China’s plans to develop coal-to-gas plants as part of efforts to reduce air pollution may pose a threat to water supplies in arid regions, according to a research group involved in climate and energy issues.
“Most of the plants are planned to be built in the west including Inner Mongolia, where China has its main coal production,” Wen Hua, a Beijing-based analyst at the World Resources Institute, said yesterday. The region is “more water-stressed,” and converting coal to gas is a water-intensive process, Wen said by phone.
A spike in pollution that pushed the air quality to “hazardous” levels caused the northeastern city of Harbin to shut schools and grounded flights on Oct. 22. Seven of the 10 Chinese cities with the worst smog in the third quarter were in the Hebei area that surrounds Beijing.
These underscore the urgency of the government’s initiative to combat air pollution in major cities. Pollution is the leading cause of social unrest in China, according to Chen Jiping, a former member of the Communist Party’s Committee of Political and Legislative Affairs.
As of September, the government approved 18 large-scale plants with a capacity to produce 75.1 billion cubic meters of the so-called synthetic natural gas converted from coal, according to data from WRI. If running at full capacity, the plants will consume at least 500 million cubic meters of fresh water annually.
SNG plants require water for cooling, production and to remove contaminants post-production. One cubic meter of SNG requires 6 to 10 liters (1.6 gallons to 2.6 gallons) of freshwater to produce, Washington-based WRI said.
Water competition
To generate the same amount of heat, embedded water consumption of burning such natural gas is about 18 times of that of coal, according to Wen.
More than 76 percent of the planned SNG capacity is where places either compete with other users for limited water supplies or have little water available at all, Wen and analysts Luo Tianyi and Tien Shiao wrote in an analysis on Oct. 23. “Eleven of the approved plants, eight from Xinjiang Province and three from Inner Mongolia, are located in catchments that do not have major reservoirs.”
China’s goal “of deriving 7.5 percent of its energy mix from natural gas by 2015 is boosting demand for the fuel,” Charlie Cao, a Beijing-based analyst from Bloomberg New Energy Finance, said. “The current supply of natural gas isn’t enough, prompting the nation to adopt the method of producing gas from coal.”
Synthetic natural gas plants may also generate more carbon emissions than mainstream fossil fuels, Wen said. Installing desulfurization equipment at power plants would be another measure to rein in air pollution, according to Greenpeace.
Heilongjiang province, of which Harbin is capital, has the lowest desulfurization coverage rates in the nation and one of the highest coal power capacities lacking equipment that helps reduce pollutants, the environmental group said yesterday in a statement.
