Low-carbon zero-emission kitchen waste oil-fertilizer co-production cyclic utilization method

Abstract

The invention provides a low-carbon zero-emission kitchen waste oil-fertilizer co-production cyclic utilization method, and belongs to the technical field of solid waste resourceful treatment. The kitchen garbage is subjected to primary reaction treatment and two-stage heating and pressurizing reaction, oil, water and solid three-phase separation is performed after standing, the obtained oil phase is bio-oil, the obtained water phase is a primary organic water-soluble fertilizer, and the obtained solid phase is hydrothermal carbon. According to the method disclosed by the invention, low-carbon zero-emission all-component resource recycling of the kitchen garbage is realized, and waste is turned into wealth.

Description

Technical Field

[0001] The present invention relates to the technical field of solid waste resource treatment, and in particular to a method for low-carbon zero-emission kitchen waste oil-fertilizer co-production and recycling. Background Art

[0002] Kitchen waste refers to the waste generated in residents' daily life and food processing, catering services, unit catering and other activities, including discarded vegetable leaves, leftovers, leftovers, fruit peels, eggshells, tea residues, bones (chicken bones, fish bones), etc. Its main sources are family kitchens, restaurants, hotels, canteens, markets and other industries related to food processing. my country produces a large amount of kitchen waste. According to statistics, the amount of kitchen waste we produce each year exceeds 90 million tons. Kitchen waste has the characteristics of high organic matter content, high moisture, high salt content and easy corruption and odor. If it is not properly disposed of, it will cause serious environmental pollution, disease transmission and waste of resources. But from another perspective, kitchen waste is also a kind of urban mineral. The resource disposal of kitchen waste can not only effectively reduce environmental pollution and waste of resources, but also produce valuable commodities, increase the economic value of kitchen waste, and turn fertilizer into treasure.

[0003] In recent years, the research and development of kitchen waste resource utilization technology in my country has been rapid. The main technologies include black soldier fly breeding, anaerobic biogas production, aerobic preparation of organic fertilizer, and coordinated incineration power generation. However, there are still problems such as low technical maturity, large land occupation, and poor environmental and economic benefits. CN202211740873 discloses a system for preparing organic fertilizer based on kitchen waste, which prepares organic fertilizer by hydrolysis and adding chemical fertilizers. CN202211717960 discloses a method and system for resource utilization of all components of kitchen waste based on thermal hydrolysis, which prepares bio-oil, leaf fertilizer, and soil conditioner through crushing and sorting, low-temperature thermal hydrolysis, high-temperature thermal hydrolysis, and blending. However, the above invention has a complex process flow, many equipment, and difficult operation, and the specific components and applications of bio-oil, aqueous products, and solid residues are not clear, and the technical process still needs to be improved.

[0004] The production of kitchen waste increases year by year, but the current kitchen waste treatment capacity is far from meeting the actual needs, resulting in a large amount of kitchen waste waste. Therefore, if an economical, efficient and environmentally friendly kitchen waste full component resource utilization technology can be developed, it can not only avoid the potential environmental and health risks caused by improper disposal of kitchen waste and reduce resource waste, but also produce high-value products such as bio-oil and liquid water-soluble fertilizer, turning fertilizer into treasure, with significant environmental, economic and social benefits. Summary of the invention

[0005] The purpose of the present invention is to provide a low-carbon and zero-emission method for the co-production and recycling of kitchen waste oil and fertilizer, which is used to solve the technical problems of difficulty in resource treatment of kitchen waste solid waste and waste of resources.

[0006] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0007] The present invention provides a method for low-carbon zero-emission kitchen waste oil-fertilizer co-production and recycling, comprising the following steps:

[0008] 1) crushing, screening and grinding the kitchen waste to obtain kitchen waste slurry;

[0009] 2) subjecting the kitchen waste slurry to a primary reaction treatment to obtain a primary raw material slurry;

[0010] 3) separating the primary raw material slurry into three phases of oil, water and solid to obtain primary oil, mixing the separated water and solid, then adding solvent and catalyst to obtain a mixture with a water content of 80-95%, grinding the mixture to obtain a secondary raw material slurry;

[0011] 4) subjecting the secondary raw material slurry to a two-stage heating and pressurizing reaction to obtain a reaction liquid;

[0012] 5) After the reaction liquid is allowed to stand, the oil, water and solid phases are separated, and the obtained oil phase is bio-oil, the obtained water phase is primary organic water-soluble fertilizer, and the obtained solid phase is hydrothermal charcoal.

[0013] Furthermore, the bio-oil contains hydrocarbons, nitrogen-containing compounds and oxygen-containing compounds; the primary organic water-soluble fertilizer contains organic matter, N, P, K and trace elements; and the hydrothermal charcoal is biochar.

[0014] Furthermore, the fineness of the kitchen waste slurry is 150-300 meshes.

[0015] Furthermore, the temperature of the primary reaction treatment is 60-180° C., and the time is 10-60 min; the primary reaction treatment is carried out under stirring, and the stirring speed is 10-500 r / min.

[0016] Further, the solvent comprises water and / or sodium hydroxide solution, and the catalyst comprises K 2 CO 3 、Na 2 CO 3 , one or more of KOH and CaO.

[0017] Furthermore, the volume concentration of the sodium hydroxide solution is independently 0.1-1%.

[0018] Furthermore, the amount of the catalyst used is 0.1-5% of the dry weight of the primary raw material slurry.

[0019] Furthermore, the fineness of the secondary raw material slurry is 200-500 mesh.

[0020] Furthermore, the two-stage heating and pressurizing reaction is specifically as follows: the secondary raw material slurry is stirred at a speed of 10 to 500 r / min, and the temperature is increased to 200 to 280°C at a speed of 5 to 50°C / min at a pressure of 4 to 10 MPa, and kept warm for 5 to 10 minutes; then, the temperature is increased to 280 to 350°C at a speed of 5 to 50°C / min at a pressure of 5 to 22 MPa, and kept warm for 10 to 60 minutes.

[0021] Furthermore, the standing time is 12 to 36 hours.

[0022] Beneficial effects of the present invention:

[0023] The method of the invention prepares kitchen waste into bio-oil, organic water-soluble fertilizer and hydrothermal charcoal. The yield of the bio-oil is 5-10% of the weight of the primary raw material slurry. The bio-oil is a black, opaque, asphalt-like substance with a pungent smell, mainly composed of hydrocarbons, nitrogen-containing compounds and oxygen-containing compounds, with a calorific value of 37-44 MJ / Kg, and can be used for further refining biodiesel, etc. The yield of the bio-char is 0.5-3% of the weight of the primary raw material slurry, and can be used for improving soil. The aqueous phase solution is a primary organic water-soluble fertilizer, with a yield of 80-90% of the weight of the primary raw material slurry. The aqueous phase solution is rich in organic matter, N, P, K and trace elements, and can be used for preparing high-efficiency organic water-soluble fertilizer.

[0024] The method of the present invention realizes low-carbon and zero-emission recycling of all components of kitchen waste resources, turning waste into treasure. DETAILED DESCRIPTION

[0025] The present invention provides a method for low-carbon zero-emission kitchen waste oil-fertilizer co-production and recycling, comprising the following steps:

[0026] 1) crushing, screening and grinding the kitchen waste to obtain kitchen waste slurry;

[0027] 2) subjecting the kitchen waste slurry to a primary reaction treatment to obtain a primary raw material slurry;

[0028] 3) separating the primary raw material slurry into three phases of oil, water and solid to obtain primary oil, mixing the separated water and solid, then adding solvent and catalyst to obtain a mixture with a water content of 80-95%, grinding the mixture to obtain a secondary raw material slurry;

[0029] 4) subjecting the secondary raw material slurry to a two-stage heating and pressurizing reaction to obtain a reaction liquid;

[0030] 5) After the reaction liquid is allowed to stand, the oil, water and solid phases are separated, and the obtained oil phase is bio-oil, the obtained water phase is primary organic water-soluble fertilizer, and the obtained solid phase is hydrothermal charcoal.

[0031] In the present invention, the bio-oil contains hydrocarbons, nitrogen-containing compounds and oxygen-containing compounds; the primary organic water-soluble fertilizer contains organic matter, N, P, K and trace elements; and the hydrothermal charcoal is biochar.

[0032] In the present invention, the fineness of the kitchen waste slurry is 150-300 meshes, preferably 200-250 meshes.

[0033] In the present invention, the temperature of the primary reaction treatment is 60-180°C, preferably 80-160°C, and more preferably 100-150°C; the time is 10-60min, preferably 20-50min, and more preferably 30-40min; the primary reaction treatment is carried out under stirring, and the stirring speed is 10-500r / min, preferably 100-400r / min, and more preferably 200-300r / min.

[0034] In the present invention, the solvent comprises water and / or sodium hydroxide solution, preferably sodium hydroxide solution; the catalyst comprises K 2 CO 3 、Na 2 CO 3 , KOH and CaO, preferably K 2 CO 3 and / or Na 2 CO 3 .

[0035] In the present invention, the volume concentration of the sodium hydroxide solution is independently 0.1 to 1%, preferably 0.2 to 0.8%, and more preferably 0.4 to 0.6%.

[0036] In the present invention, the amount of the catalyst used is 0.1-5% of the dry weight of the primary raw material slurry, preferably 1-4%, and more preferably 2-3%.

[0037] In the present invention, the fineness of the secondary raw material slurry is 200-500 mesh, preferably 300-400 mesh, and more preferably 350 mesh.

[0038] In the present invention, the two-stage heating and pressurizing reaction is specifically as follows: the secondary raw material slurry is stirred at a speed of 10 to 500 r / min, and the temperature is increased to 200 to 280°C at a speed of 5 to 50°C / min at a pressure of 4 to 10 MPa, and kept warm for 5 to 10 minutes; then, the temperature is increased to 280 to 350°C at a speed of 5 to 50°C / min at a pressure of 5 to 22 MPa, and kept warm for 10 to 60 minutes.

[0039] In the present invention, the two-stage heating and pressurizing reaction is preferably: the secondary raw material slurry is stirred at a speed of 100 to 400 r / min, and the temperature is increased to 220 to 260°C at a speed of 10 to 40°C / min at a pressure of 6 to 8 MPa, and kept warm for 6 to 8 minutes; then, the temperature is increased to 280 to 320°C at a speed of 10 to 40°C / min at a pressure of 10 to 20 MPa, and kept warm for 20 to 50 minutes.

[0040] In the present invention, the two-stage heating and pressurizing reaction is further preferably: the secondary raw material slurry is stirred at a speed of 200-300 r / min, and the temperature is increased to 240-250°C at a speed of 20-30°C / min at a pressure of 6-8 MPa, and kept warm for 7-8 min; then, the temperature is increased to 280-320°C at a speed of 20-30°C / min at a pressure of 10-15 MPa, and kept warm for 30-40 min.

[0041] In the present invention, the standing time is 12 to 36 hours, preferably 20 to 30 hours, and more preferably 25 to 28 hours.

[0042] The technical solutions provided by the present invention are described in detail below in conjunction with the embodiments, but they should not be construed as limiting the protection scope of the present invention.

[0043] Example 1

[0044] 1) crushing, screening and grinding the kitchen waste to obtain kitchen waste slurry with a slurry fineness of 200 meshes;

[0045] 2) introducing the kitchen waste slurry into a primary reaction tank for primary reaction treatment, stirring and heating, the stirring speed is 400 r / min, the preheating temperature is 120° C., and the reaction time is 50 min to obtain a primary raw material slurry;

[0046] 3) The primary raw material slurry is separated into three phases of oil, water and solid to obtain primary oil (swill oil). After the oil is separated, the solid and water are mixed, water is added, and then catalyst K is added. 2 CO 3 The mass of the catalyst is 3% of the dry weight of the primary raw material slurry, and finally a mixture with a water content of 80% is prepared, introduced into a grinder, and continued to be ground until the slurry fineness is 400 mesh, and introduced into a secondary reaction tank to obtain a secondary raw material slurry;

[0047] 4) The secondary raw material slurry is subjected to program stirring, heating and pressurization, with a stirring speed of 400 r / min and a program heating rate of 20°C / min, and the temperature is raised to 280°C, and the reaction time is maintained for 8 minutes and the pressure is 10 MPa; then the temperature is continued to be raised to 300°C, the pressure is 20 MPa, and the reaction time is maintained for 30 minutes to obtain a reaction liquid;

[0048] 5) The reaction liquid is introduced into a standing separation tank and allowed to stand for 24 hours to separate oil, water and solid. The oil phase is bio-oil with a yield of 10% of the weight of the primary raw material slurry. It is a black, opaque, asphalt-like substance with a pungent odor, mainly composed of hydrocarbons, nitrogen-containing compounds and oxygen-containing compounds, with a calorific value of 44MJ / Kg, which can be used for further refining biodiesel, etc. The solid phase is hydrothermal charcoal, which belongs to biochar, with a yield of 3% of the weight of the primary raw material slurry, which can be used to improve soil; the aqueous phase solution is primary organic water-soluble fertilizer with a yield of 87% of the weight of the primary raw material slurry. The aqueous phase solution is rich in organic matter, N, P, K and trace elements, and can be used to prepare high-efficiency organic water-soluble fertilizer.

[0049] Example 2

[0050] 1) crushing, screening and grinding the kitchen waste to obtain kitchen waste slurry with a slurry fineness of 300 meshes;

[0051] 2) introducing the kitchen waste slurry into a primary reaction tank for primary reaction treatment, stirring and heating, with a stirring speed of 500 r / min, a preheating temperature of 100° C., and a reaction time of 60 min to obtain a primary raw material slurry;

[0052] 3) separating the primary raw material slurry into three phases of oil, water and solid to obtain primary oil (swill oil), mixing the solid and water after separating the oil, adding 3% sodium hydroxide solution, and then adding catalyst KOH, the mass of the catalyst is 2% of the dry weight of the primary raw material slurry, and finally preparing a mixture with a water content of 85%, introducing it into a grinder, and continuing to grind it until the slurry fineness is 500 mesh, and introducing it into a secondary reaction tank to obtain a secondary raw material slurry;

[0053] 4) The secondary raw material slurry is subjected to program stirring, heating and pressurization, with a stirring speed of 500 r / min and a program heating rate of 30° C. / min, and the temperature is raised to 250° C., and the reaction time is maintained for 8 min and the pressure is 5 MPa; then the temperature is further raised to 350° C., the pressure is 10 MPa, and the reaction time is maintained for 30 min to obtain a reaction solution;

[0054] 5) The reaction liquid is introduced into a standing separation tank and allowed to stand for 24 hours to separate oil, water and solid. The oil phase is bio-oil with a yield of 8% of the weight of the primary raw material slurry. It is a black, opaque, asphalt-like substance with a pungent odor, mainly composed of hydrocarbons, nitrogen-containing compounds and oxygen-containing compounds, with a calorific value of 40MJ / Kg, which can be used for further refining biodiesel, etc. The solid phase is hydrochar, which belongs to biochar, with a yield of 1% of the weight of the primary raw material slurry, which can be used to improve soil; the aqueous phase solution is primary organic water-soluble fertilizer with a yield of 91% of the weight of the primary raw material slurry. The aqueous phase solution is rich in organic matter, N, P, K and trace elements, and can be used to prepare high-efficiency organic water-soluble fertilizer.

[0055] Example 3

[0056] 1) crushing, screening and grinding the kitchen waste to obtain kitchen waste slurry with a slurry fineness of 300 meshes;

[0057] 2) introducing the kitchen waste slurry into a primary reaction tank for primary reaction treatment, stirring and heating, the stirring speed is 400 r / min, the preheating temperature is 60° C., and the reaction time is 60 min to obtain a primary raw material slurry;

[0058] 3) The primary raw material slurry is separated into oil, water and solid phases to obtain primary oil (swill oil). After the oil is separated, the solid and water are mixed, and 1% sodium hydroxide solution is added, and then the catalyst Na 2 CO 3 The mass of the catalyst is 5% of the dry weight of the primary raw material slurry, and finally a mixture with a water content of 90% is prepared, introduced into a grinder, and further ground to a slurry fineness of 400 mesh, and introduced into a secondary reaction tank to obtain a secondary raw material slurry;

[0059] 4) The secondary raw material slurry is subjected to program stirring, heating and pressurization, with a stirring speed of 400 r / min and a program heating rate of 50° C. / min, and the temperature is raised to 200° C., and the reaction time is maintained for 10 min and the pressure is 4 MPa; then the temperature is further raised to 280° C., the pressure is 15 MPa, and the reaction time is maintained for 30 min to obtain a reaction solution;

[0060] 5) The reaction liquid is introduced into a standing separation tank and allowed to stand for 36 hours to separate oil, water and solid. The oil phase is bio-oil with a yield of 5% of the weight of the primary raw material slurry. It is a black, opaque, asphalt-like substance with a pungent odor, mainly composed of hydrocarbons, nitrogen-containing compounds and oxygen-containing compounds, with a calorific value of 37MJ / Kg, which can be used for further refining biodiesel, etc. The solid phase is hydrothermal charcoal, which belongs to biochar, with a yield of 2% of the weight of the primary raw material slurry, which can be used to improve soil; the aqueous phase solution is primary organic water-soluble fertilizer with a yield of 93% of the weight of the primary raw material slurry. The aqueous phase solution is rich in organic matter, N, P, K and trace elements, and can be used to prepare high-efficiency organic water-soluble fertilizer.

[0061] Example 4

[0062] 1) crushing, screening and grinding the kitchen waste to obtain kitchen waste slurry with a slurry fineness of 200 meshes;

[0063] 2) introducing the kitchen waste slurry into a primary reaction tank for primary reaction treatment, stirring and heating, the stirring speed is 400 r / min, the preheating temperature is 180° C., and the reaction time is 50 min to obtain a primary raw material slurry;

[0064] 3) separating the primary raw material slurry into three phases of oil, water and solid to obtain primary oil (swill oil), mixing the solid and water after the oil is separated, adding water, and then adding a catalyst CaO, wherein the mass of the catalyst is 0.5% of the dry weight of the primary raw material slurry, and finally preparing a mixture with a water content of 95%, introducing the mixture into a grinder, and continuing to grind the mixture until the slurry fineness is 400 mesh, and introducing the mixture into a secondary reaction tank to obtain a secondary raw material slurry;

[0065] 4) The secondary raw material slurry is subjected to program stirring, heating and pressurization, with a stirring speed of 400 r / min and a program heating rate of 5°C / min, and the temperature is raised to 200°C, and the reaction time is maintained for 8 minutes and the pressure is 10 MPa; then the temperature is further raised to 320°C, the pressure is 20 MPa, and the reaction time is maintained for 30 minutes to obtain a reaction liquid;

[0066] 5) The reaction liquid is introduced into a standing separation tank and allowed to stand for 24 hours to separate the oil, water and solid. The oil phase is bio-oil with a yield of 7% of the weight of the primary raw material slurry. It is a black, opaque, asphalt-like substance with a pungent odor, mainly composed of hydrocarbons, nitrogen-containing compounds and oxygen-containing compounds, with a calorific value of 39MJ / Kg, which can be used for further refining biodiesel, etc. The solid phase is hydrothermal charcoal, which belongs to biochar, with a yield of 0.5% of the weight of the primary raw material slurry, which can be used to improve soil; the aqueous phase solution is primary organic water-soluble fertilizer with a yield of 92.5% of the weight of the primary raw material slurry. The aqueous phase solution is rich in organic matter, N, P, K and trace elements, and can be used to prepare high-efficiency organic water-soluble fertilizer.

[0067] As can be seen from the above embodiments, the present invention provides a method for the co-production and recycling of low-carbon and zero-emission kitchen waste oil-fertilizer. The method of the present invention prepares kitchen waste into bio-oil, organic water-soluble fertilizer, and hydrothermal charcoal. The yield of bio-oil is 5-10% of the weight of the primary raw material slurry. It is a black, opaque, asphalt-like substance with a pungent odor, mainly composed of hydrocarbons, nitrogen-containing compounds and oxygen-containing compounds, with a calorific value of 37-44MJ / Kg, which can be used for further refining biodiesel, etc.; the yield of bio-char is 0.5-3% of the weight of the primary raw material slurry, which can be used to improve soil; the aqueous phase solution is a primary organic water-soluble fertilizer, with a yield of 80-90% of the weight of the primary raw material slurry. The aqueous phase solution is rich in organic matter, N, P, K and trace elements, and can be used to prepare high-efficiency organic water-soluble fertilizer.

[0068] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A method for low-carbon zero-emission kitchen waste oil-fertilizer co-production and recycling, characterized in that: The following steps are involved: 1) crushing, screening and grinding the kitchen waste to obtain kitchen waste slurry; 2) subjecting the kitchen waste slurry to a primary reaction treatment to obtain a primary raw material slurry; 3) separating the primary raw material slurry into three phases of oil, water and solid to obtain primary oil, mixing the separated water and solid, then adding solvent and catalyst to obtain a mixture with a water content of 80-95%, grinding the mixture to obtain a secondary raw material slurry; 4) subjecting the secondary raw material slurry to a two-stage heating and pressurizing reaction to obtain a reaction liquid; 5) After the reaction liquid is allowed to stand, the oil, water and solid phases are separated, and the obtained oil phase is bio-oil, the obtained water phase is primary organic water-soluble fertilizer, and the obtained solid phase is hydrothermal charcoal.

2. The method for low-carbon zero-emission kitchen waste oil-fertilizer co-production and recycling according to claim 1, characterized in that: The bio-oil contains hydrocarbons, nitrogen-containing compounds and oxygen-containing compounds; the primary organic water-soluble fertilizer contains organic matter, N, P, K and trace elements; and the hydrothermal charcoal is biochar.

3. The method for low-carbon zero-emission kitchen waste oil-fertilizer co-production and recycling according to claim 1 or 2, characterized in that: The fineness of the kitchen waste slurry is 150-300 meshes.

4. The method for low-carbon zero-emission kitchen waste oil-fertilizer co-production and recycling according to claim 3, characterized in that: The temperature of the primary reaction treatment is 60-180° C., and the time is 10-60 min. The primary reaction treatment is carried out under stirring, and the stirring speed is 10-500 r / min.

5. The method for low-carbon zero-emission kitchen waste oil-fertilizer co-production and recycling according to claim 1, 2 or 4, characterized in that: The solvent comprises water and / or sodium hydroxide solution, and the catalyst comprises one or more of K2CO3, Na2CO3, KOH and CaO.

6. The method for low-carbon zero-emission kitchen waste oil-fertilizer co-production and recycling according to claim 5, characterized in that: The volume concentration of the sodium hydroxide solution is independently 0.1-1%.

7. The method for low-carbon zero-emission kitchen waste oil-fertilizer co-production and recycling according to claim 1 or 6, characterized in that: The amount of the catalyst used is 0.1-5% of the dry weight of the primary raw material slurry.

8. The method for low-carbon zero-emission kitchen waste oil-fertilizer co-production and recycling according to claim 7, characterized in that: The fineness of the secondary raw material slurry is 200-500 meshes.

9. The method for low-carbon zero-emission kitchen waste oil-fertilizer co-production and recycling according to claim 1, 2, 6 or 8, characterized in that: The two-stage heating and pressurizing reaction is specifically as follows: the secondary raw material slurry is stirred at a speed of 10 to 500 r / min, and the temperature is increased to 200 to 280°C at a speed of 5 to 50°C / min at a pressure of 4 to 10 MPa, and kept warm for 5 to 10 minutes; then, the temperature is increased to 280 to 350°C at a speed of 5 to 50°C / min at a pressure of 5 to 22 MPa, and kept warm for 10 to 60 minutes.

10. The method for low-carbon zero-emission kitchen waste oil-fertilizer co-production and recycling according to claim 9, characterized in that: The standing time is 12 to 36 hours.