Industrial application of LNG production from coke oven gas

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Industrial application of LNG production from coke oven gas Author: Xin Ming Source: China Chemical Industry News Update date: 03-05-2010 The low-temperature separation process requires less investment and offers high efficiency. The project for producing liquefied natural gas (LNG) through the comprehensive utilization of coke oven gas in Hejin, Shanxi, which is led technically by the Institute of Physical Chemistry, Chinese Academy of Sciences, has successfully produced qualified LNG products after 7 days of operation. This is another world first achieved by the Institute of Physical and Chemical Technology, Chinese Academy of Sciences, following the liquefaction and separation of oxygen-containing coalbed methane to produce LNG. Its successful debugging marks another new model for the comprehensive utilization of coke oven gas in China. 　　The new process employs a combined purification method to remove impurities such as sulfur, benzene, naphthalene, tar, CO2, and water from coke oven gas; thereafter, membrane separation is used to extract hydrogen. The methane-rich gas obtained after hydrogen extraction is sent to a liquefaction distillation unit, where qualified LNG is produced through low-temperature distillation. Finally, the LNG flows automatically to the LNG product storage tanks due to the pressure in the distillation tower. 　　Once the facility is put into operation, the LNG produced can be transported to various locations using cryogenic tankers, where it can be used as a fuel for vehicles in place of diesel. The hydrogen generated as a by-product will serve as high-quality raw material for the ammonia synthesis project in the second phase of this initiative. 　　This innovative achievement not only solves the problem of comprehensive utilization of coke oven gas but also helps alleviate the domestic shortage of natural gas. It holds great significance for energy conservation and emission reduction in China’s coking industry. At the same time, it marks the entry into industrial application of a new process for utilizing coke oven gas developed by the Institute of Physics and Chemistry, Chinese Academy of Sciences – the low-temperature separation technology for producing LNG. 　　This project features smooth production processes, low investment costs, good market prospects for its products, no pollution, and excellent economic benefits. It represents an excellent option for coking enterprises to address the issue of comprehensive utilization of coke oven gas, while also contributing to energy savings and the reduction of greenhouse gas emissions. 　　Currently, researchers at the Institute of Physical and Chemical Technology, Chinese Academy of Sciences, are once again striving to reach new heights in the comprehensive utilization of coke oven gas. They are carrying out methanation reactions using the excess hydrogen in coke oven gas, along with carbon monoxide and CO2, to produce methane; this converts the excess hydrogen into methane, which is then used to produce LNG through low-temperature separation. This approach **increases the production of LNG, while any remaining small amount of hydrogen is fed back into the coke ovens for use as fuel. The industrial-scale facility for the comprehensive utilization of coke oven gas through methanation to produce LNG, which is under their overall responsibility, has now entered the implementation phase, with commissioning scheduled for October 2010.