Methanol washing, purifying and recycling device for synthetic recycle gas
By designing a synthesis recycled gas methanol water washing purification and recovery device in the methanol synthesis reaction system, the system pressure increase and methanol loss caused by inert gas aggregation is solved, efficient recycling and purification of methanol is achieved, and synthesis conversion rate and system stability are improved. sex.
Patent Information
- Application Number
- CN202420930579.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-04-30
- Publication Date
- 2025-02-14
- Estimated Expiration
- 2034-04-30
AI Technical Summary
In methanol synthesis reaction, the aggregation of inert gas causes the system pressure to rise, the partial pressure of the effective gas to decrease, affecting the reaction efficiency, and the high content of effective gas in the exhaust gas cannot be recovered, resulting in methanol loss and unstable operation of the compressor.
Design a synthetic circulating gas methanol water washing purification and recovery device. By connecting an air cooler, a water cooler and a crude methanol separator at the bottom of the synthesis tower, and performing gas-liquid separation and purification treatment in the methanol water washing tower, the methanol in the synthesis gas is recovered. And the purified gas phase is circulated to the synthesis tower.
It realizes efficient recycling and purification of methanol, reduces the circulating gas volume and compression work, improves the synthesis conversion rate, and solves the problems of unstable operation of the compressor and the reduction in the efficiency of the synthesis system.
Smart Images
Figure CN222468563U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the field of methanol water washing purification, in particular to a methanol water washing purification and recovery device for synthetic circulating gas. Background Art
[0002] The methanol synthesis reaction is mainly the reaction of carbon monoxide, carbon dioxide and hydrogen to produce methanol under the action of a catalyst. The single-pass conversion rate of methanol synthesis is low, and the gas after the reaction needs to be recycled, while the inert gas in the synthesis gas does not participate in the reaction. As the inert gas gathers in the system, the pressure of the system will become higher and higher, and the effective partial pressure of the effective gas will decrease, which is not conducive to the entire synthesis reaction. Therefore, it is necessary to discharge a part of the inert gas through the purge gas to achieve a balance of the inert gas in the system. This part of the purge gas has a high content of effective gas. If the methanol carried in the purge gas is not recovered before entering the compressor, it will not only cause the loss of methanol, but also be detrimental to the smooth operation of the compressor. At the same time, it will lead to a high outlet temperature of the crude methanol separator, a decrease in the efficiency of the methanol reaction unit of the synthesis system, carbon accumulation, and an increase in by-products. A series of problems. Utility Model Content
[0003] The purpose of the utility model is to provide a synthesis cycle gas methanol water washing purification and recovery device, which realizes the efficient purification and recovery of methanol in the synthesis cycle gas, and at the same time solves the problems of liquid hammer compressor, reduced efficiency of methanol reaction unit in the synthesis system, carbon accumulation, and increased by-products, thereby ensuring the long-term stable operation of the system.
[0004] The technical solution adopted by the utility model to solve the above problems is as follows:
[0005] A synthesis circulating gas methanol water washing purification and recovery device comprises a synthesis tower, and is characterized in that an air cooler, a water cooler and a crude methanol separator are connected in sequence through pipelines at the bottom of the synthesis tower, the gas phase at the top of the crude methanol separator is connected to the middle and lower part of the methanol water washing tower through a pipeline, and the liquid phase at the bottom of the tower is connected to a subsequent distillation unit; the top of the methanol water washing tower is connected to a circulating gas compressor through a pipeline, and the circulating gas compressor is connected to a raw gas pipeline entering the synthesis tower through a pipeline.
[0006] There are multiple groups of tower plates in the methanol water washing tower, and a gas distributor is set at the inlet. The gas distributor is connected to the tower body of the methanol water washing tower, and consists of a main pipe and several branch pipes with injection pipes or injection holes. The tower plate is located above the gas distributor and below the demister. A boiler water inlet is set between the tower plate and the demister, close to the tower plate, and a demister is set above the boiler water inlet.
[0007] The utility model has the following beneficial effects
[0008] Compared with the traditional technology, the utility model has the following advantages: the synthesis gas is further washed and purified before being recycled into the synthesis system, which not only recovers the methanol in the synthesis gas but also facilitates the stable operation of the compressor and improves the synthesis conversion rate. Based on 300,000 tons of synthesis gas, the circulating gas volume can be reduced by 210,000 Nm 3 / h, it is estimated that the compression work of the circulating gas can be reduced by 11%. At the same time, a series of problems such as high outlet temperature of crude methanol separator, decreased efficiency of methanol reaction unit in synthesis system, carbon accumulation and increased by-products were solved. BRIEF DESCRIPTION OF THE DRAWINGS
[0009] Figure 1 This is a schematic diagram of a methanol water-washing purification and recovery device for synthetic circulating gas according to the utility model;
[0010] Explanation of the accompanying drawings: synthesis tower 1, air cooler 2, water cooler 3, crude methanol separator 4, methanol water washing tower 5, gas distributor 5-1, tower plate 5-2, demister 5-3, circulating gas compressor 6. DETAILED DESCRIPTION
[0011] The present invention is described in detail below in conjunction with the accompanying drawings.
[0012] like Figure 1 As shown, a synthesis circulating gas methanol water washing purification and recovery device, at the bottom of the synthesis tower 1, an air cooler 2, a water cooler 3 and a crude methanol separator 4 are connected in sequence through pipelines, the top gas phase of the crude methanol separator 4 is connected to the middle and lower part of the methanol water washing tower 5 through a pipeline, and the bottom liquid phase is connected to the subsequent distillation unit; the top of the methanol water washing tower 5 is connected to the circulating gas compressor 6 through a pipeline, and the circulating gas compressor 6 is connected to the raw gas pipeline entering the synthesis tower 1 through a pipeline.
[0013] The crude methanol separator 4 is located before the methanol water scrubber 5 and is a gas-liquid separation container structure. Its function is to separate methanol from the mixed gas so that the methanol content in the mixed gas reaches the final requirement. The structure of the crude methanol separator 4 generally consists of a feed part, a separation part and an exhaust part. The gas phase is connected to the methanol water scrubber 5, and the liquid phase is the separated crude methanol to the subsequent distillation unit.
[0014] In order to reduce the inlet temperature of the refined methanol separator 4 to 40° C., an air cooler 2 and a water cooler 3 are arranged before the refined methanol separator 4 .
[0015] The methanol water washing tower 5 adopts a tower structure containing multiple groups of tower plates, with an air outlet at the top, an air inlet at the middle and lower part, and a liquid discharge port at the bottom, and the liquid is discharged to the subsequent distillation unit.
[0016] A plurality of trays 5-2 are arranged in the methanol water washing tower 5, and a gas distributor 5-1 is arranged at the inlet. The gas distributor 5-1 is connected to the tower body of the methanol water washing tower 5, and is composed of a main pipe and a plurality of branch pipes with injection pipes or injection holes. The tray 5-2 is located above the gas distributor 5-1 and below the demister 5-3. The number of trays is determined by process calculations such as gas processing volume and concentration. A boiler water inlet is arranged between the tray 5-2 and the demister 5-3, near the tray 5-2. A demister 5-3 is arranged above the boiler water inlet, and the demister 5-3 is located above the tray 5-2 at a distance of more than 1m. The type of demister is not limited to the wire mesh demister and fiber bed demister commonly used in the industry.
[0017] The raw gas enters the synthesis tower 1 for chemical reaction. Since the reaction is an exothermic reaction, the synthesis gas leaving the tower is as high as about 200°C, so it needs to be cooled.
[0018] The gas after the synthesis reaction first enters the air cooler 2 to reduce the temperature to about 60°C, and then enters the water cooler 3 to cool down to 40°C. The cooled synthesis gas enters the crude methanol separator 4 for gas-liquid separation. The liquid phase after separation is crude methanol and is discharged to the subsequent distillation process. The separated gas phase enters the methanol water washing tower 5 for further purification and recovery due to the inevitable problem of mist entrainment.
[0019] The gas phase separated by the crude methanol separator 4 enters the methanol water washing tower 5 from the middle and lower part, and the gas distributor 5-1 evenly sprays the gas phase into the methanol water washing tower 5, which is conducive to the full contact between the gas and liquid phases and improves the washing efficiency. After further demisting and purification by the tower tray 5-2 and the demister 5-3, part of the purified gas phase is discharged as the purge gas, and part of it is processed by the circulating gas compressor 6 and enters the synthesis tower 1 for circulation treatment.
Claims
1. A synthesis cycle gas methanol washing purification and recovery device, comprising a synthesis tower (1), characterized in that The bottom of the synthesis tower (1) is connected to an air cooler (2), a water cooler (3) and a crude methanol separator (4) in sequence through pipelines; the gas phase at the top of the crude methanol separator (4) is connected to the middle and lower part of a methanol water washing tower (5) through a pipeline, and the liquid phase at the bottom of the tower is connected to a subsequent distillation unit; the top of the methanol water washing tower (5) is connected to a circulating gas compressor (6) through a pipeline, and the circulating gas compressor (6) is connected to a raw gas pipeline entering the synthesis tower (1) through a pipeline; A plurality of tower plates (5-2) are arranged in the methanol water washing tower (5), and a gas distributor (5-1) is arranged at the inlet. The gas distributor (5-1) is connected to the tower body of the methanol water washing tower (5), and is composed of a main pipe and a plurality of branch pipes with injection pipes or injection holes. The tower plate (5-2) is located above the gas distributor (5-1) and below the demister (5-3). A boiler water inlet is arranged between the tower plate (5-2) and the demister (5-3) and near the tower plate (5-2), and a demister (5-3) is arranged above the boiler water inlet.