Can the methanol synthesis tower be made domestically?

There is a gap between the largest contract signed by Hangzhou Linda, 600,000 tons per year, and those abroad.

East China University of Science and Technology has several sets of 200,000 tons in operation. Zhejiang Linda has two sets of 200,000 tons. I heard that one set of 300,000 tons has been delivered. The 600,000-ton horizontal reactor is still being designed.； Basically, Nanjing Guochang has not yet put any large-scale equipment into production, but the tower type is quite distinctive. It is said that it is designing twin towers in series with a single set of up to 900,000 tons. None of these companies have very convincing operating experience, and the Chinese people still need to work hard.

East China University of Science and Technology's 200,000-ton coking unit in Shanghai has been in operation for many years. However, due to the limitation of the shell-and-tube filling factor, the size of a 200,000-ton single tower has reached Φ4000mm. Due to transportation restrictions, it is difficult to further expand the size. Increasing the synthetic pressure can increase production capacity to a certain extent. Hangzhou Linda has three sets of 200,000 tons in operation, Inner Mongolia Tianye (natural gas), Shaanxi Weihua (Texaco coal-water slurry) and Yunnan Qujing (coke oven gas). The 300,000-ton synthesis tower delivered is Dalian Dahua (SHELL). The plate reactor now launched by Nanjing Guochang is similar to the casale. The gas flow method in the tower is different, and it has not yet achieved more than 200,000 tons.

The scale of methanol to be installed now is 600,000 tons or larger! Does it mean that both the process and the equipment have to be imported? By the way, I heard that the synthesis tower process of the 500,000 methanol synthesis tower in Yongcheng, Henan Province is that Topsoe's synthesis tower shell is made in China. Is this true? Can any boss who knows please let me know?

Difficulties in manufacturing synthesis towers (reposted) Technical Difficulties: 1. The methanol synthesis tower basically uses a hot-wall pressure shell. After enlargement, the diameter and wall thickness of the cylinder will increase. However, in my country's current relevant standards, the materials and wall thickness often cannot meet the requirements. If foreign steel grades and standards are used, the manufacturing cost of the equipment will increase significantly and the equipment will lose its competitiveness. Therefore, at this stage, the diameter and pressure level of large-scale domestic equipment have to be limited within a certain range. 2. For the tower types of air-cooled tubes and water-cooled tubes that were common in the past, the manufacturing requirements are very high. Once the diameter increases to 4000-6000mm, the manufacturing difficulty will increase exponentially, not to mention that there is no technology and experience in this area in China so far. 3. The vast majority of raw materials for methanol synthesis in my country at this stage are coal. Since my country's coal production areas are mainly distributed in the inland central and western regions, the diameter of large-scale devices will be limited due to installation, transportation and other issues. 4. Solving the pipelines and valves of large-scale methanol plants is a recognized problem. Therefore, when the daily output is greater than 1,000 tons, the synthesis pressure needs to be increased to 8.0 to 10.0Mpa, or even higher. At the same time, the net alcohol value must be increased to reduce the amount and flow rate of synthesis gas through the pipelines and equipment, and reduce the diameter of the pipelines and equipment as much as possible. 5. After the equipment is enlarged, another important factor is to reduce energy consumption. For the methanol synthesis tower, this requires starting from two aspects. One is to increase the waste heat recovery rate, and the other is to increase the net alcohol value. Both aspects are indispensable. 6. For end users, equipment price is often an important factor that cannot be ignored. In this regard, localized technology may have an advantage over imported technology. However, if equipment and materials rely on imports, and processing and transportation are more difficult, this advantage may be lost.

The manufacturing of the synthesis tower depends on the pressure level, temperature and medium conditions during the process. pressure level: Currently, there are four types of steel stamps issued by ASME in the manufacturing of pressure vessels. The U stamp (ASME Code Volume VIII-1) covers pressure vessels with a pressure not exceeding 3000 psi (207 bar), which basically covers most of the pressure-bearing equipment in petroleum, chemical and petrochemical projects. Judging from the domestically produced ASME stamp products, the U stamp accounts for the vast majority. Therefore, the U stamp is the stamp with the greatest practical value. U2 steel stamp (ASME Code Volume VIII-2, Analysis and Design) provides a more economical solution for large, high-pressure, thick-walled vessels and vessels operating under alternating loads. Due to its high manufacturing requirements and the design documents need to be reviewed by a registered professional engineer (Registered Professional Engineer) in the United States or Canada, domestic enterprises have fewer opportunities to undertake production. So far, only one enterprise has undertaken the U2 steel stamp project. The S steel seal (ASME Code Volume I) includes steam boilers with a pressure greater than 15 psi (1.03 bar) and high-temperature hot water boilers with a working pressure greater than 160 psi (11 bar) and/or high temperature hot water boilers with an operating temperature greater than 250℉ (121 ℃). According to domestic classification, power station boilers and most industrial boilers fall into the S steel seal category. Therefore, it is the first choice steel seal for boiler manufacturing enterprises. The scope of the H stamp (ASME Code Section IV) includes steam boilers with a working pressure not exceeding 15 psi (1.03 bar) and hot water boilers with a working pressure not exceeding 160 psi (11 bar) and/or working temperature not exceeding 250℉ (121℃). According to the information currently available, there are only two domestic companies holding the H steel seal, one of which is a cast iron hot water boiler. In the methanol synthesis process, high pressure, high temperature and hydrogen are contained, so requirements are also placed on the materials of the pressure vessel. In the manufacturing process, materials are a key issue, and cutting and welding are another key issue. At the end of 2005, China's first hydrogenation reactor for a direct coal liquefaction unit was manufactured by First Heavy Machinery Group for Shenhua Company, with a diameter of 5.5 m.

With a length of 62 m, a thickness of 337 mm, and a weight of 2,060 t, it is the largest and heaviest forged-welded structure hydrogenation reactor in the world today. It adopts fully automatic double-wire narrow gap submerged arc welding technology with domestic independent intellectual property rights. Each girth weld requires continuous welding for 5 days. The difficulty of processing can be imagined. Therefore, I think there are several conditions that must be met. First, process autonomy. At present, we can only introduce foreign technology and create it independently. Otherwise, how to make it domestically? For example, the synthesis towers of many companies are not a problem that cannot be built, but a problem of why you are allowed to create them. Second, alloy materials. At present, only Wuyang Steel Plant in China can produce some brands of special steel. If all the materials have to be bought abroad, it is not enough trouble. Or, if you don’t buy it, use the thickest domestic steel plates to make them, which will cause processing difficulties and transportation difficulties. This involves steel smelting. Third, material processing. Once you have the materials, you can’t cut them, and you can’t weld them. This also involves welding machines and welding (you can't just weld with a welding rod), as well as processing tools, testing equipment, etc. Welding is a job that requires experience in addition to theory, and also involves the ability of the personnel. Fourth, catalyst. Catalyst research is actually at the forefront, and industries such as polypropylene were created around the invention of catalysts. Involves basic research. This post was last edited by ouyangjunhua on 2008-2-27 18:42 ]