The United States Environmental Protection Agency awarded a task order for a prefeasibility and feasibility study of the potential to develop a methane emissions reduction project utilizing medium quality coal mine methane (CMM) drained and recovered from mines located in the
Songzao coal basin which is situated in Chongqing Municipality of China. Coal mine methane is drained from each of the coal mines operated by Songzao Coal and Electricity Company (SCEC). Presently, six SCEC mines operate in the northern part of the coal basin: the Songzao, Tonghua, Fengchun, Yuyang, Shihao, and Datong. An outlying district of the Fengchun mine is accessed by the Zhangshiba mine shaft which is located in the southern part of the basin far from the northernmost shafts. The Liyuanba mine, which is located even further south, is presently under development on the far southern margin of the Songzao coal basin. Not withstanding their location, the Zhangshiba shaft and the Liyuanba mine will liberate significant volumes of methane as coal is extracted during the period time considered by this study.
CMM is presently being used in the Songzao basin. Some of the gas is metered as it is being used for civil, industrial and commercial purposes, and by SCEC related entities for cooking, heating and power generation. In addition, a sizable but unmetered amount of gas is also used by local farmers and villagers. After civil and industrial consumption has been deducted from production, large quantities of CMM remain unused as it is vented to atmosphere. Three technically feasible options for using the remaining unused gas are considered in this study:
1. LNG Only Option? comprises linking the six mines located in the northern part of the basin, and the Zhangshiba shaft and Liyuanba mine to a gathering and storage system, which will feed CMM to a gas purification and liquefaction system to be located near the Anwen power plant;
2. Power Generation Only Option? entails installing CMM fueled internal combustion power generation facilities at each of the active mines in the northern part of the basin, the Zhangshiba shaft, and the Liyuanba mine to follow when CMM flow is sufficient to provide adequate fuel;
3. Optimized Option? begins by linking the six active mines to a gathering and storage facility, but delays the decision for linking the Zhangshiba shaft and Liyuanba mine until 2013, when CMM production from the southern area can be more accurately determined. A decision to link the southern production into the centralized gas gathering system, thereby executing a LNG only option can be taken, or the gas production can be used to fuel distributed power generation facilities installed at one or both of the southern locations.