Source: China Chemical Industry News
This newspaper (Reporter Zhang Xinggang) The Shell pulverized coal gasification high water-gas ratio transformation low water-gas ratio conversion process implemented by Henan Zhongyuan Dahua Group Co., Ltd. passed the expert appraisal organized by the Henan Provincial Science and Technology Department last week. This achievement replaced the imported high water-gas ratio catalyst with a low water-gas ratio sulfur-resistant conversion domestic catalyst, and transformed the high water-gas ratio conversion process, which not only saved steam consumption, but also reduced the amount of process condensate to be processed, avoided desulfurization, and achieved a major innovation and breakthrough in the sulfur-resistant conversion process.
The carbon monoxide content in the raw gas of Shell pulverized coal gasification is as high as 60%. In order to avoid the occurrence of methanogenic side reactions in the conversion section, the high water-gas ratio conversion process is mostly used in the design. However, this process has problems such as high steam consumption, leakage of toxic and combustible gases, rapid catalyst deactivation, and unstable operation. In order to reduce steam consumption and make the device run safely, stably and for a long period of time, with the assistance of Qingdao Lianxin Chemical Company, Zhongyuan Dahua implemented technical measures such as replacing the device with a low water-gas ratio QDB-04 catalyst and modifying the device pipeline while keeping the original device pipeline and equipment unchanged to the maximum extent, and the device was successfully started at one time.
Compared with before the transformation, the device after the transformation saves steam consumption. The first conversion furnace can convert the process gas with high CO content to a gas composition similar to that of water-coal slurry gasification without adding steam and under mild conditions, which significantly reduces the steam consumption. Before the transformation, the outlet temperature of the conversion furnace operated at around 500℃ for a long time, which brought great hidden dangers to production safety. After the transformation, the outlet temperature basically did not exceed 430℃. The device operation was flexible, convenient and stable, ensuring the safe and stable operation of the equipment. At the same time, it effectively avoided the problem of catalyst desulfurization and widened the range of raw coal selection. In addition, the catalyst after the transformation has a mild use condition and a long service life, which reduces the discharge of process condensate and does not cause methanogenic side reactions.
The successful start-up of Shell's pulverized coal gasification high water-gas ratio sulfur-resistant shift modification unit demonstrated the technical and energy-saving advantages of the low water-gas ratio sulfur-resistant shift process, filling the international gap in the production of methanol from high-CO feed gas under low water-gas ratio shift process conditions. It has opened up a new shift process path for the production of synthesis gas using pulverized coal gasification, which is characterized by stable production and operation, energy saving, and significant environmental protection effects. It has good prospects for promotion and application in the coal chemical industry and related industries.
