CN203229513U - Device for preparing engine gas by using kitchen waste or organic waste - Google Patents

Abstract

The utility model is a device for producing engine gas from kitchen waste or organic waste, including: anaerobic fermentation tank, hydrogen buffer gas storage cabinet, methane buffer gas storage cabinet, aerobic fermentation tank, air blower, methane gas deacidification equipment , methane gas dehydration and adsorption equipment, air pump, methane gas blending tank, methane gas compressor, heat exchanger, circulation delivery pump, engine methane gas compression storage tank, fermentation residue dehydration separator, pressure safety alarm device, automatic temperature control The device and the gas monitoring device are connected in sequence. The automatic control panel is equipped with a temperature controller, a pressure safety alarm and a gas monitor; the sensors of the temperature controller are respectively connected to the inside of the fermentation tank to contact the fermentation material; the connection line of the pressure safety alarm It is configured on the hydrogen buffer gas storage tank, and the connection line of the gas monitor is configured on the methane gas compression storage tank. The utility model can ferment food waste, agricultural and forestry waste, poultry manure, sludge, sewage and domestic garbage as raw materials to produce engine gas; the utility model has good industrial applicability.

Description

Equipment for producing engine gas from kitchen waste or organic waste

technical field

The utility model relates to equipment for preparing engine gas from kitchen garbage or organic waste, which belongs to chemical equipment. the

Background technique

With the continuous improvement of people's daily life, the amount of kitchen waste and organic waste is increasing, and the low-cost utilization and management of kitchen waste and organic waste can make it harmless, reduce and recycle To prevent food waste from entering the feed food chain and to maintain people's food hygiene and health is a major concern of today's society and has great environmental and social significance. the

Relevant food waste is the existing many reports of the method for raw material production biogas; In CN101134684B, disclose " a kind of method of food waste two-phase anaerobic fermentation hydrogen production methane ", the generation concentration of hydrogen in the first phase fermentation is More than 50%, the maximum concentration of methane in the second phase fermentation is more than 60%, which has the defect of low calorific value of the fermentation gas product; the raw materials that can be biochemically fermented in nature are mainly carbohydrates such as starch, protein, cellulose and hemicellulose , such as kitchen waste, urban organic waste, crop straw, sawdust, rice husk, organic sewage, poultry manure, sludge, etc.; according to the principle of biochemical reactions, the production of methane by fermentation is carried out under the isolation of air (or oxygen) Anaerobic fermentation, anaerobic fermentation mainly includes three stages: hydrolysis acidification stage, hydrogen production acetic acid stage and methane production stage; in the two stages of hydrolysis acidification and hydrogen production acetic acid production, the fermentation gas discharged from the fermentation equipment contains A large amount of hydrogen is an inevitable process. In the final mixed gas product collected during the entire anaerobic biochemical treatment process, in addition to a large amount of methane gas, there is also a certain amount of hydrogen mixed in, which belongs to the mixture of hydrogen and methane gas, resulting in the loss of the entire fermentation system. Methane production decreases; according to the principle of biochemical reactions, hydrolysis bacteria and hydrogen-producing acetogenic bacteria have good activity at a pH value of 5-6.5, which can accelerate the process of hydrogen production and acetic acid reaction, while methanogens are inhibited at a pH value of 5-6.5 , inactive, and does not produce methane; methanogens have good activity and produce methane in an environment with a pH of 6.8-7.5; The decomposition gas is mainly a mixed gas composed of hydrogen and a small amount of carbon dioxide; therefore, the biogas produced by conventional kitchen waste or/and organic waste anaerobic fermentation contains a large amount of low calorific value hydrogen (H ₂ , 10798KJ/m ³ , under the standard state); On July 1, 2001, China promulgated and implemented the national standard GB18047-2000 for compressed natural gas for vehicles, which stipulates that the high-level calorific value of gas must be greater than 31.4MJ/m ³ (or 31400KJ/m ³ under the standard state), there is strict control over traces of carbon dioxide (CO ₂ ), sulfur oxide (SO ₂ ), hydrogen sulfide (H ₂ S) and other acidic substances (such as NO ₂ , HCl), and Does not contain moisture; therefore, the biogas produced by conventional food waste or/and organic waste anaerobic fermentation contains a large amount of hydrogen with low calorific value (H ₂ , 10798KJ/m ³ , under standard conditions), and carbon dioxide and Other harmful gases have low calorific value, generally in the standard state of 20-25MJ/m ³ , with complex components and many impurities, which cannot meet the fuel requirements of engines (or internal combustion engines), and cannot be used as engine fuels; usually, this Gas with low calorific value is mainly used for power plants. Heat sources, as well as heating and gas supply for industrial or domestic use;

In particular, the oxidation of organic matter in anaerobic catabolism is not complete, and aerobic fermentation must be carried out under the condition of sufficient oxygen supply, and the remaining organic pollutants of anaerobic fermentation are decomposed by the life activity process of aerobic microorganisms and facultative microorganisms. It is further oxidized into relatively stable inorganic substances through the biochemical process of aerobic fermentation, and finally, the organic waste is completely decomposed, and the harmless treatment of kitchen waste or/and organic waste is truly achieved. Food waste contains a large amount of carbohydrates such as starch (such as leftover rice), protein (such as leftover meat and fish), fat (edible oil) and cellulose (such as vegetable residues). The composition is complex, and the methane produced by fermentation The gas contains a large amount of nitrogen (N), sulfur (S), carbon dioxide and organic macromolecular impurities. The methane gas must be refined to meet the quality standards of engine gas. the

So far, in Chinese and world patent literature databases, related books, publications, magazines, and industrial production applications, no equipment has been found that uses food waste as raw material to produce high-calorific-value vehicle and ship engine gas through biochemical fermentation. ;

The purpose of this utility model is to overcome and make up for the defects and deficiencies of the prior art, thereby providing a method to collect and store the hydrogen produced in the fermentation of the hydrolysis acidification stage and the hydrogen production and acetic acid production stage, and then pass the hydrogen into the methane production stage In the advanced fermentation equipment, methane is converted into methane under the action of methane bacteria to increase the conversion rate of methane gas; acidic substances or organic macromolecular impurities in methane gas are further decomposed, refined, blended, compressed, and biochemical conversion technology is used. Equipment for producing high calorific value vehicle engine (or internal combustion engine) gas. the

Contents of the invention

Equipment for producing engine gas from kitchen waste or organic waste, including: anaerobic fermentation tank, hydrogen buffer gas storage cabinet, methane buffer gas storage cabinet, aerobic fermentation tank, air blower, methane gas deacidification equipment, methane gas dehydration And adsorption equipment, air pump, methane gas adjustment tank, methane gas compressor, heat exchanger, circulation pump, methane gas compression storage tank, fermentation residue dehydration separator, pressure safety alarm device, automatic temperature control device and gas monitoring Devices and other equipment are connected in sequence; it is characterized in that: the automatic control panel (5) is equipped with a temperature controller (25), a pressure safety alarm (24) and a gas monitor (23); wherein, the temperature controller (25) The sensors are respectively connected inside the fermentation tanks (1, 3, 4) to contact with the fermentation material; the connection line of the pressure safety alarm (24) is arranged on the hydrogen buffer gas storage cabinet (2), and the connection line of the gas monitor (23) is arranged On the methane gas compression storage tank (9); the manholes (18, 19, 20) for feeding are all configured on the top of the anaerobic fermentation tank (1, 3) and the aerobic fermentation tank (4), and the fermentation tank (1, 3 , 4) The bottom outlet pipes are respectively connected with the inlet pipes of the circulation delivery pumps (12, 13, 15), and the outlets of the circulation delivery pumps (12, 13, 15) are respectively connected with the heat exchange tube inlets of the heat exchanger (11) , the heat exchange tube outlets of the heat exchanger (11) are respectively connected to the top of the fermentation tank (1, 3, 4); the top outlet of the anaerobic fermentation tank (1) is connected to the inlet of the one-way valve (22), and the one-way valve ( The outlet of 22) is connected with the air inlet of the hydrogen buffer gas storage tank (2); the gas outlet of the hydrogen buffer gas storage tank (2) passes through the air pump (21) and the bottom aeration of the anaerobic fermentation tank (3) producing methane The inlet pipe mouth of pipe (27) is connected; The air outlet of the top gas outlet of anaerobic fermentation tank (3) is connected with the inlet of one-way valve (26), and the gas outlet of one-way valve (26) is connected with methane buffer gas storage tank ( 6) the air inlets are connected; the gas outlet of the methane buffer gas storage tank (6) is connected to the internal gas receiving pipe (28) of the methane gas deacidification equipment (7) through the air pump (17); the methane gas deacidification equipment (7) ) The air outlet pipe of the upper gas storage chamber is communicated with the air inlet of the dehydration and adsorption equipment (30), the air outlet of the dehydration and adsorption equipment (30) is communicated with the air inlet of the methane gas blending tank (8), and the methane gas blending tank ( 8) The gas outlet is connected to the methane gas compression storage tank (9) through the methane gas compressor (16); the bottom of the fermentation tank (3, 4) is equipped with a gas diffuser (27, 32), and the aerobic fermentation tank (4) The bottom is connected to the air outlet of the air blower (14); the outlet of the circulation delivery pump (15) is connected to the fermentation residue dehydration separator (10);

Described fermentor or fermenting equipment, can adopt the well-known complete mixed anaerobic reactor (CSTR) on the market, upflow solid bed reactor (USR), plug-flow anaerobic reactor (PFR), buoyancy Type fermenter, vertical enamel reactor with stirring and heat exchange jacket, plug flow digester, fully mixed digester, conventional digester, retention digester, internal circulation anaerobic reactor (IC), attachment Membrane digester, MBR (aerobic digester) and other known related fermenters;

The utility model can accelerate the fermentation speed of raw materials, especially, can better recycle the hydrogen produced in the stages of hydrolysis acidification and hydrogen production and acetic acid production; the hydrogen is input into the fermenter (3), and under the action of methane bacteria, Make hydrogen with low calorific value and carbon dioxide produced by fermentation undergo methanation reaction, convert it into methane with high calorific value, increase the methane production of the entire fermentation system, and increase the calorific value of gas produced by biochemical gas production from kitchen waste or/and organic waste, It is one of the main features of this utility model to make the gas collected by fermentation meet and reach the standard of vehicle and ship engine fuel, and the following reactions mainly take place:

In the treatment of the described aerobic fermenting tank (4), under the condition of sufficient oxygen supply, utilize the life activity process of aerobic bacteria and facultative microorganism (as the activated sludge of sewage treatment plant), the anaerobic fermentation remaining The undecomposed part of the organic matter is oxidized and decomposed into relatively stable carbon dioxide, water and inorganic matter, so that the fermentation product is completely harmless, and the MBR aerobic process technology and equipment are mainly used; the chemical principle is as follows:

The purpose of this utility model is to provide equipment for producing high calorific value engine (or internal combustion engine) gas, strictly control the percentage content of various harmful gases in the gas [such as carbon dioxide (CO ₂ )] to the lowest point, is to improve the gas calorific value and One of the keys for producing qualified vehicle gas; therefore, the utility model absorbs harmful gases such as carbon dioxide and hydrogen sulfide in the fermentation gas through the alkaline substance (29) in the methane gas deacidification equipment (7), and improves the purity of methane And percentage content, its chemical principle is as follows:

2NaOH+CO ₂ →Na ₂ CO ₃ +H ₂ O (or 2KOH+CO ₂ →K ₂ CO ₃ +H ₂ O)

2NaOH+H ₂ S→Na ₂ S+2H ₂ O (or 2KOH+H ₂ S→K ₂ S+2H ₂ O)

In the above reaction, the acidic substances and organic impurities contained in the methane can be well neutralized and removed, so that the quality of the methane gas product meets the national standard for vehicle and ship engine gas; this is one of the characteristics of the utility model

Through the dehydration and adsorption equipment (30), moisture and other trace impurities in the methane gas can be further removed; the dehydration and adsorption equipment (30) is equipped with partitions and drain valves for separating moisture, and is equipped with adsorption impurities. Granular active carbon or molecular sieve; In order to prevent and guard against the external leakage of methane gas, the tetrahydrothiophene (THT) odorant of 0.001% (Wt%) is added to methane gas deployment tank (8) through delivery pump (31) middle;

The food waste and/or organic waste further includes the following substances:

Carbohydrates, such as starch, cellulose, hemicellulose, protein, polysaccharide, lignin, or organic compounds composed of C, H, and O elements; organic waste mainly refers to: biomass, such as agricultural and forestry waste, crop straw, human and animal waste And poultry manure, sludge, and municipal solid waste. the

According to the principle of biochemical reaction, activated sludge contains a variety of enzymes or bacteria that decompose starch, protein and cellulose, which can ferment and decompose organic kitchen waste and crop straw into biogas, carbon dioxide and water

Compared with the prior art, the utility model has the following advantages:

1. It can control the pressure of recovered hydrogen in the production process and the temperature during fermentation, and automatically alarm the pressure in the gas compression storage tank of the methane engine if it exceeds the standard;

2. It can accelerate the fermentation speed of raw materials. In particular, it can better recycle the hydrogen produced in the stages of hydrolysis acidification and hydrogen production to produce acetic acid, and convert hydrogen into methane to increase the conversion rate or percentage of methane gas in biogas content;

3. It can convert low-value biogas into high-value engine gas that meets the national standard of GB18047-2000 compressed natural gas for vehicles;

4. After biogas fermentation, the remaining organic residues are further treated by aerobic fermentation (MBR process), and have been completely decomposed into carbon dioxide and water, so that the fermented organic wastewater is purified, that is, aerobic (MBR) biochemical degradation treatment After further disinfection and treatment, the water quality can reach the national standard "GB18918-200" urban sewage treatment plant discharge standard, and the production process is harmless;

5. The equipment used in this utility model belongs to the conventional fermentation equipment and supporting equipment in the market, and has a large selectivity;

6. The utility model has strong selectivity, and can ferment food waste, carbohydrates, agricultural and forestry crop waste, human, livestock and poultry manure, domestic wastewater, etc. as raw materials to produce engine methane gas;

The utility model will be further described below in conjunction with accompanying drawing and embodiment, but present embodiment is not limited thereto;

Description of drawings

Fig. 1 is a structure diagram of the utility model

In Fig. 1, (1) hydrolytic acidification and hydrogen production acetic acid fermentation tank; (2) hydrogen buffer gas storage tank; (3) methane production fermentation tank; (4) aerobic fermentation tank; (5) automatic control panel; (6) Methane buffer gas storage tank; (7) Methane gas deacidification equipment; (8) Methane gas deployment tank; (9) Engine methane gas compression storage tank; (10) Fermentation sludge dehydration separator; (11) Heater; (12) liquid circulation delivery pump; (13) circulation delivery pump; (14) air blower; (15) circulation delivery pump; (16) methane gas compressor; (17) suction pump; (18) raw material feeding (19) manhole; (20) feeding manhole; (21) suction pump; (22) one-way valve; (23) gas monitor; (24) pressure safety alarm; (25) temperature controller; (26) one-way valve; (27) gas diffuser; (28) gas receiving pipe; (29) deacidified lye; (30) dehydration and adsorption equipment; (31) odorant feeding pump; (32) Gas diffuser; (33) gas product output pipe; (34) MBR membrane module; (35) outlet pump;

Example

First remove the non-fermentable substances (such as inorganic substances, chopsticks, waste plastics, etc.) Fermentation bacteria) are added into the fermenter (1) through the feeding manhole (18); according to the biochemical reaction principle and ingredient requirements of fermentation to produce methane, the fermented material in the fermented tank (1) is prepared to contain solid fermented material 10 % (Wt%), the activated sludge concentration is 18kg/m ³ anaerobic fermentation substrate, the C/N ratio of adjustment fermentation substrate reaches 20: 1 and PH is 5-6.6, carries out the fermentation of hydrolytic acidification and hydrogen production acetic acid Procedure: During the entire fermentation process, the fermentation solution is circulated from top to bottom in the fermenter by using pumps (12, 13, 15) regularly or irregularly, so that the fermentation solution continuously passes through the heat exchanger (11) Perform heat exchange (steam heating or cold water cooling), control the temperature of the fermented material in the fermenter (1, 3, 4) in the range of 31-37°C; in the fermenter (1), isolate the air all the time, ) stirring and activated sludge (i.e. hydrogen-producing acetate bacteria), the organic matter (starch, protein, cellulose, etc.) in the food waste in the fermenter (1) begins to decompose in the range of pH5-6. Water-soluble substances, and finally, water-soluble organic matter is decomposed by bacteria into a mixed gas composed of acetic acid and hydrogen as the main component and a small amount of carbon dioxide, and the mixed gas is continuously input into the hydrogen gas through the one-way valve (22). stored in the buffer gas holder (2); after 10 days of fermentation, no hydrogen was produced in the fermenter (1), and the fermentation process of hydrolysis acidification and hydrogen production and acetic acid production was completed; the hydrogen buffer gas holder (2) collected In the mixed gas, the content of hydrogen is 82.5% (Wt%), the content of carbon dioxide is 15% (Wt%), and other is 2.5% (Wt%); Further, the fermented material in the fermentor (1) is passed through the pump ( 12) input into the fermenter (3), then a certain amount of activated sludge containing methanogens is added into the fermenter (3) from the feeding port (19), and the concentration of readjustment and proportioning activated sludge is 18kg/m ³ , pH is 6.8-7.5, and the fermentation temperature is controlled in the range of 31-37°C. Under the action of methanogenic bacteria, the fermentation process of methane production is carried out; during the fermentation, the hydrogen in the gas storage tank (2) is buffered The mixed gas with hydrogen as the main component is transported to the gas disperser (27) of the fermenter (3) by the pump (21), fully mixed with the fermentation material, and under the action of the methanogenic bacteria, the hydrogen and the carbon dioxide produced by fermentation are generated. The methanation reaction generates methane; the generated methane gas is introduced into the methane buffer gas storage tank (6) through the one-way valve (26) for temporary storage; in the fermented gas collected, the content of methane is 96.5% (Wt%), other It is 3.5% (Wt%); The methane gas of the methane buffer gas holder (6) is input in the methane gas deacidification equipment (7) through the air pump (17), the gas receiving pipe (28), and the deacidification material hydrogen Sodium oxide solution ( 29) Contact, neutralization reaction occurs to remove acid gas, introduce the gas that has removed acidic substances into the dehydration and adsorption equipment (30), remove the moisture in the methane gas and remove other impurities by adsorption, and introduce it into the methane gas preparation tank (8), join the tetrahydrothiophene (THT) odorant of 0.001% (Wt%) with pump (31) in the methane gas preparation tank (8), after testing, the content of methane is 99.5% (Wt%) ), the calorific value is 36.6MJ/m ³ (standard state), and all indexes all reach and meet the national standard of GB18047-2000 compressed natural gas for vehicles; the methane in the deployment tank (8) is transported with a special-purpose methane compressor (16) Put it into the engine methane gas compression storage tank (9), and use it up to 24MPa for standby, and the gas is discharged to the user through the valve (38); the fermented residual liquid fermented in the fermenter (3) is input to the aerobic fermentation with the pump (13) In the tank (4), the activated sludge containing aerobic bacteria is added into the fermenter (4) through the feeding manhole (20), and a certain amount of air is input through the gas diffuser (32) by the air blower (14). Enter the fermenter (4), aerate with air, use air aeration bubbles to fully contact the aerobic sludge (or aerobic flora) with organic matter, and aerobic degradation reaction of organic matter occurs, according to the biochemical process of aerobic fermentation principle and operating conditions to oxidize and decompose organic matter, and finally convert the remaining organic waste after methane production into carbon dioxide and water; regularly transport the excess sludge formed in the fermenter (4) to the fermented sewage by pump (15) In the mud dehydration separator (10), the sludge is separated; the water in the fermenter (4) is continuously extracted from the MBR membrane cavity into the disinfection tank (36) with a pump (35), and a certain amount of hydrogen peroxide disinfectant Join in the disinfection pool (36) to make the water quality reach the "GB18918-2002" standard, pump out the water up to the standard with the pump (37) and carry out green irrigation or enter the underground drain. The methane fuel produced by this embodiment and the GB18047-2000 compressed natural gas for vehicles sold at the gas station of the petroleum company carry out a 1000-kilometer driving test comparison test of a car. The results were consistent in terms of mileage totals, vehicle acceleration, and engine corrosion and wear.

Claims (2)

1. Equipment for producing engine gas from kitchen waste or organic waste, including: anaerobic fermentation tanks, hydrogen buffer gas storage cabinets, methane buffer gas storage cabinets, aerobic fermentation tanks, air blowers, methane gas deacidification equipment, methane Gas dehydration and adsorption equipment, air pump, methane gas adjustment tank, methane gas compressor, heat exchanger, circulation pump, methane gas compression storage tank, fermentation residue dehydration separator, pressure safety alarm device, automatic temperature control device and gas The monitoring devices are connected sequentially; it is characterized in that: the automatic control panel (5) is equipped with a temperature controller (25), a pressure safety alarm (24) and a gas monitor (23); wherein, the temperature controller (25) The sensors are respectively connected inside the fermentation tanks (1, 3, 4) to be in contact with the fermented material; the connection line of the pressure safety alarm (24) is arranged on the hydrogen buffer gas storage cabinet (2), and the connection line of the gas monitor (23) is arranged on the On the methane gas compression storage tank (9); the manholes (18, 19, 20) for feeding are all configured on the top of the anaerobic fermentation tank (1, 3) and the aerobic fermentation tank (4), and the fermentation tank (1, 3, 4) The outlet pipes at the bottom of the pumps are respectively connected to the inlet pipes of the circulating delivery pumps (12, 13, 15), and the outlets of the circulating delivery pumps (12, 13, 15) are respectively connected to the inlets of the heat exchange tubes of the heat exchanger (11), The outlets of the heat exchange tubes of the heat exchanger (11) are respectively connected to the tops of the fermentation tanks (1, 3, 4); the top outlets of the anaerobic fermentation tanks (1) are connected to the inlets of the one-way valves (22), and the one-way valves (22 ) outlet is connected with the inlet of the hydrogen buffer gas storage tank (2); the gas outlet of the hydrogen buffer gas storage tank (2) passes through the bottom aeration pipe of the anaerobic fermentation tank (3) of the anaerobic fermentation tank (3) producing methane through the air pump (21) The inlet pipe mouth of (27) is connected; The top gas outlet of anaerobic fermentation tank (3) is connected with the inlet of one-way valve (26), and the gas outlet of one-way valve (26) is connected with methane buffer gas holder (6) ) is connected to the air inlet; the gas outlet of the methane buffer gas storage tank (6) is connected to the internal gas receiving pipe (28) of the methane gas deacidification equipment (7) through the air pump (17); the methane gas deacidification equipment (7) The outlet pipe of the upper gas storage chamber is communicated with the air inlet of the dehydration and adsorption equipment (30), the air outlet of the dehydration and adsorption equipment (30) is communicated with the air inlet of the methane gas blending tank (8), and the methane gas blending tank (8) ) gas outlet and the methane gas compression storage tank (9) through the methane gas compressor (16); Connect the air outlet of the air blower (14); the outlet of the circulation delivery pump (15) is connected with the fermentation residue dehydration separator (10). the 2. according to the equipment of claim 1, it is characterized in that: described fermentor, can adopt CSTR mixed type anaerobic reactor, USR upflow type solid bed reactor, PFR push flow type anaerobic reactor, buoyant type Fermentation tank, vertical enamel reaction kettle with stirring and heat exchange jacket, plug flow digester, fully mixed digester, conventional digester, retention digester, IC internal circulation anaerobic reactor, attached film digestion device, MBR aerobic digestion equipment. the

Images