CN102321673B - Method for producing biogas from solid organic waste - Google Patents

Abstract

A method and a device for producing biogas by solid organic wastes. The method comprises the following steps of: a pretreatment step; a solid-liquid separation step; a liquid anaerobic fermentation step; a solid anaerobic fermentation step; a secondary integrated anaerobic fermentation step, and a biogas collection utilization and residue liquid treatment step. The device comprises a solid-liquid separator, a liquid anaerobic fermentation system, a solid anaerobic fermentation system, a secondary integrated anaerobic fermentation reactor, a gas collection and utilization system, and a biogas residue liquid treatment system; the solid-liquid separator is connected with the liquid anaerobic fermentation system and the solid anaerobic fermentation system respectively; the liquid anaerobic fermentation system and the solid anaerobic fermentation system are connected with the secondary integrated anaerobic fermentation reactor respectively; the secondary integrated anaerobic fermentation reactor is connected with the gas collection and utilization system and the biogas residue liquid treatment system respectively. The invention realizes the harmless treatment and energy utilization of organic wastes.

Description

Method for producing biogas from solid organic waste

technical field

The invention relates to a method for treating solid organic waste, in particular to a method and equipment for producing biogas by anaerobic fermentation of solid organic waste. the

Background technique

With the continuous and rapid development of my country's economy, the output of organic solid waste, including municipal solid waste, agricultural waste, intensive livestock and poultry manure, sewage sludge, etc., is huge, and its composition is very complex, often containing a large amount of water, volatile substances, Environmental pollutants such as pathogens, parasite eggs and heavy metals can cause serious harm to the natural and social environment if not handled properly. Such as simple open-air stacking, occupying land, destroying the landscape, and the harmful components in the waste can be airborne through the wind, or invade the soil and groundwater sources through rain, and pollute rivers. the

According to the characteristics of organic solid waste, the main methods currently used are landfill, incineration, anaerobic fermentation, etc. The landfill method is very simple to deal with solid organic waste, but it requires a lot of freight and landfill sites. With the growth of population and the development of urbanization, the land available for landfill is decreasing, and the landfill of waste is limited by the site; in addition, the decomposition and decay of waste after landfill will release a large amount of methane and other gases, resulting in a greenhouse effect ; Moreover, exposure to sunlight and rainwater leachate and leachate will pollute groundwater, cause eutrophication of water bodies, and bring secondary pollution to water resources in serious shortage; for incineration, it is not only expensive in equipment, but also high in maintenance costs. , In the process of incineration, some highly toxic organic pollutants such as dioxins will be produced. At present, the government and the public are also cautious about incineration. Anaerobic fermentation treatment of solid organic waste is to use the decomposition of microorganisms to make it harmless and transform it into energy, food, feed and fertilizer, etc., to achieve resource utilization and obtain biogas while processing waste. the

The anaerobic fermentation of organic solid waste is divided into wet fermentation and dry fermentation according to the content of total solids (TS). Wet fermentation means that the solid content of the feed is less than 15%, and dry anaerobic fermentation means that the solid content of the feed is 20%-50%. Wet anaerobic fermentation technology is relatively mature, and its design and operation management are relatively perfect, but a large amount of biogas slurry will be produced after fermentation, and improper treatment may easily cause secondary pollution. Compared with wet fermentation, dry fermentation has many advantages, such as small footprint, low energy consumption, low operating costs, no need to add fresh water during the process, small amount of biogas slurry after fermentation, simple pretreatment without sand removal, and no The generation of scum and sediment, etc., is more and more concerned. However, due to the disadvantages of difficult feeding and discharging, mass transfer and heat transfer in the dry fermentation system, it is still difficult to apply it in large-scale and industrial projects. the

The application number is "201010130966" and the Chinese invention patent application titled "A method for generating biogas by enhanced hydrolysis and anaerobic digestion of urban domestic organic waste" adopts the method of enhanced hydrolysis and anaerobic fermentation to generate biogas, which can realize Energy utilization of organic waste, but the process needs to reduce the crushing of organic matter to less than 1cm, put the crushed raw materials into the raw material adjustment tank, and need to add water or fermentation broth to adjust the solid concentration of raw materials, and control the solid concentration of raw materials to less than 15 %, so it still cannot overcome the drawbacks of wet fermentation technology. the

Contents of the invention

The technical problem to be solved by the present invention is to provide a method and equipment for producing biogas from solid organic waste, which can overcome the need to add fresh water in the wet fermentation technology in the prior art, and produce a large amount of biogas slurry after fermentation, which is easy to cause secondary Pollution and dry fermentation have difficulties in feeding and discharging materials, mass transfer and heat transfer, etc., so as to realize the harmless treatment and energy utilization of organic waste. the

In order to achieve the above object, the present invention provides a method for producing biogas from solid organic waste, which comprises the following steps:

a. Pretreatment step, collecting, sorting and/or crushing organic waste, and pre-inoculating and acclimating the sludge used for anaerobic fermentation;

b, the solid-liquid separation step, the organic waste after the pretreatment step is directly subjected to solid-liquid separation;

c, liquid anaerobic fermentation step, performing anaerobic fermentation on the liquid raw material separated in the solid-liquid separation step to prepare biogas, and collecting the prepared biogas;

d. Solid anaerobic fermentation step, performing anaerobic fermentation on the solid material separated in the solid-liquid separation step to prepare biogas, and collecting the prepared biogas;

e, two-level integrated anaerobic fermentation step, continue to ferment the raw materials treated in the liquid anaerobic fermentation step and the solid anaerobic fermentation step to prepare biogas, and collect the prepared biogas;

f. Biogas utilization and slag liquid treatment step, the biogas collected in the liquid anaerobic fermentation step, the solid anaerobic fermentation step and the two-stage integrated anaerobic fermentation step is purified, utilized and discharged for treatment The slag liquid produced in the two-stage integrated anaerobic fermentation step. the

The above-mentioned method for producing biogas from solid organic waste, wherein the liquid anaerobic fermentation step comprises:

c1, the liquid pretreatment heating step, the liquid raw material separated in the solid-liquid separation step is subjected to conditioning, inoculation, and preheating;

c2, the mesophilic anaerobic fermentation step, the liquid raw material heated through the liquid pretreatment and heating step is subjected to mesophilic anaerobic fermentation to prepare biogas. the

The above-mentioned method for producing biogas from solid organic waste, wherein, the liquid pretreatment heating step includes, transporting the liquid raw material after the solid-liquid separation step to a liquid pretreatment adjustment tank for pretreatment, tempering and inoculation , controlling the temperature of the liquid pretreatment adjustment tank to be 20° C. to 35° C., and the time for the liquid raw material to stay in the liquid pretreatment adjustment tank is 1 to 1.5 days. the

The above-mentioned method for producing biogas from solid organic waste, wherein, the step of mesophilic anaerobic fermentation includes pumping the raw material after the liquid pretreatment and heating step into a mesophilic anaerobic fermentation reactor for mesophilic anaerobic fermentation, and controlling The temperature of the mesophilic anaerobic fermentation reactor is 30°C-38°C, the pH is 6-8, and the residence time is 10-35 days. the

The above-mentioned method for producing biogas from solid organic waste, wherein the solid anaerobic fermentation step comprises:

d1, solid pretreatment heating step;

d2. High-temperature anaerobic fermentation step, performing high-temperature anaerobic fermentation on the solid raw material heated in the solid pretreatment heating step to prepare biogas; and

d3. A second solid-liquid separation step, performing a second solid-liquid separation on the material after the high-temperature anaerobic fermentation step, and the separated liquid continues to be fermented by the second-stage integrated anaerobic fermentation step. the

The above-mentioned method for producing biogas from solid organic waste, wherein, the solid pretreatment and heating step includes: transporting the solid raw material after the solid-liquid separation step to a solid heating pretreatment tank for heating and tempering, and controlling the The temperature of the solid heating pretreatment pool is 50° C. to 70° C., and the residence time of the solid raw material in the warming pool is 1 to 2 days. the

The above-mentioned method for producing biogas from solid organic waste, wherein, the high-temperature anaerobic fermentation step includes, transporting the solid raw material treated in the solid pretreatment and heating step to a solid high-temperature fermentation reactor for high-temperature anaerobic fermentation, Control the temperature of the solid high-temperature fermentation reactor to 50°C to 60°C, the pH value to 6.5 to 7.8, and the residence time to be 15 to 25 days, and make the solid raw material run from one end of the solid high-temperature fermentation reactor to The time at the other end of the solid high-temperature fermentation reactor is equal to the time that the solid raw material stays in the solid high-temperature fermentation reactor. the

In order to better achieve the above purpose, the present invention also provides a device for producing biogas from solid organic waste, which includes a solid-liquid separator, a liquid anaerobic fermentation system, a solid anaerobic fermentation system, a two-stage integrated anaerobic An oxygen fermentation reactor, a gas collection and utilization system, and a biogas residue treatment system, the solid-liquid separator is respectively connected with the liquid anaerobic fermentation system and the solid anaerobic fermentation system, the liquid anaerobic fermentation system and The solid anaerobic fermentation system is respectively connected with the two-stage integrated anaerobic fermentation reactor, and the two-stage integrated anaerobic fermentation reactor is respectively connected with the gas collection and utilization system and the biogas residue treatment system connect. the

The above-mentioned equipment for producing biogas from solid organic waste, wherein the liquid anaerobic fermentation system includes a liquid pretreatment heating tank and a medium temperature anaerobic fermentation reactor, and the feed port of the liquid pretreatment heating tank is connected to the solid The liquid outlet of the liquid separator is connected, and the mesophilic anaerobic fermentation reactor is respectively connected with the liquid pretreatment heating pool and the two-stage integrated anaerobic fermentation reactor. the

The above-mentioned equipment for producing biogas from solid organic waste, wherein, the solid anaerobic fermentation system includes a solid mixing and conveying device, a solid pretreatment heating tank, a solid high-temperature fermentation reactor and a secondary solid-liquid separator, and the solid The mixing and conveying device is respectively connected with the solid-liquid separator and the solid pretreatment heating tank, and the solid high-temperature fermentation reactor is respectively connected with the solid pretreatment heating tank, the secondary solid-liquid separator, the The secondary integrated anaerobic fermentation reactor is connected to the solid mixing and conveying device, and the secondary solid-liquid separator is connected to the secondary integrated anaerobic fermentation reactor. the

The technical effect of the present invention is that: the present invention can process solid organic wastes to produce biogas through anaerobic fermentation, without adding fresh water in the process, and the heat generated by the system itself can be used for its own energy consumption needs without additional energy. The pretreatment process is simple, the process operation management is simple, the floor area is small, the biogas slurry production is small, the organic matter removal rate is high, and the raw material gas production rate is high, which can not only reduce the pollution of organic waste to the environment, but also generate clean and renewable energy Biogas can realize the energy utilization of solid waste and has good environmental and economic benefits. the

The present invention will be described in detail below in conjunction with the accompanying drawings and specific embodiments, but not as a limitation of the present invention. the

Description of drawings

Fig. 1 is the method flowchart of the anaerobic fermentation of solid organic waste of the present invention biogas;

Fig. 2 is a block diagram of the equipment structure of biogas produced by anaerobic fermentation of solid organic waste of the present invention;

Fig. 3 is a schematic structural diagram of equipment for anaerobic fermentation of solid organic waste to produce biogas according to an embodiment of the present invention. the

Among them, reference signs

1 Solid-liquid separator

2 liquid anaerobic fermentation system

21 Liquid pretreatment heating pool

22 mesophilic anaerobic fermentation reactor

3 Solid anaerobic fermentation system

31 Solid mixing and conveying device

32 Solid pretreatment heating pool

33 Solid high temperature fermentation reactor

34 Secondary solid-liquid separator

4 Two-level integrated anaerobic fermentation reactor

5 Gas collection and utilization system

51 Gas purification device

52 Generator set and waste heat utilization device

6 Biogas residue treatment system

a～f, c1, c2, d1～d3 steps

Detailed ways

Below in conjunction with accompanying drawing, structural principle of the present invention and principle of work are specifically described:

Referring to Fig. 1, Fig. 1 is a flow chart of the method for producing biogas by anaerobic fermentation of solid organic waste according to the present invention. The method for producing biogas from solid organic waste of the present invention comprises the following steps:

In the pretreatment step a, the organic waste is collected, sorted and/or crushed, and the sludge used for anaerobic fermentation is pre-inoculated and domesticated;

In the solid-liquid separation step b, the organic waste treated in the pretreatment step is directly subjected to solid-liquid separation; in this embodiment, the solid-liquid separation machine is used to directly separate the organic waste without adding fresh water. Adjust the total solids content of the liquid phase and the raw material concentration. Divide organic waste into solid flow and liquid flow, the TS concentration in the solid flow is greater than 30%, and the TS concentration in the liquid flow is between 4 and 5%;

Liquid anaerobic fermentation step c, performing anaerobic fermentation on the liquid raw material separated in the solid-liquid separation step to prepare biogas, and collecting the prepared biogas;

Described liquid anaerobic fermentation step c comprises again:

Liquid pretreatment heating step c1, the liquid raw material separated in the solid-liquid separation step is subjected to conditioning, inoculation, and preheating; the liquid raw material is pumped to the liquid pretreatment adjustment tank for sand settling treatment and raw material preheating, heating There is a stirring device in the pool, and the temperature of the liquid pretreatment adjustment pool is controlled to be 20°C to 35°C, and the time for the liquid raw material to stay in the liquid pretreatment adjustment pool is 1 to 1.5 days;

In step c2 of mesophilic anaerobic fermentation, the liquid raw material heated through the liquid pretreatment and heating step is subjected to mesophilic anaerobic fermentation to prepare biogas. Pump the above-mentioned pretreated and warmed raw materials into the mesophilic anaerobic fermentation reactor 22 for mesophilic anaerobic fermentation. Stirring and hydraulic circulation can be set in the mesophilic anaerobic fermentation reactor 22 to achieve uniform mass transfer and heat transfer of materials. Complete the anaerobic fermentation and decomposition of organic matter in the liquid to produce biogas, control the anaerobic fermentation temperature at 30°C to 38°C, preferably 33°C to 38°C, and the pH value is 6 to 8, preferably 6.5 to 7.8, and the material stays The time is 10 to 35 days, and the preferred residence time is 15 to 20 days; the inoculum used for mesophilic anaerobic fermentation at the initial stage of start-up is inoculated and domesticated with mesophilic anaerobic living sludge from biogas plants or municipal sewage treatment plants. the

Solid anaerobic fermentation step d, performing anaerobic fermentation on the solid raw material separated in the solid-liquid separation step to prepare biogas, and collecting the prepared biogas;

The solid anaerobic fermentation step d comprises:

Solid pretreatment heating step d1; after solid-liquid separation, the solid is sent to the solid heating pretreatment tank through the conveying device for heating and tempering, and the temperature of the solid heating pretreatment tank is controlled at 50°C to 70°C. The residence time in the warming pool is 1 to 2 days, and a stirring device can be installed in the solid heating pretreatment pool to enhance mass transfer and heat transfer;

In the high-temperature anaerobic fermentation step d2, the solid raw material heated in the solid pretreatment and heating step is subjected to high-temperature anaerobic fermentation to prepare biogas. After the solid material is preheated, it is sent to the solid high-temperature fermentation reactor 33 through the conveying device, and the solid high-temperature fermentation reactor 33 can be equipped with stirring, temperature-increasing, and heat-preserving devices; Carry out high-temperature anaerobic fermentation in the solid high-temperature fermentation reactor 33, control the temperature of the solid high-temperature fermentation reactor 33 to be 50°C-60°C, the pH value is 6-8, preferably the pH value is 6.5-7.8, and the material residence time is 10 ~25 days, the preferred residence time is 15 to 25 days, and the time for the solid raw material to run from one end of the solid high-temperature fermentation reactor 33 to the other end of the solid high-temperature fermentation reactor 33 is equal to that of the solid raw material The residence time in the solid high-temperature fermentation reactor 33. The inoculum used for high-temperature anaerobic fermentation at the initial stage of start-up comes from the inoculation and domestication of high-temperature anaerobic activated sludge from biogas plants or municipal sewage treatment plants; or adopts mesophilic anaerobic bacteria from biogas plants or municipal sewage treatment plants Activated sludge inoculation and acclimatization, the temperature increase method is gradually increased by 1 °C per day to high temperature (50 °C ~ 60 °C);

In the second solid-liquid separation step d3, the material after the high-temperature anaerobic fermentation step is subjected to a second solid-liquid separation, and the separated liquid is continuously fermented by the second-level integrated anaerobic fermentation step. After the solid-phase dry fermentation is completed, the solid-liquid separation is carried out on the discharge, the solid part is directly composted, and the liquid part enters the secondary integrated anaerobic fermentation reactor 4 to continue fermentation; after the solid-phase dry fermentation is completed, a part of the discharge is refluxed to The solid mixing and conveying device 31 performs inoculation and tempering, and the rest enters the secondary solid-liquid separator 34 for secondary solid-liquid separation. the

Step e of the two-stage integrated anaerobic fermentation, continue to ferment the raw materials treated in the liquid anaerobic fermentation step and the solid anaerobic fermentation step to prepare biogas, and collect the prepared biogas; two-stage integrated fermentation After the reaction and fermentation is completed, the biogas slurry is regularly discharged, and the biogas residue is stored in the biogas residue pond; Equipped with side stirring device. In the secondary integrated anaerobic fermentation reactor 4, the fermentation can continue to generate biogas, store biogas slurry, and collect biogas. The secondary integrated anaerobic fermentation reactor 4 can be equipped with a heat preservation device, and the pH value is 6-8. The residence time is 20-30 days; after the secondary reaction, the biogas residue is discharged to the biogas residue pond through the biogas residue liquid treatment system 6, and is regularly transported to farmland for fertilization. the

Biogas utilization and slag liquid treatment step f, the biogas prepared and collected in the liquid anaerobic fermentation step, the solid anaerobic fermentation step and the two-stage integrated anaerobic fermentation step is purified, utilized and discharged for treatment The slag liquid produced by the above steps. The biogas collected in each step is stored above the secondary integrated anaerobic fermentation reactor 4; the biogas is dehydrated, desulfurized, and impurity-removed by the gas purification device 51 and then passed through the generator set and the waste heat utilization device 52 for power generation , the waste heat from power generation is supplied to the liquid pretreatment heating pool 21, the solid pretreatment heating pool 32, the medium temperature anaerobic fermentation reactor 22, and the solid high temperature fermentation reactor 33 to increase temperature and keep warm; the biogas slurry in the secondary integrated anaerobic fermentation reactor 4 of the above steps Part of it is refluxed into the liquid pretreatment heating pool 21 for inoculation and mass transfer to increase the amount of microorganisms in the feed and strengthen the fermentation effect. the

Referring to Fig. 2 and Fig. 3, Fig. 2 is a block diagram of the equipment structure of the anaerobic fermentation of solid organic waste to produce biogas according to the present invention, and Fig. 3 is a schematic diagram of the equipment structure of the anaerobic fermentation of solid organic waste to produce biogas according to an embodiment of the present invention. The present invention also provides ancillary equipment suitable for the method for preparing biogas by anaerobic fermentation of solid organic waste of the present invention, including a solid-liquid separator 1, a liquid anaerobic fermentation system 2, a solid anaerobic fermentation system 3, The two-stage integrated anaerobic fermentation reactor 4 can also include a gas collection and utilization system 5 and a biogas residue liquid treatment system 6, and the solid-liquid separator 1 is connected with the liquid anaerobic fermentation system 2 and the solid anaerobic fermentation system respectively. The oxygen fermentation system 3 is connected, the liquid anaerobic fermentation system 2 and the solid anaerobic fermentation system 3 are respectively connected with the two-stage integrated anaerobic fermentation reactor 4, the gas collection and utilization system 5 and the The biogas residue treatment system 6 is respectively connected to the two-stage integrated anaerobic fermentation reactor 4 . In this embodiment, the gas collection and utilization system 5 includes a gas purification device 51 , a generator set and a waste heat utilization device 52 . Wherein, the liquid anaerobic fermentation system 2 includes a liquid pretreatment heating pool 21 and a mesophilic anaerobic fermentation reactor 22, a stirring device can be arranged in the liquid pretreatment heating pool 21, and the liquid pretreatment heating pool 21 The feed port is connected to the liquid outlet of the solid-liquid separator 1, and the mesophilic anaerobic fermentation reactor 22 is respectively connected to the liquid pretreatment heating pool 21 and the two-stage integrated anaerobic fermentation reactor 4. The solid anaerobic fermentation system 3 comprises a solid mixing and delivery device 31, a solid pretreatment heating tank 32, a solid high-temperature fermentation reactor 33 and a secondary solid-liquid separator 34, and the solid mixing and delivery device 31 is respectively connected with the The solid-liquid separator 1 is connected to the solid pretreatment heating pool 32, and the solid high-temperature fermentation reactor 33 is respectively integrated with the solid pretreatment heating pool 32, the secondary solid-liquid separator 34, and the secondary solid-liquid separator. The anaerobic fermentation reactor 4 is connected to the solid mixing and conveying device 31, and the secondary solid-liquid separator 34 is connected to the secondary integrated anaerobic fermentation reactor 4. the

The method and equipment of the present invention will be described in detail below with two specific embodiments. the

Embodiment one:

The raw material is cow manure from a dairy farm in city A, and the anaerobic fermentation inoculum comes from anaerobic activated sludge from a biogas plant. the

In the mesophilic anaerobic fermentation reactor 22, the mesophilic anaerobic activated sludge from the biogas plant is used for inoculation and acclimatization. the

In the solid high-temperature fermentation reactor 33, high-temperature anaerobic activated sludge from a biogas plant is used for inoculation and acclimatization. the

After the inoculation and acclimatization is completed, the fermentation process of cattle manure is carried out according to the following steps:

(1) The feces from the cattle farm are collected by a forklift and sent to the solid-liquid separator 1 through the conveying device for solid-liquid separation;

(2) Pump the liquid separated by the solid-liquid separator 1 to the liquid pretreatment heating pool 21 for heating, control the temperature of the liquid pretreatment heating pool 21 to 22° C., and fully stir to make the heating even. the

(3) Pump the above-mentioned warmed liquid raw materials into the mesophilic anaerobic fermentation reactor 22 for mesophilic anaerobic fermentation, complete the anaerobic fermentation of organic matter in the liquid to produce biogas, control the mesophilic anaerobic fermentation temperature to 33°C, and pH to 6.8, the material residence time is 15 days;

(4) After completing the mesophilic anaerobic fermentation in step (3), the liquid raw material is transported from the mesophilic anaerobic fermentation reactor 22 to the secondary integrated anaerobic fermentation reactor 4 for further fermentation to produce biogas. The second-level integrated anaerobic fermentation reactor 4 does not increase the temperature, but only keeps warm, and utilizes the waste heat in the previous step to control the residence time of the materials in the second-level integrated anaerobic fermentation reactor 4 to 30 days, and the pH value is 6.8 ;

(5) The solids separated by the solid-liquid separator 1 fall into the solid pretreatment heating pool 32 by gravity, and the temperature of the solid pretreatment heating pool 32 is controlled at 60° C., and fully stirred to make the heating uniform. the

(6) The above-mentioned warmed solid raw material is transported to the solid high-temperature fermentation reactor 33 through the rotor lobe pump, and then fermented to produce biogas. The solid high-temperature fermentation reactor 33 is equipped with a stirring device, so that the time for the raw material in the solid high-temperature fermentation reactor 33 to run from the inlet end to the discharge end is equal to the residence time of the material in the solid high-temperature fermentation reactor 33, and the solid high-temperature fermentation reactor 33 is controlled. The internal temperature is 55°C and the pH value is 6.5;

(7) After dry fermentation in the above step (6), a part of the output of the solid high-temperature fermentation reactor 33 is refluxed for inoculation and tempering, and the other part is separated from the solid-liquid after solid-liquid separation, and the separated liquid is transported to Secondary integrated anaerobic fermentation reactor 4;

(8) After the fermentation is completed in the secondary integrated anaerobic fermentation reactor 4, the biogas slurry is regularly discharged to the farmland for fertilization, and the biogas residue enters the biogas residue pond of the biogas residue treatment system 6 for storage until use. the

(9) The top trachea of the medium-temperature anaerobic fermentation reactor 22 and the solid high-temperature fermentation reactor 33 communicate with the top gas storage membrane of the two-stage integrated anaerobic fermentation reactor 4 to collect the biogas prepared in the above steps. the

(10) After the biogas collected in the secondary integrated anaerobic fermentation reactor 4 is desulfurized, dehydrated, and impurity removed by the gas purification device 51, it generates electricity through the generator set and the waste heat utilization system 52, and the waste heat of the power generation is used for the liquid pretreatment heating pool 21. The solid pretreatment heating pool 32, the mesophilic anaerobic fermentation reactor 22, and the solid high-temperature fermentation reactor 33 are heated to increase temperature. the

Embodiment two:

The raw materials are sorted organic kitchen waste from city B, and the anaerobic fermentation inoculum comes from anaerobic activated sludge from municipal sewage treatment plants. the

In the mesophilic anaerobic fermentation reactor 22, adopt the above-mentioned municipal sewage treatment plant mesophilic anaerobic activated sludge inoculation domestication;

In the solid high-temperature fermentation reactor 33, the anaerobic activated sludge of the above-mentioned municipal sewage treatment plant is used for inoculation and acclimatization, and the temperature increase mode of increasing 1 ° C per day is gradually raised to a high temperature (58 ° C). Inoculum. the

After the domestication and inoculation is completed, the sorted urban kitchen organic waste is anaerobically fermented to produce biogas according to the following steps:

(1) Utilize the solid-liquid separator 1 to carry out solid-liquid separation of the food waste collected, sorted and crushed;

(2) The liquid part of the food waste after the above-mentioned solid-liquid separation flows to the liquid pretreatment heating pool 21 by itself;

(3) Return part of the biogas slurry in the two-level integrated anaerobic fermentation reactor 4 to the liquid pretreatment heating pool 21, perform inoculation, tempering, preheating with the above step (2), and fully stir to control the temperature in the heating pool. Temperature 25°C;

(4) The solid part after the above-mentioned solid-liquid separation is transported to the solid pretreatment heating pool 32;

(5) Reflux the solid in the discharge part of the solid high-temperature fermentation reactor 33 to the solid mixing and conveying device 31, perform pretreatment inoculation, preheating, and sufficient stirring with the above step (4), and control the temperature in the heating tank to 60°C ;

(6) Pump the raw material after the temperature increase of the above-mentioned liquid pretreatment heating pool 21 into the mesophilic anaerobic fermentation reactor 22 to carry out mesophilic anaerobic fermentation to produce biogas, control the temperature of the mesophilic anaerobic fermentation reactor 22 to be 38 ° C, and the pH value is 7.0, and the material residence time is 25 days;

(7) The solid raw material after the above-mentioned solid pretreatment heating pool 32 is warmed is sent into the solid high-temperature fermentation reactor 33 through the cam rotor pump to carry out high-temperature anaerobic fermentation to produce biogas, and the temperature of the solid high-temperature fermentation reactor 33 is controlled to be 58 °C, the pH value is 7.2, and the material residence time is 22 days;

(8) After the fermentation in the medium-temperature anaerobic fermentation reactor 22 is completed, the discharge enters the secondary integrated anaerobic fermentation reactor 4 through the discharge device, and the secondary integrated anaerobic fermentation reactor 4 is not provided with temperature increase, but only with heat preservation The device is equipped with side stirring to enhance mass transfer and shell breaking, the pH value is 7.2, and the material residence time is 55 days;

(9) After the solid high-temperature fermentation reactor 33 ferments, the material is subjected to secondary solid-liquid separation through a secondary solid-liquid separator 34, and the separated liquid is pumped into the secondary integrated anaerobic fermentation reactor 4, and the solid is directly composted;

(10) The biogas slurry in the two-level integrated anaerobic fermentation reactor 4 is regularly discharged during the fertilization season for farmland fertilization, and the biogas residue enters the biogas residue pond of the biogas residue treatment system 6 for storage, and is discharged for external use during the fertilization season. the

The invention can process the anaerobic fermentation of solid organic wastes to produce biogas without adding fresh water, and the heat generated by the fermentation process itself can be used for its own energy consumption without additional energy. The pretreatment process is simple, the process operation and management are simple, the floor area is small, the biogas slurry production is small, the organic matter removal rate is high, and the raw material gas production rate is high, which can not only reduce the pollution of organic waste to the environment, but also generate clean and renewable energy Biogas can realize the energy utilization of solid waste and has good environmental and economic benefits. the

Certainly, the present invention also can have other multiple embodiments, without departing from the spirit and essence of the present invention, those skilled in the art can make various corresponding changes and deformations according to the present invention, but these corresponding Changes and deformations should belong to the scope of protection of the appended claims of the present invention. the

Claims (3)

1. a method for solid organic castoff biological flue gas processed, is characterized in that, comprises the following steps:

A, pre-treatment step, to organic waste collect, sorting and/or fragmentation, and in advance to inoculating domestication for the mud of anaerobically fermenting;

B, solid-liquid separation step, organic waste after described pre-treatment step is processed is directly carried out to solid-liquid separation, without adding fresh water, regulate liquid phase total solids level material concentration, described organic waste is divided into efflux of solids and liquid stream, in described efflux of solids, TS concentration is greater than 30%, and in described liquid stream, TS concentration is between 4～5%;

C, liquid anaerobically fermenting step, carry out anaerobically fermenting to prepare biological flue gas by the isolated liquid starting material of described solid-liquid separation step, and collect prepared biological flue gas, comprising:

C1, liquid pre-treatment heating steps, by the liquid starting material after described solid-liquid separation step separation carry out modified, inoculate, preheat, liquid starting material after described solid-liquid separation step is delivered to liquid pre-treatment equalizing tank, carry out pre-treatment, modified and inoculation, controlling described liquid pre-treatment equalizing tank temperature is 20 ℃～35 ℃, and the time that described liquid starting material stops in described liquid pre-treatment equalizing tank is 1～1.5 day;

C2, intermediate temperature anaerobic fermentation step, carry out intermediate temperature anaerobic fermentation to prepare biological flue gas by the liquid starting material after described liquid pre-treatment heating steps heats, and comprising:

Raw material after described liquid pre-treatment heating steps is pumped in intermediate temperature anaerobic fermentation reactor and carries out intermediate temperature anaerobic fermentation, and controlling intermediate temperature anaerobic fermentation temperature of reactor is 30 ℃～38 ℃, and pH value is 6～8, and the residence time is 10～35 days;

D, solid anaerobic fermentation step, carry out anaerobically fermenting to prepare biological flue gas by the isolated solid material of described solid-liquid separation step, and collect prepared biological flue gas, comprising:

D1, solid pre-treatment heating steps, solid material after described solid-liquid separation step is delivered to solid heat pre-treatment pond, heat, modified, controlling described solid heat pre-treatment pond temperature is 50 ℃～70 ℃, described solid material residence time in heating pond is 1～2 day;

D2, high-temperature anaerobic fermentation step, solid material after described solid pre-treatment heating steps is heated carries out high-temperature anaerobic fermentation to prepare biological flue gas, solid material after described solid pre-treatment heating steps is processed is delivered in solid thermophilic fermentation reactor and carries out high-temperature anaerobic fermentation, the temperature of controlling described solid thermophilic fermentation reactor is 50 ℃～60 ℃, pH value is 6.5～7.8, and the residence time is 10～25 days;

E, secondary integral anaerobic fermentation step, continue fermentation to prepare biological flue gas by the raw material after described liquid anaerobically fermenting step and described solid anaerobic fermentation step process, and collect prepared biological flue gas;

F, biological flue gas utilization and slag liquid treatment step, the biological flue gas of collecting in described liquid anaerobically fermenting step, described solid anaerobic fermentation step and described secondary integral anaerobic fermentation step is utilized after purifying and emission treatment described in the slag liquid that produces of secondary integral anaerobic fermentation step.

2. the method for solid organic castoff as claimed in claim 1 biological flue gas processed, is characterized in that, described solid anaerobic fermentation step also comprises:

D3, secondary solid-liquid separation step, carry out secondary solid-liquid separation to the material after described high-temperature anaerobic fermentation step, and the liquid after separation continues fermentation by described secondary integral anaerobic fermentation step.

3. the method for solid organic castoff as claimed in claim 1 or 2 biological flue gas processed, it is characterized in that, described high-temperature anaerobic fermentation step also comprises, described solid material runs to the other end of described solid thermophilic fermentation reactor time from one end of described solid thermophilic fermentation reactor equals the time that described solid material stops in described solid thermophilic fermentation reactor.

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