On Aug 27, Southwest Research and Design Institute signed an 800-million-cubic-meter LNG deal with Jiujiang Coal Storage and Transportation Co. The project will be the largest single unit utilizing coke oven gas-to-LNG through methanation in China.
The project adopts the institute’s self-developed patented technology, which can process 100,000 standard cubic meters of coke oven gas per hour, or 800 million cubic meters a year. It makes full use of rich limekiln gas and produces 236,000 tons of liquefied natural gas, mainly for civil use or LNG vehicles.
The project involves a total investment of about 1.2 billion yuan ($196 million), and is expected to be put into operation in July 2014. It can produce 330 million cubic meters of LNG a year, with zero coke oven gas emissions. It will cut emissions of carbon dioxide by 3 million tons a year, sulfur dioxide by 2,420 tons, and dust by 32 tons. All investments will be made back in four years. The project will also have a demonstration and promotion effect in the national development and utilization of coke oven gas.
The institute’s coke oven gas methanation technology is a key project supported by the national science and technology plan. It has the following characteristics. First, the catalyst can help methanation, deoxidization and multi-carbon hydrocarbon conversion. Second, the gas circulation and steam recycling in the methanation process can properly remove methanation reaction heat. Third, it has made innovations on coke oven gas purification, methanation and cryogenic separation. At the same time, the tail gas is rich in hydrogen, and can be purified to 99.99 percent through pressure swing adsorption, which raises industrial added-value. Index of the technology are well above its counterparts in China and abroad, and the project investment is only 30-40 percent of traditional projects. It can conserve energy and reduce emissions, with remarkable economic and social benefits. The institute has already signed deals with dozens of domestic companies, such as Shanxi Sunlight Coking Group and Shanxi Xiangkuang Hengtong, laying a solid foundation for increasing market share.
China is currently the world's biggest coke producer, consumer and exporter, with overall production capacity of more than 360 million tons, accounting for more than 60 percent of global output. The country has more than 2,000 coking companies, which by-produce 89.1 billion cubic meters of coke oven gas a year. Apart from being used in heating, synthesis ammonia and methanol production, or for civil purposes, about 20 billion cubic meters of coke oven gas, which is rich in methane, carbon monoxide, carbon dioxide and hydrogen, is being released without any utilization. The heat value amounts to that of the total natural gas in the first phase of the West-East natural gas transmission project, causing environmental pollution and a huge waste of energy. If 20 billion cubic meters of coke oven gas can be recycled every year, roughly 7-8 billion cubic meters of compressed natural gas can be created every year, the equivalent of 5.2-5.9 million tons of gasoline, thus effectively improving the ratio of natural gas in the energy consumption structure, helping to improve and optimize the energy structure and reducing environmental pollution.