Utilization of semicoke tail gas

    2022-05-06 10:05:06

In 2020, the total output of blue carbon exhaust gas in China was about 45 billion cubic meters, of which coal tar hydrogenation consumed about 8 billion cubic meters of blue carbon exhaust gas, accounting for 17.7%. Calcination and reduction in the production of magnesium consume about 8 billion cubic meters of blue carbon tail gas, accounting for 17.7%; Power generation consumes about 29 billion cubic meters of blue carbon tail gas, accounting for 64.6%, forming an installed capacity of about 2,700MW and generating about 19 billion KWH of electricity annually. According to the above data, the main application field of blue carbon tail gas is power generation. The single scale of blue carbon tail gas power generation is relatively small at 30-50MW. The average standard coal consumption of blue carbon tail high temperature and high pressure generator is 405g/degree. It is much higher than the average power supply coal consumption of thermal power units less than 300 g/d in 2025 (including gas power) in the Notice of National Development and Reform Commission and National Energy Administration on Carrying out National Coal Power Unit Transformation and Upgrading [2].
At present, the tail gas of orchid carbon has begun to develop from the traditional raw gas of hydrogen production and fuel gas of power generation to the direction of chemical raw gas. In September 2019, Xinjiang Guanghui launched the project of producing 400,000 tons of ethylene glycol from waste gas byproduct of the 10 million tons of nuomao Lake coal quality utilization (LAN Charcoal) with a total investment of 3.56 billion yuan. The project was contracted by EPC of China's Fifth Ring Project and jointly developed the third generation technology of "WHB syngas to polyester grade ethylene glycol" by Wuhuan, Huasuo and Hebi BMW. Through a series of processes, such as conversion, conversion, low temperature methanol washing, PSA adsorption separation and so on, the high value syngas components H2 and CO in waste gas are extracted, and the high-end chemical product-polyester glycol is produced through carbonylation, hydrogenation and refining technology. This project has set a precedent for large-scale and high value-added utilization of blue carbon exhaust gas. The new generation charcoal furnace being developed by Shenmu Sanjiang company uses pure oxygen to assist combustion. The CONTENT of N2 in the tail gas of charcoal is reduced to 3-5%, CO+H2 in tail gas is more than 65%, and CH4 is more than 20%. It is a high-quality raw material gas for the production of ethylene glycol, methanol and LNG. An enterprise in Shenmu is planning 10 million tons of low-rank coal quality utilization project, and plans to produce 6 million tons of coke, 1 million tons of methanol and 400,000 tons of LNG annually. The project will completely change the concept of traditional LAN charcoal enterprises: first, it is the first large-scale use of low-rank coal pure oxygen internal thermal distillation technology; The second is the large-scale use of blue carbon exhaust to produce high-end chemicals; Three is the use of photovoltaic hydrogen production, as one of the hydrogen sources of syngas; Fourth, all the remaining carbon dioxide is liquefied, and methanol is synthesized with green hydrogen to realize the collection and storage of carbon; Fifth, the whole phenolic ammonia wastewater resource utilization, recovery of ammonia, coal tar and crude phenol. The design, construction and operation of the project will take green factory as the standard, and actively realize land intensification, harmless raw materials, clean production, solid waste resource recovery and low carbonization of energy.