Method for harmless treatment of organic waste

Abstract

The application discloses a harmless treatment method for organic waste, which comprises the following steps: in step 1, the waste is separated into solid waste and liquid waste through a solid-liquid separation device, the solid waste is crushed, and then the non-treatable substances in the solid waste are screened through a fan. The harmless treatment method for organic waste can treat different forms of waste respectively by separating the waste, can maximize the value of the waste, can eliminate the harmful substances in the waste to the minimum, and can cooperate with a subcritical water technology to generate strong decomposition and dissolution under a high-temperature and high-pressure state to treat the comprehensive organic waste, reduce the combination degree between lignin and cellulose and hemicellulose in the comprehensive organic waste, and can kill miscellaneous bacteria, insect eggs and viruses in the waste.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of waste treatment, and particularly relates to a harmless treatment method for organic waste. BACKGROUND

[0002] Organic waste refers to solid, liquid or gaseous organic substances and articles that are discarded or abandoned in production, life and other activities and have lost original use value or have not lost use value. According to the form, organic waste mainly includes organic solid waste, organic wastewater and organic waste gas. Organic waste refers to solid or liquid organic substances and articles that are discarded or abandoned in production activities and have lost original use value or have not lost use value, including agricultural organic waste (mainly including crop straw vines, livestock and poultry manure and aquaculture waste, etc.), industrial organic waste (mainly including high-concentration organic wastewater, organic waste residue, etc.), and municipal organic garbage (mainly including garden greenery waste, municipal sludge, animal contents in slaughterhouses, kitchen garbage, etc.).

[0003] At present, organic waste such as poultry manure is generally treated by composting, that is, organic waste such as poultry manure is directly transported to an organic fertilizer factory for centralized composting treatment. After composting treatment, the organic waste can be converted into high-quality and safe organic fertilizer for use. However, the current composting treatment has the problems of long fermentation period and strong odor. The current composting period is generally about 45 days. The long composting period not only leads to large carbon and nitrogen loss of the material, but also leads to large composting area and large infrastructure investment, and high composting treatment cost. Strong odor will cause air pollution and affect the working environment of the organic fertilizer factory and the normal life of the surrounding residents. SUMMARY

[0004] To solve the problems in the background art, the present application provides a harmless treatment method for organic waste.

[0005] To achieve the above-mentioned purpose, the present application provides the following technical scheme: a harmless treatment method for organic waste, comprising the following steps,

[0006] Step 1: separating the waste into solid waste and liquid waste by a solid-liquid separation device, crushing the solid waste, and then screening the non-treatable substances in the solid waste by a fan;

[0007] Step 2: heating and evaporating the separated liquid waste, preheating the screened solid waste through a steam pipeline, and then condensing and separating by a condenser to obtain distillation residue;

[0008] Step 3, the pretreated solid waste is placed in a cracking kettle, the temperature and pressure in the cracking kettle are gradually adjusted to the temperature and pressure of the subcritical water technology, and reaction is carried out for 30-50 min to obtain semi-cracking solid waste;

[0009] Step 4, the gas generated in the cracking process is adsorbed by an adsorbent to adsorb harmful substances in the gas, and a precipitate is obtained;

[0010] Step 5, the distillation residue of step 2 and the precipitate of step 4 are added into the cracking kettle and uniformly mixed with the semi-cracking solid waste, and then the cracking kettle is gradually adjusted to the temperature and pressure of the subcritical water technology, and reaction is carried out for 3-6 h.

[0011] In one preferred embodiment of the present application, in step 1, the unmanageable objects are any one or more of rubber, glass, metal and ceramic.

[0012] In one preferred embodiment of the present application, in step 2, the distillation temperature is 100-300 DEG C, and the distillation time is 30-50 min.

[0013] In one preferred embodiment of the present application, in step 2, the preheating temperature of the solid waste is 45-60 DEG C.

[0014] In one preferred embodiment of the present application, in step 3, the temperature in the cracking kettle is adjusted to 150-370 DEG C at a temperature increasing rate of 10-15 DEG C per minute.

[0015] In one preferred embodiment of the present application, in step 3, the pressure in the cracking kettle is adjusted to 0.4-8.6 MPa at a pressure increasing rate of 0.15-0.2 MPa per minute.

[0016] In one preferred embodiment of the present application, in step 4, the adsorbent is any one of activated carbon, activated alumina and magnesium oxide.

[0017] In one preferred embodiment of the present application, in step 5, the temperature in the cracking kettle is adjusted to 240-370 DEG C at a temperature increasing rate of 20-25 DEG C per minute.

[0018] In one preferred embodiment of the present application, in step 5, the pressure in the cracking kettle is adjusted to 1.5-12.15 MPa at a pressure increasing rate of 0.3-0.5 MPa per minute.

[0019] In one preferred embodiment of the present application, in step 5, the standing time is 40-60 min.

[0020] The present application solves the defects in the background art and has the following beneficial effects:

[0021] 1. The organic waste harmless treatment method can treat different forms of waste separately, maximizes the value of waste, minimizes harmful substances in waste, and uses subcritical water technology to produce strong decomposition and dissolution under high temperature and high pressure to treat comprehensive organic waste, reduce the binding degree between lignin, cellulose and hemicellulose in comprehensive organic waste, and kill bacteria, insect eggs and viruses in waste.

[0022] 2. The organic waste harmless treatment method can absorb harmful substances in the gas by adding activated carbon adsorbent in the gas, and the pore structure of activated carbon changes under subcritical water, so that larger molecules can enter the pore channel, thereby improving the adsorption capacity of activated carbon; thin pore wall also makes the pore channel easier to be filled, thereby improving the adsorption speed and the treatment speed of waste.

[0023] 3. The organic waste harmless treatment method can extract volatile organic compounds in liquid waste by distillation, and form condensate by condensation; difficult to volatilize substances are separated into a cracking kettle and treated by high temperature and high pressure; the high temperature steam in the distillation process can also preheat the solid waste, reducing the heating time of the solid waste in the cracking kettle and improving the cracking speed of the waste.

[0024] 4. The organic waste harmless treatment method can break the molecular chain of various high molecular polymers in waste under high temperature and high pressure, reduce them to small molecular polymers, and make them become nutrient ingredients easily absorbed by plants, finally realizing the goals of environmental protection, resource utilization, recycling and harmlessness, while the reaction time is greatly shortened compared with conventional composting time, the occupied area is greatly reduced, and the treatment cost and environmental impact are reduced.

[0025] 5. The organic waste harmless treatment method can completely treat waste by gas-solid-liquid and twice cracking, which not only avoids the secondary treatment of exhaust gas in the conventional cracking process, but also obtains different types and forms of organic matter, facilitating the classification and use of subsequent organic matter and reducing the overall treatment process. DETAILED DESCRIPTION

[0026] The application will be further described in detail in combination with the embodiments.

[0027] Embodiment one

[0028] An organic waste harmless treatment method, characterized in that it comprises the following steps,

[0029] Step 1, separating the waste into solid waste and liquid waste by a solid-liquid separation device, crushing the solid waste, and then screening the unmanageable substances in the solid waste by a fan; in step 1, the unmanageable substances are any one or more of rubber, glass, metal, and ceramic.

[0030] Step 2, heating and evaporating the separated liquid waste, preheating the screened solid waste by a steam pipeline, and then condensing and separating by a condenser to obtain distillation residues; in step 2, the distillation temperature is 100℃, and the distillation time is 30 min; in step 2, the preheating temperature of the solid waste is 45℃.

[0031] Step 3, placing the pretreated solid waste in a cracking kettle, gradually adjusting the temperature and pressure in the cracking kettle to the temperature and pressure of the subcritical water technology, reacting for 30 min to obtain semi-cracked solid waste; in step 3, the temperature in the cracking kettle is adjusted to 200℃ at a heating rate of 10℃ per minute; in step 3, the pressure in the cracking kettle is adjusted to 2 MPa at a pressurizing rate of 0.15 MPa per minute.

[0032] Step 4, adsorbing harmful substances in the gas generated during the cracking process by an adsorbent to obtain precipitates; in step 4, the adsorbent is any one of activated carbon, activated alumina, and magnesium oxide.

[0033] Step 5, adding the distillation residues of step 2 and the precipitates of step 4 into the cracking kettle and uniformly mixing with the semi-cracked solid waste, standing, and then gradually adjusting the cracking kettle to the temperature and pressure of the subcritical water technology, and reacting for 3 h; in step 5, the temperature in the cracking kettle is adjusted to 260℃ at a heating rate of 20℃ per minute; in step 5, the pressure in the cracking kettle is adjusted to 3.5 MPa at a pressurizing rate of 0.3 MPa per minute; in step 5, the standing time is 40 min.

[0034] Example Two

[0035] An organic waste harmless treatment method, characterized in that it comprises the following steps,

[0036] Step 1, separating the waste into solid waste and liquid waste by a solid-liquid separation device, crushing the solid waste, and then screening the unmanageable substances in the solid waste by a fan; in step 1, the unmanageable substances are any one or more of rubber, glass, metal, and ceramic.

[0037] Step 2, the separated liquid waste is heated and evaporated, the screened solid waste is preheated through a steam pipeline, and then condensed and separated through a condenser to obtain distillation residues; in step 2, the distillation temperature is 300 DEG C, and the distillation time is 50 min; in step 2, the preheating temperature of the solid waste is 60 DEG C; the organic waste harmless treatment method can extract volatile organic compounds in the liquid waste through distillation, and form condensates through condensation; substances difficult to volatilize are separated into a cracking kettle and treated in a high-temperature and high-pressure environment; meanwhile, the high-temperature steam in the distillation process can preheat the solid waste, reduce the heating time of the solid waste in the cracking kettle, and improve the cracking speed of the waste.

[0038] Step 3, the pretreated solid waste is placed in a cracking kettle, the temperature and pressure in the cracking kettle are gradually adjusted to the temperature and pressure of the subcritical water technology, and the reaction is carried out for 50 min to obtain semi-cracked solid waste; in step 3, the temperature in the cracking kettle is adjusted to 350 DEG C at a temperature increasing rate of 15 DEG C per minute; in step 3, the pressure in the cracking kettle is adjusted to 7.5 MPa at a pressure increasing rate of 0.2 MPa per minute; the organic waste harmless treatment method can break the molecular chains of various high molecular polymers in the waste into small molecular polymers under high temperature and high pressure, so that the waste becomes nutrient ingredients that plants can easily absorb, and finally realizes the goals of environmental protection, resource utilization, recycling and harmlessness; meanwhile, the reaction time is greatly shortened compared with the conventional composting time, the occupied area is greatly reduced, and the treatment cost and the influence on the environment are reduced.

[0039] Step 4, the harmful substances in the gas generated in the cracking process are adsorbed by the adsorbent to obtain precipitates; in step 4, the adsorbent is any one of activated carbon, activated alumina and magnesium oxide; the organic waste harmless treatment method can absorb the harmful substances in the gas by adding activated carbon adsorbent in the gas, and the pore structure of the activated carbon changes under subcritical water, so that larger molecules can enter the pore channel, thereby improving the adsorption capacity of the activated carbon; the thinning of the pore wall also makes the pore channel easier to be filled, thereby improving the adsorption speed and the treatment speed of the waste.

[0040] Step 5, the distillation residues of step 2 and the precipitates of step 4 are added into the cracking kettle and uniformly mixed with the semi-cracked solid waste, and then the cracking kettle is gradually adjusted to the temperature and pressure of the subcritical water technology, and the reaction time is 6 h; in step 5, the temperature in the cracking kettle is adjusted to 370 DEG C at a temperature increasing rate of 25 DEG C per minute; in step 5, the pressure in the cracking kettle is adjusted to 8.6 MPa at a pressure increasing rate of 0.5 MPa per minute; in step 5, the standing time is 60 min.

[0041] The organic waste harmless treatment method can treat different forms of waste respectively through separation, can maximize the value of waste, can eliminate harmful substances in waste to the minimum, can kill miscellaneous bacteria, insect eggs and viruses in waste by cooperating with the subcritical water technology to produce strong decomposition and dissolution under high temperature and high pressure to treat the comprehensive organic waste, reduce the combination degree between lignin and cellulose and hemicellulose in the comprehensive organic waste, and can completely treat the waste by gas-solid-liquid and twice cracking, can avoid the secondary treatment of the exhaust gas in the conventional cracking process, and can obtain different types and forms of organic matter, so that the subsequent classification and use of the organic matter are facilitated, and the overall treatment process is reduced.

[0042] The organic waste harmless treatment method provided by the application comprises the following steps,

[0043] Step 1, separating the waste into solid waste and liquid waste by a solid-liquid separation device, crushing the solid waste, and then screening the non-treatable substances in the solid waste by a fan;

[0044] Step 2, heating and evaporating the separated liquid waste, preheating the screened solid waste through a steam pipeline, and then condensing and separating by a condenser to obtain distillation residues;

[0045] Step 3, placing the pretreated solid waste in a cracking kettle, gradually adjusting the temperature and pressure in the cracking kettle to the temperature and pressure of the subcritical water technology, reacting for 30-50 min to obtain semi-cracked solid waste;

[0046] Step 4, adsorbing the harmful substances in the gas generated in the cracking process by an adsorbent, and obtaining precipitates;

[0047] Step 5, adding the distillation residues of step 2 and the precipitates of step 4 into the cracking kettle, uniformly mixing with the semi-cracked solid waste, standing, and then gradually adjusting the cracking kettle to the temperature and pressure of the subcritical water technology, and reacting for 3-6 h.

[0048] In the description of the application, it should be understood that the terms "first", "second" are only for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features. Therefore, the features defined as "first", "second" can explicitly or implicitly include one or more of the features. In the description of the application, the meaning of "multiple" is two or more, unless otherwise specifically limited.

[0049] In the description of the specification, the description of the terms "one embodiment", "some embodiments", "an embodiment", "example", "specific example" or "some examples" etc. means that the specific feature, structure, material or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present application. In the specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or example.

[0050] Although the embodiments of the present application have been shown and described above, it is understood that the above-described embodiments are exemplary, and are not to be construed as limiting the present application, and the ordinary skilled in the art can make changes, modifications, replacements and variations to the above-described embodiments within the scope of the present application.

Claims

1. A method for innocuous treatment of organic waste, characterized by, The method comprises the following steps: Step 1, separating the waste into solid waste and liquid waste by a solid-liquid separation device, crushing the solid waste, and then screening the non-treatable substances in the solid waste by a fan; Step 2, heating and evaporating the separated liquid waste, preheating the screened solid waste through a steam pipeline, and then condensing and separating the preheated solid waste through a condenser to obtain distillation residues; Step 3, placing the pretreated solid waste in a cracking kettle, gradually adjusting the temperature and pressure in the cracking kettle to the temperature and pressure of the subcritical water technology, and reacting for 30-50 min to obtain semi-cracked solid waste; Step 4, adsorbing harmful substances in the gas generated in the cracking process by an adsorbent, and obtaining precipitates; Step 5, adding the distillation residues of step 2 and the precipitates of step 4 into the cracking kettle, uniformly mixing the semi-cracked solid waste, and then gradually adjusting the temperature and pressure in the cracking kettle to the temperature and pressure of the subcritical water technology, and reacting for 3-6 h.

2. The organic waste innocuity treatment method according to claim 1, characterized by: In step 1, the non-treatable substances are any one or more of rubber, glass, metal, and ceramic.

3. The method of claim 1, wherein the organic waste is selected from the group consisting of food waste, garden waste, and yard waste. In step 2, the distillation temperature is 100-300℃, and the distillation time is 30-50 min.

4. The method of claim 1, wherein the organic waste is selected from the group consisting of food waste, garden waste, and yard waste. In step 2, the preheating temperature of the solid waste is 45-60℃.

5. The method of claim 1, wherein the organic waste is selected from the group consisting of food waste, garden waste, and yard waste. In step 3, the temperature in the cracking kettle is adjusted to 150-370℃ at a temperature increasing rate of 10-15℃ per minute.

6. The method of claim 1, wherein the organic waste is selected from the group consisting of food waste, garden waste, and yard waste. In step 3, the pressure in the cracking kettle is adjusted to 0.4-8.6 MPa at a pressure increasing rate of 0.15-0.2 MPa per minute.

7. The method of claim 1, wherein the organic waste is selected from the group consisting of food waste, garden waste, and yard waste. In step 4, the adsorbent is any one of activated carbon, activated alumina, and magnesium oxide.

8. The method of claim 1, wherein the organic waste is selected from the group consisting of food waste, garden waste, and yard waste. In step 5, the temperature in the cracking kettle is adjusted to 240-370℃ at a temperature increasing rate of 20-25℃ per minute.

9. The method of claim 1, wherein the organic waste is selected from the group consisting of food waste, garden waste, and yard waste. In step 5, the pressure in the cracking kettle is adjusted to 1.5-12.15 MPa at a pressure increasing rate of 0.3-0.5 MPa per minute.

10. The method of claim 1, wherein the organic waste is selected from the group consisting of food waste, garden waste, yard waste, and combinations thereof. In step 5, the standing time is 40-60 min.