A process system and method for directional preparation of synthesis gas by using industrial organic waste liquid

Abstract

The application discloses a kind of process system and method for preparing synthesis gas by utilizing industrial organic waste liquid, wherein the process system includes combustion unit and gasification unit;The combustion unit includes oxygen supply device and first reactor, so that organic waste liquid and pure oxygen occur incomplete combustion reaction in the first reactor, and generate combustion products with CO and H2O as main components;The gasification unit includes steam generating device and second reactor, so that combustion products and water vapor are heat exchanged and then occur gasification reforming reaction in the second reactor, to promote the conversion of CO and H2O to CO2 and H2, thereby obtaining gasification products with CO and H2 reaching a set ratio.The present application fully realizes the carbon, hydrogen and oxygen resource utilization in industrial organic waste liquid, effectively simplifies the preparation process, and the gasification reaction temperature is relatively low, effectively reduces fuel consumption and equipment investment cost, and the whole process is clean and environmentally friendly, without secondary pollution.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of resource utilization of organic waste liquid, and particularly relates to a process system and method for preparing synthesis gas by using industrial organic waste liquid. BACKGROUND

[0002] The wastewater with high content of organic matter is generally referred to as organic waste liquid, and the sources of the organic waste liquid are very wide, mainly including industrial petroleum chemical waste liquid, metallurgical waste liquid, papermaking black liquor, tanning black liquor, pharmaceutical black liquor, textile printing and dyeing waste liquid, and so on, and also including municipal domestic sewage, pesticide waste liquid, landfill leachate and so on.

[0003] Different organic waste liquids have great differences in composition, form, property and pollutant concentration. The higher the content of organic matter in the waste liquid is, the higher the heat value is generally, and when the heat value is higher than 10500kJ / kg, the waste liquid can be self-sustained in thermal chemical conversion without adding auxiliary fuel, and has potential value of high-value recovery.

[0004] It is well known that the production of high-value chemical products by directional pyrolysis of biomass has become a main way of biomass energy utilization development, and the industrial organic waste liquid belongs to the biomass category in a broad sense, and the preparation of synthesis gas by using the industrial organic waste liquid can realize the maximum utilization of resources, reduce the dependence on existing resources, reduce the demand for fossil energy, and promote resource recycling and sustainable development.

[0005] At present, the method for resource utilization of organic waste liquid mainly uses the organic waste liquid and solid fuel such as raw coal or organic solid waste to prepare slurry, and then makes the slurry and pure oxygen have high-temperature cracking and gasification reaction under high-temperature conditions to generate high-temperature synthesis gas with CO and H2 as main components. The above method needs to cooperate with solid fuel such as raw coal or organic solid waste to prepare coal water slurry, so as to realize gasification treatment, the gasification reaction temperature is relatively high (the highest average temperature of the gasification reaction zone can reach 2000℃), the requirement for equipment performance is relatively high, the energy utilization rate is relatively low, the treatment process is relatively complicated, and the input cost of fuel and equipment is relatively high. SUMMARY

[0006] The present application provides a process system and method for preparing synthesis gas by using industrial organic waste liquid, which can effectively simplify the preparation process, reduce fuel consumption and equipment investment cost.

[0007] The present application provides a process system and method for preparing synthesis gas by using industrial organic waste liquid, which can effectively simplify the preparation process, reduce fuel consumption and equipment investment cost.

[0008] The combustion unit includes an oxygen supply device and a first reactor. The oxygen supply device provides pure oxygen, which causes the organic waste liquid to undergo an incomplete combustion reaction with the pure oxygen in the first reactor to generate high-temperature crude syngas, which is mainly composed of CO and H2O, i.e., the combustion product.

[0009] The gasification unit includes a steam generator and a second reactor. The steam generator produces low-temperature steam, which exchanges heat with the combustion products and then undergoes a gasification reforming reaction in the second reactor. This process promotes the conversion of CO and H2O in the flue gas into CO2 and H2, thereby obtaining gasification products in which CO and H2 reach a set ratio.

[0010] In this invention, the combustion flue gas and low-temperature water vapor first exchange heat and then undergo gasification reforming. On the one hand, this reduces the temperature of the combustion flue gas to reach the preset gasification reaction temperature range. On the other hand, it increases the H2O content in the flue gas to ensure the smooth conversion of CO and H2O to CO2 and H2, ultimately achieving a set ratio of CO and H2 in the final flue gas.

[0011] Specifically, the actual oxygen supply of the oxygen supply device is less than the amount of oxygen required for the complete combustion of organic waste liquid, but not less than the amount of oxygen required for the incomplete combustion of organic waste liquid.

[0012] Specifically, the combustion reaction temperature of the first reactor is in the range of 900℃ to 1100℃ to ensure that the organic waste liquid reacts fully, and the gasification reaction temperature of the second reactor is in the range of 550℃ to 650℃ to ensure that the conversion process of CO and H2O to CO2 and H2 proceeds smoothly.

[0013] Furthermore, the process system also includes a pretreatment unit for treating the organic waste liquid into a combustion raw material with a water content of less than 40% and a calorific value of more than 10,500 kJ / kg, so that it undergoes an incomplete combustion reaction with pure oxygen in the first reactor.

[0014] Furthermore, the pretreatment unit includes a waste liquid tank, a filtration device, and an evaporation and concentration device connected in sequence. The organic waste liquid in the waste liquid tank is pretreated by the filtration device and the evaporation and concentration device before being fed into the first reactor.

[0015] Furthermore, the process system also includes a purification unit for purifying the gasification products to remove residual impurities.

[0016] Furthermore, the purification unit includes a water storage tank and a condenser. The gasification products exchange heat with cooling water through the condenser, and the cooling water after heat exchange is stored in the water storage tank. It is then converted into steam by a steam generator for supply, making full use of water resources and reducing costs.

[0017] Furthermore, the purification unit also includes a pressure swing adsorption device for performing pressure swing adsorption treatment on the condensed gasification products to remove residual H2O and CO2.

[0018] Furthermore, the gasification unit also includes a heat exchanger, through which the steam generated by the steam generator exchanges heat with the combustion products before being introduced into the second reactor.

[0019] Furthermore, this invention also provides a process for the directional preparation of syngas using industrial organic waste liquid, comprising: firstly, incomplete combustion reaction of organic waste liquid and pure oxygen in a first reactor to generate high-temperature crude syngas, i.e., combustion products, with CO and H2O as the main components; then, gasification reforming reaction of the combustion products in a second reactor after heat exchange with low-temperature water vapor to promote the conversion of CO and H2O in the combustion products into CO2 and H2, thereby obtaining gasification products with CO and H2 reaching a set ratio.

[0020] Beneficial effects:

[0021] This invention achieves the directional preparation of syngas from industrial organic waste liquid using two sets of reactors. The organic waste liquid undergoes an incomplete combustion reaction with pure oxygen in the first reactor to generate high-temperature crude syngas with CO and H2O as the main components. After heat exchange with low-temperature water vapor, it undergoes a gasification reforming reaction in the second reactor to promote the conversion of CO and H2O in the flue gas into CO2 and H2, thereby generating terminal flue gas with CO and H2 as the main components for further use by users (synthetic methanol, domestic coal gas, etc.).

[0022] This invention eliminates the need for solid fuel in the preparation of coal-water slurry, fully realizing the resource utilization of carbon, hydrogen, and oxygen in industrial organic waste liquid. It effectively simplifies the preparation process and reduces fuel consumption and equipment investment costs due to the lower gasification reaction temperature. Simultaneously, in the first reactor, N in the industrial organic waste liquid is converted into N2 and discharged, while S and Na are converted into salt-containing components such as sulfate and sodium chloride, which are then transferred to liquid slag under high-temperature conditions. The entire process is clean and environmentally friendly, without generating secondary pollution. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the process system in an embodiment of the present invention;

[0024] The diagram includes: Ⅰ. Pretreatment unit, Ⅱ. Combustion unit, Ⅲ. Gasification unit, Ⅳ. Purification unit, 1. Waste liquid tank, 2. Filtration device, 3. Evaporation and concentration device, 4. Oxygen supply tank, 5. First control valve, 6. First reactor, 7. Heat exchanger, 8. Second reactor, 9. Steam generator, 10. Second control valve, 11. Condenser, 12. Water storage tank, 13. Pressure swing adsorption device, 14. User. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are some embodiments of the present invention, but not all embodiments.

[0026] Reference Figure 1 This embodiment provides a process system for the directional preparation of syngas using industrial organic waste liquid, including a pretreatment unit I, a combustion unit II, a gasification unit III, and a purification unit IV.

[0027] The pretreatment unit I includes a waste liquid tank 1, a filter device 2, and an evaporation and concentration device 3. In this embodiment, the organic waste liquid (raw liquid) in the waste liquid tank 1 has a water content of more than 70%. After being processed by the filter device 2 and the evaporation and concentration device 3, it becomes a combustion raw material with a water content of less than 40% and a calorific value of more than 10,500 kJ / kg.

[0028] Combustion unit II includes an oxygen supply tank 4 and a first reactor 6. The oxygen supply tank 4 is used to supply pure oxygen, so that the pretreated organic waste liquid and pure oxygen undergo incomplete combustion in the first reactor 6 to generate high-temperature crude syngas with CO and H2O as the main components, i.e. combustion products.

[0029] Gasification unit III includes a heat exchanger 7, a second reactor 8, and a steam generator 9. The steam generator 9 is used to generate low-temperature steam (approximately 100℃~150℃). After the high-temperature crude syngas and the low-temperature steam exchange heat in the heat exchanger 7, they undergo gasification reforming in the second reactor 8 to promote the conversion of CO and H2O in the flue gas into CO2 and H2, thereby obtaining gasification products with CO and H2 in a set ratio.

[0030] Purification unit IV includes a condenser 11, a water storage tank 12, and a pressure swing adsorption device 13. The gasification products are condensed and treated by the condenser 11 and the pressure swing adsorption device 13 and can then be used by the user 14. The water storage tank 12 is used to store the cooling water after heat exchange in the condenser 11 (it can also be used for heat preservation to reduce heat loss). The cooling water in the water storage tank 12 is converted into low-temperature steam by the steam generator 9 and supplied.

[0031] Through industrial and elemental analysis, the theoretical oxygen demand for incomplete combustion (main products are CO and H2O) and complete combustion (main products are CO2 and H2O) of organic waste liquid can be determined. Therefore, the actual oxygen supply of oxygen supply tank 4 should be less than the theoretical oxygen demand for complete combustion of organic waste liquid, but not less than the theoretical oxygen demand for incomplete combustion of organic waste liquid, in order to provide the heat required for incomplete combustion of organic waste liquid.

[0032] Specifically, the combustion reaction temperature of the first reactor is controlled within the range of 900℃ to 1100℃ to ensure complete combustion of the organic waste liquid; the gasification reaction temperature of the second reactor is controlled within the range of 550℃ to 650℃. Since the conversion process of CO and H2O to H2 and CO2 is an exothermic reaction, the higher the temperature, the lower the conversion rate. Within the temperature range of 550℃ to 650℃, the conversion rate of CO can reach 65-70%, and the volume ratio of CO to H2 can be controlled at about 1:2.

[0033] Furthermore, the oxygen supply tank 4 can control the amount of oxygen entering the first reactor 6 via the first control valve 5, and the heat exchanger 7 can control the amount of steam entering the second reactor 8 via the second control valve 10. In addition, the steam after heat exchange in the heat exchanger 7 can be supplied not only to the second reactor 8, but also to the evaporation and concentration unit 3 for heat reuse, making full use of the heat generated by the combustion reaction and greatly improving energy efficiency.

[0034] Reference Figure 1 This embodiment also provides a process for the directional preparation of syngas from industrial organic waste liquid, including the following steps:

[0035] S1. Organic waste liquid (raw liquid) with a water content higher than 70% is pretreated (including filtration and evaporation concentration) into a combustion raw material with a water content lower than 40% and a calorific value higher than 10500kJ / kg.

[0036] S2. The pretreated organic waste liquid undergoes incomplete combustion with pure oxygen in the first reactor 6. The reaction temperature is controlled within the range of 900℃~1100℃ to generate high-temperature crude syngas with CO and H2O as the main components, which is the combustion product.

[0037] S3. After heat exchange between high-temperature crude syngas and low-temperature steam, a gasification reforming reaction occurs in the second reactor 8. The reaction temperature is controlled within the range of 550℃ to 650℃ to promote the conversion of CO and H2O into CO2 and H2, thereby obtaining gasification products with CO and H2 in a set ratio.

[0038] S4. The gasification products are then condensed and subjected to pressure swing adsorption treatment before being supplied to user 14 for further use.

[0039] The cooling water, after condensation and heat exchange, can be converted into low-temperature steam, which can then be further exchanged with high-temperature crude syngas and undergo gasification and reforming reactions to achieve full utilization of resources and energy.

[0040] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., 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 process system for the directional preparation of syngas from industrial organic waste liquid, characterized in that, It includes a pretreatment unit, a combustion unit, a gasification unit, and a purification unit; The pretreatment unit processes the organic waste liquid into a combustion feedstock with a water content of less than 40% and a calorific value of more than 10,500 kJ / kg. The combustion unit includes an oxygen supply device and a first reactor. The pretreated organic waste liquid and pure oxygen undergo an incomplete combustion reaction in the first reactor at 900℃~1100℃ to generate combustion products with CO and H2O as the main components. The actual oxygen supply of the oxygen supply device is less than the amount of oxygen required for the complete combustion of the organic waste liquid and not less than the amount of oxygen required for the incomplete combustion of the organic waste liquid. The gasification unit includes a steam generator, a heat exchanger, and a second reactor. The steam generated by the steam generator exchanges heat with the combustion products through the heat exchanger, and then undergoes a gasification reforming reaction at 550℃~650℃ in the second reactor to promote the conversion of CO and H2O into CO2 and H2, thereby obtaining gasification products in which CO and H2 reach a set ratio. The purification unit includes a water storage tank, a condenser, and a pressure swing adsorption device. The gasification products are condensed by the condenser and the residual H2O and CO2 are adsorbed and removed by the pressure swing adsorption device to obtain purified synthesis gas. The cooling water after heat exchange in the condenser is stored in the water storage tank and converted into steam by the steam generator for circulation supply.

2. The process system according to claim 1, characterized in that, The pretreatment unit includes a waste liquid tank, a filtration device, and an evaporation and concentration device connected in sequence. The organic waste liquid is filtered, evaporated, and concentrated to form the combustion raw material.

3. The process system according to claim 1, characterized in that, The steam generated after heat exchange in the heat exchanger is also supplied to the evaporation and concentration device of the pretreatment unit for heat reuse.

4. The process system according to claim 1, characterized in that, The incomplete combustion reaction in the first reactor converts N in the industrial organic waste liquid into N2 and discharges it, while S and Na are converted into sulfate and sodium chloride salt components and transferred to the liquid slag.

5. A process for the directional preparation of syngas from industrial organic waste liquid, characterized in that, Includes the following steps: S1. Pretreatment: The organic waste liquid is filtered, evaporated and concentrated to become a combustion feedstock with a water content of less than 40% and a calorific value of more than 10,500 kJ / kg. S2. Incomplete combustion: The pretreated combustion raw materials and pure oxygen are introduced into the first reactor. The reaction temperature is controlled at 900℃~1100℃ and the oxygen supply is less than the oxygen required for complete combustion of organic waste liquid but not less than the oxygen required for incomplete combustion. Incomplete combustion reaction occurs to generate combustion products with CO and H2O as the main components. S3, Gasification Reforming: The steam generated by the steam generator and the combustion products are passed into a heat exchanger for heat exchange, and then sent to the second reactor and the reaction temperature is controlled at 550℃~650℃ to carry out a gasification reforming reaction to promote the conversion of CO and H2O into CO2 and H2, and obtain gasification products with CO and H2 in a set ratio. S4. Purification cycle: The gasification products are condensed and heat exchanged in a condenser. The cooling water after heat exchange is stored in a water tank and circulated to the steam generator to be converted into water vapor. The condensed gasification products are adsorbed and removed by a pressure swing adsorption device to remove residual H2O and CO2, and purified syngas is obtained. In step S3, the steam after heat exchange in the heat exchanger is also supplied to the evaporation and concentration stage in step S1 for heat reuse.

6. The process method according to claim 5, characterized in that, The incomplete combustion reaction described in step S2 converts N in the industrial organic waste liquid into N2 and discharges it, while S and Na are converted into sulfate and sodium chloride salt components and transferred to the liquid slag.

7. The process method according to claim 5, characterized in that, The gasification reforming reaction described in step S3 is an exothermic reaction. At 550℃~650℃, the CO conversion rate can reach 65-70%, and the volume ratio of CO to H2 can be controlled at about 1:2.

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