Smog and the energy structure

The 100-year development history of UCG technology indicates that it could be a good solution for the energy shortage and environmental pollution in China. In fact, the technology has demonstrated the following advantages:

• UCG keeps solid waste underground, so coal gangue and slag will not accumulate on the surface. Coagulation sol formed by solid dust, SO2 and NOx are important components of smog, and they can be eliminated through the UCG treating processes.

• UCG can help to save the operational costs of the long distance transportation of coal, and also reduce losses and pollution during transportation.

• UCG operations require few miners to work underground; therefore it is beneficial for miners' health and safety.

• As the industry chain for UCG is shorter, the capitalized cost is lower, almost the same as the cost on an open pit mine, excluding the costs of CO2 capture. The total cost for UCG including CO2 capture and storage is lower than that for gasification on surface (IGCC), and it can even compete with nuclear power generation.

• From a long-term strategic perspective, UCG will help to ensure the security of energy supply for China, a country rich in coal but short of oil and gas.

• Coal resources can be tapped and used to the maximum.

Although UCG may cause groundwater contamination and land subsidence, there is evidence that such an environmental impact could be avoided and resolved through careful selection of the sites and the adoption of all necessary measures.

The former Soviet Union was the first country in the world to apply the UCG technology in the 1930s. By the 1960s, five industrial UCG bases had been established in the country. They stopped operations with the discovery of abundant oil and gas resources, except the UCG gas station in Angren, Uzbekistan which has been in operation since 1961.

In China, the syngas produced during the industrial UCG tests contains 50-70 percent hydrogen. Britain and Australia have developed technology to convert UCG syngas to hydrogen and then combine it with alkaline fuel cell (AFC) to produce electricity, achieving zero emissions. The European Union has completed an experimental "hydrogen oriented underground coal gasification for Europe (HUGE)" project (with seven countries including Poland). The British government has also made it a requirement that UCG projects must be combined with CO2 capture and storage function. The EU has also put into practice the "UCG & CO2 Storage Project" (in seven countries including Bulgaria).

Zhu Ming is a retired researcher from the Institute of Geology and Geophysics, Chinese Academy of Sciences.

Han Meng is a researcher from the Institute of Economics, Chinese Academy of Social Sciences.

Xu Daoyi works with the Institute of Geology, China Earthquake Administration.

Yu Xuedong is from China University of Mining and Technology in Beijing.

Wang Zuotang is from China University of Mining and Technology in Xuzhou.

Sun Wenpeng is from the China National Nuclear Corporation Beijing Research Institute of Uranium Geology.