May I ask at what pressure methanol is synthesized?

Currently, gasification or natural gas to methanol processes generally use the low-pressure method, namely around 5.0–10.0 MPa

Methanol synthesis is divided into three methods based on the pressure in the synthesis tower: high-pressure, medium-pressure, and low-pressure methods. With the development of synthesis technology, the low-pressure method is now generally used, with pressures ranging from 6 MPa to 10 MPa.

Based on the pressure used, it can be divided into three methods: high-pressure method, medium-pressure method, and low-pressure method. 1. The high-pressure method involves using carbon monoxide and hydrogen, along with zinc-chromium oxide as a catalyst, to synthesize methanol at high temperatures (340–420°C) and high pressures (30.0–50.0 MPa). The use of this method for producing methanol dates back over eighty years; it was the main method for manufacturing methanol in countries around the world before the 1980s. However, the high-pressure method involves excessive production pressure, high energy consumption, complex equipment, and poor product quality. 2. The low-pressure method involves using carbon monoxide and hydrogen as raw materials to synthesize methanol at a low pressure of 5.0 MPa and a temperature of around 275°C, with a copper-based catalyst (Cu-Zn-Cr) being used in this process. This method is the synthetic methanol process that achieved industrialization in the 1970s. The key to the success of the low-pressure method is the use of copper-based catalysts, which are much more active than zinc-chromium catalysts, allowing the methanol synthesis reaction to take place at lower pressures and temperatures. Copper-based catalysts have better selectivity than zinc-chromium catalysts; as a result, less raw material gas is consumed in side reactions, and there are fewer impurities in the crude methanol. However, the equipment is large in size, has a low production capacity, and yields a low yield in methanol synthesis. 3. Medium-pressure method: With the rapid development of the methanol synthesis industry, the scale of new plants is also increasing steadily; there are already facilities in operation with a daily production capacity of over 5,000 tons. If a low-pressure method is used to build such large-scale plants, the large volume of gas to be processed leads to the disadvantages of bulky equipment and high initial investment, as well as difficulties in manufacturing and transporting the equipment. Therefore, in the 1970s, a process for synthesizing methanol using medium-pressure methods was developed. This method, which is based on the low-pressure approach, involves synthesizing methanol at pressures of 5–10 MPa. It successfully overcame the problems associated with high pressures in the high-pressure method regarding equipment and operational challenges. At the same time, it resolved the issues related to the large size of the equipment required for methanol production under low-pressure conditions, as well as the limited production capacity and inability to scale up production; this led to a significant reduction in construction costs and the cost of producing methanol. The key to this method lies in the use of a new copper-based catalyst (Cu-Zn-Al), whose comprehensive utilization efficiency is better than that of the low-pressure method. To ensure a high methanol content in the gas exiting the reactor, a higher reaction pressure is generally used. This post was last edited by mlh517 on 2007-12-6 09:19.]

The pressure used in methanol synthesis is related to the type of catalyst; however, current methanol production plants with a capacity of 600,000 tons typically operate at a medium pressure of 8.3 MPa. At this pressure, the catalyst can function properly, and both the size of the equipment and the diameter of the pipelines are reduced.

The development of catalysts can lead to breakthroughs in chemical engineering technology. High temperature and high pressure are options resorted to when no other alternatives are available; under such conditions, the investment required for equipment materials and similar things is very high. However, if the pressure is too low, the low first conversion rate in methanol synthesis, coupled with the fact that it is a gas-phase reaction, leads to the need for extremely large reaction equipment. Therefore, based on technical and economic considerations, the most cost-effective temperature and pressure values are chosen.

Most methanol production plants today use low-pressure synthesis, with pressures typically ranging from 5.0 to 10.0 MPa! The lower the pressure, the less energy is consumed! Of course, the level of synthesis pressure is also related to the operating pressure of the previous system’s gasifier! But it will never exceed 10 MPa; usually it’s around 8.5 MPa! However, our plant’s gasification furnace operates at 4.0 MPa, with a synthesis pressure of 5.5 MPa! !

At present, the vast majority of international facilities use the low-pressure method to synthesize methanol (with a reaction pressure of 50 kilograms)

Typical low-pressure methods operate at 5-10 MP; I heard that those used in Kasari reach around 8 MP!

Typical low-pressure methods operate at 5-10 MP; I heard that those used in Kasari reach around 8 MP!

Depending on the scale of the installation and taking investment into account, there are those at 50 bar and those above 80 bar

In fact, pressure needs to be considered comprehensively; it is closely related to temperature as well as the catalyst used

The pressure for methanol synthesis also needs to take into account the pressure in the preceding processes, especially gasification; some processes use a pressure of 5 MPa for synthesis, while higher pressures are used in some cases. Hydroformylation is generally carried out at pressures below 12 MPA, and high-pressure processes are now virtually non-existent.

Our company has two synthesis processes, both using diols. 13 MPa and 270 MPa – in both cases, Zhengyuan’s own designed processes and internal components are used. Our company has also installed methanol synthesis furnaces specifically for increasing methanol production, with excellent results. This post was last edited by liuyz79 on 2007-12-14 12:36.]

Due to the high pressures required for ammonia synthesis, glycol is generally produced using medium or high pressure processes. In the early days, when production capacities were below 300,000 tons, processes with a pressure of around 5.0 MPa were used. Nowadays, in order to achieve larger production scales in a single facility, a gasification pressure of 8.7 MPa is employed for capacities of 600,000 tons, with a synthesis pressure of around 7.5 MPa.

Currently, most are at 6-10 MPa, but the specific pressure still needs to be determined in relation to the design scale of the device.

Currently, water-cooled towers generally operate at a pressure of 50 kilograms, while air-cooled ones have a pressure of 80 kilograms. High-pressure systems are quite rare; those with a pressure of over 100 kilograms are mostly of the mixed alcohol type.

Methanol is synthesized using natural gas as a raw material, with a synthesis pressure of around 8.0 MPa, which falls within the medium-pressure range.