China's push to turn coal into cleaner-burning fuel will have serious consequences for climate change, environmental experts warn.
The government has pledged to cut smog in Beijing and over 300 other cities with a five-year action plan that would curb coal consumption in urban areas.
High-polluting coal now accounts for 68 percent of China's energy, the Ministry of Environmental Protection said last month.
But some new projects appear to be aimed at making use of more coal rather than reducing consumption.
On Oct. 6, officials in the Xinjiang Uighur Autonomous Region announced plans for a giant coal gasification project with investment of 183 billion yuan ($29.7 billion), the official Xinhua news agency reported.
The project in the Zhundong area of Changji Hui Autonomous Prefecture is intended to produce 30 billion cubic meters (1 trillion cubic feet) of gas, using 90 million tons of coal annually, Xinhua said.
It would be the biggest such project in China to date.
The volume of gas is about three times the amount consumed by Beijing last year, based on figures from Platts energy news service and the National Development and Reform Commission (NDRC).
The gas would be pumped by pipeline to the eastern and coastal provinces of Zhejiang and Guangdong, creating at least 18,000 jobs, according to Xinhua.
Trading one set of problems for another
Such projects may ease the urban smog crisis in cities like Beijing, which plans to replace all its coal-fired power plants with gas-fueled generation by 2015.
But the process of creating synthetic natural gas (SNG) from coal may only be trading one set of pollution problems for another, warns Robert Jackson, a professor and director of Duke University's Center on Global Change in Durham, North Carolina.
Turning coal into SNG requires high temperatures and pressures, using large amounts of energy in a low-oxygen environment, said Jackson in an interview.
"You're cooking the stuff, basically," he said.
"In the process of gasifying coal you can strip out sulfur and other pollutants," said Jackson. "But as a consequence, you're using much more energy in a carbon dioxide-producing process."
Building the largest SNG industry in the world
In a recent paper for the journal Nature Climate Change, Jackson and research scientist Chi-Jen Yang said China is building the largest SNG industry in the world with over 40 proposed projects that would produce some 200 billion cubic meters of gas per year.
That amount is nearly double the volume that China produced and 36 percent more than it consumed from all sources last year, according to official figures.
More global warming emissions
"Even if only part of these announced plans will be implemented, the consequences for energy and the environment in China would be substantial for decades," the authors said.
The heavy investment in SNG projects means the plants would be operating for the next 40 years. Over that lifespan, SNG production would emit about seven times more greenhouse gases than using conventional natural gas, said the study.
If SNG is used to generate electricity, it would produce 36-82 percent more global warming emissions that burning coal for power, it said.
Cost to western regions
In addition to climate change consequences, the SNG push may raise questions about creating environmental benefits in eastern cities at the cost of pollution in distant western regions.
Even before the Zhundong investment was announced, three of the nine SNG projects approved by the government so far were located in Xinjiang.
Jackson said shifting pollution may be a factor but that pipelines allow energy resources to be transported more easily, once coal is converted into SNG.
An abiding commitment to coal
The SNG drive may also be a sign of China's abiding commitment to coal as its primary resource, despite the government's plan to reduce its use in and around cities.
"Coal is abundant in China and there are a lot of local interests in the provinces that are driving coal use," Jackson said. "It's about pollution, but it's also about energy security and money."
Under the government's five-year action plan, China would reduce coal's share of total energy use, but only from 68 to 65 percent by 2017, leaving it as the dominant fuel.
The newest SNG project for Xinjiang would tap into massive resources. The Zhundong area has estimated coal reserves of 390 billion tons, Xinhua said.
In addition to air quality and climate change consequences, China's SNG projects are also expected to use large amounts of water, a problem in arid areas.
Nearly all the projects approved by the government so far are in Inner Mongolia and Xinjiang.
The Duke study estimated that the nine approved projects will use over 200 million tons of water annually.
It concluded that "SNG production could worsen water shortages in areas already under significant water stress."
While it is unclear from the Xinhua report what technology will be used for the Zhundong venture, some Chinese experts have raised similar concerns about gasification projects in the past.
Many gasification facilities in China use an early-stage technology, consuming large amounts of coal and emitting carbon dioxide and waste water, said Gong Xin, a professor at East China University for Science and Technology, China Daily reported last year.