A method for resource utilization of saline organic waste

Abstract

This invention belongs to the field of waste resource utilization technology, specifically relating to a method for the resource utilization of saline organic waste. The invention uses saline organic waste and non-salt organic waste liquid as raw materials to prepare a high-concentration inorganic salt mixture. This high-concentration inorganic salt mixture is then vaporized and subjected to quenching water cooling, causing the organic matter to generate syngas, which is then used to produce various chemical products for efficient utilization. Simultaneously, the inorganic salts are introduced into the aqueous phase and subsequently recovered through vacuum distillation and crystallization. Furthermore, when the saline organic waste also contains bromine and / or iodine, the invention further includes the extraction of the halogen-containing mother liquor obtained after crystallization to recover elemental bromine and / or iodine. Through the combination of various process steps, this invention can recover inorganic salts while preparing syngas, achieving the harmless disposal and high-value resource utilization of saline organic waste, with a comprehensive resource utilization rate exceeding 95%.

Description

Technical Field

[0001] This invention belongs to the field of waste resource utilization technology, specifically relating to a method for the resource utilization of saline organic waste. Background Technology

[0002] Industrial production processes generate a large amount of saline organic waste. These wastes are primarily generated through chemical processes such as chlorination, diazotization, acidification, nitration, oxidation, and condensation, as well as wastewater treatment processes including neutralization, filtration, evaporation, and crystallization. The main types of inorganic salts in saline organic waste include sodium, calcium, ammonium, and potassium salts, with sodium and potassium salts being the most abundant.

[0003] The existing treatment methods for saline organic waste can be divided into two types: harmless disposal and resource utilization. Among them, harmless disposal is mainly carried out by landfill. According to GB 18598-2019 "Standard for Pollution Control of Hazardous Waste Landfill", waste with a total water-soluble salt content ≥10% or an organic matter content ≥5% must be placed in rigid landfills. Therefore, saline organic waste should mostly be placed in rigid landfills. However, there are four disadvantages to placing saline organic waste in rigid landfills: (1) For landfills of the same scale, rigid landfills require more investment and occupy a larger area than flexible landfills; (2) Most landfills in my country are flexible landfills, and the number of rigid landfills is small, which restricts the landfilling of saline organic waste; (3) The landfill cost of saline organic waste is as high as RMB 4,000 / ton or more; (4) Organic pollutants in saline organic waste may enter the environment with leachate, causing environmental pollution.

[0004] Resource utilization of saline organic waste can avoid the problems associated with harmless disposal. Currently, the resource utilization of saline organic waste mainly adopts methods such as oxidation, pyrolysis, and melting. This involves first removing the organic matter from the saline organic waste, and then performing membrane separation, electrolysis, and crystallization separation on the inorganic salts to achieve purification and refining. However, this treatment method converts organic matter into greenhouse gas emissions, fails to efficiently and rationally utilize saline organic waste at the elemental level, and thus leads to a waste of chemical resources. Summary of the Invention

[0005] The purpose of this invention is to provide a method for the resource utilization of saline organic waste. By using the method provided by this invention to treat saline organic waste, syngas and inorganic salts can be obtained simultaneously, and bromine and iodine can be recovered, thereby achieving efficient recycling of saline organic waste.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] A method for resource utilization of saline organic waste includes the following steps:

[0008] (1) A mixture of saline organic waste and non-salt organic waste liquid is prepared to obtain a high-concentration inorganic salt mixture; the concentration of inorganic salts in the high-concentration inorganic salt mixture is more than 90% of the saturation concentration of inorganic salts; the high-concentration inorganic salt mixture has a fluorine content of less than 5 wt%, a silicon content of less than 3 wt%, an aluminum content of less than 3 wt%, a sulfur content of less than or equal to 2 wt%, a magnesium content of less than 5 wt%, a phosphorus content of 0.1~5 wt%, a calcium content of 1~10 wt%, and a calorific value of not less than 10000 J / g; the inorganic salts in the saline organic waste include sodium salts and / or potassium salts;

[0009] The non-salt organic waste liquid includes organic waste liquid and water; the water content of the non-salt organic waste liquid is 20~60wt%, and the calorific value is 10000~30000 J / g;

[0010] (2) The high-concentration inorganic salt mixture is subjected to gasification and quenching water in sequence to obtain gas-water mixture, first liquid phase water and solid slag respectively;

[0011] (3) The gas-water mixture is subjected to gas-water separation to obtain syngas and a second liquid phase water, respectively;

[0012] (4) The first liquid water and the second liquid water are mechanically filtered to obtain a high-salt water body and a water-quenched fine slag, respectively; the total content of potassium salt and / or sodium salt in the high-salt water body is not less than 15 wt%.

[0013] (5) The high-salt water body is concentrated and crystallized in sequence to obtain sodium salt and / or potassium salt.

[0014] Preferably, the organic waste liquid is a waste organic solvent, and the waste organic solvent is a compound containing carbon and hydrogen elements;

[0015] The saline organic waste is either solid saline organic waste or liquid saline organic waste;

[0016] The mass ratio of water in the solid saline organic waste and the non-salt organic waste liquid is 0.1~2:1;

[0017] The mass ratio of organic waste liquid to non-salt organic waste liquid in the liquid saline organic waste liquid is 0.2~0.8:1.

[0018] Preferably, after obtaining the high-concentration inorganic salt mixture, the method further includes adding an additive to the high-concentration inorganic salt mixture; the additive is at least one of limestone, coal powder and activated carbon.

[0019] Preferably, the vaporization temperature is based on the ash melting point of the sparingly soluble substance in the high-concentration inorganic salt mixture: when the ash melting point of the sparingly soluble substance is higher than 1300 °C, the vaporization temperature is 1350 ~ 1400 °C;

[0020] When the ash melting point of the sparingly soluble substance is below 1100 °C, the vaporization temperature is 1050 ~ 1100 °C;

[0021] When the ash melting point of the sparingly soluble substance is between 1100 and 1250 °C, the vaporization temperature is 50 to 100 °C higher than the ash melting point of the sparingly soluble substance.

[0022] The pressure of the vaporization is 0~10 MPa; the vaporizing agent is oxygen; the volume ratio of oxygen to high-concentration inorganic salt mixture during the vaporization process is 300~600:1.

[0023] Preferably, the mass flow ratio of the chilling water to the high-concentration inorganic salt mixture used for the chilling water quench is 4~10:1.

[0024] Preferably, the concentration method is vacuum distillation; the vacuum distillation temperature is 25~140 ℃ and the pressure is -200~-50 KPa.

[0025] Preferably, when the inorganic salts in the saline organic waste are sodium and potassium salts, the crystallization separation is as follows: the concentrated solution is first cooled and crystallized to obtain sodium salt, and then the solution obtained from the first cooling and crystallization is second cooled and crystallized to obtain potassium salt; the final temperature of the first cooling and crystallization is 60~100 ℃; the final temperature of the second cooling and crystallization is 25~60 ℃.

[0026] When the inorganic salt in the saline organic waste is sodium salt, the crystallization separation is as follows: the concentrated solution is cooled to 60~100℃ for crystallization to obtain sodium salt;

[0027] When the inorganic salt in the saline organic waste is potassium salt, the crystallization separation is performed by cooling the concentrated solution to 25~60℃ for crystallization to obtain potassium salt.

[0028] Preferably, the crystallization separation also yields brine mother liquor; when the brine mother liquor contains bromide, the process further includes introducing chlorine gas into the brine mother liquor and then blowing it out with nitrogen gas to obtain elemental bromine.

[0029] Preferably, when the brine mother liquor also contains iodide, the method further includes mixing the remaining mother liquor after nitrogen is blown out with an extractant for extraction to obtain elemental iodine.

[0030] Preferably, when the total content of sodium and / or potassium salts in the filtrate obtained by mechanical filtration is less than 15 wt%, the filtrate is recycled as chilling water for quenching until the total content of sodium and / or potassium salts in the filtrate obtained by mechanical filtration is not less than 15 wt%.

[0031] The condensate produced by the vacuum distillation is recycled as quench water for quenching.

[0032] This invention provides a method for the resource utilization of saline organic waste. The method achieves efficient elemental-level utilization of saline organic waste. Using saline organic waste and non-salt organic waste liquid as raw materials, the invention combines various process flows to produce syngas and recover inorganic salts, achieving the harmless disposal and comprehensive, efficient, and high-value resource utilization of saline organic waste. Specific beneficial effects are as follows:

[0033] (1) Efficient utilization of organic matter in saline organic waste

[0034] Compared with traditional resource utilization processes for saline organic waste, the present invention provides a more efficient and rational method for treating organic matter in saline organic waste: The present invention combines saline organic waste and non-salt organic waste liquid, so that the mixture meets the gasification conditions. Through gasification, the organic matter in the saline organic waste is fully utilized, while avoiding interference from organic matter with the subsequent recovery of inorganic salts. The syngas produced by the gasification of organic matter can be used directly as a product or as a raw material for the production of other chemical products.

[0035] (2) Gasification and quenching to remove impurities

[0036] This invention utilizes a high-concentration inorganic salt mixture to achieve the resource utilization of organic matter through gasification, while simultaneously melting or partially melting the inorganic salts. Following quenching with rapid cooling water, the insoluble substances and harmful metals in the saline organic waste are solidified to form a solidified slag. This process removes toxic inorganic substances from the saline organic waste, achieving its harmless treatment. Through gasification, this invention achieves a glass transition rate of >90% for heavy metals and an acid loss rate of <2%, meeting all the requirements of the "Technical Requirements for Vitrification Treatment Products of Solid Waste" (GB / T41015-2021).

[0037] (3) Organic combination of inorganic salt extraction process

[0038] All processes in this invention facilitate subsequent inorganic salt extraction: Composition adjustment is achieved through mixing saline organic waste and non-salt organic wastewater, with strict control over the chemical composition of the mixture during this stage. This ensures that calcium and magnesium ions form phosphate precipitates during the gasification and quenching process, preventing interference from calcium and magnesium ions in inorganic salt extraction. The gasification and quenching process also enables efficient gasification and utilization of organic matter, avoiding interference with subsequent processes. Furthermore, in the high-salinity wastewater extraction stage, potassium and sodium salts in the water are first utilized for resource recovery, followed by bromine and iodine extraction from the resulting concentrated liquid, increasing extraction efficiency. The overall resource recovery rate can reach over 95%.

[0039] In summary, the resource-based treatment method of the present invention is an organic whole, with each process organically combined with the goal of efficient resource utilization, ultimately achieving high-value resource utilization of saline organic waste. Attached Figure Description

[0040] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0041] Figure 1 A process flow diagram of the resource utilization method for saline organic waste provided by the present invention. Detailed Implementation

[0042] This invention provides a method for the resource utilization of saline organic waste, comprising the following steps:

[0043] (1) A mixture of saline organic waste and non-salt organic waste liquid is prepared to obtain a high-concentration inorganic salt mixture; the concentration of inorganic salts in the high-concentration inorganic salt mixture is more than 90% of the saturation concentration of inorganic salts; the high-concentration inorganic salt mixture has a fluorine content of less than 5 wt%, a silicon content of less than 3 wt%, an aluminum content of less than 3 wt%, a sulfur content of less than or equal to 2 wt%, a magnesium content of less than 5 wt%, a phosphorus content of 0.1~5 wt%, a calcium content of 1~10 wt%, and a calorific value of not less than 10000 J / g; the inorganic salts in the saline organic waste include sodium salts and / or potassium salts;

[0044] The non-salt organic waste liquid includes organic waste liquid and water; the water content of the non-salt organic waste liquid is 20~60wt%, and the calorific value is 10000~30000 J / g;

[0045] (2) The high-concentration inorganic salt mixture is subjected to gasification and quenching water in sequence to obtain gas-water mixture, first liquid phase water and solid slag respectively;

[0046] (3) The gas-water mixture is subjected to gas-water separation to obtain syngas and a second liquid phase water, respectively;

[0047] (4) The first liquid water and the second liquid water are mechanically filtered to obtain a high-salt-content body and a water-quenched fine slag, respectively; the total content of sodium salt and / or potassium salt in the high-salt-content body is not less than 15 wt%.

[0048] (5) The high-salt water body is concentrated and crystallized in sequence to obtain sodium salt and / or potassium salt.

[0049] This invention mixes saline organic waste and non-salt organic waste liquid to obtain a high-concentration inorganic salt mixture. In this invention, the inorganic salts in the saline organic waste include sodium and / or potassium salts; the sodium salt preferably includes one or both of sodium chloride and sodium carbonate, and the potassium salt preferably includes one or both of potassium chloride and potassium carbonate; in specific embodiments of this invention, the inorganic salts in the saline organic waste may be only sodium and / or potassium salts, or in addition to sodium and / or potassium salts, may also contain one or more of sodium sulfate, potassium sulfate, sodium iodide, and sodium bromide.

[0050] In this invention, the saline organic waste is preferably solid or liquid saline organic waste; the solid content of the liquid saline organic waste is preferably 15-35 wt%, more preferably 20-30 wt%; the solid saline organic waste is preferably waste salt generated by acid-base neutralization reaction during industrial production; the liquid saline organic waste is preferably saline wastewater generated during industrial production; in this invention, the liquid saline organic waste includes inorganic salts and organic solvents, wherein the organic solvents preferably include one or more of aromatic hydrocarbons, aliphatic hydrocarbons, alicyclic hydrocarbons, halogenated hydrocarbons, alcohols, ethers, esters, ketones, and diol derivatives; the aromatic hydrocarbons preferably include benzene, toluene, and xylene. One or more of benzene; the aliphatic hydrocarbon preferably includes one or more of pentane, hexane, and octane; the alicyclic hydrocarbon preferably includes one or more of cyclohexane, cyclohexanone, and toluenecyclohexanone; the halogenated hydrocarbon preferably includes one or more of chlorobenzene, dichlorobenzene, and dichloromethane; the alcohol preferably includes one or more of methanol, ethanol, and isopropanol; the ether preferably includes one or two of diethyl ether and propylene oxide; the ester preferably includes one or more of methyl acetate, ethyl acetate, and propyl acetate; the ketone preferably includes one or more of acetone, methyl butyl ketone, and methyl isobutyl ketone; the diol derivative preferably includes one or more of ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, and ethylene glycol monobutyl ether.

[0051] In this invention, the saline organic waste is preferably one, two, or more saline organic wastes; that is, saline organic wastes can be treated alone or multiple saline organic wastes can be mixed for treatment, and this invention does not make specific limitations.

[0052] In this invention, the non-salt organic waste liquid is preferably a homogeneous system or a multiphase fluid; the non-salt organic waste liquid includes organic waste liquid and water, the organic waste liquid is preferably a waste organic solvent, and the waste organic solvent is preferably a compound containing carbon and hydrogen elements, specifically including one or more of aromatic hydrocarbons, aliphatic hydrocarbons, alicyclic hydrocarbons, halogenated hydrocarbons, alcohols, ethers, esters, ketones, and diol derivatives; the aromatic hydrocarbons preferably include one or more of benzene, toluene, and xylene; the aliphatic hydrocarbons preferably include one or more of pentane, hexane, and octane; the alicyclic hydrocarbons preferably include one or more of cyclohexane, cyclohexanone, and toluenecyclohexanone; the halogenated hydrocarbons preferably include chlorobenzene, dichlorobenzene, and dichlorobenzene. The non-salt organic waste liquid contains one or more of benzene and dichloromethane; the alcohol preferably includes one or more of methanol, ethanol, and isopropanol; the ether preferably includes one or two of diethyl ether and propylene oxide; the ester preferably includes one or more of methyl acetate, ethyl acetate, and propyl acetate; the ketone preferably includes one or more of acetone, methyl butyl ketone, and methyl isobutyl ketone; the diol derivative preferably includes one or more of ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, and ethylene glycol monobutyl ether; the water content of the non-salt organic waste liquid is 20-60 wt%, preferably 25-55 wt%, more preferably 30-50 wt%, and the calorific value is 10,000-30,000 J / g, preferably 15,000-30,000 J / g, more preferably 20,000-30,000 J / g. The water content of the non-salt organic waste liquid is fundamental to ensuring that saline organic waste can dissolve in the non-salt organic waste liquid, and its calorific value requirement can meet the heat source supply in the subsequent gasification process.

[0053] In this invention, the non-salt organic waste liquid is preferably one, two, or more types of non-salt organic waste liquid; the non-salt organic waste liquid preferably includes one or more organic solvents generated in pharmaceutical, leather production, chemical synthesis, and raw material cleaning processes. The non-salt organic waste liquid in this invention can be prepared from a single source or multiple sources.

[0054] In this invention, the mass ratio of water in the solid saline organic waste and the non-salt organic waste liquid is preferably 0.1~2:1, more preferably 0.1~1:1, and even more preferably 0.5~1:1; the mass ratio of organic waste liquid in the liquid saline organic waste and the non-salt organic waste liquid is preferably 0.2~0.8:1, more preferably 0.3~0.7:1, and even more preferably 0.4~0.6:1. In this invention, the mixing process of saline organic waste and non-salt organic waste liquid is based on the water content in the non-salt organic waste liquid. Through mixing, the saline organic waste is fully dissolved, and the non-salt organic waste liquid is transformed into a saline organic fluid.

[0055] In this invention, the mixing of saline organic waste and non-salt organic waste liquid is preferably carried out by premixing a portion of the saline organic waste and non-salt organic waste liquid, and then mixing the resulting saline organic fluid with the remaining portion of saline organic waste to obtain a high-concentration inorganic salt mixture. In this invention, after the premixing of the saline organic waste and non-salt organic waste liquid, it is preferable to further perform chemical analysis on the resulting saline organic fluid. The chemical analysis preferably includes analyzing the saturated salt content and chemical composition of the saline organic fluid to determine the amount of saline organic waste to be added subsequently. The chemical composition preferably includes, but is not limited to, phosphorus content, fluorine content, silicon content, aluminum content, sulfur content, calcium content, and magnesium content. In this invention, the fluorine content of the saline organic fluid is preferably less than 5 wt%, the silicon content is less than 3 wt%, the aluminum content is less than 3 wt%, the sulfur content is less than or equal to 2 wt%, the magnesium content is preferably less than 5 wt%, the phosphorus content is preferably 0.1~5 wt%, and the calcium content is preferably 1~10 wt%. This invention involves a stepwise mixing and dissolving of saline organic waste and non-salt organic waste liquid. First, a preliminary premixing is performed to form a saline organic fluid. Then, saline organic waste is added to increase the inorganic salt concentration, forming a high-concentration inorganic salt mixture, thereby increasing the processing capacity of saline organic waste in a single treatment.

[0056] In this invention, after obtaining the high-concentration inorganic salt mixture, it is preferable to further add an additive to the high-concentration inorganic salt mixture; the additive is preferably at least one of limestone, coal powder, and activated carbon; the limestone is used to remove impurities such as fluorine and silicon, and the coal powder or activated carbon can increase the calorific value. By adding the additive, this invention enables the various indicators of the high-concentration inorganic salt mixture to meet the gasification requirements; this invention does not have special requirements on the amount of additive added, but adds it according to actual needs, so that the content of impurities such as fluorine and silicon or the calorific value of the high-concentration inorganic salt mixture meets the above requirements. In this invention, the particle size of the coal powder is preferably 40 mesh to 300 mesh, more preferably 100 mesh to 200 mesh.

[0057] In this invention, the concentration of inorganic salts in the high-concentration inorganic salt mixture is more than 90% of the saturated concentration of inorganic salts, preferably more than 95%, and more preferably a saturated inorganic salt mixture; the high-concentration inorganic salt mixture has a fluorine content of less than 5 wt%, a silicon content of less than 3 wt%, an aluminum content of less than 3 wt%, a sulfur content of less than or equal to 2 wt%, a magnesium content of less than 5 wt%, a phosphorus content of 0.1~5 wt%, a calcium content of 1~10 wt%, and a calorific value of not less than 10000 J / g. This invention controls the phosphorus content within the aforementioned range, allowing phosphorus to generate phosphate ions during gasification, thereby removing calcium and magnesium ions from high-salt water. It also controls the fluorine content within the aforementioned range, preventing high fluorine levels from affecting subsequent inorganic salt extraction during the treatment of saline organic waste. Furthermore, controlling the calcium content within the aforementioned range ensures that calcium ions in high-concentration inorganic salt mixtures will precipitate calcium fluoride during quenching, thus removing fluoride ions. Controlling the silicon and aluminum content within the aforementioned range reduces the viscous flow temperature during the melting process of water-quenched slag, thereby controlling the gasifier temperature. Finally, controlling the sulfur and magnesium content within the aforementioned range reduces sulfate production during gasification to a reasonable level, contributing to improved product salt quality.

[0058] After obtaining a high-concentration inorganic salt mixture, the present invention sequentially vaporizes and quenches the mixture with water to obtain a gas-water mixture, a first liquid phase water (i.e., the quenched water after use), and a solid slag, respectively. In this invention, the vaporization temperature is preferably based on the ash melting point of the sparingly soluble component in the high-concentration inorganic salt mixture: when the ash melting point of the sparingly soluble component is higher than 1300 °C, the vaporization temperature is preferably 1350~1400 °C, more preferably 1350~1380 °C; when the ash melting point of the sparingly soluble component is lower than 1100 °C, the vaporization temperature is preferably 1050~1100 °C, more preferably 1070~1100 °C; when the ash melting point of the sparingly soluble component is between 1100~1250 °C, the vaporization temperature is preferably 50~100 °C higher than the ash melting point of the sparingly soluble component, more preferably 60~90 °C, and even more preferably 70~80 °C.

[0059] In this invention, the gasification pressure is preferably 0-10 MPa, more preferably 1-8 MPa, and even more preferably 2-6 MPa; the gasifying agent is preferably oxygen; the volume ratio (denoted as oxygen-to-material ratio) of the oxygen-to-material mixture during the gasification process is preferably 300-600:1, more preferably 400-500:1, and even more preferably 450:1; the gasification equipment is preferably a gasifier. This invention uses gasification to pyrolyze organic matter in saline organic waste at high temperatures to generate syngas. The main components of the syngas include CO, H2, and CO2; the volume fraction of CO in the syngas is preferably ≥30%, and the volume fraction of H2 is preferably ≥30%.

[0060] In this invention, the calorific value and ash melting point of the high-concentration inorganic salt mixture are preferably analyzed and determined before gasification. When the calorific value of the high-concentration inorganic salt mixture is less than 10,000 J / g, non-salt organic waste liquid is preferably added during the gasification process until the calorific value meets the requirements. The addition of non-salt organic waste liquid is preferably carried out using a multi-channel feeding method. This invention determines the ash melting point of sparingly soluble substances by analyzing the ash melting point, providing a reference for temperature selection during the gasification process.

[0061] In the gasification process of this invention, organic matter is converted into CO, CO2, and H2. These gases create a strong reducing atmosphere for the gasification process, which causes the sulfate in the inorganic salts to undergo a reduction reaction to generate H2S. Although this reaction consumes some of the syngas (CO, CO2, and H2), it removes most of the sulfate ions, preventing any impact on subsequent resource utilization processes. Furthermore, the inorganic matter in the high-concentration inorganic salt mixture will form a molten or partially molten state. At the same time, the phosphate ions generated during the gasification process can remove calcium and magnesium ions, reducing the content of metal cations in the high-salt-content water.

[0062] In this invention, the mass flow ratio of the quenching water to the high-concentration inorganic salt mixture used for quenching is preferably 4-10:1, more preferably 5-9:1, and even more preferably 6-8:1. During the quenching process, the molten or partially molten inorganic matter generated by vaporization comes into contact with the quenching water. Water-soluble substances migrate and transform into the quenching water, while insoluble substances are transformed into water-quenched slag (solid slag). Through water quenching, this insoluble substance forms a glassy structure, thus removing insoluble inorganic salts from salt-containing organic waste. Adding the aforementioned amount of quenching water during the quenching process prevents the precipitation of crystallized salts.

[0063] After obtaining a gas-water mixture, a first liquid phase of water, and a solid slag, the present invention performs gas-water separation on the gas-water mixture to obtain syngas and a second liquid phase of water (i.e., the aqueous phase obtained from gas-water separation). In the present invention, the gas-water separation equipment is preferably a conventional industrial tray-type gas-water separator.

[0064] In this invention, the gas obtained after gas-water separation is preferably washed; the washing water is preferably fresh water or evaporated water generated during vacuum distillation of the high-salt-content gas.

[0065] After obtaining the first and second liquid phase water, the present invention mechanically filters the first and second liquid phase water to obtain high-salinity water and water-quenched fine slag, respectively. In the present invention, the mechanical filtration is preferably plate and frame filtration.

[0066] In this invention, the high-salt water body is an unsaturated high-salt water body, and the total content of potassium and sodium salts in the high-salt water body is not less than 15 wt%, preferably 15 wt% to 20 wt%. In this invention, when the total content of sodium and / or potassium salts in the filtrate obtained by mechanical filtration is less than 15 wt%, the filtrate is preferably used as quench water for quenching and evaporation until the total content of sodium and / or potassium salts in the filtrate obtained by mechanical filtration is not less than 15 wt%, at which point the obtained filtrate is a high-salt water body.

[0067] After obtaining a high-salt-content water body, the present invention sequentially concentrates and crystallizes the high-salt-content water body to obtain sodium salt and / or potassium salt. In the present invention, the concentration method is preferably vacuum distillation; the temperature of the vacuum distillation is preferably 25~140 ℃, more preferably 50~80 ℃, and the pressure is preferably -200~-50 kPa, more preferably -100~-50 kPa; the time of vacuum distillation is preferably based on reducing the water content of the high-salt-content water body to the sodium chloride precipitation point. The present invention forms a saturated solution by vacuum distilling the high-salt-content water body.

[0068] In this invention, when the inorganic salts in the saline organic waste are sodium and potassium salts, the crystallization separation is preferably performed by: first cooling and crystallizing the concentrated solution to obtain sodium chloride, and then second cooling and crystallizing the solution obtained from the first cooling and crystallization to obtain potassium chloride; the final temperature of the first cooling and crystallization is preferably 60-100 °C, more preferably 70-90 °C, and even more preferably 80 °C; the final temperature of the second cooling and crystallization is preferably 25-60 °C, more preferably 35-60 °C, and even more preferably 45-60 °C. This invention utilizes the difference in solubility between sodium and potassium salts at different temperatures to crystallize and separate sodium and potassium salts.

[0069] In this invention, when the inorganic salt in the salt-containing organic waste is sodium salt, the crystallization separation is performed by cooling the concentrated solution to 60~100 ℃ to crystallize and obtain sodium salt.

[0070] In this invention, when the inorganic salt in the salt-containing organic waste is potassium salt, the crystallization separation is performed by cooling the concentrated solution to 25-60°C to crystallize the potassium salt.

[0071] In this invention, after obtaining the sodium salt, the process preferably further includes: mixing the sodium salt, carbon dioxide, and ammonia to undergo a metathesis reaction to obtain ammonium chloride and sodium carbonate (alkali production via the combined alkali process). The potassium salt obtained by this invention can be used to produce downstream potassium salt products, and the sodium salt can be used for alkali production, thus realizing the resource utilization of potassium and sodium salts in high-salt water bodies.

[0072] In this invention, the crystallization separation also yields brine mother liquor; when the brine mother liquor contains bromide, the process further includes introducing chlorine gas into the brine mother liquor followed by nitrogen blowing to obtain elemental bromine. In this invention, the mass ratio of the brine mother liquor to chlorine gas is preferably 100:1~5, more preferably 100:2~4, and even more preferably 100:3; the nitrogen blowing is preferably performed using a bubbling device.

[0073] In this invention, when the brine mother liquor also contains iodides, the process further includes mixing the remaining mother liquor after nitrogen purging with an extractant for extraction to obtain elemental iodine. In this invention, the mass ratio of the remaining mother liquor after nitrogen purging to the extractant is preferably 100:5~15, more preferably 100:8~12, and even more preferably 100:10; the extractant preferably includes carbon tetrachloride.

[0074] In this invention, the obtained iodine-free mother liquor is preferably treated as wastewater after extraction. In this invention, brine mother liquor is obtained through crystallization and separation, and then further concentrated and enriched with bromine and iodine. This invention utilizes chlorine gas to extract bromine from the brine mother liquor, reducing bromide ions to elemental bromine and simultaneously reducing iodide ions to elemental iodine, followed by extraction to extract iodine.

[0075] This invention achieves efficient utilization of soluble inorganic salts from saline organic waste by organically combining different methods for utilizing high-salinity water bodies. First, sodium chloride and potassium chloride are extracted sequentially from the high-salinity water body to reduce the sodium, potassium, and chloride content. Simultaneously, bromine and iodine in the water body are concentrated. The concentrated brine mother liquor is then used for further extraction of bromine and iodine, achieving highly efficient extraction.

[0076] To further illustrate the present invention, the following detailed description of the embodiments is provided in conjunction with the present invention, but these descriptions should not be construed as limiting the scope of protection of the present invention.

[0077] Example 1

[0078] A method for treating solid saline organic waste produced by triple-effect evaporation in a fertilizer plant was proposed. However, the mother liquor contained a large amount of organic matter, resulting in the presence of organic matter in the resulting salts, making direct separation and purification of the solid saline organic waste difficult. The main component of this solid saline organic waste was sodium chloride, along with certain amounts of sodium sulfate, potassium sulfate, sodium iodide, and sodium bromide.

[0079] The non-salt organic waste liquid used in this embodiment is a waste organic solvent produced by the organic synthesis of vitamin C in a pharmaceutical factory. Its main components are acetone and pyridine, etc., with a water content of 36wt% and a calorific value of 16587 J / g. This non-salt organic waste liquid meets the requirements and can be used directly.

[0080] First, solid saline organic waste (the proportion of solid saline organic waste in non-salt organic waste liquid is 12wt%) is added to the non-salt organic waste liquid and mixed thoroughly to obtain saline organic fluid. The chemical composition is shown in Table 1.

[0081] Table 1 Chemical composition of salt-containing organic fluids

[0082] Element Phosphorus content Fluorine content Calcium content magnesium content Sulfur content Silicon content Aluminum content Salt content Proportion 4wt% 2wt% 2.5wt% 3wt% 2wt% 2wt% 2wt% 11wt%

[0083] The saline organic fluid meets the requirements of the preceding indicators. Simultaneously, analysis shows that the saturated salt content of the saline organic fluid is 13.5 wt%, and the current salt content is 11 wt%. Adding crystalline waste salt, whose main components are sodium chloride and sodium carbonate, to form a saturated solution yields a high-concentration inorganic salt mixture. Testing shows that the calorific value of the obtained high-concentration inorganic salt mixture is 15471 J / g, and the ash melting point is 1121 ℃. Because the calorific value of the high-concentration inorganic salt mixture meets the gasification requirements, separate feeding is used for gasification during the material gasification process.

[0084] During the gasification process, the gasifier temperature is controlled at 1200 ℃, the pressure at 3 MPa, the oxygen-to-material ratio at 550, the material throughput at 10 tons / hour, and the quench water flow rate at 60 tons / hour. During the gasification process, the volume fractions of each gas in the syngas are H2: 38%, CO: 40%, and CO2: 22%. After gas-liquid separation and gas washing, the syngas is used to produce products such as ammonia water and ammonium bicarbonate.

[0085] The process involves quenching water to obtain a first liquid phase water (i.e., the used quench water) and a gas-water mixture. After separation by a gas-water separator, a second liquid phase water is obtained. The first and second liquid phase waters are mixed and filtered to obtain a saline body with a salt content of 5 wt%, which does not meet the extraction requirements. This saline body is then recycled as quench water. After three cycles, the salt content is 25 wt%. This high-salt-content body is filtered through a plate and frame filter to obtain a clear liquid, which is then distilled to remove some of the water while maintaining a temperature of 100 ℃. The crystals precipitated during this process are sodium chloride. When the water volume is reduced to the potassium chloride precipitation point, the water body is cooled to 25 ℃. The crystals precipitated during this process are potassium chloride.

[0086] The sodium salt obtained from crystallization is used to prepare soda ash using the combined alkali process. The mother liquor is then used to extract bromine in the next step, which involves adding 10 wt% hydrogen peroxide (30 wt%) and 10 wt% concentrated hydrochloric acid to the mother liquor. After the reaction is completed, the water is stripped using a bubble column. The stripped gas is then absorbed by water containing sulfur dioxide. This step enriches the bromine. 4% phosgene is then introduced into the sulfur dioxide-containing water, and extraction is performed using carbon tetrachloride. After this step, bromine is extracted.

[0087] The stripped liquid is directly extracted with carbon tetrachloride to obtain elemental iodine. After extraction, the remaining iodine content in the iodine-free mother liquor is less than 1 wt%, the bromine content is less than 1 wt%, and the total inorganic salt content is less than 5 wt%. This iodine-free mother liquor is then treated as wastewater.

[0088] Example 2

[0089] The treatment process addresses liquid saline organic waste generated by hydrochloric acid production enterprises. This waste, primarily composed of sodium chloride, hydrochloric acid, and water, has a low calorific value and high salt content. In subsequent treatment, high-calorific-value waste organic solvents are used to increase its calorific value, forming a slurry that meets the requirements for gasification.

[0090] The waste organic solvent used in this embodiment is a waste organic solvent generated by a leather manufacturing plant. Its main component is DMF, its water content is 8wt%, and its calorific value is 18541 J / g.

[0091] Neither material can be used alone; they must be mixed.

[0092] After preliminary screening, liquid saline organic waste and waste organic solvent were mixed at a mass ratio of 2:3 to obtain an inorganic salt mixture with a salt content of 10 wt%, the salt being sodium chloride. The resulting mixture contained 0.1 wt% fluorine, 0.3 wt% silicon, 0.3 wt% aluminum, 0.2 wt% sulfur, 3 wt% magnesium, 2 wt% phosphorus, and 5 wt% calcium. Its calorific value was 19000 J / g, and its ash melting point was 1140 ℃. The resulting inorganic salt mixture was then directly subjected to gasification treatment.

[0093] During the gasification process, the gasifier temperature is controlled at 1200 ℃, the pressure at 3 MPa, the oxygen-to-material ratio at 550, the material throughput at 11 tons / hour, and the quench water flow rate at 60 tons / hour. The material generates syngas during the gasification process, and the volume fractions of each component in the syngas are H2: 39%, CO: 37%, and CO2: 24%. After gas-liquid separation and gas washing, the syngas is used to produce products such as ammonia water and ammonium bicarbonate.

[0094] The quenching process yields a first liquid phase water (i.e., the used quench water) and a gas-water mixture. After separation by a gas-water separator, a second liquid phase water is obtained. The first and second liquid phase waters are mixed and filtered to obtain a saline body with a salt content of 6.5 wt%, which does not meet the extraction requirements. This saline body is recycled as quench water. After three cycles, the salt content is 21 wt%. This high-salt-content body is filtered through a plate and frame filter to obtain a clear liquid, which is then distilled to remove some of the water while maintaining a temperature of 100 ℃. The crystals precipitated during this process are sodium chloride. Since the only inorganic salt in this process is sodium chloride, the subsequent process is not repeated.

[0095] Comparative Example 1

[0096] The solid saline organic waste in Example 1 was treated using existing conventional treatment methods, which involved incineration to remove organic matter from the solid saline organic waste, and then landfilling the ash.

[0097] In Example 1, the solid saline organic waste contained more than 13.5 wt% salt, and its main component was chloride. During the incineration process, a large amount of dioxin carcinogens were generated, making the subsequent treatment and analysis of this gas extremely difficult.

[0098] Comparative Example 2

[0099] To test the effect of sulfur content on the extraction process, hazardous waste with a high sulfur content was added to the high-salt mixed solution of Example 2, so that the sulfur content was greater than 2%. Extraction was carried out according to the method of Example 2. The results showed that during the recycling of the saline body, the quench water contained a large amount of sulfate. Although it did not have a significant impact on the gasification process, the sulfate in it would reduce the purity of the crystallized salt during the inorganic salt separation process, and could not meet the extraction requirements of sodium and potassium salts.

[0100] As can be seen from the above embodiments, the resource utilization method provided by the present invention uses saline organic waste and non-salt organic waste liquid as raw materials, and the various process flows are combined with each other. The synthesized gas can be used to produce chemical products, and inorganic salts are recovered, thus achieving efficient elemental utilization of saline organic waste.

[0101] Although the above embodiments have provided a detailed description of the present invention, they are only some embodiments of the present invention, and not all embodiments. Other embodiments can be obtained based on these embodiments without creative effort, and these embodiments all fall within the protection scope of the present invention.

Claims

1. A method for recycling salt-containing organic waste, comprising the following steps: (1) mixing salt-containing organic waste and non-salt organic waste liquid to obtain a high-concentration inorganic salt mixture; the concentration of inorganic salt in the high-concentration inorganic salt mixture is more than 90% of the saturated concentration of inorganic salt; the high-concentration inorganic salt mixture contains less than 5 wt% fluorine, less than 3 wt% silicon, less than 3 wt% aluminum, less than or equal to 2 wt% sulfur, less than 5 wt% magnesium, 0.1-5 wt% phosphorus, 1-10 wt% calcium, and a heat value of no less than 10000 J / g; the inorganic salt in the salt-containing organic waste includes sodium salt and / or potassium salt; the salt-containing organic waste is solid salt-containing organic waste or liquid salt-containing organic waste, and the mass ratio of water in the solid salt-containing organic waste to the non-salt organic waste liquid is 0.1-2:1, and the mass ratio of organic waste liquid in the liquid salt-containing organic waste to the non-salt organic waste liquid is 0.2-0.8:1; the non-salt organic waste liquid includes organic waste liquid and water; the water content of the non-salt organic waste liquid is 20-60 wt%, and the heat value is 10000-30000 J / g; (2) sequentially gasifying and quenching the high-concentration inorganic salt mixture to obtain a gas-water mixture, first liquid-phase water, and solid residue, respectively; (3) separating the gas-water mixture into synthesis gas and second liquid-phase water; (4) mechanically filtering the first liquid-phase water and the second liquid-phase water to obtain a high-salt water body and water-quenching fine residue, respectively; the total content of potassium salt and / or sodium salt in the high-salt water body is no less than 15 wt%; (5) sequentially concentrating and crystallizing the high-salt water body to obtain sodium salt and / or potassium salt; the crystallization also obtains a brine mother liquor; when the brine mother liquor contains bromide, the method further comprises introducing chlorine into the brine mother liquor and then blowing out nitrogen to obtain elemental bromine; when the brine mother liquor also contains iodide, the method further comprises mixing the mother liquor remaining after the nitrogen blowing out with an extraction agent to extract and obtain elemental iodine. The organic waste liquid is waste organic solvent, and the waste organic solvent is a compound containing carbon and hydrogen elements.

2. The method of claim 1, wherein, After obtaining the high-concentration inorganic salt mixture, the method further comprises adding an additive to the high-concentration inorganic salt mixture; the additive is at least one of limestone, coal powder, and activated carbon.

3. The resource utilization method according to claim 1 or 2, characterized by, The temperature of the gasification is determined according to the ash melting point of the insoluble substance in the high-concentration inorganic salt mixture: when the ash melting point of the insoluble substance is higher than 1300 ℃, the temperature of the gasification is 1350-1400 ℃; 4. The method of claim 1, wherein, when the ash melting point of the insoluble substance is lower than 1100 ℃, the temperature of the gasification is 1050-1100 ℃; when the ash melting point of the insoluble substance is between 1100-1250 ℃, the temperature of the gasification is 50-100 ℃ higher than the ash melting point of the insoluble substance; the pressure of the gasification is 0-10 Mpa; the gasification agent is oxygen; and the volume ratio of oxygen to the high-concentration inorganic salt mixture during the gasification is 300-600:

1. ​ 5. The method of claim 1, wherein, The mass flow ratio of the quenching water mixed with the high-concentration inorganic salt solution is 4-10:

1.

6. The method of claim 1, wherein, The concentration method is reduced-pressure distillation, and the reduced-pressure distillation is performed at a temperature of 25-140 ℃ and a pressure of-200--50 KPa.

7. The method of resource utilization of claim 1, wherein, When the inorganic salt in the salt-containing organic waste is sodium salt and potassium salt, the crystallization separation is: first cooling crystallization of the concentrated solution to obtain sodium salt, and then second cooling crystallization of the solution obtained in the first cooling crystallization to obtain potassium salt; the final temperature of the first cooling crystallization is 60-100 ℃; and the final temperature of the second cooling crystallization is 25-60 ℃. When the inorganic salt in the salt-containing organic waste is sodium salt, the crystallization separation is: cooling the concentrated solution to 60-100 ℃ for crystallization to obtain sodium salt. When the inorganic salt in the salt-containing organic waste is potassium salt, the crystallization separation is: cooling the concentrated solution to 25-60 ℃ for crystallization to obtain potassium salt.

8. The method of claim 6, wherein, When the total content of sodium salt and / or potassium salt in the filtrate obtained by mechanical filtration is less than 15wt%, the filtrate is recycled as quenching water for quenching. The condensed water produced by the reduced-pressure distillation is recycled as quenching water for quenching.

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