BEIJING: A leading Chinese coal mining firm Lu’an group has built the world’s largest facility to utilize methane gas from coal mines to generate electricity.
The 30 megawatt facility at Shanxi Province in north China is expected to start operation soon. It is capable of utilising 99 percent of methane gas discharged from the coal mine, a government official told Customs Today.
The coalbed methane (CBM) is a common emission during underground mining. Normally, mines liquify the gas into methyl alcohol if it has a concentration higher than 30 per cent; for concentrations between 10 per cent and 20 per cent, it is captured and used to fuel internal combustion engines.
Methane concentrations lower than 10 per cent, which accounts for 81 percent of the gas released during mining, cannot be consumed through direct combustion.
Jia Jian, deputy head of Lu’an Group’s Methane Gas Research Institute, said new technology has helped tackle the problem of how to dispose of the waste gas.
The newly built facility would decompose the gas into carbon dioxide and water under temperatures more than 950 Celsius, and use the heat and steam for power generation.
Jian added the project is expected to help reduce 1.4 million tonnes of greenhouse gases and produce 200 million kilowatt-hours of electricity a year. The project of making waste profitable has a good market potential, Jia said.
Methane gas has been responsible for numerous explosions in the mines in recent times, causing hundreds of casualties in China.
The facility installed at Gaohe Coal Mine has drawn interest from a number of coal mining firms, as the coal industry is facing significant pressure to control carbon emissions as part of government efforts to meet the goal of reducing emissions per unit of gross domestic product (GDP) by 40 to 45 percent from the level in 2005.
By 2013, carbon emissions per unit of GDP dropped by 28.56 percent from 2005.
In the first three quarters of 2014, energy consumption per unit of GDP dropped by 4.6 percent from a year earlier and carbon emissions were down by 5 percent, according to data.
