A system and method for treating bdo organic waste liquid

Abstract

The application discloses a system and method for treating BDO organic waste liquid, and mainly comprises the following steps: decomposing BDO organic waste liquid to obtain gas small molecules; adding a certain amount of oxygen into the gas small molecules to obtain products by using gasification reaction; separating the products; and electrolyzing water to obtain oxygen for the gasification reaction and hydrogen for sale. The application is a device and method for extracting synthesis gas with lower energy consumption, better impurity separation and large-scale production, and heat is transferred from high-temperature substances to low-temperature substances in the process, so that heat waste is greatly reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of waste liquid recycling treatment, in particular to a system and method for treating BDO organic waste liquid, which uses a gasification method combined with electrolysis of water to produce hydrogen to treat BDO organic waste liquid to achieve maximum recycling rate. BACKGROUND

[0002] BDO, also known as 1,4-butanediol, is an important organic chemical and fine chemical raw material, which can generate various derivatives such as tetrahydrofuran (THF), polytetrahydrofuran (PTMEG), gamma-butyrolactone (GBL), etc. BDO and its derivatives can be widely used in polybutylene terephthalate (PBT), plastics, spandex, polyurethane, pharmaceuticals, cosmetics, etc.

[0003] A large amount of waste liquid containing BDO and sodium salt is generated in the process of producing BDO by Reppe method, which is currently generally incinerated, which will cause low utilization rate and economic benefit and cause environmental pollution, etc. SUMMARY

[0004] In order to overcome the problems existing in the prior art, the purpose of the present application is to provide a system and method for treating BDO organic waste liquid, which can be scaled up for production with lower energy consumption and more syngas, and can recover water and oxygen in the process, greatly reducing the emission of pollutants.

[0005] In order to achieve the above purpose, the present application adopts the following technical scheme:

[0006] A system for treating BDO organic waste liquid, comprising a BDO organic waste liquid fixed bed gasifier 1, the inlet of the BDO organic waste liquid fixed bed gasifier 1 is connected to the BDO organic waste liquid, the outlet of the BDO organic waste liquid fixed bed gasifier 1 is connected to the inlet of the BDO organic waste liquid gas flow bed gasifier 2, the outlet of the BDO organic waste liquid gas flow bed gasifier 2 is connected to the inlet of the product heat exchanger 3, the outlet of the product heat exchanger 3 is connected to the inlet of the heat exchanger 4, the outlet of the heat exchanger 4 is connected to the inlet of the gas-liquid-solid separation tank 5, the top of the gas-liquid-solid separation tank 5 is connected to the waste outlet, the middle of the gas-liquid-solid separation tank 5 is connected to the liquid mixer 8, the bottom of the gas-liquid-solid separation tank 5 is connected to the ash and sodium carbonate outlet, the top of the gas-liquid-solid separation tank 5 is connected to the cold side inlet of the gas heat exchanger 6, the hot side outlet of the gas heat exchanger 6 is connected to the gas compressor 7, the compressed gas is packaged and delivered to the user, the liquid mixer 8 mixes the water separated from the gas-liquid-solid separation tank 5 with fresh water and is connected to the inlet of the electrolytic water hydrogen production system 9, the outlet of the electrolytic water hydrogen production system 9 is connected to the gas-liquid separation tank 10, the oxygen outlet at the top of the gas-liquid separation tank 10 is connected to the inlet of the BDO organic waste liquid gas flow bed gasifier 2, the liquid water outlet at the bottom of the electrolytic water hydrogen production system 9 is connected to the electrolytic water hydrogen production system 9, and the hydrogen produced by the electrolytic water hydrogen production system 9 is taken out from the top of the gas-liquid separation tank 10.

[0007] The separation of synthesis gas and waste gas at the top of the gas-liquid-solid separation tank 5 and the separation of oxygen and hydrogen at the top of the gas-liquid separation tank 10 are achieved by arranging different gas permeation membranes in the gas pipelines in the gas-liquid-solid separation tank 5 and the gas-liquid separation tank 10 according to the different permeation rates of different gases.

[0008] The BDO organic waste liquid fixed bed gasifier 1 is provided with a gasifier nozzle.

[0009] The bottom of the gas-liquid-solid separation tank 5 is provided with a quenching tank and an ash hopper.

[0010] The heat of the BDO organic waste liquid gas flow bed gasifier 2 is transferred to the electrolytic water hydrogen production system 9.

[0011] The heat of the product heat exchanger 3 is transferred to the gas heat exchanger 6.

[0012] The working method of the system for treating BDO organic waste liquid, comprising the following steps:

[0013] Step 1: BDO organic waste liquid is treated by gasification method: the BDO organic waste liquid is introduced into a BDO organic waste liquid fixed bed gasification furnace 1 to decompose macromolecules of the BDO organic waste liquid into small molecules, and the small molecules are introduced into a BDO organic waste liquid gas flow bed gasification furnace 2 to perform a gasification reaction, and the product is cooled by a product heat exchanger 3 and a heat exchanger 4, and separated by a gas-liquid-solid separation tank 5, wherein the top part is synthesis gas and part of methane and carbon dioxide waste generated by the gasification reaction, the part of methane and carbon dioxide waste is discharged, the synthesis gas generated at the top part is heated by a gas heat exchanger 6 and then introduced into a compressor 7 to be compressed and sent to a user, and the bottom part of the gas-liquid-solid separation tank 5 is ash and sodium carbonate solids generated, which are packaged and sold;

[0014] Step 2: hydrogen is prepared by electrolysis of water:

[0015] The water generated by the BDO organic waste liquid gas flow bed gasification furnace 2 is separated by the gas-liquid-solid separation tank 5, introduced into a liquid mixer 8 together with fresh water, and then introduced into a hydrogen production system 9 by electrolysis of water, the gas generated from the hydrogen production system 9 by electrolysis of water is introduced into a gas-liquid separation tank 10, the oxygen separated at the top of the gas-liquid separation tank 10 is introduced into the BDO organic waste liquid gas flow bed gasification furnace 2 as a gasification agent, the hydrogen separated at the top of the gas-liquid separation tank 10 is sold, and the unreacted liquid water in the hydrogen production system 9 by electrolysis of water is separated by the gas-liquid separation tank 10 and then returned to the hydrogen production system 9 by electrolysis of water for continuous reaction.

[0016] In step 1, the gasification reaction is performed at normal pressure, the temperature is 600-1000℃, and the temperature of the synthesis gas after heat exchange by the gas heat exchanger 6 is 300℃.

[0017] In step 2, the efficiency of the water in the hydrogen production system 9 by electrolysis of water into hydrogen and oxygen is more than 68%, and is related to the water feed, the water separated by the gas-liquid separation tank 10 is used as raw material for the hydrogen production by electrolysis of water, if the generated oxygen is not enough to supply the gas flow bed gasification furnace 2 to perform the gasification reaction, a suitable amount of fresh water is added in the liquid mixer 8 according to the oxygen consumption, or a suitable amount of oxygen is directly introduced into the BDO organic waste liquid gas flow bed gasification furnace 2.

[0018] Compared with the prior art, the present application has the following advantages:

[0019] 1. The purpose of the present application is to provide a harmless, reduced and resourceful BDO organic waste liquid treatment system and method, which combines the hydrogen production system by electrolysis of water with the gasification method, increases the recycling of resources, reduces the economic cost, and increases the economic benefit.

[0020] 2. The method for treating BDO organic waste liquid by gasification method in the present application greatly reduces the emission of pollutants compared with the existing incineration method, and significantly improves the environmental protection level and economic efficiency.

[0021] 3、The system for producing hydrogen by electrolysis of water is combined with the gasification method to treat BDO organic waste liquid, heat is maximally utilized, resource recycling is increased, and cost is saved. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 is a schematic diagram of the system of the present application.

[0023] Figure 2 is a flow chart of the method of the present application.

[0024] BRIEF DESCRIPTION OF DRAWINGS

[0025] 1. BDO organic waste liquid fixed bed gasification furnace, 2. BDO organic waste liquid gas flow bed gasification furnace, 3. Product heat exchanger, 4. Heat exchanger, 5. Gas-liquid-solid separation tank, 6. Gas heat exchanger, 7. Gas compressor, 8. Liquid mixer, 9. System for producing hydrogen by electrolysis of water, 10. Gas-liquid separation tank. DETAILED DESCRIPTION

[0026] In order to make the purpose, technical scheme and advantages of the present application more clear and simple, the present application is further described in detail below in combination with the drawings and examples. It should be understood that the specific examples described herein are only used to explain the present application and do not limit the present application.

[0027] As Figure 1 and Figure 2As shown, after the BDO organic waste liquid passes through the BDO organic waste liquid fixed bed gasification furnace 1, the macromolecules of the BDO organic waste liquid are decomposed into small molecules, and the BDO organic waste liquid small molecules enter the BDO organic waste liquid gas flow bed gasification furnace 2 for gasification reaction. A certain amount of oxygen gasification agent is added to make it fully gasify at a temperature of 744℃. Product heat exchanger 3 and heat exchanger 4 are used for cooling, and then enter the gas-solid-liquid separation tank 5 to separate the generated substances. The gas flows out from the top of the gas-solid-liquid separation tank 5, and the sodium carbonate solid and ash flow out from the bottom of the gas-solid-liquid separation tank 5. The synthesis gas enters the gas heat exchanger 6, and after being warmed by the gas heat exchanger 6, it is compressed by the gas compressor 7 and packaged for delivery to the user. The waste discharged from the top of the gas-solid-liquid separation tank 5 is part of the methane and carbon dioxide, and the generated ash and sodium carbonate solid are discharged from the bottom. The water produced by the BDO organic waste liquid gas flow bed gasification furnace 2 is discharged from the middle of the gas-solid-liquid separation tank 5 and mixed with a certain amount of fresh water in the liquid mixer 8, and then enters the electrolytic water hydrogen production system 9. The generated substances are separated by the gas-liquid separation tank 10, and hydrogen and oxygen flow out from the top. The hydrogen is sold, and the oxygen enters the BDO organic waste liquid gas flow bed gasification furnace 2 as a gasification agent to provide energy for the gasification reaction. The unreacted water flows out from the bottom of the gas-liquid separation tank 10 and returns to the electrolytic water hydrogen production system 9 for further reaction. The heat generated by the BDO organic waste liquid gas flow bed gasification furnace 2 is transferred to the electrolytic water hydrogen production system 9, and the heat required by the electrolytic water system is provided by the BDO organic waste liquid gas flow bed gasification furnace. The heat generated by the product heat exchanger 3 is transferred to the gas heat exchanger 6 for warming, achieving full utilization of heat.

[0028] Example 1: The BDO organic waste liquid is introduced into a BDO organic waste liquid fixed bed gasifier 1 at 200℃ and 0.1MPa, the macromolecules of the BDO organic waste liquid are decomposed into small organic molecules of C, H, O, N, etc., and then sprayed into a BDO organic waste liquid gas flow bed gasifier 2 to perform a gasification reaction under the action of oxygen as a gasification agent at 744℃ and 0.7MPa, to generate molecules of CO, CO2, H2, CH4, N2, Na2CO3, NH3, H2O, HCL, etc., which are introduced into a product heat exchanger 3 to perform heat exchange and cooling to 632℃, and then introduced into a heat exchanger 4 to perform further cooling to 33.61℃, and then the product is introduced into a gas-liquid-solid separation tank 5 after two-step cooling, to separate the product, the synthesis gas and waste are discharged from the top of the tank, and sodium carbonate solids and ash are discharged from the bottom of the tank, the synthesis gas at the top of the gas-liquid-solid separation tank 5 is heated to 300℃ by a gas heat exchanger 6, and then introduced into a 5MPa gas compressor 7, and then packaged and sent to a user. The water generated by the BDO organic waste liquid gas flow bed gasifier 2 is discharged from the middle of the gas-liquid-solid separation tank 5, mixed with a certain amount of fresh water in a liquid mixer 8, and then introduced into a 0.6MPa electrolytic water hydrogen production system 9, the amount of fresh water is determined by the amount of oxygen generated by the electrolytic water hydrogen production system, and the electrolytic water hydrogen production system mainly converts water into hydrogen and oxygen, and the conversion rate is 0.8. The hydrogen and oxygen generated by the electrolytic water hydrogen production system 9 and the unreacted water are introduced into a gas-liquid separation tank 10 for separation, the hydrogen and oxygen are discharged from the top of the gas-liquid separation tank 10, the hydrogen is sold, and the oxygen is introduced into the gas flow bed gasifier 2 as a gasification agent to provide energy for the gasification reaction, and the unreacted water is discharged from the bottom of the gas-liquid separation tank 10 and returned to the electrolytic water hydrogen production system 9 for continuous reaction. The heat generated by the temperature in the gas flow bed gasifier 2 is transferred to the electrolytic water hydrogen production system 9, and the heat provided by the gas flow bed gasifier 2 can completely meet the heat required by the electrolytic hydrogen production system 9. The heat generated by the product heat exchanger 3 is transferred to the gas heat exchanger 6 for heating, and the heat provided by the product heat exchanger 3 can completely meet the heat required by the gas heat exchanger 6, so that the heat is fully utilized.

[0029] The results show that the content of synthesis gas in the process of example 1 reaches 64.9%, and the water recovery rate reaches 18.05%.

[0030] The present application adopts a gasification method to dispose of BDO tar residues and residual liquid, compared with the traditional incineration method, no dioxin, nitrogen oxide, sulfur oxide and other gas pollutants are generated in the process, the emission of dust and other gas pollutants is also greatly reduced, and the environmental protection level is significantly improved. Recycling BDO in waste liquid not only reduces the environmental protection pressure of waste liquid treatment, but also brings economic benefits to enterprises, which has important practical significance.

[0031] The application has great economy in treating BDO organic waste liquid by combining the gasification method with the water electrolysis hydrogen production system. The hydrogen produced by the water electrolysis hydrogen production technology is widely used in energy chemical industry, aerospace, pharmaceutical industry, steel metallurgy and other fields. And hydrogen will also have huge market space in transportation, power generation, energy storage and other fields. The produced oxygen can be supplied to the gasifier for use, realizing resource recycling.

Claims

1. A system for treating BDO organic waste liquid, characterized in that: The system includes a BDO organic waste liquid fixed-bed gasifier (1), with BDO organic waste liquid introduced into the inlet of the BDO organic waste liquid fixed-bed gasifier (1). The outlet of the BDO organic waste liquid fixed-bed gasifier (1) is connected to the inlet of the BDO organic waste liquid entrained gasifier (2). The outlet of the BDO organic waste liquid entrained gasifier (2) is connected to the inlet of the product heat exchanger (3). The outlet of the product heat exchanger (3) is connected to the inlet of the heat exchanger (4). The outlet of the heat exchanger (4) is connected to the inlet of the gas-liquid-solid separator (5). Waste gas is discharged from the top of the gas-liquid-solid separator (5). Water separated from the middle of the gas-liquid-solid separator (5) is connected to a liquid mixer (8). Ash and sodium carbonate are discharged from the bottom outlet of the gas-liquid-solid separator (5). The top syngas outlet of the gas separator (5) is connected to the cold side inlet of the gas heat exchanger (6), and the hot side outlet of the gas heat exchanger (6) is connected to the gas compressor (7). After compression, the gas is packaged and sent to the user. The liquid mixer (8) mixes the water separated from the gas-liquid-solid separator (5) with fresh water and connects it to the inlet of the water electrolysis hydrogen production system (9). The outlet of the water electrolysis hydrogen production system (9) is connected to the gas-liquid separator (10). The oxygen outlet at the top of the gas-liquid separator (10) is connected to the inlet of the BDO organic waste liquid flow bed gasification furnace (2). The liquid water outlet at the bottom of the water electrolysis hydrogen production system (9) is connected to the water electrolysis hydrogen production system (9). The hydrogen produced by water electrolysis hydrogen production exits from the top of the gas-liquid separator (10).

2. The system for treating BDO organic waste liquid according to claim 1, characterized in that: The separation of syngas and waste gas at the top of the gas-liquid-solid separator (5) and the separation of oxygen and hydrogen at the top of the gas-liquid separator (10) are achieved by setting different gas permeation membranes in the gas pipelines of the gas-liquid-solid separator (5) and the gas-liquid separator (10), and the separation of different gases is achieved according to the different permeation rates of different gases.

3. The system for treating BDO organic waste liquid according to claim 1, characterized in that: The BDO organic waste liquid fixed bed gasifier (1) is equipped with a gasifier nozzle.

4. The system for treating BDO organic waste liquid according to claim 1, characterized in that: The bottom of the gas-liquid-solid separator (5) is equipped with a quench tank and an ash hopper.

5. The system for treating BDO organic waste liquid according to claim 1, characterized in that: The heat from the BDO organic waste liquid gasification furnace (2) is transferred to the water electrolysis hydrogen production system (9).

6. The system for treating BDO organic waste liquid according to claim 1, characterized in that: The heat from the product heat exchanger (3) is transferred to the gas heat exchanger (6).

7. The method of operating the system for treating BDO organic waste liquid according to any one of claims 1 to 6, characterized in that: Includes the following steps: Step 1: Gasification treatment of BDO organic waste liquid: BDO organic waste liquid is fed into a BDO organic waste liquid fixed bed gasifier (1) to decompose the large molecules of BDO organic waste liquid into small molecules of BDO organic waste liquid. The small molecules of BDO organic waste liquid then enter the BDO organic waste liquid fluidized bed gasifier (2) for gasification reaction. The product heat exchanger (3) and heat exchanger (4) are used to cool down the product. The product is separated by a gas-liquid-solid separator (5). The top of the gasifier contains the syngas produced by the gasification reaction and some methane and carbon dioxide waste. Some methane and carbon dioxide waste are discharged. The syngas produced at the top is heated by a gas heat exchanger (6) and then compressed in a compressor (7) before being sent to the user. The bottom of the gas-liquid-solid separator (5) contains the ash and sodium carbonate solid produced, which are packaged and sold. Step 2: Electrolysis of water to produce hydrogen: The water produced by the BDO organic waste liquid entrained gasification furnace (2) is partially separated in the gas-liquid-solid separator (5) and enters the liquid mixer (8) together with fresh water, and then enters the water electrolysis hydrogen production system (9). The gas from the water electrolysis hydrogen production system (9) enters the gas-liquid separator (10). The oxygen separated at the top of the gas-liquid separator (10) enters the BDO organic waste liquid entrained gasification furnace (2) as the gasification agent for the gasification reaction. The hydrogen separated at the top of the gas-liquid separator (10) is sold. The liquid water that has not been completely reacted in the water electrolysis hydrogen production system (9) is separated by the gas-liquid separator (10) and then returned to the water electrolysis hydrogen production system (9) to continue the reaction.

8. The working method according to claim 7, characterized in that: In step 1, the gasification reaction is carried out at atmospheric pressure and the temperature is 600-1000℃. The temperature of the synthesis gas after heat exchange through the gas heat exchanger (6) is 300℃.

9. The working method according to claim 7, characterized in that: In step 2, the efficiency of converting water into hydrogen and oxygen in the water electrolysis hydrogen production system (9) is over 68% and is related to the water feed. The water separated by the gas-liquid separator (10) is used as the raw material for water electrolysis hydrogen production. If the generated oxygen is insufficient to supply the fluidized bed gasifier (2) for gasification reaction, an appropriate amount of fresh water is added to the liquid mixer (8) according to the amount of oxygen used, or an appropriate amount of oxygen is directly introduced into the BDO organic waste liquid fluidized bed gasifier (2).

Images