CN-224221300-U - Methanol synthesis system with low circulation ratio and low energy consumption

CN224221300UCN 224221300 UCN224221300 UCN 224221300UCN-224221300-U

Abstract

The utility model provides a methanol synthesis system with low circulation ratio and low energy consumption, and belongs to the technical field of methanol synthesis. The utility model adopts two methanol synthesis units connected in series, and removes crude methanol and water generated by the reaction in time through the separation device, thereby reducing the degradation rate of the catalyst and improving the overall operation stability, and simultaneously, the gas after the crude methanol and water are separated by the first separation device enters the second synthesis device, thereby improving the reaction driving force of the second synthesis device, further improving the single-pass conversion rate and reducing the circulation ratio. The methanol synthesis system has ingenious layout of gas connection and cyclic utilization, reasonably mixes fresh synthesis gas and recycle gas in the first synthesis device, separates unreacted gas and then enters the second synthesis device for continuous reaction, obviously improves the single-pass conversion rate and reduces the circulation ratio, and simultaneously enriches unreacted hydrogen through the hydrogen recovery device and returns to the system for reuse to form a high-efficiency circulation system, thereby greatly reducing the energy consumption while reducing the raw material waste.

Inventors

LIU SHENGKAI
WANG CONG
GAO ZHIHUI
LI LU
QU JUNTING
XU JUN
WANG QIAOYI
HU WENJIA
ZHU JUN
XUE MEICHEN
LIN BINBIN
YI SHUPING
LI GUANGSHEN

Assignees

中国天辰工程有限公司

Dates

Publication Date: 20260512
Application Date: 20250413

Claims (10)

1. The methanol synthesis system with low circulation ratio and low energy consumption is characterized by comprising two methanol synthesis units connected in series, wherein each methanol synthesis unit comprises a synthesis device, a separation device and a heat exchange device; The gas inlet of the first synthesis device is connected with a first branch pipeline of the synthesis gas and a circulating gas pipeline, the outlet of the first synthesis device is connected with the inlet of the first separation device through a first heat exchange device, the gas outlet of the first separation device and a second branch pipeline of the synthesis gas are connected with the gas inlet of the second synthesis device together, and the liquid outlet of the first separation device is connected with the flash evaporation device; The outlet of the second synthesis device is connected with the inlet of the second separation device through the second heat exchange device, the air outlet of the second separation device is connected with the circulating gas pipeline and the hydrogen recovery device, the outlet of the hydrogen recovery device is connected with the hydrogen-rich pipeline, the hydrogen-rich pipeline and the fresh synthesis gas pipeline are connected with the synthesis gas pipeline together, and the liquid outlet of the second separation device is connected with the flash evaporation device.
2. The low cycle ratio, low energy consumption methanol synthesis system of claim 1, further comprising an on-line analytical monitoring device for monitoring the inlet gas composition and/or hydrogen-to-carbon ratio of the first synthesis device and/or the second synthesis device.
3. The low cycle ratio, low energy consumption methanol synthesis system of claim 1, wherein a first flow regulator valve is disposed on the hydrogen rich gas conduit and/or a second flow regulator valve is disposed on the syngas second branch conduit.
4. The low-circulation-ratio, low-energy-consumption methanol synthesis system according to claim 1, further comprising an MTO stage methanol stabilizer or a methanol rectification pre-tower, wherein the outlet of the first synthesis device is connected to a bottoms reboiler of the MTO stage methanol stabilizer or the methanol rectification pre-tower via a first heat exchange device.
5. The low cycle ratio, low energy consumption methanol synthesis system of claim 4 wherein the outlet of the second synthesis unit is connected via a second heat exchange unit to a first preheater located at the feed inlet of the MTO stage methanol stabilizer or methanol rectification pre-tower.
6. The low-cycle-ratio, low-energy-consumption methanol synthesis system of claim 1, wherein the methanol synthesis unit further comprises a methanol-wax removal separation device, an outlet of the first synthesis device is connected to an inlet of the first methanol-wax removal separation device via a first heat exchange device, an outlet of the first methanol-wax removal separation device is connected to an inlet of the first separation device via a heat exchange device, and a liquid outlet of the first methanol-wax removal separation device is connected to a flash evaporation device.
7. The low-circulation-ratio, low-energy-consumption methanol synthesis system according to claim 6, wherein the outlet of the second synthesis device is connected to the inlet of the second methanol-wax removal separation device via a second heat exchange device, the outlet of the second methanol-wax removal separation device is connected to the inlet of the second separation device via a heat exchange device, and the outlet of the second methanol-wax removal separation device is connected to the flash evaporation device.
8. The low cycle ratio, low energy consumption methanol synthesis system of claim 1 or any one of claims 6-7, further comprising a hydraulic turbine generator set, wherein the liquid outlet of the separation device and/or methanol de-waxing separation device is connected to the flash evaporation device via the hydraulic turbine generator set.
9. The low cycle ratio, low energy consumption methanol synthesis system of claim 1, wherein the methanol synthesis unit further comprises a drum, the first drum being connected to the first synthesis device and/or the second drum being connected to the second synthesis device.
10. The low cycle ratio, low energy consumption methanol synthesis system of claim 4 wherein the flash unit outlet is connected to the MTO stage methanol stabilizer or methanol rectification pre-tower via a preheater.

Description

Methanol synthesis system with low circulation ratio and low energy consumption Technical Field The utility model relates to the technical field of methanol synthesis, in particular to a methanol synthesis system with low circulation ratio and low energy consumption. Background Methanol is an important organic chemical raw material, solvent and high-quality fuel, and is widely used in the industries of organic synthesis, medicine, pesticide, paint, dye, plastic, automobile, national defense and the like. In recent years, the application of the new field of methanol is continuously expanded, such as the preparation of olefin from methanol and aromatic hydrocarbon from methanol by taking MTO grade methanol as raw materials, and the market demand is greatly increased, and the increasing speed of the existing methanol productivity is difficult to meet the increasing market demand. In China, MTO grade Methanol To Olefin (MTO) is the first most demanding scene downstream of methanol, and demands account for about 60% of the total consumption of Chinese methanol. In addition, in order to achieve the aim of 'double carbon', china releases a series of encouraging policies for preparing and applying green methanol. Under the support of the low-carbon policy, the green methanol has huge potential application market in the scenes of automobile fuel, fuel cells, ship fuel, organic additives and the like. However, the existing methanol production technology has a plurality of problems to be solved urgently, and further development of the methanol industry is severely restricted. In the existing technology for producing methanol, the problems of low reaction conversion rate and large circulation gas amount generally exist, and the existing technology cannot realize efficient conversion in terms of the reaction conversion rate, so that raw materials cannot be fully converted into target products, waste of the raw materials is caused, complexity and cost of subsequent treatment are increased, and the problem of large circulation gas amount brings heavy burden to the operation of the device. At present, the circulation ratio of a large-scale methanol device is generally between 1.6 and 3.5, and finally, the operation energy consumption of the device is high, the high circulation ratio also brings a series of other negative effects, equipment in a synthetic ring needs to bear larger pressure and flow because of large circulation gas quantity, and the size of the equipment is often designed to be larger in order to meet the requirements, so that the manufacturing difficulty and cost of the equipment are increased, and the occupied area of the whole device is greatly increased. At present, the scale of a newly built methanol device is generally more than 200 ten thousand tons/year, the large-scale development of the device makes the problems more remarkable, the development of the methanol technology is severely restricted, the construction and operation production cost of the device is high, and the wide application of methanol and downstream products thereof is also influenced. In view of the foregoing, there is a need to optimize a methanol synthesis system, reduce the recycle ratio and energy consumption, reduce equipment investment, and improve the reaction efficiency. Disclosure of utility model Aiming at the defects in the prior art, the utility model discloses a methanol synthesis system with low circulation ratio and low energy consumption, which improves the single-pass conversion rate and reduces the circulation gas quantity by optimizing the methanol synthesis system, thereby reducing the operation cost and providing technical support for the green and efficient development of the methanol industry. In order to achieve the technical aim, the utility model provides a methanol synthesis system with low circulation ratio and low energy consumption, which comprises two methanol synthesis units connected in series, wherein each methanol synthesis unit comprises a synthesis device, a separation device and a heat exchange device; The gas inlet of the first synthesis device is connected with a first branch pipeline of the synthesis gas and a circulating gas pipeline, the outlet of the first synthesis device is connected with the inlet of the first separation device through a first heat exchange device, the gas outlet of the first separation device and a second branch pipeline of the synthesis gas are connected with the gas inlet of the second synthesis device together, and the liquid outlet of the first separation device is connected with the flash evaporation device; The outlet of the second synthesis device is connected with the inlet of the second separation device through the second heat exchange device, the air outlet of the second separation device is connected with the circulating gas pipeline and the hydrogen recovery device, the outlet of the hydrogen recovery device is connected with the hydrogen-rich pipeline, th