CN112066384A - A kind of straw domestic waste waste bundle burning pyrolysis synergistic treatment method - Google Patents

Abstract

The invention discloses a method for bundling, burning, pyrolysis and co-processing of straw domestic waste waste, which belongs to the field of waste treatment and solves the problems that toxic and harmful substances in domestic waste cannot be completely sorted and the ash and slag treatment cost is relatively high. It includes the following steps: garbage disposal, garbage pyrolysis, straw bale combustion, pyrolysis gas reuse, the heat generated in the straw bale burning boiler is supplied to the pyrolysis furnace for the pyrolysis of garbage, and the garbage is sorted and then transported to the pyrolysis furnace For pyrolysis, the straw is burned in the straw bale burning boiler, and the pyrolysis gas generated by the pyrolysis of the garbage is passed to the secondary combustion chamber of the straw bale burning boiler under high temperature conditions for combustion together with the volatile gas. The invention can process two kinds of wastes, straw and garbage at the same time, and reduce the problems of environment, land, resource waste and the like caused by random burning of straw and garbage landfill.

Description

A kind of straw domestic waste waste bundle burning pyrolysis synergistic treatment method

technical field

The invention belongs to the field of waste treatment, and in particular relates to a method for the co-processing of straw domestic waste waste bundle burning and pyrolysis.

Background technique

With the gradual improvement of the level of rural urbanization in my country, the amount of domestic waste generated has also increased rapidly, and its components have become more and more complex, and the components of hazardous waste and industrial waste are gradually increasing. Therefore, the harmless, reduced, and resourceful disposal of rural domestic waste is related to the national economy and people's livelihood, and is one of the important contents of my country's realization of the strategic goal of sustainable development.

At present, the main methods of rural garbage disposal are landfill and incineration. The landfill method will occupy a lot of land resources, and the landfill land cannot be reused. Improper treatment will also cause serious secondary pollution to the soil and water, and the inability to effectively utilize the organic solid waste in the garbage results in a waste of resources. Although the incineration method has the functions of volume reduction and energy recovery, the cost of incineration equipment is high and the operation is complicated. During the combustion process, more toxic and harmful substances such as dioxin and fly ash will be produced, and a stricter flue gas purification system is required. The waste pyrolysis treatment technology not only has high energy utilization rate, but also produces less secondary pollutants than incineration. It is a more reasonable treatment method for waste treatment.

The traditional co-processing method of domestic waste and straw is to pulverize the domestic waste and straw for mixed pyrolysis, but the pulverization process requires a large amount of energy, and the straw bales usually contain some hard substances such as stones, which are easy to cause damage to the pulverizing device. damage. At the same time, the pyrolysis furnace generally adopts internal heating, and its pyrolysis temperature is difficult to control, and the product is usually unstable and easy to produce more tar. The external heating treatment method consumes more energy and has problems such as less energy imbalance and less production capacity. At the same time, there are inevitably some toxic and harmful substances in the domestic garbage that cannot be sorted thoroughly. After the garbage and straw are mixed and pyrolyzed, these toxic substances will be transferred to the ash, so that the ash cannot be effectively used, and the treatment cost is high. As a good fertilizer, straw ash has been widely used, and if it is discarded, it will cause a large waste of resources.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a method for the co-processing of straw household waste and other waste bundle burning and pyrolysis, so as to solve the problem that the toxic and harmful substances in the household waste cannot be completely sorted and the ash processing cost is relatively high.

The technical scheme of the present invention is as follows: a method for co-processing straw bales and waste bales and pyrolysis, comprising the following steps: garbage disposal, garbage pyrolysis, straw bales combustion, pyrolysis gas recycling, and straw bales burning heat generated in a boiler Supply the pyrolysis of waste in the pyrolysis furnace,

A. After the garbage is sorted and stored to remove part of the moisture, it is transferred to the pyrolysis furnace for pyrolysis; after the garbage is transported to the pyrolysis furnace, a slow pyrolysis reaction occurs under high temperature and anoxic conditions; During the solution process, it is necessary to ensure that its temperature gradually increases;

B. Combustion of straw bales for heating: After the straw is crushed and bundled, it is transported to the straw bale burning boiler for combustion;

C. Reuse of pyrolysis gas: The pyrolysis gas produced by pyrolysis is passed to the secondary combustion chamber of the straw bale burning boiler under high temperature conditions to be burned together with the volatile gas.

Further, the heating rate of waste pyrolysis is maintained at 150-200°C/min, and the reaction time of waste in the pyrolysis furnace is 10-15 minutes.

Further, the high temperature conditions in the steps A and C are 800-1000°C.

Further, the straw bundle burning boiler includes a primary combustion chamber, a secondary combustion chamber, a primary air duct, a tertiary air duct, and a secondary air duct; the straw bundle burning boiler is divided into a primary combustion chamber and a secondary combustion chamber by a furnace arch. ; The rotary pyrolysis furnace is arranged above the straw bundle burning boiler, and there is a flue gas channel between the outer ring of the rotary pyrolysis furnace and the furnace body of the rotary pyrolysis furnace; the upper end of the outlet of the rotary pyrolysis furnace is connected with the pyrolysis gas reuse pipe through the The secondary combustion chamber of the straw bale burning boiler is connected.

Further, the excess air coefficient in the primary combustion chamber is controlled at 0.6 to 1.0, and the excess air coefficient in the secondary combustion chamber is controlled at 0.7 to 1.1. The premixing area, and the rear section is the high temperature combustion chamber.

The present invention utilizes part of the heat generated by the burning of the straw bales to supply the waste for pyrolysis, and part to exchange heat with water to provide hot water to the outside. At the same time, the pyrolysis gas generated by the pyrolysis enters the high temperature combustion zone of the bundle burning boiler combustion chamber under high temperature conditions for complete combustion, avoiding the production of tar and other toxic and harmful substances. At the same time, the pyrolysis ash and straw ash are treated separately to improve the utilization rate of resources. The above treatment methods are more in line with the actual situation of my country's rural areas, the treatment methods are more reasonable, and have higher environmental protection and economic benefits.

The characteristics of the present invention are as follows:

(1) The heat generated by the burning of straw bales is used to supply waste for pyrolysis reaction, which can treat both wastes of straw and waste at the same time, reducing the environmental, land and resource waste caused by random burning of straw and landfill. .

(2) Pyrolysis slag and straw bale burning boiler slag are treated separately. Due to the complex composition of the waste, the pollution of the straw bundle burning boiler slag caused by the pyrolysis slag is avoided. The straw bale burning boiler slag can be directly returned to the field as fertilizer, and can also be mixed with other substances for composting and reuse.

(3) The pyrolysis gas generated by the pyrolysis of waste is directly introduced into the furnace at high temperature, and is mixed with high-temperature flue gas and air for combustion in the high-temperature combustion area, so as to avoid the production of tar and other substances during the condensation process of the pyrolysis gas. pollutants, and more toxic organic substances are produced when the combustion temperature is too low.

Description of drawings

Fig. 1 is a flow chart of a method for the co-processing of straw domestic waste waste bundle burning and pyrolysis;

FIG. 2 is a schematic structural diagram of a device used in a method for co-processing straw domestic waste waste bundle burning and pyrolysis.

Detailed ways

The following examples may further illustrate the present invention, but do not limit it in any way.

Straw-waste co-processing mainly includes 7 processes, namely waste pretreatment, waste pyrolysis, pyrolysis gas reuse, straw bale combustion for heating, flue gas purification, pyrolysis slag recycling, and straw bale burning boiler slag recycling.

Example 1

Process 1 - Garbage pretreatment: Garbage is transported by garbage trucks to the garbage recycling station. After sorting the garbage, the non-perishable organic garbage is poured into the garbage storage pit. The garbage storage pit is a negative pressure environment and the garbage is poured into the garbage. An air curtain is set at the hole to ensure that the odor in the garbage storage pit will not overflow. After the garbage is stored for 3-7 days, part of the water is removed, which can improve the pyrolysis efficiency of the garbage, and then the garbage is transferred to the pyrolysis furnace for pyrolysis by the hanging claws. In winter, due to the low temperature, the residence time of garbage in the storage pit can be appropriately extended.

Process 2 - Garbage pyrolysis: After the garbage is transported to the pyrolysis furnace, under the action of the pusher and the feeding mechanism, the domestic garbage undergoes a slow pyrolysis reaction under the condition of high temperature and oxygen deficiency. In order to ensure that more pyrolysis gas is generated during the pyrolysis process, the temperature of the waste pyrolysis process needs to be gradually increased. The heating rate can be controlled by controlling the pushing speed of the pushing mechanism, the heating rate is kept at 150-200℃/min, and the reaction time of the waste in the pyrolysis furnace is 10-15min.

Process 3 is the reuse of pyrolysis gas: the main components of the pyrolysis gas generated by pyrolysis are CO, H ₂ , and CH ₄ , and the generated pyrolysis gas does not undergo condensation, purification, etc. Combustion is carried out together with volatile gas in the secondary combustion chamber. In order to prevent the temperature of the pyrolysis gas from dropping too much, it will condense and generate more tar to block the pipeline and cause a safety accident. In order to improve the combustion efficiency of the pyrolysis gas, a swirl device can be installed at the outlet of the pyrolysis gas, so that the pyrolysis gas is fully mixed with the high temperature flue gas, furnace volatiles and air and then enters the high temperature combustion area for combustion. The temperature of the high temperature combustion zone is controlled at 800-1000°C to ensure that the dioxins and volatile organic compounds in the pyrolysis process can be completely burned.

Step 4 is the combustion and heating of straw bales: the straw is crushed and bundled, and then transported to the processing site. It is transported by the feeding device to the straw bale burning boiler for combustion.

As shown in Fig. 2, the straw bale burning boiler (3) includes a primary combustion chamber 304, a secondary combustion chamber (305), a primary air duct 307, a tertiary air duct 308, and a secondary air duct 309; The arch 312 is divided into a primary combustion chamber 304 and a secondary combustion chamber (305);

The rotary pyrolysis furnace (203) is arranged above the straw bundle burning boiler (3), and a flue gas channel is provided between the outer ring of the rotary pyrolysis furnace and the furnace body of the rotary pyrolysis furnace.

The upper end of the outlet of the rotary pyrolysis furnace (203) is connected to the secondary combustion chamber (305) of the straw bale burning boiler (3) through a pyrolysis gas recycling pipeline (204).

As the heat is gradually absorbed, the temperature of the flue gas gradually decreases from the right end to the left end, so that the temperature of the rotary pyrolysis furnace gradually decreases from the right end to the left end, ensuring the heating rate of the waste in the rotary pyrolysis furnace, so as to obtain more pyrolysis. gas.

The straw bale contains a lot of volatile matter, in order to improve its combustion efficiency, the straw bale burning boiler needs to adopt a graded combustion system. Among them, the primary combustion chamber mainly creates an oxygen-deficient combustion environment, and the excess air coefficient is controlled at 0.6 to 1.0, so that more volatile matter is precipitated from the straw bales. The secondary combustion chamber is mainly for the mixed combustion of volatile matter and pyrolysis gas. The excess air coefficient is controlled at 0.7 to 1.1. For the high temperature combustion chamber. The two combustion chambers are equipped with separate air distribution systems, which can adjust the air distribution. The heat generated in the straw bale burning boiler is mainly supplied to the pyrolysis of garbage in the pyrolysis furnace, and the excess heat is supplied to the outside of the device after heat exchange through the water cycle, which can be used for heating or other places where hot water is needed.

Example 2

On the basis of Example 1, the following steps are added,

Process 5 is flue gas purification: dust removal and purification of flue gas, mainly to ensure that toxic and harmful gases such as acid gas and particulate matter generated by combustion are fully purified and discharged after reaching the standard. You can choose to settle the particulate matter in the furnace, and then use the rotary spray tower, SCR, SNCR, activated carbon adsorption, bag dust removal and other methods to process the flue gas after the flue gas is discharged, and the flue gas is discharged after reaching the standard.

Example 3

On the basis of Example 1, the following steps are added,

Step 6 is the reuse of pyrolysis slag: the main components in the pyrolysis slag are biochar and some incompletely pyrolyzed substances, and the biochar extracted after screening can be used as a soil conditioner for the growth of crops. Substances that are not completely pyrolyzed can also be sintered at high temperature to produce roadbed materials.

Example 4

On the basis of Example 1, the following steps are added, and step 7 is the reuse of straw bales burning boiler slag: the slag generated after the straw bale burning is cleaned out in the straw bale burning boiler and can be composted with livestock and poultry manure as fertilizer. applied to crops. Fertilizers made from straw ash are more environmentally friendly and economical. During the growth of straw, the nutrients absorbed from the soil are returned to the field again, which can avoid problems such as soil compaction and soil fertility decline caused by excessive fertilization at the same time.

Claims (7)

1. A method for co-processing straw domestic waste waste bundle burning and pyrolysis, characterized in that it comprises the following steps: garbage disposal, garbage pyrolysis, straw bale combustion, pyrolysis gas recycling, and supply of heat generated in a straw bale burning boiler. Pyrolysis of waste in a pyrolysis furnace, A. After the garbage is sorted and stored to remove part of the moisture, it is transferred to the pyrolysis furnace for pyrolysis; after the garbage is transported to the pyrolysis furnace, a slow pyrolysis reaction occurs under high temperature and anoxic conditions; During the solution process, it is necessary to ensure that its temperature gradually increases; B. Combustion of straw bales for heating: After the straw is crushed and bundled, it is transported to the straw bale burning boiler for combustion; C. Reuse of pyrolysis gas: The pyrolysis gas produced by pyrolysis is passed to the secondary combustion chamber of the straw bale burning boiler under high temperature conditions to be burned together with the volatile gas. 2 . The method for co-processing straw household waste waste bundle burning and pyrolysis according to claim 1 , wherein the heating rate of waste pyrolysis is maintained at 150-200° C./min, and the waste reacts in the pyrolysis furnace. 3 . The time is 10-15min. 3 . The method for synergistic treatment of straw domestic waste waste bundle burning and pyrolysis according to claim 1 or 2 , wherein the high temperature conditions in the steps A and C are 800-1000° C. 4 . 4. A method for co-processing straw domestic waste bales burning and pyrolysis according to claim 3, characterized in that: the straw bale burning boiler (3) comprises a primary combustion chamber (304), a secondary combustion chamber ( 305), primary air duct (307), tertiary air duct (308), and secondary air duct (309), the straw bundle burning boiler is divided into primary combustion chamber (304) and secondary combustion chamber (304) by furnace arch (312). 305); the rotary pyrolysis furnace (203) is arranged above the straw bundle burning boiler (3), and a flue gas channel is provided between the outer ring of the rotary pyrolysis furnace and the furnace body of the rotary pyrolysis furnace; the rotary pyrolysis furnace (203) The upper end of the outlet is connected to the secondary combustion chamber (305) of the straw bale burning boiler (3) through a pyrolysis gas reuse pipe (204). 5 . A method for co-processing straw household waste and waste bundle burning and pyrolysis according to claim 4 , wherein the excess air coefficient in the primary combustion chamber is controlled at 0.6 to 1.0, and the excess air coefficient in the secondary combustion chamber is controlled at 0.6 to 1.0 5 . From 0.7 to 1.1, the front section of the secondary combustion chamber is the premixed area of pyrolysis gas, high temperature flue gas, volatile matter and air, and the rear section is the high temperature combustion chamber. 6. A method for co-processing straw household waste waste bundle burning and pyrolysis according to claim 5, characterized in that: it further comprises a flue gas purification step: dust removal and purification treatment of flue gas, mainly to ensure the acidity generated by combustion Gas, particulate matter and other toxic and harmful gases are fully purified and discharged after reaching the standard; particulate matter is settled in the furnace, and after the flue gas is discharged, the rotary spray tower, SCR, SNCR, activated carbon adsorption, and bag dust removal are combined for treatment, and the flue gas meets the standard. rear discharge. 7. A method for co-processing straw domestic waste waste bundle burning and pyrolysis according to claim 6, characterized in that: it further comprises a pyrolysis slag recycling step: biochar extracted after screening the pyrolysis slag As a soil conditioner; the incompletely pyrolyzed material is sintered at high temperature to produce roadbed materials.

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