust gas generated during the carbonization into the shaft furnace.

(13) The method for producing biochar as described in (1), wherein,

dry distillation of biomass to form dry distillation biomass,

Gas and tar generated by carbonization of the biomass are brought into contact with the carbonization biomass, and carbon components in the gas and tar are deposited on the carbonization biomass.

(14) The method for producing biochar as described in (13), wherein,

The dry distillation biomass has a specific surface area of 10 m ² /g or more.

(15) The method for producing biochar as described in (13), wherein,

The carbonization temperature of the biomass is 450°C to 700°C, and the temperature at which the carbon components in the gas and tar are attached and precipitated on the dry distillation biomass is 450°C to 700°C.

(16) The method for producing biochar as described in (13), wherein,

The dry distillation is carried out through a rotary dry distillation furnace.

(17) The method for producing biochar as described in (13), wherein,

The deposition of carbon components in the tar to the dry distillation biomass is carried out in a packed bed or moving bed method coking furnace.

(18) The method for producing biochar as described in (1), wherein,

The carbonization of the biomass includes carbonizing the biomass to generate carbonized biomass and waste gas containing tar, and coking the carbonized biomass,

The contacting of at least a part of the tar includes contacting the waste gas containing the tar with the dry distillation biomass, and making the carbon components in the gas and the tar adhere to and deposit on the dry distillation biomass.

(19) The method for producing biochar as described in (1),

Biomass charcoal is produced by dry-distilling biomass using a double-tower filled moving-bed system furnace having two carbonylation furnaces connected to each other, wherein,

contacting gases and tars produced by the retort of biomass in one retort with biomass in another retort,

During the carbonization of the biomass in the other carbonization furnace, carbon components in the gas and the tar are attached and deposited on the biomass in the other carbonization furnace.

(20) The method for producing biochar as described in (19), wherein,

The carbonization temperature of the biomass in the carbonization furnace is set to 400°C to 800°C.

(21) The method for producing biochar as described in (19), wherein,

The residence time of the biomass in the carbonization furnace is set to 30 minutes or more.

(22) The method for producing biochar as described in (1), wherein,

The carbonization of the biomass includes carbonizing the biomass in the first carbonization furnace to generate gas and tar,

The contacting of at least a part of the tar includes contacting the gas and tar generated in the first carbonization furnace with the biomass in the second carbonization furnace, and the gas and the The tar adheres and precipitates on the biomass in the second carbonization furnace.

(23) A manufacturing device for biochar, comprising:

Shaft furnaces for carbonizing biomass to produce biochar;

The input port of the biomass provided on the top or side upper part of the shaft furnace;

an exhaust gas discharge port provided on the top or side upper part of the shaft furnace;

A hot air blowing inlet provided at the bottom of the shaft furnace, or at a position below the outlet, that is, at the lower side; and

A partial burner for combusting at least a portion of said exhaust gas at an air ratio of less than one.

(24) The biocoke manufacturing apparatus as described in (23), wherein,

It also has a separator for separating at least gas components and tar from the exhaust gas.

According to the present invention, biomass charcoal can be efficiently produced by carbonizing biomass using a shaft furnace, and the yield of biochar can be improved. The quality of the produced biocoke was higher than the biocoke to which only tar was attached.

In addition, tar is effectively used, and the burden of tar treatment is also reduced. The dry distillation product can be reduced in weight, and the exhaust gas treatment process can also be reduced. As a result, the recycling of biomass can be promoted and contribute to the reduction of CO ₂ emissions.

Description of drawings

FIG. 1 is a diagram showing one embodiment of a biocoke manufacturing apparatus according to Embodiment 1. FIG.

FIG. 2 is a diagram showing another embodiment of the biocoke manufacturing apparatus according to Embodiment 1. FIG.

FIG. 3 is a diagram showing another embodiment of the biocoke manufacturing apparatus according to Embodiment 1. FIG.

FIG. 4 is a diagram showing another embodiment of the biocoke manufacturing apparatus according to Embodiment 1. FIG.

FIG. 5 is a diagram showing another embodiment of the biocoke manufacturing apparatus according to Embodiment 1. FIG.

FIG. 6 is a diagram showing another embodiment of the biocoke manufacturing apparatus according to Embodiment 1. FIG.

FIG. 7 is an explanatory diagram of an embodiment of Embodiment 2. FIG.

FIG. 8 is an explanatory diagram of another embodiment of Embodiment 2. FIG.

Fig. 9 is a schematic diagram of a biocoke manufacturing apparatus using a double-tower filled moving-bed system furnace according to a third embodiment.

Fig. 10 is a cross-sectional view of the retort shown in Fig. 9 .

FIG. 11 is an explanatory diagram of an embodiment of the present invention using the apparatus of FIG. 9 .

FIG. 12 is a schematic diagram of a double-tower filled moving-bed system furnace used in an example of Embodiment 3. FIG.

FIG. 13 is an explanatory diagram of another embodiment of the third embodiment.

Detailed ways

[Embodiment 1]

Biomass refers to the general term for the accumulation of a certain amount of animal and plant resources and wastes derived from them. However, fossil resources do not belong to biomass. As the biomass used in Embodiment 1, any biomass that is thermally decomposed to produce charred products such as agriculture, forestry, livestock, fishery, and waste can be used. It is preferable to use biomass with high effective calorific value, and it is preferable to use woody biomass.

Examples of woody biomass include the following.

·Pulp black liquor, sawdust and other papermaking by-products, bark, sawdust and other wood processing by-products,

・Forest residual materials such as branches, leaves, treetops, and short-sized materials,

· Cedar, cypress, pine and other harvested materials,

・Materials from special forest products such as waste shiitake wood from edible fungi,

·Forestry biomass such as fuelwood forest materials such as Castanopsis, Quercus japonica, and pine, short-cutting forestry such as willow, poplar, eucalyptus, and pine,

・General waste such as pruned trees and branches of trees in the streets of cities, towns, and villages, trees in the gardens of individual houses,

・Pruning of branches of trees in the streets of the country and prefectures, trees in the gardens of companies, etc.,

·Industrial waste such as construction/construction waste.

Classified by agricultural biomass, rice husks, wheat straw, rice straw, sugar cane gas, palm, etc. with waste/by-products as sources, or rice bran, rapeseed, soybeans, etc. with energy crops as sources Part of the biomass can also be suitably used as woody biomass.

In Embodiment 1, biomass is carbonized using a shaft furnace as a carbonization furnace, and biocoke, which is a carbonized product, is produced. As a shaft furnace, a pit furnace is preferably used.

Carbonization in the case of carbonizing biomass refers to cutting off or limiting the supply of air (oxygen) and heating to obtain gas (also referred to as wood gas), liquid (tar), and solid (char) products. By changing the heating temperature and heating time, the components and ratios of the obtained gas, liquid, and solid are changed. In Embodiment 1, the tar in the exhaust gas generated during carbonization is recovered together with the gas, and at least a part of the tar is blown together with hot air into a shaft furnace for carbonizing biomass, thereby making the tar adhere to the biomass charcoal, Furthermore, the carbonized product of tar is precipitated on the biochar, and the yield of biochar is improved. By carbonizing the tar generated by the carbonization of biomass again in the shaft furnace and depositing it on the biochar, the biochar has a lower oxygen content and a higher calorific value than the state where only the tar is attached, and the reactivity Low and pyrophoric also reduced, so the safety is high and the quality is improved.

Here, "the carbonized product of tar is precipitated on the bio-coke" means "the thermal decomposition reaction or polymerization reaction of the tar proceeds on the bio-coke, whereby the tar is converted into a carbonized product on the bio-coke". To cause such a thermal decomposition reaction or polymerization reaction, it is necessary to first attach tar to the biocoke, and to heat the biocoke with the tar attached thereto to increase the temperature. In the shaft furnace according to Embodiment 1, tar is deposited on the biocoke at the low-temperature part of the upper part of the furnace, and the biocoke on which the tar is attached falls to the lower part of the furnace and is heated to a higher temperature, so carbonized products of tar are produced. Precipitated on biochar.

The tar generated by the carbonization of biomass is carbonized again in the shaft furnace and precipitated on the biochar. As a result, the biochar has a lower oxygen content, higher calorific value, and higher reactivity than the state where only tar is attached. and the pyrophoric properties are also reduced, resulting in high safety and improved quality. The biocoke according to Embodiment 1 obtained a calorific value of about 30 MJ/kg, which was the same as conventional biocoke to which no tar was attached. For example, when tar is deposited by the method shown in Patent Document 1, since the calorific value of tar is about 10 MJ/kg, the amount of tar deposition is calculated hypothetically based on the ratio of energy yield improvement according to the examples of Patent Document 1. , only about 14 to 20 MJ/kg of heat can be obtained. Assuming that in Patent Document 1, even if the adhering tar is a dark brown highly viscous liquid in which a brown transparent liquid (acetic acid) is separated and removed by standing or distilling the liquid obtained by thermally decomposing biomass, after removing the acetic acid The calorific value of tar is also about 20MJ/kg at most, and the calorific value of biochar reaches 23-27MJ/kg as a result.

As above, in order to carbonize biomass to produce biochar, in Embodiment 1, biomass is fed from the top or side upper part of the shaft furnace to form a filling layer in the furnace, and blown from the bottom or side lower part of the shaft furnace The biomass is carbonized by entering hot air, exhaust gas containing tar generated during carbonization is discharged from the upper part of the shaft furnace, and at least a part of the tar is blown into the shaft furnace together with the hot air to carbonize the biomass. Hereinafter, the top or the side upper part is collectively referred to as "upper part". Hereinafter, the bottom or the side lower part is collectively referred to as "lower part". Biomass charcoal deposited with tar and precipitated as carbonized products is discharged from the lower part of the shaft furnace. The position where the hot air is blown is lower than the discharge position of the exhaust gas. Biomass is carbonized by sensible heat of hot air. Here, the side upper part refers to the side part of the upper half in the height direction of the shaft furnace, but it is more preferably the upper 1/4 or more. Similarly, the side lower part means the side part of the lower half part in the height direction of a shaft furnace, but it is more preferable that it is below 1/4.

The tar is separated from the exhaust gas and at least part of the tar is blown into the shaft furnace. Preferably, 10 to 100% of the tar separated from the exhaust gas is blown into the shaft furnace, and the tar is brought into contact with the above-mentioned biomass and/or the above-mentioned biocoke. When it is 10% or more, the effect of improving the carbonization yield is large. More preferably, 50-100% of the tar separated from the exhaust gas is blown into the shaft furnace. The method of blowing in is arbitrary, and it is preferable to blow into the position of the lower half of the biomass filling bed (from the hot air blowing position to the filling bed surface). When the tar is mixed with the hot air and blown together with the hot air, the efficiency of converting the tar into carbonized products is improved, and it is convenient in terms of facilities, so it is preferable. Preferably, 10 to 100% of the tar contacted with the biomass and/or the biochar is converted into charred products. From the viewpoint of improving the carbonization yield, it is preferably 10% or more. More preferably, it is 20 to 100%. Alternatively, the tar-containing exhaust gas is partially combusted as it is, and at least a part thereof is used as hot air, whereby it can be blown together with the hot air.

The hot air can use any source of hot air, hot air generated by a hot blast stove, etc. can be used, or the hot air obtained by partially burning the gas separated from the tar and water from the exhaust gas can be recycled, or the exhaust gas can be directly partially burned by recycling. Get hot air.

Since the biocoke in the shaft furnace is high temperature, it is preferable to cool the biocoke cut out and discharged. In order to facilitate this cooling, it is preferable to supply cooling gas into the furnace from the lower part of the shaft furnace. As the cooling gas, exhaust gas is preferably recycled, and part of the gas obtained by partially burning the gas obtained by separating tar and water from the exhaust gas can be used by cooling. Cooling gas also needs to cut off or limit the supply of air (oxygen).

It is preferable to mix a part of the tar generated at the time of biomass carbonization with the above-mentioned cooling gas, and supply the tar together with the cooling gas into the shaft furnace. Tar adheres to the cooled biochar, and the yield of biochar increases. This ratio is smaller than that of the tar blown in together with the hot air, but a part of the tar supplied together with the cooling gas is also carbonized in the furnace and deposited on the biomass charcoal. In the case where exhaust gas is circulated for the cooling gas, tar is blown in in a state mixed with the cooling gas in advance.

It is also possible to add externally generated tar to the tar blown in together with hot air or cooling gas. As the externally generated tar, it is preferable to use a biomass-derived tar that may be charred, and it is particularly preferable to use a tar generated by thermally decomposing biomass at 700° C. or lower.

The rest of the waste gas can be used as fuel, or burned by a burner or the like, and used as high-temperature waste gas for heat recovery, biomass drying, and the like.

The height of the filled layer of biomass in the shaft furnace is the height from the position where the hot air is blown to the surface of the filled layer. The height of the filled layer is preferably not less than 2 m and less than 15 m. If the height of the portion where the biomass is heated is too low, the heat exchange is inefficient, and the effect of improving the yield by tar is also small. On the other hand, if the height of the portion where the biomass is heated is too high, the pressure loss will be too large and the equipment cost will increase.

One embodiment of Embodiment 1 will be described using FIG. 1 .

Raw materials 1 such as woody biomass are supplied from an upper inlet to a carbonization furnace 10 serving as a shaft furnace. Moreover, the hot air 5 is supplied from the hot air inlet 11 which is a hot air blowing inlet. The hot air 5 is oxygen-free or low-oxygen in order not to cause combustion of the furnace filling and carbonization. Hypoxic means, for example, an oxygen content of less than 1% by volume. Tar 4 can be mixed in hot air 5 .

The raw material 1 forms a filling layer 12 in the carbonization furnace 10 , is heated by the hot air 5 , is carbonized, and is discharged as a carbonized product 2 from the lower cutting device 13 . By providing a rotating mechanism or the like at the hot air inlet 11, it is possible to accelerate cutting out of carbonized material. On the other hand, the exhaust gas 3 generated from the packed bed 12 is discharged from the discharge port at the upper part of the furnace. The generated gas is roughly anaerobic and mixed with tar.

The form of the raw material 1 is preferably a form that does not hinder the gas flow in the packed layer, that is, a block with a size of about 5 mm to 200 mm as the main body (90% by mass or more). As for the particle size here, 200 mm or less means the state of passing through a sieve with a mesh size of 200 mm, and 5 mm or more means the state of passing through a 5 mm sieve.

When the raw material 1 is supplied to the carbonization furnace 10, it is preferable that the upper surface of the filled layer 12 is in a flattened state to some extent. This is to prevent the drift of gas and achieve effective carbonization.

The temperature of the hot air 5 is preferably 400 to 1200°C. This is because if the blowing temperature is too low, the carbonization of the raw material will not proceed sufficiently, and if it is too high, the yield of carbonized products will decrease and the equipment cost will increase. Preferably it is 600-1200 degreeC, More preferably, it is 600-1000 degreeC.

The temperature of carbonization produced by carbonization is preferably about 300 to 700°C. This is because if the temperature is too low, carbonization will not proceed sufficiently, and if it is too high, the yield of carbonized products will decrease and the equipment cost will increase. Preferably it is 400-700 degreeC, More preferably, it is 400-600 degreeC. When cutting out by the cutting device 13, the carbonized material 2 can be cut out at a safe temperature by indirect cooling such as a water cooling jacket or direct cooling by water spray.

The temperature of the exhaust gas discharged from the discharge port on the upper part of the packed bed 12 is preferably about 50 to 300°C. This is because if the temperature is too low, water cannot be sufficiently discharged from the filled layer, and if the temperature is too high, the discharge of tar components from the filled layer is too large, the yield of carbonized products is reduced, and tar problems are likely to occur downstream. It is preferably about 70 to 200°C.

Mix tar 4 in hot air 5. As the tar 4, tar separated from the exhaust gas 3 is preferably used. By mixing the tar 4 in the hot air 5, a part of the tar 4 adheres to the carbonized product 2 and is recovered as a carbonized product, so that the yield of the carbonized product 2 can be increased. By using a part of the exhaust gas 3 as the hot air 5 as it is, it is also possible to blow the hot air mixed with tar.

The tar 4 is mixed with the hot air 5 and supplied to the filling layer 12 in the furnace, and contributes to an increase in the yield of the carbonization 2 by being adsorbed on the carbonization in the filling layer. Most of the tar 4 is thermally decomposed in the filled bed 12 to generate a carbon component, that is, a carbonized product.

The hot air 5 is supplied from the bottom of the furnace through the hot air inlet as shown in the figure, but it may also be supplied from the lateral direction of the furnace using nozzles.

Another embodiment of the present invention will be described using FIG. 2 .

The raw material 1 is supplied to the carbonization furnace 10 from above. In addition, hot air 21 is supplied to the intermediate portion in the furnace. The tar 22 is mixed in the hot air 21 . In addition, cold air 23 is supplied into the furnace from a cold air inlet 25 . The tar 24 can be mixed in the cold air 23 . The hot air 21 and the cold air 23 are oxygen-free or low-oxygen in order not to cause combustion of the furnace filling and carbonization.

The raw material 1 forms the filling layer 12 in the furnace, is heated by the hot air 21 to be carbonized, and is cooled by the cold air 23 after carbonization, and is discharged as the carbonized product 2 from the lower cutting device 13 . The cold air inlet 25 can promote cutting out of carbonized material by providing a rotating mechanism or the like. On the other hand, the exhaust gas 3 generated from the packed bed 12 is discharged from the upper part of the furnace.

The form of the raw material 1 is preferably a form that does not hinder the gas flow in the packed layer, that is, a block with a size of about 5 mm to 200 mm as the main body (90% by mass or more). As for the particle size here, 200 mm or less means the state of passing through a sieve with a mesh size of 200 mm, and 5 mm or more means the state of passing through a 5 mm sieve.

When the raw material 1 is supplied to the carbonization furnace 10, it is preferable that the upper surface of the filled layer 12 is in a flattened state to some extent. This is to prevent the drift of gas and achieve effective carbonization.

The temperature of the hot air 21 is blown at 400 to 1200°C. This is because if the blowing air temperature is too low, the carbonization of the raw material will not proceed sufficiently, and if it is too high, the yield of carbonized products will decrease and the equipment cost will increase. Preferably it is 600-1000 degreeC.

The temperature of the carbonized product near the inlet of the hot air 21 in the middle section of the filled bed is preferably about 300 to 700°C. If the temperature is too low, carbonization will not proceed sufficiently, and if it is too high, the yield of carbonized products will decrease and the equipment cost will increase. Preferably it is 400-700 degreeC, More preferably, it is 400-600 degreeC.

The temperature of cold air 23 is desirably 200° C. or lower. Preferably it is 100°C or less. This is because cooling is not efficient if the temperature is too high.

When cutting out by the cutting device 13, the carbonized material 2 can be cut out at a safe temperature by indirect cooling such as a water cooling jacket or direct cooling by water spray.

The temperature of the exhaust gas discharged from the upper part of the packed bed 12 is preferably about 50 to 300°C. This is because if the temperature is too low, water cannot be fully discharged from the filled layer, and if the temperature is too high, the discharge of tar components from the filled layer is too large, the yield of carbonized products decreases, and tar problems are likely to occur downstream. More preferably, it is about 70 to 200°C.

When the tar 22 is mixed in the hot air 21 , the tar separated from the exhaust gas 3 is used for the tar 22 . By mixing the tar 22 in the hot air 21, a part of the tar 22 is contained in the carbonized product 2, and therefore, the yield of the carbonized product 2 can be increased. When a part of the exhaust gas 3 is directly used as the hot air 21, the hot air mixed with tar may be injected.

It is also possible to mix tar 24 in the cold air 23 , and the tar 24 is preferably the tar separated from the exhaust gas 3 . By mixing the tar 24 in the cold air 23, a part of the tar 24 is contained in the generated carbonized product 2, and therefore, the yield of the carbonized product 2 can be increased.

The tar 22 or tar 24 is mixed with the hot air 21 or the cold air 23 and supplied to the filling bed 12 in the furnace, and contributes to an increase in the yield of the carbonization 2 by being adsorbed to the carbonization in the filling bed. The tar 22 or 24 is further thermally decomposed in the filled layer 12 to generate a carbon component, that is, a carbonized product, which contributes to an increase in the yield of the carbonized product 2 . The tar 24 includes not only the tar that is thermally decomposed in the furnace to generate carbon components, but also the tar that is discharged out of the furnace while adhering to carbonized products.

As shown in the figure, tar 22 or tar 24 is mixed with hot air 21 and cold air 23 and supplied into the furnace, but may be directly supplied to the furnace filling layer 12 without being mixed with hot air or cold air.

As shown in the drawing, the cold air 23 is supplied from the lower part of the furnace through the hot air inlet, but it may also be supplied from the lateral direction of the furnace using nozzles.

Another embodiment of the present invention will be described using FIG. 3 .

The raw material 1 is supplied to the carbonization furnace 10 from above, and the filling layer 12 is formed in the furnace, and it is carbonized by heating with the hot air 5, and it discharge|emits as the carbonized material 2.

The exhaust gas 3 generated in the filling layer 12 is separated into gas 32 , acetic acid 33 , and tar 34 by the separator 311 . The tar obtained here refers to a dark brown highly viscous liquid in which a liquid obtained by thermally decomposing biomass is separated by standing or distillation and a brown transparent liquid (acetic acid) is removed. The calorific value of tar in this case is about 20 MJ/kg at the maximum by removing acetic acid. As the form of the separator 311, the liquid phase of acetic acid and tar can be separated at a temperature below the condensation temperature of acetic acid, and the gas and gas phase can be separated. If the liquid phase can be separated into a water phase (acetic acid phase) and an oil phase (tar phase) The structure is not particularly limited. Water-soluble organic substances are also contained in the aqueous phase. In the separator 311, the separation efficiency can be improved by cooling as necessary.

Part of the gas 32 separated by the separator 311 and the separated tar 34 are subjected to so-called incomplete combustion with air 35 by the partial burner 312 . Here, the amount of air 35 is such that the air ratio is less than 1, and oxygen-free or extremely low-oxygen hot air 36 is generated. When raising the temperature of the hot air to a predetermined temperature, the air ratio may be less than 1 if a normal biomass raw material is used, but is preferably 0.5 or more. In addition, since tar remains in the hot air, the air ratio is preferably 0.8 or less.

The acetic acid separated by the separator 311 is discarded or the dissolved water-soluble organic matter is effectively utilized. Depending on the situation, combustion treatment is carried out by the burner 313 and discharged as exhaust gas 38 .

A part of the hot air 36 generated by the partial burner 312 is sent to the carbonization furnace 10 as the hot air 5 and becomes a heat source for carbonization.

Part of the tar 34 separated by the separator 311 is sent to the carbonization furnace 10 as the tar 4 together with the hot air 5 .

Part of the hot air generated by the partial burner 312 is mixed with the air 37 by the burner 313 to burn remaining combustible gas components, and exhaust gas 38 is discharged.

The form and the like of the raw material 1 are the same as those described in the embodiment using FIGS. 1 and 2 .

The temperature of the hot air 5 is preferably 400 to 1200°C. This is because if the temperature is too low, the carbonization of the raw material will not proceed sufficiently, and if the temperature is too high, the yield of charred products will decrease and the equipment cost will increase. More preferably, it is 600-1000 degreeC.

The temperature of the generated carbide is desirably about 300 to 700°C. This is because if the temperature is too low, carbonization will not proceed sufficiently, and if the temperature is too high, the yield of carbonized products will decrease and the equipment cost will increase. Preferably it is 400-700 degreeC, More preferably, it is 400-600 degreeC.

The temperature of the exhaust gas 3 discharged from the upper part of the filled bed 12 is desirably about 50 to 300°C. This is because if the temperature is too low, water cannot be sufficiently discharged from the filled layer, and if the temperature is too high, the discharge of tar components from the filled layer is too large, the yield of carbonized products is reduced, and tar problems are likely to occur downstream. It is preferably about 70 to 200°C.

The tar 4 which is part of the tar 34 separated by the separator 311 is mixed in the hot air 5 . By mixing the tar 4 with the hot air 5, a part of the tar 4 is contained in the carbonized product 2, so that the yield of the carbonized product 2 can be increased.

The tar 4 is mixed with the hot air 5 and supplied to the filling bed 12 in the furnace, and is adsorbed on the carbonization in the filling bed, thereby contributing to an increase in the yield of the carbonization 2 . The tar 4 is further thermally decomposed in the filled layer 12 to generate a carbon component, that is, a carbonized product, which contributes to an increase in the yield of the carbonized product 2 .

As shown in the figure, the tar 4 is mixed with the hot air 5 and supplied into the furnace, but it may be directly supplied to the filling bed 12 in the furnace without being mixed with the hot air 5 .

By separating the tar 34 by the separator 311, the tar can be effectively used and the yield of the carbonized product 2 can be improved.

By separating the acetic acid 33 by the separator 311, compared with the case where the acetic acid is not separated, the acetic acid component supplied to the partial burner 312 can be reduced, so there are the following effects.

First, the temperature of the partial burner 312 at the same air ratio can be raised, and necessary heat can be easily supplied to the carbonization furnace 10 .

Second, since the water vapor contained in the hot air 5 can be reduced, it has the effect of suppressing the carbon consumption reaction caused by the water vapor in the carbonization furnace, resulting in an increase in the yield of charred products.

The heat of the exhaust gas 38 can be utilized for drying of the raw material 1 and the like.

Another embodiment of the present invention will be described using FIG. 4 .

The raw material 1 is supplied to the carbonization furnace 10 from above. In addition, the hot air 21 may be supplied to the middle section in the furnace, and the tar 22 may be mixed in the hot air 21 . In addition, cold air 23 may be supplied into the furnace, and tar 24 may be mixed with cold air 23 . The hot air 21 and the cold air 23 are oxygen-free or low-oxygen for dry distillation so as not to cause combustion of the furnace filling.

The raw material 1 forms the filling layer 12 in the furnace, is heated by the hot air 21 to be carbonized, is cooled by the cold air 23 after carbonization, and is discharged as the carbonized product 2 .

The exhaust gas 3 generated from the filling layer is discharged from the upper part of the furnace and separated into gas 32 , acetic acid 33 and tar 34 by a separator 311 . As the form of the separator 311, it is possible to separate the liquid phase of acetic acid and tar at a temperature below the condensation temperature of acetic acid, and to separate the gas and gas phases. If it is a structure that can separate the liquid phase into a water phase and an oil phase (tar phase), then Not particularly limited. In the separator 311, the separation efficiency can be improved by cooling as necessary.

Part of the gas 32 separated by the separator 311 and the separated tar 34 are subjected to so-called incomplete combustion with air 35 by the partial burner 312 . Here, the amount of air 35 is such that the air ratio is less than 1, and oxygen-free or extremely low-oxygen hot air 36 is generated. When raising the temperature of the hot air to a predetermined temperature, the air ratio may be less than 1 if a normal biomass raw material is used, but is preferably 0.5 or more. In addition, the air ratio is preferably 0.8 or less so that tar remains in the hot air.

The acetic acid separated by the separator 311 is discarded or the dissolved water-soluble organic matter is effectively utilized. Depending on the situation, the combustion process is carried out by the burner 313 and discharged as exhaust gas 38 .

A part of the hot air 36 generated by the partial burner 312 is sent to the carbonization furnace 10 as the hot air 21 and becomes a heat source for carbonization.

A part of the hot air 36 generated by the partial burner 312 is cooled by the cooling machine 411, sent to the carbonization furnace 10 as cold air 23, and used for cooling the carbonized product.

A part of the hot air generated by the partial burner 312 is mixed with the air 37 by the burner 313 to burn remaining combustible gas components, and exhaust gas 38 is discharged.

The form and the like of the raw material 1 are the same as those described in the embodiment using FIGS. 1 and 2 .

The temperature of the hot air 21 is preferably 400 to 1200°C. This is because if the temperature is too low, the carbonization of the raw material will not proceed sufficiently, and if the temperature is too high, the yield of charred products will decrease and the equipment cost will increase. More preferably, it is 600-1000 degreeC.

The temperature of the carbonized product near the inlet of the hot air 21 in the middle section of the filled bed is preferably about 300 to 700°C. This is because if the temperature is too low, carbonization will not proceed sufficiently, and if the temperature is too high, the yield of carbonized products will decrease and the equipment cost will increase. More preferably, it is 400-700 degreeC, Most preferably, it is 400-600 degreeC.

The temperature of cold air 23 is preferably 200° C. or lower. More preferably, it is 100° C. or lower. Cooling is not efficient if the temperature is too high.

The temperature of the exhaust gas discharged from the upper part of the packed bed 12 is preferably about 50 to 300°C. This is because if the temperature is too low, water cannot be fully discharged from the filled layer, and if the temperature is too high, the discharge of tar components from the filled layer is too large, the yield of carbonized products is reduced, and tar problems are likely to occur downstream. More preferably, it is about 70 to 200°C.

The tar 22 is mixed in the hot air 21 . The tar 34 separated by the separator 311 is used for the tar 22 . By mixing the tar 22 in the hot air 21, a part of the tar 22 is contained in the carbonized product 2, and therefore, the yield of the carbonized product 2 can be increased.

The tar 24 can be mixed in the cold air 23, and the tar 24 is preferably the tar 34 separated by the separator 311. By mixing the tar 24 in the cold air 23, a part of the tar 24 is contained in the produced carbonized product 2, and thus the yield of the carbonized product 2 can be increased.

The tar 22 or tar 24 is mixed with the hot air 21 or the cold air 23 and supplied to the filling bed 12 in the furnace, and contributes to an increase in the yield of the carbonization 2 by being adsorbed to the carbonization in the filling bed. The tar 22 or 24 is further thermally decomposed in the filled layer 12 to generate a carbon component, that is, a carbonized product, which contributes to an increase in the yield of the carbonized product 2 . The tar 24 includes not only tar that is thermally decomposed in the furnace to generate carbon components, but also tar that is discharged out of the furnace while adhering to carbonized products.

As shown in the figure, tar 22 or tar 24 is mixed with hot air 21 and cold air 23 and supplied into the furnace, but may be directly supplied to furnace filling layer 12 without being mixed with hot air 5 .

As shown in the drawing, the cold air 23 is supplied from the lower part of the furnace through the hot air inlet, but it may also be supplied from the lateral direction of the furnace using nozzles.

By separating the tar 34 by the separator 311, the yield of the carbonized product 2 can be improved by effectively utilizing the tar.

By separating the acetic acid 33 by the separator 311, compared with the case where the acetic acid is not separated, the acetic acid component supplied to the partial burner 312 can be reduced, so it has the following effects. First, the temperature of the partial burner 312 at the same air ratio can be raised, and necessary heat can be easily supplied to the carbonization furnace 10 . Second, since the water vapor contained in the hot air 5 can be reduced, it has the effect of suppressing the carbon consumption reaction caused by the water vapor in the carbonization furnace, leading to an improvement in the yield of charred products.

The heat of the exhaust gas 38 can be used for drying of the raw material 1 and the like.

Another embodiment of the present invention will be described using FIG. 5 .

In FIG. 5 , instead of the cold air 23 and the tar 24 in FIG. 4 , a part of the exhaust gas 3 is used as the cold air 523 .

The exhaust gas 3 contains generated tar and is low temperature, so it can contribute to the cooling of the charred product in the carbonization furnace 10 and the improvement of the yield of the charred product 2 .

Compared with the situation in Fig. 4, the equipment in Fig. 5 can be further simplified, which is low cost.

Another embodiment of the present invention will be described using FIG. 6 .

In FIG. 6, the separator 311 in FIG. 5 is omitted.

The exhaust gas 3 contains generated tar and is low temperature, so it can contribute to the cooling of the charred product in the carbonization furnace 10 and the improvement of the yield of the charred product 2 .

Compared with the situation in Fig. 5, the equipment in Fig. 6 can be further simplified, which is low cost.

[Example 1]

Using the same equipment as shown in Fig. 3, biomass was dry-distilled to conduct a test for producing biocoke.

The comparison of the yield of the carbonized product 2 was performed between the case where the tar 4 was mixed with the hot air 5 and the case where the tar 4 was not mixed. As raw material 1, the residue of a biomass system composed of empty fruit bunch (EFB) of oil palm produced in the process of producing palm oil was used. The water content of EFB was 30% by mass.

In the case of mixing the tar 4 with the hot air 5 (the example of the present invention), when the mass flow rate of the raw material 1 for drying the substrate is 1, the mass flow rate of the tar 4 mixed with the hot air 5 is 0.1. The blowing temperature of the hot air 5 was 930°C, and the carbonization temperature, that is, the temperature of the carbonized product immediately before cutting was 500°C. The temperature of the exhaust gas 3 discharged from the upper part of the packed bed is 100°C.

When the hot air 5 was not mixed with the tar 4 (comparative example), the blowing temperature of the hot air 5 was 910°C, and the carbonization temperature, that is, the temperature of the carbonized product immediately before cutting was 500°C. The temperature of the exhaust gas 3 discharged from the upper part of the packed bed is 100°C.

In the case of the comparative example in which the hot air 5 was not mixed with the tar 4 , when the mass flow rate of the dry base material 1 was set to 1, the mass flow rate of the carbonized product 2 produced was 0.25. That is, the yield of carbonized product on the dried substrate was 25%. On the other hand, in the case of the example of the present invention in which tar 4 is mixed, when the mass flow rate of the dry base material 1 is 1, the mass flow rate of the carbonized product 2 produced is 0.28. That is, the yield of carbonized product on the dried substrate was 28%. By using the method of the present invention, the yield of carbonization is increased by more than 10%.

[Example 2]

Using the same facility as that shown in FIG. 4 , a test was conducted in which the same biomass as in Example 1 was dry-distilled to produce biocoke.

The comparison of the yield of carbonized product 2 was performed between the case where tar was mixed with the hot air 21 and the cold air 23 and the case where no tar was mixed.

In the case of mixing tars 22 and 24 in the hot air 21 and the cold air 23 (example of the present invention), when the mass flow rate of the raw material 1 for drying the substrate is 1, the mass flow rate of the tar 22 mixed in the hot air 21 is 0.1, Let the mass flow rate of the tar 24 mixed with the cold air 23 be 0.03. The blowing temperature of the hot air 21 was 990°C, and the carbonization temperature, that is, the temperature of the carbonized product immediately before cutting was 500°C. The temperature of the cold air 23 is 80°C. The temperature of the exhaust gas 3 discharged from the upper part of the packed bed is 100°C.

When the hot air 21 and the cold air 23 were not mixed with the tars 22 and 24 (comparative example), the blowing temperature of the hot air 21 was 910°C, and the carbonization temperature, that is, the temperature of the carbonized product immediately before cutting was 500°C. The temperature of the cold air 23 is 80°C. The temperature of the exhaust gas 3 discharged from the upper part of the packed bed is 100°C.

In the case of the comparative example in which the hot air 21 and the cold air 23 were not mixed with the tars 22 and 24, when the mass flow rate of the raw material 1 for drying the substrate was 1, the mass flow rate of the carbonized product 2 produced was 0.25. That is, the yield of carbonized product on the dried substrate was 25%. On the other hand, in the case of the example of the present invention in which the tars 22 and 24 were mixed, when the mass flow rate of the dry base material 1 was 1, the mass flow rate of the carbonized product 2 produced was 0.29. That is, the yield of carbonized product on the dried substrate was 29%. By using the method of the present invention, the carbonized product yield is increased by more than 1.5%.

[Example 3]

Using the same facility as shown in FIG. 5 , a test was conducted in which the same biomass as in Example 1 was dry-distilled to produce biocoke.

The comparison of the yield of carbonized product 2 was performed between the case where tar was mixed with the hot air 21 and the cold air 523 and the case where no tar was mixed.

When the tar 22 is mixed in the hot air 21 (example of the present invention), when the mass flow rate of the raw material 1 for drying the substrate is 1, the mass flow rate of the tar 22 mixed in the hot air 21 is 0.1. The blowing temperature of the hot air 21 was 990°C, and the carbonization temperature, that is, the temperature of the carbonized product immediately before cutting was 500°C. The mass flow rate of the tar mixed in the cold air 523 was 0.06, and its temperature was 80°C. The temperature of the exhaust gas 3 discharged from the upper part of the packed bed is 100°C.

When the hot air 21 was not mixed with the tar 22, the blowing temperature of the hot air 21 was 910°C, and the carbonization temperature, that is, the temperature of the carbonized product immediately before cutting was 500°C. The mass flow rate of tar mixed with cold air 523 is 0.06, and its temperature is 80°C. The temperature of the exhaust gas 3 discharged from the upper part of the packed bed is 100°C.

Assuming that the case where no tar is mixed with the hot air 21 and the cold air 523 is a comparative example, the case of the comparative example of the above-mentioned Example 2 corresponds to it. In this case, when the mass flow rate of the dry base material 1 is set to 1, the mass flow rate of the carbonized product 2 to be produced is 0.25. That is, the yield of carbonized product on the dried substrate was 25%.

In the case of the example of the present invention in which the tar 22 is mixed, when the mass flow rate of the raw material 1 of the dry base is 1, the mass flow rate of the carbonized product 2 produced is 0.29. That is, the yield of carbonized product on the dried substrate was 29%. By using the method of the present invention, the yield of carbonization is increased by more than 10%. In addition, when the hot air 21 is not mixed with the tar 22, when the mass flow rate of the dry base material 1 is set to 1, the mass flow rate of the carbonized product 2 produced is 0.26. That is, the yield of carbonized product on the dried substrate was 26%. As a result, the carbonized product yield increased by about 0.4%.

[Example 4]

Using the same facility as that shown in FIG. 6 , a test was conducted in which the same biomass as in Example 1 was dry-distilled to produce biocoke.

Tar was mixed in the hot air 21 obtained by incomplete combustion of the exhaust gas 3 by the partial burner, and the mass flow rate thereof was 0.04. In addition, since the cold air 523 also uses a part of the exhaust gas, tar is mixed, and the mass flow rate thereof is 0.06.

In the case of using the hot air 21 and the cold air 523 without separating tar from the exhaust gas (example of the present invention), the blowing temperature of the hot air 21 is 990°C, and the carbonization temperature, that is, the temperature of the carbonized product immediately before cutting is 500°C. The temperature of the cold air 523 is 80°C. The temperature of the exhaust gas 3 discharged from the upper part of the packed bed is 100°C.

When the case where no tar is mixed with the hot air 21 and the cold air 523 is taken as a comparative example, the case of the comparative example of the above-mentioned Example 2 corresponds to it.

In this case, when the mass flow rate of the dry base material 1 is 1, the mass flow rate of the produced carbonized product 2 is 0.25. That is, the yield of carbonized product on the dried substrate was 25%. On the other hand, in the case of the example of the present invention, when the mass flow rate of the dry base material 1 is 1, the mass flow rate of the produced carbonized product 2 is 0.27. That is, the yield of carbonized product on the dried substrate was 27%. By using the method of the present invention, the carbonized product yield is increased by 0.8%.

[Description of labels]

1 Raw material, 2 Carbonized product

3 exhaust, 4 tar

5 hot air, 10 carbonization furnace

11 hot air inlet, 12 filling layer

13 cutting device, 21 hot air

22 Tar, 23 Cold Wind

24 tar, 25 cold air inlet

32 gas, 33 acetic acid

34 Tar, 35 Air

36 hot air, 37 air

38 waste gas, 311 separator

312 part burner, 313 burner

411 cooler, 523 cold air

[Embodiment 2]

In Embodiment 2, carbonization products (gas, tar) generated during carbonization of biomass are brought into contact with carbonization biomass obtained by carbonization of biomass at high temperature, and carbonization of char in the carbonization product on the carbonization biomass can be obtained. The precipitated biochar. As a result, the amount of tar and gas produced during the dry distillation of biomass can be minimized, and the yield of biochar can be increased. The biochar obtained in Embodiment 2 differs from the direct adhesion of tar, etc., because it is coked and adhered as charcoal, so the oxygen content is low, the calorific value is high, the volatile matter is small, the reactivity is low, and it is pyrophoric. It is also reduced, the safety is improved, and it is high-quality. It can be preferably used as a carbon material for a sintering furnace in the iron and steel process, especially in the iron-making and steel-making processes.

Biomass refers to the general term for the accumulation of a certain amount of animal and plant resources and wastes derived from them. However, fossil resources do not belong to biomass. As the biomass used in Embodiment 2, any biomass that is thermally decomposed into carbonized products such as agricultural, forestry, animal husbandry, fishery, and waste can be used. It is preferable to use biomass with high effective calorific value, and it is preferable to use woody biomass. Examples of woody biomass include: pulp black liquor, papermaking by-products such as sawdust, wood processing by-products such as bark and sawdust, woodland residue materials such as branches, leaves, treetops, and short-sized materials, cedar, cypress, Harvesting materials such as pine trees, materials from special forest products such as waste shiitake wood from edible fungi, firewood forest materials such as oak oak, oak, and pine, and short-cutting forestry such as willow, poplar, eucalyptus, and pine Substances, city, town, and village street trees, individual house garden trees and other pruned tree branches, etc., national and prefectural street trees, company garden trees and other pruned tree branches, construction/construction waste, etc. Industrial waste things etc. Classified by agricultural biomass, rice husk, wheat straw, rice straw, sugarcane gas, palm, etc., with waste/by-products as the source, and rice bran, rapeseed, soybean, etc., with energy crops as the source Part of the material can also be suitably used as woody biomass.

In addition, the dry distillation of biomass refers to thermal decomposition of biomass, cutting off or limiting the supply of air (oxygen) and heating to obtain gas (also called wood gas), liquid (tar), and solid (char) products. technology. Tar is also sometimes referred to as a dark brown, highly viscous liquid in which a brown transparent liquid (acetic acid) is separated and removed from the liquid obtained by thermally decomposing biomass by standing or distillation. However, in Embodiment 2, The liquid in the state of mixing tar and acetic acid is called tar.

One embodiment of Embodiment 2 will be described using FIG. 7 . 110 denotes a carbonization furnace, 120 denotes a coking furnace, and 130 denotes a combustion furnace for generating gas generated from the coking furnace. Biomass 101 is supplied to pyrolysis furnace 110 by a supply device not shown, and pyrolysis biomass (char) 102 and pyrolysis products (gas, tar) 103 are produced. The carbonized biomass 102 is supplied to the coking furnace 120 by a supply device not shown in the figure, and the carbonized distillation product 103 is also supplied to the coking furnace 120 at the same time. In the coking furnace 120 , the pyrolysis product 103 comes into contact with the pyrolysis biomass 102 , and char in the pyrolysis product 103 is deposited on the pyrolysis biomass 102 . Biomass charcoal 105 after charcoal deposition is discharged from coking furnace 120 and utilized in iron and steel processing and the like. On the other hand, the dry distillation product 103 is lightened by the precipitation of char in the coking furnace 120 , and is discharged from the coking furnace 120 as a light gas 106 . Since the light gas 106 is mainly composed of lower hydrocarbons and hydrogen, it is combusted by the combustion device 130 and utilized as a heat source for the carbonization furnace 110 and the coking furnace 120 . 108 denotes fuel gas supplied from outside other than light gas, and 109 denotes combustion air.

Biomass is thermally decomposed by heating, water in biomass evaporates, and carbon, hydrogen, and oxygen are discharged as volatiles. Pores are found in biomass through evaporation of water or/and volatilization of volatiles. A site where tar such as hydrocarbons can be physically/chemically adsorbed is formed on the inner surface of the generated pores. The tar penetrates into the pores and is physically/chemically adsorbed to the biomass. When the biomass adsorbed by the tar is further heated, the tar undergoes a dehydrogenation reaction, becomes heavy, and finally becomes a carbonized product. In addition, a site where tar can be adsorbed is also generated on the surface of the biomass by heating, and the same phenomenon occurs on the surface of the biomass.

As described above, the precipitation of char into the pyrolysis biomass is firstly the adsorption of tar on the pyrolysis biomass, and then the adsorbed tar is dehydrogenated to precipitate char. Therefore, the specific surface area, pore volume, and average pore diameter of carbonized biomass become important. Even if the specific surface area and pore volume are sufficiently large, tar does not intrude into the pores when the average pore diameter is small, and the amount of adsorption is small. Therefore, it is preferable that the average pore diameter is 1 nanometer or more, and therefore, the specific surface area of carbonized biomass is preferably 10 m ² /g or more. The larger the specific surface area of carbonized biomass, the more the pore volume increases, and the average pore diameter becomes larger, and the contact area between the gas and tar generated by the carbonized biomass becomes larger, and a large amount of carbon components can be effectively made Attach and precipitate on dry distillation biomass. If the specific surface area is less than 10 m ² /g, the pore volume is small, and the pore diameter is less than 1 nanometer, the amount of tar adsorption is small, and the carbon deposition is reduced.

The carbonization temperature of biomass may be within the temperature range for dehydration of biomass and generation of carbonization products, and may be within the range of 450 to 800°C where the specific surface area of the carbonization biomass 102 is 10 m ² /g or more. In consideration of the yield of the biocoke 105, it is more preferable to perform dry distillation at 450 to 700°C.

The temperature of the coking furnace 120 is a condition under which the biomass 101 is not carbonized in the coking furnace 120 , and is preferably in the same temperature range as the carbonizing furnace 110 . In addition, the residence time of the pyrolysis biomass 102 in the coking furnace 120 is preferably the time until the fine pores of the pyrolysis biomass 102 are blocked by the deposition of char. After the pores are completely closed, when further char is precipitated, the char in the carbonization product 103 is deposited on the surface of the carbonization biomass 102, and the carbonization biomass 102 adheres to each other and becomes lumpy. Furnace charges fall poorly. The residence time is appropriately determined according to the specific surface area of the carbonized biomass.

As the carbonization furnace 110 , as long as it can carbonize the biomass 101 , a common batch type, rotary type, shaft furnace, etc. can be used. It is preferable to use a rotary type which can be employed as a continuous process.

Since the carbonized biomass 102 is in uniform contact with the carbonized product 103 , and the carbonized product 103 needs to be decomposed and char is deposited on the carbonized biomass 102 , the coking furnace 120 is preferably a packed bed or moving bed method.

The heating method of the carbonization furnace 110 and the coking furnace 120 can be performed by burning and heating the light gas 106 generated from the coking furnace 120, and can also be used as heating gas by burning a fuel gas 8 such as heavy oil or propane. In addition, heating by electric heating may be performed other than the method of burning fuel gas. In the case of electric heating, the carbonization furnace 110 and the coking furnace 120 can be separately divided and temperature controlled.

When carbonizing the biomass 101 in the carbonizing furnace 110, it is considered that the carbonizing biomass 102 is pulverized. In this case, in order to reduce the pressure loss in the coking furnace 120 , the powder in the obtained pyrolysis biomass 102 may be removed and supplied to the coking furnace 120 . As for the method of removing the powder, conventionally known methods such as sieve and air classification may be used. The sieve size is determined according to the operating conditions of the coking furnace 120 .

The material supplied to the coking furnace 120 is pyrolysis biomass 102 obtained by pyrolysis of biomass, but a substance having the same specific surface area as the pyrolysis biomass may be added to the pyrolysis biomass 102 for use. For example, biomass charcoal, activated carbon, etc. that have been subjected to carbonization treatment separately can replace coal in iron and steel processing.

Another embodiment of Embodiment 2 will be described using FIG. 8 . FIG. 7 shows an invention example in a case where the carbonization furnace 110 is a rotary furnace 150 and the coking furnace 120 is a shaft furnace 160 . 140 is a biomass quantitative supply device, that is, a screw feeder, 150 is an indirect heating rotary furnace, 160 is a shaft furnace, 111 is a coking part, and 112 is a cooling part for biomass charcoal. The carbonized biomass 102 carbonized by the rotary furnace 150 is supplied from the upper part to the shaft furnace 160 , and the carbonized biomass 105 in which the carbon content of the carbonized product 103 is precipitated is discharged from the lower part after being cooled by nitrogen 113 in the cooling part 112 .

The cooling gas 113 should just be an inert gas. In addition, the biomass charcoal 105 discharged from the cooling part 112 should just be in the temperature range which does not ignite, and should just be 200 degrees C or less. More preferably, it is 100° C. or lower.

[Example 1]

Using the same equipment as shown in FIG. 8 , a carbonization test of biomass and a coking test of generated gas were performed. Among them, the heating method of the rotary furnace 150 and the shaft furnace (coking furnace) 160 is electric heating divided into three parts, and the light gas generated from the shaft furnace 160 is discharged to the outside of the system. The inner diameter of the rotary kiln 150 is 15 cm, the length is 1.0 m, and the inclination angle is 1 degree. The dry distillation time is about 50 minutes when the rotation speed is 1.5 rpm. The shaft furnace 160 has an inner diameter of 6.6 cm and a length of 40.0 cm. The dry distillation biomass 102 is supplied by the rotary valve provided at the upper part of the furnace, and the biomass charcoal 105 is discharged from the rotary valve provided at the lower part of the furnace. The adjustment of the residence time of the charge in the shaft furnace 160 is performed by adjusting the initial charge amount. As the biomass, cedar that was pulverized and classified into 3 mm to 10 mm was used. Table 1 shows the composition of the biomass used.

Table 1 is

The biomass supply rate to the rotary kiln was 1.0 kg/h, and the dry distillation biomass was recovered from the rotary kiln 150 and filled in the shaft furnace 160 . The test conditions were changed as shown in Table 2, and the tests of Examples 1 to 8 of the present invention were carried out to measure the yields of produced biomass charcoal, gas, tar, and water, the specific surface area of carbonized biomass, and the produced gas composition. The results are shown in Table 2 together.

Table 2

Next, based on the above, except not using the shaft furnace 160, it tested similarly to the above, and obtained the comparative examples 1-6. In addition to the specific surface area of carbonized biomass, the pore volume and average pore diameter were also measured. The test conditions and results are shown in Table 2 together.

As can be seen from Table 2, the yield of biocoke was improved by attaching tar and gas generated by passing through the rotary kiln in the shaft furnace 160 to pyrolysis biomass, heating and carbonizing it. In addition, the tar component was analyzed using GC-MS (a mass analyzer directly connected to a gas chromatograph), and as a result, it was found that the tar component was reduced in weight. High yields of more than 23% by mass are obtained in examples 1 to 5, 7, and 8 of the present invention whose rotary kiln dry distillation temperature and shaft furnace coking temperature are 400 to 700° C., but the rotary kiln dry distillation temperature and shaft furnace coking temperature are 800° C. The yield in Example 6 of the present invention at ℃ is slightly lower.

In addition, in Comparative Example 6 where the rotary kiln carbonization temperature is 400°C, the specific surface area of the dry distillation biomass is less than 10m ² /g, and the average pore diameter is less than 1 nanometer, and the rotary kiln carbonization temperature and shaft furnace coking temperature are 400°C in the example of the present invention. 8, compared with Comparative Example 6, the yield of biochar hardly increased.

[Description of labels]

101 Biomass, 102 Dry Distilled Biomass

103 Dry distillation product (gas, tar), 104 Combustion waste gas

105 Biochar, 106 Light Gas

107 Combustion exhaust gas, 108 Fuel gas supplied from outside other than light gas

109 Air for combustion, 110 Dry distillation furnace

111 Coking section, 112 Cooling section

113 cooling gas, 120 coking furnace

130 combustion furnace, 140 biomass quantitative supply device

150 indirect heating rotary furnace, 160 shaft furnace

[Embodiment 3]

In Embodiment 3, when biomass is dry-distilled to produce biocoke, a furnace of a double-tower type packed moving bed system is used. The double-tower filled moving-bed furnace is a type of well-type furnace, and is also called a Maerz furnace. The Maerz furnace reduces pyrogen units by alternately repeating combustion and heat storage in two vertical wells connected to each other, and can produce stable and high-quality products. It is known that the thermal efficiency is better than that of a rotary furnace. Currently, a Maerz furnace is used as a lime burning furnace, etc. In each shaft, the air supplied from above is used to burn the fuel gas blown in from the burner lance inserted into the filling layer, and the combustion heat is used to burn Limestone (CaCO ₃ ), etc. In the case of limestone it burns to quicklime (CaO). The combustion gas moves down the shaft furnace to preheat limestone etc. in another shaft furnace. One shaft furnace is used for firing and the other is used for preheating. Fuel is periodically fed alternately via burner lances to a shaft.

Biomass is dry-distilled using a double-tower packed moving-bed system furnace having two carbonylation furnaces connected to each other, whereby the gas and tar produced by the dry distillation of biomass in one carbonization furnace are separated from the other. The biomass contact in one carbonization furnace can cause the carbon components in the gas and tar to be attached and precipitated on the biomass in the other carbonization furnace when the biomass in the other carbonization furnace is carbonized. That is, carbonization products (gas, tar) generated during biomass carbonization can be brought into contact with biomass in another carbonization furnace or carbonized biomass obtained by biomass carbonization at high temperature, and carbonization products can be effectively obtained. Biomass charcoal that is precipitated from the charcoal in the material. Thereby, the amount of tar and gas generated during carbonization of biomass can be minimized, and the yield of biochar can be increased. In order to accelerate the carbonization of the pyrolysis product, it is also preferable to separately heat only the lower portion of the pyrolysis furnace. As for the biochar obtained in Embodiment 3, unlike the direct adhesion of tar and the like, it adheres in the state of coked charcoal, so it has less volatile matter and is of high quality. The process is suitable for use as a carbon material for a sintering furnace.

In addition, the dry distillation of biomass refers to thermal decomposition of biomass, cutting off or limiting the supply of air (oxygen) and heating to obtain gas (also called wood gas), liquid (tar), and solid (char) products. technology. Tar is also sometimes referred to as a dark brown, highly viscous liquid in which a brown transparent liquid (acetic acid) is separated from the liquid obtained by thermally decomposing biomass by standing or distillation. However, in Embodiment 3, the mixed The liquid in the state of tar and acetic acid is called tar.

One embodiment of Embodiment 3 will be described using FIG. 9 .

Fig. 9 is a biocoke manufacturing apparatus using a double-tower filled moving bed furnace. Biomass 202 crushed by a not-shown crushing device into a size that can be loaded into the carbonization furnace body 201 is supplied to the carbonization furnace body 201 by a not-shown supply device. The main body 201 of the carbonization furnace is a structure in which a carbonization furnace A (left side in FIG. 9 ) 203 and a carbonization furnace B (right side in FIG. 9 ) 204 are connected at the bottom. Fill to dry distillation furnace B204. When the level of biomass filled in the carbonization furnace B204 reaches a predetermined value, the raw material switching valve 205 is switched to the carbonization furnace A203, and the biomass 202 is supplied to the carbonization furnace A203. When the level of biomass charged in the carbonization furnace A203 reaches a predetermined amount, charging of the biomass 202 is temporarily stopped, and carbonization is started.

First, in order to supply the heat required for carbonization in the carbonization furnace A203, fuel 208 is supplied to the spray gun A206 arranged and air 209 is sent from the upper part of the carbonization furnace A203, and the fuel 208 discharged from the spray gun A206 is combusted. The spray gun A206 is arranged as shown in the X-X' section of the pyrolysis furnace A203 shown in FIG. 10 (FIG. 9). The spray gun B207 mentioned later is also arrange|positioned similarly. The combustion gas and pyrolysis gas/tar 221 move downward in the packed bed 210 while supplying heat to the biomass, enter the pyrolysis furnace B204, and move upward in the biomass packed bed 211 while preheating the biomass in the pyrolysis furnace B204 . At this time, part of carbonization gas/tar generated by carbonization contacts with biomass charcoal or biomass in carbonization furnace A203 and carbonization furnace B204, adsorbs and/or absorbs, and deposits carbon components. The pyrolysis gas 212 from which the heat supplied to the biomass and the tar have been removed is discharged from the pyrolysis furnace B204, and the dust component in the gas is removed by the primary dust collector 213. Carbonization gas 214 discharged from primary dust collector 213 is light hydrocarbons such as CO and methane, and is supplied to carbonization furnace A203 as a heat source required for carbonization. At this time, the fuel 208 used first is reduced by the amount of heat of the supplied pyrolysis gas 214 . When the temperature of the thermometer installed between the carbonization furnace A203 and the carbonization furnace B204 reaches a predetermined temperature, the biomass charcoal 223 in the packed bed 210 is discharged from the discharge valve A215 and discharged out of the system through the discharge valve 216 . Here, the supply of fuel to the pyrolysis furnace A203 and the supply of pyrolysis gas are temporarily stopped. The raw material switching valve 205 is switched to the carbonization furnace A203 side, and the biomass 202 is loaded into the carbonization furnace A203. Next, the fuel 208 is supplied to the lance B207 arranged in the pyrolysis furnace B204, and the air 209 is supplied to burn the fuel 208 discharged from the lance B207. The combustion gas carbonizes the preheated biomass in the carbonization furnace B204 as described above, and produces biomass char and carbonization gas/tar. The combustion gas and pyrolysis gas/tar move downward in the biomass filling layer 211 while supplying heat to the biomass, and enter the carbonization furnace A203, and move upward in the biomass filling layer 210 while preheating the biomass in the carbonization furnace A203. move. At this time, the tar generated by carbonization is adsorbed and/or absorbed by the biomass charcoal or biomass in the carbonization furnace B204 and the carbonization furnace A201. The carbonization gas 212 from which the combustion gas and the tar which supplied heat to the biomass were removed is discharged from the carbonization furnace A203, and the dust component in the gas is removed by the primary dust collector 213. The carbonization gas 214 discharged from the primary dust collector 213 is light hydrocarbons such as CO and methane, and is supplied to the carbonization furnace B204 as a heat source required for carbonization. At this time, the fuel 208 used first only reduces the amount of heat of the supplied pyrolysis gas 214 . When the temperature of the thermometer installed between the carbonization furnace B204 and the carbonization furnace A203 reaches a predetermined temperature, the biomass charcoal in the carbonization furnace B204 is discharged through the discharge valve B217 and discharged out of the system through the discharge valve 216 .

By repeating the above operations, biomass charcoal is produced by carbonizing biomass and depositing char in a carbonization product generated during biomass carbonization on the carbonized biomass.

The lower limit of the carbonization temperature of the biomass in the carbonization furnace is preferably equal to or higher than the temperature at which carbonization gas/tar is generated from the biomass. The temperature of normal biomass is preferably 400°C or higher. On the other hand, biomass pyrolysis gas/tar contains moisture generated by decomposition in addition to moisture attached to biomass. In Embodiment 3, for the purpose of increasing the recovery rate of char in biomass, the upper limit of the heating/carbonization temperature is preferably below the temperature at which moisture does not significantly generate and react. The temperature of normal biomass is preferably 800°C or lower. More preferably, it is 450-750 degreeC.

In order to produce biochar from biomass with a high yield, it is preferable to carry out the above-mentioned temperature conditions, but it is particularly preferable to carry out at a low temperature with a low temperature increase rate, and to carry out with a long residence time in the carbonization furnace. By increasing the residence time, the generated tar components and the like are easily attached to the biomass charcoal in the lower part of the carbonization furnace. Specifically, as shown in FIG. 11 , instead of discharging all the biomass charcoal produced by one treatment in the carbonization furnace, 50% by volume of the biomass in the carbonization furnace can be discharged, and the remaining 50 volume % % of the top of the biochar is filled with new biomass to increase the yield of the biochar. Biomass charcoal is produced as shown in Fig. 11 (a) to (f).

(a): Dry distillation of the biomass in the carbonization furnace A203.

(b): A part of the biomass charcoal produced in the carbonization furnace A203 is discharged.

(c): The biomass 202a is newly charged into the carbonization furnace A203.

(d): dry distillation of the biomass in the carbonization furnace B204.

(e): A part of the biocoke produced in the carbonization furnace B204 is discharged.

(f): The biomass 202b is newly charged into the pyrolysis furnace B204.

It is preferable that the residence time in the pyrolysis furnace from loading of biomass to discharge is 30 minutes or more. When the time is less than 30 minutes, the carbonization is insufficient, and the low calorific value of the biochar may decrease. In addition, when the residence time exceeds 60 minutes, the yield of biochar decreases, and the volume of the carbonization furnace needs to be increased, so it is not economical. For example, if the residence time in the carbonization furnace is 30 minutes in the case of discharging every 50% by volume, the primary carbonization time is 7.5 minutes, and it becomes carbonization 7.5 minutes→adhesion and precipitation of carbon components (stand time) 7.5 minutes→ Dry distillation for 7.5 minutes→adhesion and precipitation of carbon components (stand time) for 7.5 minutes. When the residence time is made constant at 30 minutes, and every 1/3 (33% by volume) is discharged, it becomes 5 minutes of dry distillation → 5 minutes of rest time → 5 minutes of dry distillation → 5 minutes of rest time → 5 minutes of dry distillation → 5 minutes of rest time, When every 1/4 (25% by volume) is discharged, it becomes 3.75 minutes of dry distillation → 3.75 minutes of rest time → 3.75 minutes of dry distillation → 3.75 minutes of rest time → 3.75 minutes of dry distillation → 3.75 minutes of rest time → 3.75 minutes of dry distillation → 3.75 minutes of rest time. From the viewpoint of improving the yield, it is preferable to shorten the primary dry distillation time within the range that can be realized on the equipment.

The number of spray guns provided in the carbonization furnace may be one, but it is preferable to arrange a plurality of them in consideration of heat supply to the packed bed.

The obtained biocoke can be used as it is in the steelmaking process, but it is preferably molded or pulverized to be used if necessary. Generally used rolling granulation using an inclined rotating disk, extrusion molding from a cylindrical die, and a compression molding machine using a briquette roll that supplies powder to a die on the surface of a rotating roll can be used for molding. Forming machine can be carried out. Micronization may be carried out using a generally used roll mill, rod mill, or the like.

As a heat source for pyrolysis of biomass, the fuel supplied from the lance in the pyrolysis furnace may be heavy oil, natural gas, liquefied petroleum gas, or the like, as long as it can be supplied from the lance.

The biocoke recovered from the carbonization furnace is discharged after high-temperature treatment, and therefore, it is preferable to cool it with an inert gas or the like in consideration of safety such as ignition. The cooling temperature should just be about 200°C, more preferably 100°C or less.

Fig. 12 shows another embodiment of the present invention. This is the case where the pyrolysis gas 214 is separately combusted in the combustion furnace 218 and supplied to the pyrolysis furnaces 203 and 204 .

[Example 1]

The dry distillation test of biomass was carried out using the equipment shown in Fig. 13 . Carbonization furnace A203 and carbonization furnace B204 have an inner diameter of 100 mm and a length of 400 mm, and nitrogen 226 is heated to a predetermined temperature by hot air sending device 225 and heated by supplying it.

Table 3 shows the composition of the biomass used.

table 3

The biomass shown in Table 3 was pulverized in advance, and filled in the carbonization furnace A203 and the carbonization furnace B204. Nitrogen 226 heated to a predetermined temperature is blown to the carbonization furnace A203, carbonization is carried out for 7.5 minutes, the supply of heating nitrogen is stopped, and the level of the upper surface of the content of the carbonization furnace A203 is measured from the lower part of the carbonization furnace A203, and 1/2 volume is discharged amount, the biomass 202 is newly supplied to the pyrolysis furnace A203. Next, heated nitrogen was supplied to the carbonization furnace B204, carbonization was performed for 7.5 minutes in the same manner, and 1/2 volume was discharged from the carbonization furnace B204. Repeat this operation. The dry distillation of biomass was carried out twice, and the residence time in the dry distillation furnace from charging of biomass to discharging was 30 minutes. The feed rate of biomass was 2.0 kg/h. The heating temperature (hot air temperature) of nitrogen 226 was changed as shown in Table 4, and the test of Examples 1-6 of this invention was performed.

Table 4

In each test, the temperature of the nitrogen + carbonization gas discharged from the carbonization furnaces A203 and B204 is collectively shown in Table 4 as the carbonization gas outlet temperature. This operation was performed for 6 hours, the properties (composition) of the discharged biocoke 223 were measured, and the biocoke yield was calculated from the contained ash concentration. In addition, the yields of recovered gas, tar, and water were measured. The results are shown in Table 4 together.

Next, every 1/3 volume is discharged from the carbonization furnace, and the carbonization time of biomass in the carbonization furnace is set to 5 minutes. In addition, the present invention example 7 is carried out under the same conditions as the above-mentioned present invention example 5. test. The dry distillation of biomass was carried out three times, and the residence time in the dry distillation furnace from charging of biomass to discharging was 30 minutes. The results are shown in Table 4 together.

Furthermore, the results in the case of performing carbonization of biomass using only the carbonization furnace A203 are collectively shown in Table 4 as Comparative Example 1.

As can be seen from Table 4, by producing biomass charcoal according to the method of the present invention using a device connected to two carbonization furnaces, the generated tar and gas can be attached to the carbonization biomass, heated and carbonized, and the one with the lower carbonization temperature will be produced. Substance char yield increased. In addition, when the residence time in the pyrolysis furnace from charging of biomass to discharging is the same, the yield is higher with shorter one-time carbonization time. Furthermore, it was found that the tar component was lightened as a result of analysis using GC-MS (mass analyzer directly connected to a gas chromatograph).

Label description

201 Dry distillation furnace main body, 202 (202a, 202b) biomass

203 Retort Furnace A, 204 Retort Furnace B

205 Material switching valve, 206 Spray gun A

207 Gun B, 208 Fuel

209 air, 210 biomass filling layer

211 Biomass filling layer, 212 Retort gas

213 1st dust collector, 214 dry distillation gas

215 discharge valve A, 216 discharge valve

217 discharge valve B, 218 combustion furnace

221 Retort gas/tar, 222 Supply valve

223 Biomass charcoal, 225 Hot air generator

226 Nitrogen

Claims (24)

1. A method for producing biochar, wherein, Carbonize biomass to form biochar, discharging exhaust gas containing tar generated during said carbonization, contacting at least a portion of said tar in said exhaust gas with said biomass and/or said biochar, At least a portion of the tar contacted with the biomass and/or the biochar is converted to char. 2. The manufacture method of biochar as claimed in claim 1, wherein, Biomass input from the top or side upper part of the shaft furnace, Hot air is blown from the bottom of the shaft furnace or a position lower than the discharge position of the exhaust gas, that is, a side lower part, charring the biomass in the shaft furnace to form biochar, discharging waste gas containing tar produced during said carbonization from the top or side upper part of said shaft furnace, blowing at least a portion of the tar in the exhaust gas into the shaft furnace to contact the biomass and/or the biochar, Converting at least a portion of the tar in contact with the biomass and/or the biochar to char. 3. The manufacture method of biochar as claimed in claim 2, wherein, At least a part of the tar in the exhaust gas is blown into the shaft furnace together with the hot air. 4. the manufacture method of biochar as claimed in claim 2 or 3, wherein, Cooling gas is supplied from the bottom or side lower part of the shaft furnace. 5. The manufacture method of biochar as claimed in claim 4, wherein, The cooling gas recycles the waste gas. 6. the manufacture method of biochar as claimed in claim 4 or 5, wherein, A part of the tar is supplied into the furnace together with the cooling gas. 7. The method for producing biocoke according to any one of claims 2 to 6, wherein, The tar is separated from the exhaust gas, and the separated tar is blown into a shaft furnace. 8. The method for producing biocoke according to any one of claims 2 to 7, wherein, The exhaust gas is burned with an air ratio of less than 1, and blown into the shaft furnace as hot air. 9. The method for producing biocoke according to any one of claims 2 to 8, wherein, The carbonization temperature of the biochar is 300-700°C. 10. The method for producing biocoke according to any one of claims 2 to 9, wherein, The temperature of the waste gas is 50-300°C. 11. The method for producing biocoke according to any one of claims 2 to 10, wherein, The hot air is anaerobic or hypoxic, and the temperature is 400-1200°C. 12. The manufacture method of biochar as claimed in claim 1, wherein, The carbonization of the biomass is carried out by feeding biomass into the shaft furnace from the top or side upper part of the shaft furnace and blowing hot air from the bottom or side lower part of the shaft furnace, The discharge of the waste gas is carried out by discharging the waste gas containing the tar generated during the carbonization from the top or side upper part of the shaft furnace, Contacting at least a part of the tar is performed by blowing at least a part of the tar in the exhaust gas generated during the carbonization into the shaft furnace. 13. The manufacture method of biochar as claimed in claim 1, wherein, dry distillation of biomass to form dry distillation biomass, Gas and tar generated by carbonization of the biomass are brought into contact with the carbonization biomass, and carbon components in the gas and tar are deposited on the carbonization biomass. 14. The manufacture method of biochar as claimed in claim 13, wherein, The dry distillation biomass has a specific surface area of 10 m ² /g or more. 15. The manufacture method of biochar as claimed in claim 13, wherein, The carbonization temperature of the biomass is 450°C to 700°C, and the temperature at which the carbon components in the gas and tar are attached and precipitated on the dry distillation biomass is 450°C to 700°C. 16. The manufacture method of biochar as claimed in claim 13, wherein, The dry distillation is carried out through a rotary dry distillation furnace. 17. The manufacture method of biochar as claimed in claim 13, wherein, The deposition of carbon components in the tar to the dry distillation biomass is carried out in a packed bed or moving bed method coking furnace. 18. The manufacturing method of biochar as claimed in claim 1, wherein, The carbonization of the biomass includes carbonizing the biomass to generate carbonized biomass and waste gas containing tar, and coking the carbonized biomass, The contacting of at least a part of the tar includes contacting the exhaust gas containing the tar with the dry distillation biomass, and making the carbon components in the gas and the tar adhere to and deposit on the dry distillation biomass. 19. the manufacture method of biochar as claimed in claim 1, Biomass charcoal is produced by dry-distilling biomass using a double-tower filled moving-bed system furnace having two carbonylation furnaces connected to each other, wherein, contacting gases and tars produced by the retort of biomass in one retort with biomass in another retort, During the carbonization of the biomass in the other carbonization furnace, carbon components in the gas and the tar are deposited on the biomass in the other carbonization furnace. 20. The manufacturing method of biochar as claimed in claim 19, wherein, The carbonization temperature of the biomass in the carbonization furnace is set to 400°C to 800°C. 21. The manufacturing method of biochar as claimed in claim 19, wherein, The residence time of the biomass in the carbonization furnace is set to 30 minutes or more. 22. The manufacturing method of biochar as claimed in claim 1, wherein, The carbonization of the biomass includes carbonizing the biomass in the first carbonization furnace to generate gas and tar, The contacting of at least a part of the tar includes contacting the gas and tar generated in the first carbonization furnace with the biomass in the second carbonization furnace, and the gas and the The tar adheres and precipitates on the biomass in the second carbonization furnace. 23. A biochar manufacturing device, comprising: Shaft furnaces for carbonizing biomass to produce biochar; The input port of the biomass provided on the top or side upper part of the shaft furnace; an exhaust gas discharge port provided on the top or side upper part of the shaft furnace; A hot air blowing inlet provided at the bottom of the shaft furnace, or at a position below the outlet, that is, at the lower side; and A partial burner for combusting at least a portion of said exhaust gas at an air ratio of less than one. 24. The manufacturing apparatus of biochar as claimed in claim 23, wherein, It also has a separator for separating at least gas components and tar from the exhaust gas.

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