The Underground coal gasification (UCG) technology has been attracting the most attention of the world coal industry for its excellent potential economic, environmental and social benefits. Since 1950s, the former Soviet Union, America, Canada, China, Australia, South Africa and other countries have studied and developed the UCG technology. Currently, there are several UCG projects, such as the Australian Linc Energy’s UCG-GTL project, South Africa's UCG power generation project, as well as Chinese ENN's UCG project, are running.
After more than five years of development, the ENN’s UCG project has constructed the pilot underground gasification system ( belong to the State Key Laboratory of the coal-based low-carbon energy, Langfang) and UCG commercialization demonstration base (Wulanchabu city, Inner Mongolia), and established a perfect UCG technology system. Many technological innovations has been made in the carbon dioxide/oxygen gasification technology, the underground combustion surface measurement by the determination of radon, gas generator design and connection of the wells, the prediction and control of the contamination as well. Lots of technological achievements has been made in UCG site evaluation, oxygen-rich gasification process, the processing stabilized control of the underground gasification, and UCG economic evaluation. ENN has applied more than 60 patents related UCG., 14 of them been authorized The ENN’s UCG project has got a number of national policy support and undertaken five national technical tasks.
As of now, it has totally gasified 120,000 tons of coal, the generator powered by UCG syngas run continuously for more than 26 months, the 3# gas generator produced gas stably last for more than 30 months, 4# industrialized gas generator was ignited in October 2012. The cumulative environmental monitoring data during the five-year shows the UCG operation hasn’t contaminated the underground aquifer. The feasibility study of the O2/CO2 underground gasification to produce LNG (liquid natural gas) shows the pre-tax internal rate of return is 19% when the LNG sales price is 2.8￥/Nm3 and the annual production capacity is 2 billion cubic meters of LNG. In the future, ENN will carry out the UCG -LNG commercial project, the total production capacity will be 600 million cubic meters LNG every year.