Methanol production methods

Overall, medium-pressure synthesis is generally used more nowadays

Brief overview of industrial methanol production methods: http://bbs.hcbbs.com/thread-193101-1-1.html

The medium-low pressure method is popular nowadays. Based on our company’s cost calculations, the medium-low pressure method results in lower costs.

The production methods of methanol depend mainly on the catalysts used for its synthesis. The current trend is toward medium- and low-pressure processes, but copper-based catalysts are also used; high-pressure processes as well yield good results

In terms of pressure: The high-pressure method is not widely used these days. The low-pressure method offers higher safety levels when it comes to pressure alone, while the medium-pressure method uses a pressure level that lies between the two. For large-scale applications, it requires less equipment compared to low-pressure methods.

Medium and low pressure, cascade synthesis, low cycle ratio, turbine-driven. Energy-efficient and high-performance.

The development of methanol synthesis processes for (monohydric) alcohols has progressed from high-pressure methods to low-pressure methods and then to medium-pressure methods. The high-pressure process is a set of techniques that arose due to limitations associated with catalysts; once low-pressure copper-based catalysts were put into industrial use, the corresponding low-pressure processes were also developed. However, the scale of application for the low-pressure method is relatively small. In an environment where methanol production facilities are becoming larger, and considering factors such as investment and efficiency, the medium-pressure method was developed to increase the pressure. Of course, various processes require corresponding catalysts to function properly. The copper-based catalysts needed in the medium-pressure process must have higher strength and better heat resistance than those used in the low-pressure process; this is because as the reaction pressure increases, while other conditions remain unchanged, the amount of catalyst required decreases, which in turn increases the resistance and thus the intensity of the reaction.

It depends on the annual production volume; if it’s 60,000 to 100,000 tons, low pressure is generally used, while for higher volumes, medium-low pressure or medium pressure is employed.

The medium-pressure method is the trend, as it can more effectively reduce plant construction costs and production costs.

Currently, the medium and low-pressure method is more commonly used

May I ask the original poster, what method do you use to produce methanol? The high-pressure process generally refers to the method of synthesizing methanol using zinc-chromium catalysts at high temperatures and pressures of 300–400°C and 30 MPa. Since the first successful synthesis of methanol using this method in 1923, it has been the standard approach for methanol production around the world for nearly 50 years, with only minor differences in design. For example, there are two main types of heat transfer methods in the methanol synthesis reactor: cold-tube continuous heat exchange and multi-stage cold-jump heat exchange. The flow pattern of the reaction gases can be axial or radial, or a combination of both; there are also processes that produce by-product steam and those that do not. In recent years, China has developed a technology for synthesizing methanol using copper-based catalysts at pressures of 25–27 MPa, with a methanol content of about 4% in the outlet gas, and a reaction temperature of 230–290°C. The ICl low-pressure methanol method is a production technique for methanol that was developed by the British company ICL in 1966. This method broke the monopoly of high-pressure methods for methanol synthesis, representing a significant advancement in methanol production technology. It uses copper-based catalyst of type 51-1, with a synthesis pressure of 5 MPa. The reactors used in this method are of the hot-wall multi-stage cold-jump type, with a simple structure; each catalyst layer is equipped with a diamond-shaped cold-jump gas distributor to ensure even distribution of cold air into the catalyst layer, thereby regulating the temperature inside the reactor. Other types of low-pressure reactors include those developed by the German company Lurgi, as well as the three-phase methanol synthesis system developed by the American Electric Research Institute. In the 1970s, the Sichuan Vinylon Factory under China’s Light Industry Ministry introduced a low-pressure methanol production facility from the French company Speichim, capable of producing 300 tons per day using acetylene waste gas as raw material (using British ICI patented technology). In the 1980s, the Second Fertilizer Plant of Qilu Petrochemical Company adopted a low-pressure methanol synthesis unit developed by the German company Lurgi. The medium-pressure method evolved from the low-pressure method. Due to the low operating pressure in the low-pressure method, the equipment required was quite large, which made it difficult to scale up methanol production. Therefore, a medium-pressure methanol synthesis method was developed, with a pressure of around 10 MPa. This method allows for lower construction costs and lower production costs for methanol. For example, ICL developed a copper-based catalyst of type 51-2, whose chemical composition and activity are similar to those of the low-pressure catalyst type 51-1, though its crystal structure differs. The manufacturing cost of this catalyst is higher than that of type 51-1. Since this catalyst can maintain its efficiency at higher pressures, ICL was able to increase the synthesis pressure from 5 MPa to 10 MPa. The reactors used in this method are also of the four-stage cold-jump type, and their process and equipment are similar to those used in the low-pressure method.