A method for co-processing carbon fixation solid waste of bio-oil and hazardous waste

Abstract

This invention belongs to the field of carbon emission reduction and hazardous waste treatment, and discloses a method for co-processing carbon and solid waste from bio-oil and hazardous waste. Taking solid hazardous waste as an example, the method includes the following steps: (1) crushing the solid hazardous waste; (2) determining the formulation scheme of the bio-oil-hazardous waste mixture; (3) mixing the bio-oil and solid particles according to the formulation scheme to obtain a bio-oil-hazardous waste mixed slurry; (4) injecting the bio-oil-hazardous waste mixed slurry into an underground storage point at a target depth, so that the bio-oil-hazardous waste mixed slurry polymerizes and solidifies at the underground storage point, thereby achieving carbon and solid waste sequestration. The method of this invention utilizes the fluid transport effect and polymerization characteristics of bio-oil to carry hazardous waste into the deep underground for polymerization and solidification, thereby achieving long-term stable sequestration of hazardous waste. At the same time, it permanently sequesters the carbon contained in the bio-oil itself underground, preventing it from being converted into carbon dioxide and emitted into the atmosphere, thus achieving co-processing carbon and solid waste sequestration.

Description

Technical Field

[0001] This invention belongs to the field of carbon emission reduction and hazardous waste treatment, and more specifically, relates to a method for co-processing bio-oil and hazardous waste to fix carbon and solid waste. Background Technology

[0002] Biomass can be converted into three products through pyrolysis: pyrolysis gas, biochar, and bio-oil. Pyrolysis gas and biochar can be used as fuel and soil conditioner, respectively, while bio-oil is difficult to utilize on a large scale due to its complex composition and high oxygen content.

[0003] On the other hand, common methods for disposing of hazardous waste are incineration and landfill. Incineration carries the risk of secondary pollution if not handled properly, and the incinerated products still require further measures for harmless treatment; landfill, on the other hand, occupies a large amount of land resources, and its leachate may cause soil or groundwater pollution. Summary of the Invention

[0004] To address the aforementioned deficiencies or improvement needs of existing technologies, the present invention aims to provide a method for the co-processing of bio-oil and hazardous waste for carbon sequestration. First, bio-oil and hazardous waste are mixed in different proportions, and a solidification test is conducted to simulate the solidification process in a deep underground environment to obtain a mixing scheme. Then, the bio-oil and hazardous waste are mixed according to the mixing scheme to obtain a mixed slurry, which is injected into an underground storage point. Utilizing the fluid transport and polymerization characteristics of bio-oil, the hazardous waste is carried and injected into the deep underground for polymerization and solidification, achieving long-term stable storage of hazardous waste. Simultaneously, the carbon contained in the bio-oil itself is permanently sealed underground, preventing it from being converted into carbon dioxide and emitted into the atmosphere, thus achieving synergistic carbon sequestration.

[0005] To achieve the above objectives, according to one aspect of the present invention, a method for co-processing carbon sequestration waste using bio-oil and hazardous waste is provided, characterized in that the method targets solid hazardous waste and includes the following steps:

[0006] (1) The solid hazardous waste is crushed into solid particles with a particle size not exceeding 5 mm through pretreatment;

[0007] (2) Determination of the blending scheme of bio-oil-hazardous waste mixture: Bio-oil and solid particles are mixed in different proportions, and then the mixture is tested for solidification under preset temperature and preset pressure conditions to simulate the solidification process of deep underground environment; If the solidification time result and the fracture toughness result of the solidified product under a certain proportion condition obtained by the test meet the preset requirements at the same time, then the proportion condition is taken as the blending scheme.

[0008] The preset temperature and preset pressure conditions are used to simulate the temperature and pressure of the deep underground environment at the target depth.

[0009] (3) According to the blending scheme determined in step (2), bio-oil and solid particles are mixed to obtain bio-oil-hazardous waste mixed slurry;

[0010] (4) The bio-oil-hazardous waste mixed slurry is injected into the underground storage point at the target depth, so that the bio-oil-hazardous waste mixed slurry polymerizes and solidifies at the underground storage point to achieve carbon and solid waste fixation; wherein, anti-coking measures are taken at the same time during injection.

[0011] According to another aspect of the present invention, the present invention provides a method for co-processing bio-oil and hazardous waste to remove carbon sequestration waste, characterized in that the method is for liquid hazardous waste and includes the following steps:

[0012] (i) Determination of the blending scheme of bio-oil-hazardous waste mixture: Bio-oil and liquid hazardous waste are blended in different proportions, and then the blended mixture is subjected to a solidification test under preset temperature and preset pressure conditions to simulate the solidification process of deep underground environment; If the solidification time result and the fracture toughness result of the solidified product under a certain proportion condition obtained by the test simultaneously meet the preset requirements, then the proportion condition is taken as the blending scheme.

[0013] The preset temperature and preset pressure conditions are used to simulate the temperature and pressure of the deep underground environment at the target depth.

[0014] (ii) According to the blending scheme determined in step (i), bio-oil and liquid hazardous waste are mixed to obtain bio-oil-hazardous waste mixed slurry;

[0015] (iii) The bio-oil-hazardous waste mixed slurry is injected into an underground storage point at a target depth, so that the bio-oil-hazardous waste mixed slurry polymerizes and solidifies at the underground storage point to achieve carbon and waste fixation; wherein, anti-coking measures are taken simultaneously during injection.

[0016] As a further preferred embodiment of the present invention, in step (2) or step (i), the mixing further includes a chelating agent added in a fixed or different proportion;

[0017] The resulting formulation also includes the proportion of chelating agents added.

[0018] As a further preferred embodiment of the present invention, the solid hazardous waste or the liquid hazardous waste is radioactive waste;

[0019] In step (2) or step (i), the curing test further includes testing the concentration of radioactive elements in the leachate of the cured product; if the curing time, fracture toughness and radioactive element concentration in the leachate of the cured product under a certain ratio condition meet the preset requirements at the same time, then the ratio condition is used as the mixing scheme.

[0020] As a further preferred embodiment of the present invention, in step (4) or step (iii), the anti-coking measures include at least one of the following: casing circulating water cooling, phase change heat dissipation cooling, and addition of polymerization inhibitor.

[0021] As a further preferred embodiment of the present invention, the underground storage point includes at least one of depleted mines, abandoned mines, natural caves, salt caverns, or difficult-to-mine coal seams.

[0022] Furthermore, the underground sealing point is located at a depth of ≥800 meters underground and ≥50 meters below the underground aquifer.

[0023] As a further preferred embodiment of the present invention, in step (2) or step (i), the preset requirement for the curing time result is a curing time of 3-12 hours; the preset requirement for the fracture toughness result of the cured product is a fracture toughness of not less than 0.5 MPa·m. 1 / 2 .

[0024] As a further preferred embodiment of the present invention, the preset requirement for the concentration of radioactive elements in the leachate of the solidified material is that the concentration of radioactive elements in the leachate of the solidified material is less than 0.3 mg / L.

[0025] As a further preferred embodiment of the present invention, the bio-oil is a liquefied product of biomass; wherein the biomass includes at least one of agricultural waste, forestry residues, wood chips, sawdust, algae, straw, and bagasse.

[0026] As a further preferred embodiment of the present invention, the different proportions are different mass ratios or different volume ratios.

[0027] Compared with the prior art, the above-described technical solutions conceived in this invention can achieve the following beneficial effects:

[0028] (1) This invention utilizes the fluid transport and polymerization properties of bio-oil to carry hazardous waste into deep underground for polymerization and solidification. Since the bio-oil has a coating effect on the hazardous waste after solidification, it can further reduce the hazard and spillage risk of the hazardous waste, and can achieve long-term stable storage of hazardous waste. At the same time, it can permanently seal the carbon contained in the bio-oil underground, preventing it from being converted into carbon dioxide and emitted into the atmosphere, thus achieving synergistic carbon sequestration and waste solidification.

[0029] (2) The present invention, which injects bio-oil into deep underground layers to directly achieve biomass carbon sequestration, is a potential negative carbon emission technology route that can reduce carbon dioxide emissions generated during biomass utilization. At the same time, due to the adsorption and fixation effect of carbon-containing solids in bio-oil on radionuclides, and the shielding effect of the organic polymer coating layer formed by the polymerization and solidification of bio-oil under high pressure conditions in deep underground layers on nuclear radiation, the present invention can especially achieve effective sequestration and disposal of radioactive hazardous waste.

[0030] (3) This invention can treat liquid hazardous waste and solid hazardous waste, such as hazardous waste and radioactive waste specified in the National Hazardous Waste List, and has wide applicability.

[0031] (4) The process flow of the present invention is simple and can be applied to large-scale processing.

[0032] (5) During the process of this invention, hazardous waste only undergoes physical processes such as crushing and mixing, without any chemical reaction process, and will not generate secondary pollutants. The treatment process is safe and pollution-free. At the same time, this invention adopts deep underground sealing, far away from the surface human living environment, avoiding the environmental pollution problems such as occupying land and polluting soil and groundwater.

[0033] (6) The present invention preferably sets the solidification time preset requirement when determining the bio-oil-hazardous waste mixture preparation scheme to 3-12 hours, which can effectively shorten the implementation cycle of the injection project and ensure the economic efficiency of the project; at the same time, the preset requirement for the fracture toughness of the solidified material is set to a fracture toughness of not less than 0.5 MPa·m. 1 / 2 This can effectively ensure the solidification effect of hazardous waste; for radioactive waste, additional attention can be paid to the concentration of radioactive elements in the leachate of the solidified material. The preset requirement for the concentration of radioactive elements in the leachate of the solidified material is less than 0.3 mg / L, which can effectively prevent radioactive leakage. Combined with the fact that the underground storage site is located deep underground, it can further ensure radioactive safety. Attached Figure Description

[0034] Figure 1 This is a schematic diagram of the process flow of the method of the present invention. Detailed Implementation

[0035] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0036] The method for co-processing carbon sequestration waste using bio-oil and hazardous waste in this invention may include, in practice, steps such as hazardous waste pretreatment, formulation of a bio-oil-hazardous waste mixture preparation plan, pulping, grouting, and solidification.

[0037] (S1) Hazardous waste pretreatment: For solid hazardous waste, it is crushed into solid microparticles and stored for later use; for liquid hazardous waste, start from step S2.

[0038] (S2) Formulation of Bio-oil-Hazardous Waste Mixture Solution: Bio-oil and pretreated hazardous waste are mixed at a specific mass ratio, with the addition of a certain proportion of chelating agent. The mixed solution is then tested and subjected to a solidification test simulating deep underground environments (primarily simulating the temperature and pressure conditions of deep underground environments). The solidification time and fracture toughness of the solidified material are the test qualification targets (e.g., a solidification time of 3-12 hours and a fracture toughness of not less than 0.5 MPa·m can be used). 1 / 2 To ensure the test meets the standard (the concentration of radioactive elements in the leachate of the solidified material must be below 0.3 mg / L), the formulation plan was adjusted and determined.

[0039] (S3) Pulping: According to the mixing scheme in step S2, the bio-oil and pretreated hazardous waste are mixed and stirred to make a bio-oil-hazardous waste mixed slurry.

[0040] (S4) Grouting: The bio-oil-hazardous waste mixture is injected into the underground storage point. The injection pipeline has anti-coking measures to prevent the mixture from solidifying inside the pipeline. The anti-coking measures can be existing anti-coking measures in the prior art, such as casing circulating water cooling, phase change heat dissipation cooling, and addition of polymerization inhibitors, to avoid the problem of coking and solidification of the bio-oil-hazardous waste mixture slurry inside the pipeline due to the temperature increase as it goes deeper underground.

[0041] (S5) Solidification: After the bio-oil-hazardous waste mixed slurry is injected into the underground storage point, it gradually polymerizes and solidifies under underground temperature and pressure due to the self-polymerization characteristics of bio-oil, thus achieving synergistic carbon sequestration and waste solidification.

[0042] The hazardous wastes to which this invention applies include, for example, hazardous wastes and radioactive wastes as specified in the National Hazardous Waste List.

[0043] The bio-oil used includes the liquefaction product of biomass (at least one of agricultural waste, forestry residues, wood chips, sawdust, algae, straw or bagasse).

[0044] Underground sealing sites include at least one of the following: depleted mines, abandoned mines, natural caverns, salt caverns, or difficult-to-mine coal seams. The sealing sites are located deep underground at the target depth (e.g., ≥800 meters) and ≥50 meters below the aquifer to avoid pollution of groundwater resources after sealing.

[0045] The following are specific examples:

[0046] Example 1

[0047] When uranium tailings sediment (radioactive waste) is leached alone, the uranium concentration is 3-4 mg / L and the thorium concentration is 1 mg / L. An experiment was conducted to mix it with coconut shell bio-oil. Specifically, the uranium tailings sediment and coconut shell bio-oil were mixed at a mass ratio of 1:5, and 5% polypropylene fiber was added. The mixture was kept at 80℃ and 10 MPa (simulating an environment 2 km underground) for 5 hours to solidify. After 30 days, the uranium and thorium concentrations in the leachate of the solidified material were measured to have decreased to below 0.1 mg / L, while the carbon sequestration rate reached 18%.

[0048] Among them, coconut shell bio-oil is coconut shell pyrolysis oil obtained by drying and crushing coconut shells and then pyrolyzing them at 500℃ for 5 hours under oxygen-free conditions in a regenerative pyrolysis furnace.

[0049] Example 2

[0050] Coking residue was crushed into solid particles with a particle size of less than 1 mm, and mixed with rice husk bio-oil at a mass ratio of 1:3. The mixture was then tested under conditions of 60℃ and 7 MPa (simulating an environment 1 km underground). The curing time of the mixture was 8 hours, and the fracture toughness of the cured product was 0.8 MPa·m. 1 / 2 The test was passed. According to this allocation plan, 10 tons of coking residue and 30 tons of rice husk bio-oil were pulped and injected into an abandoned coal mine at a depth of about 1 kilometer underground to achieve co-sequestration of coking residue and rice husk bio-oil, with a carbon sequestration of 3.9 tons.

[0051] Among them, rice husk bio-oil is rice husk pyrolysis oil obtained by pyrolyzing dried and crushed rice husks at 450℃ under anaerobic conditions in a horizontal pyrolysis furnace for 4 hours.

[0052] Example 3

[0053] Medical waste incineration residue was crushed into solid microparticles with a particle size of less than 1 mm. These microparticles were mixed with rice husk bio-oil at a mass ratio of 1:4, and 5% cement mortar was added. The mixture was then tested at 40℃ and 3 MPa (simulating an environment 500 meters underground). The curing time was 6 hours, and the fracture toughness of the cured product was 1.1 MPa·m. 1 / 2The test was passed. According to this allocation plan, 2 tons of coking residue, 8 tons of rice husk bio-oil, and 0.5 tons of cement mortar were mixed and injected into a depth of 500 meters underground to achieve co-sequestration of medical waste incineration residue and rice husk bio-oil, with a carbon sequestration of 1.5 tons.

[0054] Among them, rice husk bio-oil is rice husk pyrolysis oil obtained by pyrolyzing dried and crushed rice husks at 450℃ under anaerobic conditions in a horizontal pyrolysis furnace for 4 hours.

[0055] Cement mortar is made of 42.5 silicate cement, medium sand and water in a mass ratio of 1:8:1.3.

[0056] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for co-disposing bio-oil and hazardous waste carbon sequestering solid waste, characterized in that, The method is aimed at solid hazardous waste, comprising the following steps: (1) The solid hazardous waste is crushed into solid particles with a particle size of not more than 5 mm through pretreatment; (2) Determination of the bio-oil-hazardous waste mixed liquid blending scheme: the bio-oil and the solid particles are mixed in different proportions, and then the mixed liquid after mixing is subjected to curing test under preset temperature and pressure conditions to simulate the curing process in deep underground environment; if the curing time result and the fracture toughness result of the cured product under a certain proportioning condition obtained by the test meet the preset requirements at the same time, the proportioning condition is taken as the blending scheme; Wherein, the preset temperature and pressure conditions are used to simulate the temperature and pressure of the deep underground environment at the target depth; (3) According to the blending scheme determined in step (2), the bio-oil and the solid particles are mixed to obtain a bio-oil-hazardous waste mixed slurry; (4) The bio-oil-hazardous waste mixed slurry is injected into the underground storage point at the target depth, so that the bio-oil-hazardous waste mixed slurry is polymerized and cured at the underground storage point, realizing carbon sequestration and waste fixation; wherein anti-coking measures are taken at the time of injection.

2. A method for co-disposal of bio-oil and hazardous waste carbon sequestering solid waste, characterized in that, The method is aimed at liquid hazardous waste, comprising the following steps: (i) Determination of the bio-oil-hazardous waste mixed liquid blending scheme: the bio-oil and the liquid hazardous waste are mixed in different proportions, and then the mixed liquid after mixing is subjected to curing test under preset temperature and pressure conditions to simulate the curing process in deep underground environment; if the curing time result and the fracture toughness result of the cured product under a certain proportioning condition obtained by the test meet the preset requirements at the same time, the proportioning condition is taken as the blending scheme; Wherein, the preset temperature and pressure conditions are used to simulate the temperature and pressure of the deep underground environment at the target depth; (ii) According to the blending scheme determined in step (i), the bio-oil and the liquid hazardous waste are mixed to obtain a bio-oil-hazardous waste mixed slurry; (iii) The bio-oil-hazardous waste mixed slurry is injected into the underground storage point at the target depth, so that the bio-oil-hazardous waste mixed slurry is polymerized and cured at the underground storage point, realizing carbon sequestration and waste fixation; wherein anti-coking measures are taken at the time of injection.

3. The method of claim 1 or 2, wherein the method is characterized by, In the step (2) or the step (i), the mixing further comprises adding a chelating agent in a fixed or different proportion; The corresponding blending scheme further comprises the addition proportion of the chelating agent.

4. The method for co-processing carbon sequestration solid waste with bio-oil and hazardous waste according to claim 1 or 2, wherein, The solid hazardous waste or the liquid hazardous waste is radioactive waste; In the step (2) or the step (i), the curing test further comprises testing the concentration of radioactive elements in the leaching liquid of the cured product; if the curing time result, the fracture toughness result of the cured product and the concentration of radioactive elements in the leaching liquid of the cured product under a certain proportioning condition obtained by the test meet the preset requirements at the same time, the proportioning condition is taken as the blending scheme.

5. The method of claim 1 or 2, wherein the bio-oil and hazardous waste co-treatment carbon sequestration solid waste is characterized by, In the step (4) or the step (iii), the anti-coking measures include at least one of the following: casing circulating water cooling, phase change heat dissipation cooling and polymerization inhibitor addition.

6. The method of claim 1 or 2, wherein the bio-oil and hazardous waste co-treatment carbon sequestration solid waste is characterized by, The underground storage point includes at least one of the following: depleted mine, abandoned mine, natural cave, salt cave or difficult-to-mine coal seam; And, the underground storage point is located at a position of more than 800 meters underground and less than 50 meters below an underground aquifer.

7. The method of claim 1 or 2, wherein the bio-oil and hazardous waste co-treatment carbon sequestration solid waste is characterized by, The preset requirement for the curing time result in the step (2) or the step (i) is that the curing time is 3-12 hours; and the preset requirement for the curing product fracture toughness result is that the curing product fracture toughness is not less than 0.5 MPa·m 1 / 2 .

8. The method of claim 4, wherein the bio-oil and hazardous waste co-treatment carbon sequestration solid waste is characterized by, The preset requirement for the concentration of the radioactive element in the solidified product leaching solution is that the concentration of the radioactive element in the solidified product leaching solution is less than 0.3 mg / L.

9. The method of claim 1 or 2, wherein the bio-oil and hazardous waste co-treatment carbon sequestration solid waste is characterized by, The biological oil is a liquefaction product of biomass; wherein the biomass includes at least one of agricultural waste, forestry residue, wood chips, sawdust, algae, straw, and sugarcane residue.

10. The method of claim 1 or 2, wherein the bio-oil and hazardous waste co-treatment carbon sequestration solid waste is characterized by, The different proportions are different mass ratios or different volume ratios.

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