Gasification high-flash gas recovery device
Through the combined device of the water washing tower, low-temperature methanol washing section and methanol washing tower, the problem of direct CO and H2 emissions during high-pressure coal gasification is solved, and the recycling of high flash gas is realized, and carbon emissions and gas waste are reduced.
Patent Information
- Application Number
- CN202421419815.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-06-20
- Publication Date
- 2025-07-04
- Estimated Expiration
- 2034-06-20
AI Technical Summary
During the process of high-pressure coal gasification, the combustible gases CO and H2 generated by step-by-step flashing of high-temperature black water are directly discharged to the torch system, resulting in gas waste and increased carbon emissions.
The combination device of water washing tower, low-temperature methanol washing section, water separation tower and methanol washing tower is adopted to remove dust through water washing, condense and separate the low-temperature methanol solution, combine heat exchanger and air cooler to cool, and circulating air compressor to boost the gas, realize the recycling and utilization of gas.
Effectively recover CO and H2 in high flash gas, reduce carbon emissions, avoid gas waste, and simplify the processing process.
Smart Images
Figure CN223060924U_ABST
Abstract
Description
Technical Field
[0001] The utility model belongs to the technical field of gas recovery equipment, and particularly relates to a gasification high flash gas recovery device. Background Technique
[0002] The Texaco coal water slurry high-pressure gasification technology is an advanced gasification technology, which uses coal water slurry as raw material for gasification reaction. The main features of this technology include a relatively wide adaptability to coal, the ability to utilize pulverized coal, a relatively large production capacity of a single gasifier, a high gasification operation temperature, liquid slag discharge, a high carbon conversion rate, good gas quality, a low methane content, and no generation of pollutants such as tar, naphthalene, and phenol.
[0003] During the high-pressure gasification process, a large amount of high-temperature black water is generated by the entire gasification device. After the high-temperature black water is cooled by stepwise flashing, the finally lower-temperature black water is discharged to a sedimentation tank for sedimentation and treatment. A large amount of saturated steam with different pressures is generated during the stepwise flashing of the high-temperature black water. These saturated steams contain a large amount of dust, corrosive media, combustible gases and other non-condensable gases.
[0004] After the black water enters the high-pressure flash tank, a large amount of combustible gas and other non-condensable gases are flashed out, which contain effective gases CO and H2. This part of the gas is discharged to the flare for combustion in the original design, resulting in a large loss of recoverable gas and an increase in carbon emissions. Content of the Utility Model
[0005] Aiming at the above existing problems, the purpose of the utility model is to provide a gasification high flash gas recovery device, which can effectively recover CO and H2 in the high flash gas, reduce costs and increase efficiency while reducing carbon emissions.
[0006] The technical solution of the utility model is as follows:
[0007] A gasification high flash gas recovery device includes: a water washing tower, to which the high flash gas is connected, and the water washing tower is used to wash the dust in the high flash gas; a low-temperature methanol washing section, including a methanol sprayer and a water separation tank connected in sequence to the gas-phase output end of the water washing tower. The methanol sprayer is used to mix the water and methanol contained in the gas output from the water washing tower to form a methanol solution, and the water separation tank is used to condense the methanol and water in the gas output from the methanol sprayer; a water separation tower, whose input end is connected to the liquid-phase output end of the water separation tank, and the methanol aqueous solution output from the water separation tank is heated in the water separation tower. Methanol is output from the top of the water separation tower, and the waste water at the bottom of the water separation tower is discharged to a sewage station; a methanol washing tower, whose input end is connected to the output end of the water separation tank, and is used to merge the output gas with the process gas in the original process in the methanol washing tower.
[0008] Further, a heat exchanger is provided on the pipeline connecting the methanol sprayer and the water separation tank. The heat exchanger is used to cool the methanol solution output by the methanol sprayer. After passing through the sprayer, the temperature of the methanol solution is relatively high, and it is necessary to transfer its heat to a cooling medium, such as water or air, through the heat exchanger. In this process, the temperature of the methanol solution will drop, while the temperature of the cooling medium will rise. In this way, the cooling of the methanol solution can be achieved.
[0009] Further, the methanol solution is cooled to below 0 degrees to keep the methanol solution in a liquid state.
[0010] Further, it also includes a recycle gas compressor, the input end of which is connected to the gas-phase output end of the water separation tank and is used to pressurize the gas output by the water separation tank. The gas-phase output end of the recycle gas compressor is connected to the input end of the methanol scrubbing tower. The characteristics of the recycle gas compressor mainly include high efficiency, stability, and reliability.
[0011] Further, it also includes an air cooler, the input end of which is connected to the high-flash gas outlet of the high-pressure flash tank and is used to cool the high-flash gas. The output end is connected to the input end of the water scrubbing tower. The air cooler is an efficient cooling device that has a wide range of applications in many fields. And compared with traditional cooling methods, the air cooler has more advantages.
[0012] Further, the methanol aqueous solution output by the water separation tank is heated in the water separation tower. This temperature needs to be determined according to the specific chemical reaction equation and the required methanol purity. The main purpose of heating is to enable better separation of methanol and water. Since the boiling point of methanol is higher than that of water, during the heating process, methanol will evaporate first and then higher-purity methanol can be obtained through condensation.
[0013] Compared with the prior art, the beneficial effects of the present utility model are as follows:
[0014] After the high-flash gas of the present utility model is cooled by the original air cooler, the saturated steam contained therein condenses, and the remaining non-condensable gas is basically CO and H2. Then, the dust contained in this part of the gas is removed through the water scrubbing tower; the gas after being washed by water is sent to the low-temperature methanol washing section, and a methanol sprayer is added to the pipeline to mix the water and methanol contained in the process gas to form a methanol solution; the methanol solution is cooled to below 0 °C, and then a water separation tank is added, and the methanol and water in the gas are condensed. The condensed methanol aqueous solution is sent to the water separation tower of the low-temperature methanol washing section, and the clean gas is sent to the purification recycle gas compressor, thereby realizing the recycling of the gas.
[0015] The utility model not only has simple structural equipment, but also has a short treatment process flow, can efficiently recover the useful gas in the gasified high flash gas, and avoids the phenomenon of waste of useful gas caused by the direct discharge of CO and H2 contained in the original high flash gas into the flare system. BRIEF DESCRIPTION OF THE DRAWINGS
[0016] Figure 1 It is a schematic diagram of the device according to Embodiment 1 of the utility model;
[0017] Figure 2 It is a schematic diagram of the device according to Embodiment 2 of the utility model;
[0018] Figure 3 It is a schematic diagram of the device according to Embodiment 3 of the utility model DETAILED DESCRIPTION OF THE EMBODIMENTS
[0019] The following combines the attached Figures 1-3 drawings to describe the specific embodiments of the present utility model in detail. In the description of the present utility model, it should be understood that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present utility model.
[0020] The terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features; in the description of the present utility model, unless otherwise specified, the meaning of "plurality" is two or more.
[0021] Embodiment 1
[0022] During the high-pressure coal gasification process, a large amount of saturated steam with different pressures is generated during the step-by-step flashing of high-temperature black water. These saturated steams contain a large amount of dust, corrosive media, combustible gases and other non-condensable gases. When the black water enters the high-pressure flash tank, a large amount of combustible gases and other non-condensable gases are flashed out, which contain useful gases CO and H2. In the original design, this part of the gas was discharged to the flare for combustion, resulting in the loss of a large amount of recoverable gas and an increase in carbon emissions. In order to efficiently recover the useful gas in the gasified high flash gas, the phenomenon of waste of useful gas caused by the direct discharge of CO and H2 contained in the original high flash gas into the flare system is avoided.
[0023] As Figure 1A gasification high flash gas recovery device shown in the figure includes: a water washing tower, a low-temperature methanol washing section, a water separation tower, and a methanol washing tower. The high flash gas is connected to the water washing tower, and the water washing tower is used to wash the dust in the high flash gas; the low-temperature methanol washing section includes a methanol sprayer and a water separation tank that are sequentially connected to the gas-phase output end of the water washing tower. The methanol sprayer can ensure that the water mist evenly covers the entire space inside the tower, improving the dust removal efficiency. Moreover, the methanol sprayer is used to mix the water and methanol contained in the gas output from the water washing tower to form a methanol solution. The water separation tank is used to condense the methanol and water in the gas output from the methanol sprayer; the input end of the water separation tower is connected to the liquid-phase output end of the water separation tank. The methanol aqueous solution output from the water separation tank is heated in the water separation tower. Methanol is output from the top of the water separation tower, and the wastewater at the bottom of the water separation tower is discharged to the sewage treatment station; the input end of the methanol washing tower is connected to the output end of the water separation tank, and is used to merge the output gas with the process gas in the original process in the methanol washing tower.
[0024] A heat exchanger is provided on the pipeline connecting the methanol sprayer and the water separation tank. After the methanol solution passes through the sprayer, its temperature is relatively high, and it is necessary to transfer its heat to a cooling medium, such as water or air, through the heat exchanger. In this process, the temperature of the methanol solution will drop, while the temperature of the cooling medium will rise. In this way, the temperature reduction of the methanol solution can be achieved.
[0025] Embodiment 2
[0026] As Figure 2 shown, the difference from Embodiment 1 is that in this embodiment, the heat exchanger is used to cool down the methanol solution output from the methanol sprayer to ensure that the methanol solution is cooled to below 0 degrees Celsius to ensure that the methanol solution remains in a liquid state.
[0027] And in this embodiment, an air cooler is further included. The input end is connected to the high flash gas outlet of the high-pressure flash tank and is used to cool down the high flash gas. The output end is connected to the input end of the water washing tower. The air cooler is an efficient cooling device that has a wide range of applications in multiple fields. And compared with traditional cooling methods, the air cooler has more advantages.
[0028] Embodiment 3
[0029] As Figure 3 shown, the difference from Embodiment 2 is that this embodiment further includes a recycle gas compressor. The input end is connected to the gas-phase output end of the water separation tank and is used to boost the pressure of the gas output from the water separation tank. The gas-phase output end of the recycle gas compressor is connected to the input end of the methanol washing tower. The characteristics of the recycle gas compressor mainly include high efficiency, stability, and reliability.
[0030] After the high-flash gas is cooled by the original air cooler, the contained saturated steam condenses, and the remaining non-condensable gas is basically CO and H2. Since this part of the gas contains dust, the dust in the gas is removed through a water scrubber; the gas after being washed with water is sent to the low-temperature methanol washing section, and a methanol sprayer is added to the pipeline to mix the water and methanol contained in the process gas to form a methanol solution; the methanol solution is cooled to below 0 °C, and then a water separation tank is added, and the methanol and water in the gas are condensed. The condensed methanol aqueous solution is sent to the water separation tower in the low-temperature methanol washing section, and the clean gas is sent to the purified recycle gas compressor, thereby realizing the recycling of the gas.
[0031] In some embodiments, the methanol aqueous solution output from the water separation tank is heated in the water separation tower. This temperature needs to be determined according to the specific chemical reaction equation and the required methanol purity. The main purpose of heating is to enable better separation of methanol and water. Since the boiling point of methanol is higher than that of water, during the heating process, methanol will evaporate first and then higher-purity methanol can be obtained through condensation.
[0032] The specific embodiments described above further elaborate on the purpose, technical solutions, and beneficial effects of the present invention. It should be understood that the above are only specific embodiments of the present invention and do not limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention are included within the protection scope of the present invention.
Claims
1. A gasification high-flash gas recovery device, characterized in that, Comprising: A water washing tower, to which the high flash gas is connected into the water washing tower, and the water washing tower is used for washing the dust in the high flash gas; The low temperature methanol washing section, including a methanol sprayer and a water separation tank connected in sequence to the gas phase output end of the water washing tower, the methanol sprayer is used for mixing the water and methanol contained in the gas output from the water washing tower to form a methanol solution, and the water separation tank is used for condensing the methanol and water in the gas output from the methanol sprayer; A water separation tower, whose input end is connected to the liquid phase output end of the water separation tank, methanol is output from the top of the water separation tower, and the waste water at the bottom of the water separation tower is discharged to the sewage treatment station; A methanol washing tower, whose input end is connected to the output end of the water separation tank, and is used for merging the output gas with the process gas of the original process in the methanol washing tower.
2. The gasification high flash gas recovery device according to claim 1, wherein, A heat exchanger is provided on the pipeline connecting the methanol sprayer and the water separation tank, and the heat exchanger is used for cooling the methanol solution output from the methanol sprayer.
3. The gasification high-flash gas recovery device according to claim 1, characterized in that, Also comprising: A recycle gas compressor, whose input end is connected to the gas phase output end of the water separation tank, and is used for boosting the gas output from the water separation tank, and the gas phase output end of the recycle gas compressor is connected to the input end of the methanol washing tower.
4. The gasification high flash gas recovery device according to claim 1, characterized in that, Also comprising an air cooler, whose input end is connected to the high flash gas outlet of the high pressure flash tank, and is used for cooling the high flash gas, and the output end is connected to the input end of the water washing tower.