Customer: Shanxi Jincheng Anthracite Coal Mining Group Co., Ltd.
Location: Jincheng City, Shanxi, China
Scope of engine use: Cat® G3520C
Cat Dealer: WesTrac China Ltd.
Coal mine methane (CMM) is a byproduct of coal formations in subterranean coal seams and is released before or during active coal mining. CMM can be hazardous to miners if not properly managed. Typically, this means venting the CMM into the atmosphere or burning it in a flare. However, methane is a greenhouse gas with more than 20 times the global warming potential of carbon dioxide, so its release into the atmosphere is considered harmful. The Shanxi Jincheng Anthracite Coal Mining Group operates the Sihe coal mine in Jincheng City, Shanxi, China. Rather than vent the CMM from the mine, the Jincheng Anthracite Mining Group decided to look into harnessing the CMM to generate power.
Project development work began in 2003. At the time, CMM-topower generation was a relatively new concept, so a lot of customer education was required. A group consisting of members of the Caterpillar Electric Power sales and engineering team and engine technology experts from Caterpillar Large Power Systems Division spent approximately 12 months laying out the business case and technical solution to the mine management team and government officials. Several large-scale CMM power plants in Australia were used as case studies by the Caterpillar team to demonstrate the project's viability. In 2004, a feasibility study was completed with a U.S. Trade Development Agency grant, paving the way for a 2005 Asia Development Bank loan to finance the development of the project. Caterpillar® won the international competitive bidding in early 2006 and awarded the contract to Cat® dealer WesTrac China Ltd.
The power plant consists of four buildings, each housing 15 Cat G3520C generator sets, integrated Cat paralleling switchgear and controls, and a heat recovery steam generator. To maximize fuel efficiency, each powerhouse is designed with a combined-cycle system that recovers waste exhaust heat to power a 5.5 MW steam turbine, which was delivered by project partner Shanghai Electric Group Co., Ltd. The result is a total system efficiency of more than 80 percent. The completed power plants produce a total of 120 MW of electric power.
The Jincheng installation — the largest CMM power plant in the world — has demonstrated numerous benefits since its formal comissioning in 2008. By capturing the previously vented methane gas and converting it into electricity, the Cat generator sets significantly reduce greenhouse gas emissions while also improving the capacity of the local power grid. The plant provides power to the electric grid that is equivalent to the demand of more than 500,000 Chinese homes. This project has also created hundreds of employment opportunities for the local community in Jincheng and the surrounding areas. The end result is reduced greenhouse gas emissions, a safer mine and more reliable electricity.