Method for realizing full-component resource utilization of mineral oil-containing waste and semi-coke by synergistic gasification

Abstract

The present application belongs to the technical field of solid waste resource utilization, and relates to a method for realizing full-component resource utilization of mineral oil-containing waste and semi-coke through synergistic gasification, comprising the following steps: S1, pyrolyzing the mineral oil-containing waste to obtain high-temperature pyrolysis gas containing tar vapor and volatile components and pyrolysis residues; S2, mixing the high-temperature pyrolysis gas with semi-coke to obtain gas-solid mixture; S3, feeding the gas-solid mixture, the pyrolysis residues and an additive (metallurgical slag and vermiculite compounded at a mass ratio of 3-5:1) into a gasifier for gasification to obtain hydrogen-rich synthesis gas and gasification residues. Through the coupling of pyrolysis-gasification process, the multifunctional integration of "adsorption-carbon source-catalysis" of semi-coke and the synergistic effect of the compounded additive, full-component resource utilization is realized. The H2 concentration in the obtained synthesis gas reaches 60%-65%, the H2 yield is as high as 1000 ml / g-mineral oil-containing waste dry basis, the carbon conversion rate is greater than or equal to 95%, and the gasification residues can be directly used for roadbed materials, realizing waste treatment with waste and high-value recycling.

Description

Technical Field

[0001] This invention belongs to the field of solid waste resource utilization technology, specifically relating to a method for achieving full-component resource utilization through the synergistic gasification of mineral oil-containing waste and semi-coke. Background Technology

[0002] Mineral oil-containing waste is hazardous waste generated during petroleum extraction, refining, storage, transportation, and use. It mainly includes oily sludge, waste mineral oil, oil-based drill cuttings, and oil-contaminated waste. Improper disposal of mineral oil-containing waste can cause serious pollution to soil and water bodies due to pollutants such as petroleum hydrocarbons and heavy metals. Currently, the main treatment technologies for mineral oil-containing waste include solvent extraction, thermal washing, biological treatment, incineration, and pyrolysis. Practice has shown that solvent extraction and thermal washing are not thorough enough for treating oily sludge; biological treatment requires stringent conditions and is difficult to scale up industrially; while incineration can reduce the volume, it results in the loss of petroleum resources and the generation of secondary pollutants such as dioxins. Pyrolysis technology, due to its ability to reduce, render harmless, and recover resources from oily waste, has become one of the most promising treatment technologies.

[0003] Semi-coke is a solid product of coal or biomass pyrolysis, characterized by its well-developed porosity, high carbon content, and the presence of alkali and alkaline earth metals. Currently, semi-coke is mainly used for fuel combustion or low-value-added utilization, failing to fully realize its value as a carbon resource and for its catalytic activity.

[0004] Existing technologies include studies on the separate gasification of oily sludge to produce hydrogen, such as patent CN118479702A which discloses a two-step supercritical water desorption gasification system for treating oily sludge to produce hydrogen. There are also studies on using semi-coke for gasification, such as patent CN116425389A which discloses a two-stage synergistic pyrolysis treatment system and method for oily sludge and oil-contaminated waste, improving the degradation efficiency of oily pollutants. However, in the pyrolysis treatment of mineral oil waste, the pyrolysis gas has a high tar content, and the tar is prone to condensation and polymerization during cooling, leading to pipeline blockage and frequent equipment maintenance. To solve this problem, existing technologies generally adopt a process route of "pyrolysis → condensation → oil-water separation → separate tar disposal." Although this route can avoid blockage, the hydrogen element in the tar cannot be effectively converted into hydrogen gas, resulting in low resource utilization. At the same time, the sensible heat of the pyrolysis gas is lost during the tar condensation process, and the separated tar still needs further treatment (such as incineration or off-site disposal), increasing treatment costs and the risk of secondary pollution.

[0005] In summary, how to avoid energy loss and disposal difficulties caused by tar condensation during the treatment of mineral oil-containing waste, while simultaneously achieving efficient conversion of carbon resources and preparation of hydrogen-rich fuel gas, is an urgent technical problem to be solved. Summary of the Invention

[0006] In view of this, the present invention provides a method for the synergistic gasification of mineral oil-containing waste and semi-coke to achieve full-component resource recovery. The present invention directly mixes the high-temperature pyrolysis gas (containing tar and volatiles) generated from the pyrolysis of mineral oil-containing waste with semi-coke without condensation. The porous structure of the semi-coke adsorbs the tar, fundamentally avoiding the problem of tar condensation and blockage. Subsequently, the tar-adsorbed semi-coke, volatiles (small molecule combustible gases such as CO and CH4), pyrolysis residue, and additives are fed together into a gasifier for synergistic gasification. Through the multiple synergistic mechanisms of "tar adsorption - volatile matter energy supply - in-situ catalytic reforming - full carbon gasification" of the semi-coke and the synergistic gasification of the pyrolysis residue, combined with the promoting effect of additives on the gasification reaction and the in-situ fixation of heavy metals, the present invention achieves full-component resource recovery of mineral oil-containing waste and semi-coke, with excellent effects of zero tar emissions, low system energy consumption, high carbon conversion rate, and high hydrogen yield.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] A method for achieving full-component resource recovery through the co-gasification of mineral oil-containing waste and semi-coke includes the following steps:

[0009] S1. The mineral oil-containing waste is pyrolyzed under an inert atmosphere to obtain high-temperature pyrolysis gas containing tar vapor and volatiles, as well as pyrolysis residue.

[0010] S2. The high-temperature pyrolysis gas obtained in step S1 is directly mixed with semi-coke without condensation, so that the tar in the high-temperature pyrolysis gas is adsorbed in the pores of the semi-coke to obtain a gas-solid mixture.

[0011] S3. The gas-solid mixture, pyrolysis residue, and additives are fed into a gasifier and a gasification reaction is carried out in the presence of a gasifying agent to obtain hydrogen-rich syngas and gasification slag; the additives are a compound of metallurgical slag and vermiculite in a mass ratio of 3 to 5:1.

[0012] Further, in step S1, the mineral oil-containing waste is selected from at least one of oily sludge, waste mineral oil, oil-based drill cuttings, and oil-contaminated waste; the water content of the mineral oil-containing waste is ≤20wt%; the total carbon content of the mineral oil-containing waste is 30~50wt% on a dry basis; the inert atmosphere is nitrogen and / or argon; the pyrolysis treatment conditions are: temperature 400~600℃, preferably 450~550℃, time 0.5~2h. During the pyrolysis process, the large molecular petroleum hydrocarbons in the mineral oil-containing waste are cracked and converted into high-temperature pyrolysis gas (containing volatiles of tar vapor and combustible gases such as hydrogen and carbon monoxide), and solid residue containing carbon and iron / aluminum oxides (i.e., pyrolysis residue).

[0013] Further, in step S2, the dry weight ratio of the semi-coke to the mineral oil-containing waste from step S1 is 1~3:1, preferably 1~2:1.

[0014] Further, in step S2, the semi-coke is selected from at least one of coal pyrolysis semi-coke, biomass pyrolysis semi-coke, and oily waste pyrolysis semi-coke; the particle size of the semi-coke is 1-5 mm, preferably 1-3 mm. The dry basis mass of the mineral oil-containing waste refers to the mass of the mineral oil-containing waste after removing moisture, expressed in m... 干基 =Calculated as mass of mineral oil-containing waste × (1 - moisture content).

[0015] Further, in step S2, the mixing conditions are as follows: semi-coke and high-temperature pyrolysis gas enter the mixer in opposite directions, and the gas and solid phases are mixed in turbulent state for 2 to 5 seconds. The mixer is a pipeline mixer or a gas-solid injector.

[0016] In step S2, the high-temperature pyrolysis gas is premixed with the semi-coke. This allows the tar vapors in the high-temperature pyrolysis gas to be fully adsorbed into the pores of the semi-coke, while the volatiles in the high-temperature pyrolysis gas remain in the gas phase, forming a gas-solid mixture. This gas-solid mixture is a mixture of semi-coke with adsorbed tar and volatiles from the high-temperature pyrolysis gas. This gas-solid mixture, along with the pyrolysis residue, is fed into the gasifier in step S3. The volatiles are preferentially combusted, providing the heat required for gasification. Subsequently, in the presence of a gasifying agent, the alkali / alkaline earth metals (K, Na, Ca, Mg) in the semi-coke act as catalytic active sites, catalyzing the adsorbed tar to undergo steam reforming, converting it into H2 and CO. This coupled mechanism of adsorption-enrichment followed by catalytic conversion not only fixes the tar within the semi-coke pores through physical adsorption, avoiding traditional condensation and blockage, but also allows direct contact between the adsorbed tar and the catalyst's active sites, significantly improving reforming efficiency. Furthermore, the semi-coke also serves as a carbon source, participating in the gasification conversion along with the pyrolysis residue.

[0017] Further, in step S3, the amount of the additive added is 5-10% of the dry basis mass of the mineral oil-containing waste in step S1.

[0018] Further, in step S3, the metallurgical slag is blast furnace slag or steel slag with a particle size of 0.5~2mm. The chemical composition of the metallurgical slag contains 40~50wt% CaO, and the total content of CaO, MgO and Fe2O3 accounts for 65~75wt% of the total content. The vermiculite has a particle size of 100~200 mesh.

[0019] The inventors unexpectedly discovered that using a blend of metallurgical slag and vermiculite as an additive during the gasification stage can produce a synergistic effect, simultaneously increasing the H2 yield of the syngas and achieving in-situ fixation of heavy metals. Possible reasons are as follows: First, metallurgical slag is rich in CaO, which can react with CO2 produced during gasification at the high temperature of the gasifier to generate CaCO3, shifting the equilibrium of the water-gas shift reaction to the right, thereby increasing the concentration and yield of H2 in the syngas. Second, the metallurgical slag forms a locally alkaline microenvironment under the action of water vapor in the gasifier. Vermiculite has a layered structure, and its interlayer ions can exchange with heavy metal ions volatilized during gasification. The alkaline microenvironment provided by the slag can improve the efficiency of this ion exchange, fixing heavy metals within the vermiculite layers. Furthermore, the porous structure formed by the high-temperature expansion characteristics of vermiculite can provide anchoring points for active components in the slag and semi-coke, preventing the active components from agglomerating at high temperatures and shortening their catalytic life. Through the above synergistic effect, the present invention improves the H2 yield and achieves in-situ fixation of heavy metals, so that the leaching toxicity of the final gasification slag meets the national standards and can be directly used as roadbed material.

[0020] Further, in step S3, the gasifier is selected from any one of fluidized bed gasifier, fixed bed gasifier, and entrained flow gasifier, preferably a fluidized bed gasifier; the gasifying agent is saturated steam, or a mixture of saturated steam and oxygen, preferably a mixture of saturated steam and oxygen; when a mixture is used, the volume fraction of oxygen is 5% to 20%.

[0021] Further, in step S3, the water-to-carbon molar ratio S / C is controlled to be 2.0~3.5, preferably 2.5~3.0, by controlling the feed rate of the gasifying agent. The water-to-carbon molar ratio S / C refers to the molar ratio of water vapor (H2O) to total carbon, where the molar amount of total carbon is calculated based on the carbon content and feed rate of the feed (including mineral oil waste and semi-coke). The carbon content of the feed can be obtained through elemental analysis or industrial analysis. The gasification reaction conditions are: a temperature of 800~950℃, preferably 850~900℃. Those skilled in the art can optimize and adjust the residence time (gasification time) of the material according to the type and scale of the gasifier. For example, in a small-scale or pilot-scale fluidized bed gasifier, the residence time of the material is generally controlled at 30~90s. Controlling the gasification temperature and water-to-carbon molar ratio within the above range ensures efficient gasification reaction and facilitates the reforming and conversion of tar, thereby obtaining high-calorific-value hydrogen-rich syngas. Taking water vapor as the gasifying agent as an example, the main reactions during the gasification process are as follows:

[0022] Water-gas reaction: C (from pyrolysis residue and semi-coke) + H2O → CO + H2

[0023] Water-gas shift reaction: CO + H2O → CO2 + H2

[0024] Tar reforming reaction: C n H m + H2O→CO + H2

[0025] It should be noted that the pyrolysis residue is not only a carbon source, but the iron / aluminum oxides in it are transformed into active forms such as Fe, FeO, and Al2O3 under the high-temperature reducing atmosphere in the gasifier. These forms a composite catalytic site with the alkali metals (K, Na, Ca, Mg) in the semi-coke, synergistically catalyzing the tar reforming and water-gas shift reactions.

[0026] Optionally, after obtaining hydrogen-rich syngas in step S3, the high-temperature sensible heat of the hydrogen-rich syngas is used to recover heat through a heat exchanger to generate saturated water vapor. The generated saturated water vapor can be used as the gasifying agent for co-gasification reaction, realizing the cascade utilization of system energy and reducing external energy consumption.

[0027] Optionally, after obtaining the gasification slag in step S3, the gasification slag is used to prepare roadbed materials. The main component of the gasification slag is stable aluminosilicate minerals, which can be used as high-quality aggregate to replace natural sand and gravel, and can be used to produce high-strength, low-carbon and environmentally friendly roadbed materials, realizing the resource utilization of solid waste components.

[0028] Compared with the prior art, the present invention has the following beneficial effects:

[0029] (1) In this invention, the high-temperature pyrolysis gas (containing tar) generated from the pyrolysis of mineral oil-containing waste is directly mixed with semi-coke without condensation and then fed into a gasifier along with the pyrolysis residue for co-gasification. On the one hand, the condensation process is avoided, simplifying the process and eliminating the risk of pipeline blockage; on the other hand, the volatiles in the pyrolysis gas are carried into the gasifier for preferential combustion to provide energy, effectively reducing external energy consumption. At the same time, the semi-coke is both a carbon source and an in-situ catalyst; the pyrolysis residue is also a carbon source, and the iron and aluminum elements in it form a composite catalyst system with the semi-coke. That is, this invention achieves the full-component resource utilization of materials through the coupling of the "pyrolysis-gasification" process, the multifunctional integration of the semi-coke's "adsorption-carbon source-catalysis" function, and the co-coupling of the pyrolysis residue and semi-coke as raw materials.

[0030] (2) The present invention adds a compound additive of metallurgical slag and vermiculite in the gasification stage, which improves the H2 yield in the synthesis gas and realizes the in-situ fixation of heavy metals, so that the leaching toxicity of the gasification slag meets the national standard and can be directly used as roadbed material.

[0031] (3) Based on the above-mentioned multiple coupling mechanisms, the present invention realizes the synergistic treatment and full-component resource utilization of two solid wastes, namely mineral oil waste and semi-coke. The H2 concentration in the synthesized gas reaches 60%~65%, the H2 yield is as high as 1000ml / g-mineral oil waste dry basis, and the carbon conversion rate is ≥95%. Moreover, the gasification slag generated in the gasification process can be directly used to prepare roadbed materials, realizing "waste treatment" and high-value recycling of resources. Attached Figure Description

[0032] Figure 1 This is a process flow diagram of the present invention. Detailed Implementation

[0033] The technical solution of the present invention will be further described in detail below with reference to specific embodiments. It should be understood that the following embodiments are only used to illustrate the present invention and should not be construed as limiting the scope of protection of the present invention; all equivalent substitutions or modifications made by those skilled in the art without departing from the concept of the present invention should fall within the scope of protection of the present invention.

[0034] Unless otherwise stated, the raw materials and reagents used in the following examples are commercially available products or can be prepared by known methods.

[0035] The oily sludge originated from sediment deposited at the bottom of an oil refinery's oil tanks (initial moisture content approximately 35.1 wt%), and its total carbon content (TOC) on a dry basis was measured to be 47.04 wt% using a TOC analyzer. The oil-based drill cuttings originated from oil-based drilling waste generated at an oil and gas drilling site (initial moisture content approximately 45.0 wt%), and their total carbon content (TOC) on a dry basis was measured to be 31.96 wt%. The semi-coke was coal pyrolysis semi-coke with a particle size of approximately 1-3 mm, and its total carbon content (TOC) was measured to be 67.21 wt% using a TOC analyzer.

[0036] The metallurgical slag is blast furnace slag from Taiyuan Iron & Steel Co., Ltd. The chemical composition shows that the CaO content is about 45.7 wt%, and the total content of CaO, MgO and Fe2O3 accounts for about 71.6 wt% of the total content, with a particle size of 1~2 mm.

[0037] Example 1

[0038] S1. The oily sludge is dried at 60°C for 12 hours to reduce its moisture content to about 18 wt%. Then it is fed into a pyrolysis furnace and pyrolyzed at 500°C for 1 hour to obtain high-temperature pyrolysis gas (about 450°C) containing tar vapor and volatiles, as well as pyrolysis residue. S2. The high-temperature pyrolysis gas from the pyrolysis furnace outlet is not condensed and is directly mixed with the semi-coke in opposite directions into a pipe mixer for 3 seconds. This allows the tar in the high-temperature pyrolysis gas to be adsorbed into the pores of the semi-coke, resulting in a gas-solid mixture (a mixture of semi-coke with adsorbed tar and volatiles in the high-temperature pyrolysis gas). The dry weight ratio of the semi-coke to the oily sludge in step S1 is 1.5:1.

[0039] S3. The gas-solid mixture, along with all the pyrolysis residue, metallurgical slag (blast furnace slag), and vermiculite (the mass ratio of metallurgical slag to vermiculite is 4:1, and the total mass of metallurgical slag and vermiculite is 8% of the dry mass of the oily sludge in step S1), is fed into a fluidized bed gasifier. A mixture of saturated steam and oxygen (oxygen volume fraction 15%) is introduced into the gasifier. By controlling the feed rate of saturated steam, the water-carbon molar ratio S / C is kept at 2.8, and the gasification temperature is controlled at 880℃ for the gasification reaction. The residence time of the material in the gasifier is controlled at 40 seconds. After the reaction, hydrogen-rich syngas and gasification slag are obtained.

[0040] The composition of the hydrogen-rich synthesis gas was analyzed by online gas chromatography. The volume concentration of H2 was 62.2%, CO was 21.9%, CO2 was 11.8%, and CH4 was 4.1%.

[0041] H2 yield and carbon conversion rate are calculated using the following formulas:

[0042] H2 yield =

[0043] Carbon conversion rate =

[0044] *Note: The total carbon mass of the raw materials is the sum of the total carbon mass of the mineral oil-containing waste entering the gasifier and the total carbon mass of the semi-coke.

[0045] The calculated H2 yield is 1050 ml / g - dry basis of mineral oil-containing waste, meaning that 1g of dry basis of mineral oil-containing waste can produce 1050 mL of hydrogen; the carbon conversion rate is 96.5%.

[0046] The gasification slag discharged from the bottom of the gasifier was tested and found to have leaching toxicity that meets the national standard (GB 5085.3-2007 "Identification Standard for Hazardous Waste - Leaching Toxicity Identification"), and can be used to prepare roadbed materials. Example 2

[0047] The rest is the same as in Example 1, except that: in step S3, the mass ratio of metallurgical slag to vermiculite is 3:1, and the total mass of metallurgical slag and vermiculite is 10% of the dry basis mass of oily sludge in step S1.

[0048] Example 3

[0049] The rest is the same as in Example 1, except that: in step S3, the mass ratio of metallurgical slag to vermiculite is 5:1, and the total mass of metallurgical slag and vermiculite is 5% of the dry basis mass of oily sludge in step S1.

[0050] Example 4

[0051] The rest is the same as in Example 1, except that: in step S1, oil-based drill cuttings are used instead of oily sludge and dried to a moisture content of about 18 wt%; correspondingly, in steps S2 and S3, the amount of semi-coke, metallurgical slag and vermiculite added is based on the dry weight of the oil-based drill cuttings.

[0052] Example 5

[0053] The rest is the same as in Example 1, except that: in step S2, the dry mass ratio of semi-coke to oily sludge is 2.5:1; in step S3, the water-carbon molar ratio S / C is 2.5, and the gasification temperature is adjusted to 800℃.

[0054] During the continuous operation of Examples 1-5 above (the pyrolysis gas delivery pipeline and mixer in each example were run continuously for 2 hours), no tar condensation or deposition was observed on the inner wall of the pipeline and mixer, and the pipeline was unobstructed.

[0055] Comparative Example 1

[0056] Similar to Example 1, except that: the pyrolysis in step S1 is skipped, and the raw materials are directly mixed and then vaporized. The specific operation is as follows:

[0057] S1. The oily sludge is dried at 60℃ for 12 hours to reduce its moisture content to about 18 wt%. Then, it is fed into a fluidized bed gasifier along with semi-coke (the dry weight ratio of semi-coke to oily sludge is 1.5:1), metallurgical slag (blast furnace slag), and vermiculite (the mass ratio of metallurgical slag to vermiculite is 4:1, and the total mass of metallurgical slag and vermiculite is 8% of the dry weight of oily sludge). A mixture of saturated steam and oxygen (oxygen volume fraction 15%) is introduced into the gasifier. By controlling the feed rate of the gasifying agent, the water-to-carbon molar ratio S / C is kept at 2.8, and the gasification temperature is controlled at 880℃ for the gasification reaction. The residence time of the material in the gasifier is controlled at 40 seconds. After the reaction, hydrogen-rich syngas and gasification slag are obtained.

[0058] Comparative Example 2

[0059] Similar to Example 1, the difference is that the premixing of high-temperature pyrolysis gas and semi-coke in step S2 is omitted. Instead, the semi-coke, high-temperature pyrolysis gas, and pyrolysis residue are fed into the gasifier separately and naturally mixed within the furnace for gasification. Specifically:

[0060] S1, Same as Example 1; S2, High-temperature pyrolysis gas from the pyrolysis furnace outlet, all pyrolysis residue obtained in step S1, semi-coke (the dry weight ratio of semi-coke to oily sludge in step S1 is 1.5:1), metallurgical slag (blast furnace slag), and vermiculite (the mass ratio of metallurgical slag to vermiculite is 4:1, and the total mass of metallurgical slag and vermiculite is 8% of the dry weight of oily sludge in step S1) are fed into a fluidized bed gasifier separately, and a mixture of saturated steam and oxygen (oxygen volume fraction 15%) is introduced into the gasifier. By controlling the feed rate of the gasifying agent, the water-to-carbon molar ratio S / C is made 2.8, and the gasification temperature is controlled at 880°C to carry out the gasification reaction. The residence time of the material in the gasifier is controlled at 40 seconds. After the reaction, hydrogen-rich syngas and gasification slag are obtained.

[0061] After 30 minutes of continuous operation, a distinct tar condensate layer with a thickness of about 1 mm appeared on the inner wall of the pyrolysis gas conveying pipeline.

[0062] Comparative Example 3

[0063] The rest is the same as in Example 1, except that metallurgical slag and vermiculite are not added in step S3.

[0064] Comparative Example 4

[0065] The rest is the same as in Example 1, except that: in step S3, only vermiculite is added and no metallurgical slag is added, and the amount of vermiculite added is 1.6% of the dry basis mass of the oily sludge (that is, the same amount of vermiculite added as in Example 1).

[0066] Testing and Analysis

[0067] Using the same method as in Example 1, the composition of the hydrogen-rich synthesis gas in the remaining examples and comparative examples was analyzed, and the H2 yield and carbon conversion rate were calculated. The specific data are shown in Table 1.

[0068] Table 1 H2 yield and carbon conversion rate

[0069]

[0070] Table 1 shows that the method of this invention can efficiently treat mineral oil-containing waste and achieve high-value utilization of semi-coke. Excellent hydrogen production performance was achieved (H2 yield up to 1000 ml / g - dry basis of mineral oil-containing waste, concentration 60%~65%), while the carbon conversion rate was ≥95%. The H2 yield and carbon conversion rate of Comparative Examples 1-3 were significantly lower than those of the Example, with Comparative Example 2 also exhibiting tar condensation problems; the H2 yield and carbon conversion rate of Comparative Example 4 were also worse than those of the Example.

[0071] Regarding environmental performance, the gasification slag discharged from the bottom of the gasifier in each embodiment was tested and found to have leaching toxicity that meets the national standard (GB 5085.3-2007 "Identification Standard for Hazardous Wastes: Leaching Toxicity Identification"), and can be used to prepare roadbed materials. However, the gasification slag from Comparative Example 3 (without added metallurgical slag and vermiculite) was tested and found to have a total chromium content of 12.6 mg / L in the leachate (GB 5085.3-2007). Standard 5085.3-2007 stipulates that the leachate concentration should not exceed 10 mg / L, exceeding the standard by 26%. Comparative Example 4 (with only vermiculite added) showed that the total chromium content in the leachate of the gasification slag was 11.5 mg / L, exceeding the standard by 15%. This indicates that while adding vermiculite alone can reduce the concentration of heavy metal leaching, it still cannot meet environmental protection requirements. This invention, based on the coupling of the "pyrolysis-gasification" process, the functional coupling of "adsorption-carbon source-catalysis" in semi-coke, and the synergistic coupling of pyrolysis residue and semi-coke as raw materials, further achieves the dual goals of efficiently generating hydrogen-rich syngas and cleaning solid waste through the synergistic compounding of metallurgical slag and vermiculite.

[0072] In summary, this invention achieves the synergistic treatment and full-component resource utilization of two types of solid waste: mineral oil waste and semi-coke. It realizes waste-to-waste treatment, has significant environmental and economic benefits, and is easy to industrialize and promote.

Claims

1. A method for achieving full-component resource recovery through the co-gasification of mineral oil-containing waste and semi-coke, characterized in that, Includes the following steps: S1. The mineral oil-containing waste is pyrolyzed under an inert atmosphere to obtain high-temperature pyrolysis gas containing tar vapor and volatiles, as well as pyrolysis residue. S2. The high-temperature pyrolysis gas obtained in step S1 is directly mixed with semi-coke without condensation, so that the tar in the high-temperature pyrolysis gas is adsorbed in the pores of the semi-coke to obtain a gas-solid mixture. S3. The gas-solid mixture, pyrolysis residue, and additives are fed into a gasifier and a gasification reaction is carried out in the presence of a gasifying agent to obtain hydrogen-rich syngas and gasification slag; the additives are a compound of metallurgical slag and vermiculite in a mass ratio of 3 to 5:

1.

2. The method according to claim 1, characterized in that, In step S1, the mineral oil-containing waste is selected from at least one of oily sludge, waste mineral oil, oil-based drill cuttings, and oil-contaminated waste; the water content of the mineral oil-containing waste is ≤20wt%; the total carbon content of the mineral oil-containing waste is 30~50wt% on a dry basis; the inert atmosphere is nitrogen and / or argon; the pyrolysis treatment conditions are: temperature 400~600℃, time 0.5~2h.

3. The method according to claim 1, characterized in that, In step S2, the dry weight ratio of the semi-coke to the mineral oil-containing waste from step S1 is 1~3:

1.

4. The method according to claim 1, characterized in that, In step S2, the semi-coke is selected from at least one of coal pyrolysis semi-coke, biomass pyrolysis semi-coke, and oily waste pyrolysis semi-coke; the particle size of the semi-coke is 1~5mm.

5. The method according to claim 1, characterized in that, In step S2, the mixing conditions are as follows: semi-coke and high-temperature pyrolysis gas enter the mixer in opposite directions, and the gas and solid phases are mixed in turbulent state for 2 to 5 seconds. The mixer is a pipeline mixer or a gas-solid injector.

6. The method according to claim 1, characterized in that, In step S3, the amount of the additive added is 5-10% of the dry basis mass of the mineral oil-containing waste from step S1.

7. The method according to claim 1, characterized in that, In step S3, the metallurgical slag is blast furnace slag or steel slag with a particle size of 0.5~2mm. The chemical composition of the metallurgical slag contains 40~50wt% CaO, and the total content of CaO, MgO and Fe2O3 accounts for 65~75wt% of the total content. The vermiculite has a particle size of 100~200 mesh.

8. The method according to claim 1, characterized in that, In step S3, the gasifier is selected from any one of fluidized bed gasifier, fixed bed gasifier, and entrained flow gasifier; the gasifying agent is saturated steam or a mixture of saturated steam and oxygen.

9. The method according to claim 1 or 8, characterized in that, The gasifying agent is a mixture of saturated water vapor and oxygen, wherein the volume fraction of oxygen is 5% to 20%.

10. The method according to claim 1, characterized in that, Furthermore, in step S3, the water-to-carbon molar ratio S / C is controlled to be 2.0-3.5 by controlling the feed amount of the gasifying agent; the conditions for the gasification reaction are: temperature 800-950℃.

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