The six massive silos standing beside this industrial port in northeastern China hold seemingly contradictory promises: They could help improve the quality of China’s polluted air, but they might also contribute to faster global warming.
The silos, which are scheduled to start operation in July, are designed to blend cleaner-burning imported coal with China’s own high-polluting domestic coal, which is contaminated with sulfur and dust.
Coal blending will produce a mixture that will help electric utilities meet China’s steadily tightening environmental regulations. It will also increase the efficiency of coal-fired plants by slightly reducing the quantity of coal needed. Burning less coal means less greenhouse gases emitted.
But critics argue there is a darker side to cleaner coal.
“Anything that makes coal more cost effective, like blending, which is only enabling China to burn more coal, is bad news for the global struggle against carbon emissions,” said Orville Schell, the Arthur Ross director of the Center on U.S.-China Relations at the Asia Society in New York.
The Chinese government’s decision this month to import more coal in order to lessen power outages — and control rising coal prices — ensures that blending will increase rapidly.
Industry executives are quick to tout the practice’s environmental benefits. Blending “is a sound solution to reducing greenhouse gas and pollutants emissions from coal-fired power plants,” said Howard Au, the director and chairman of Petrocom Energy Ltd., which owns the blending facility here.
But environmentalists worry that by reducing the amount of sulfur and dust emitted from burning coal, blending makes coal more acceptable in the short-term and stalls the conversion to cleaner or renewable fuels. They say coal blending strengthens the case for companies — and countries — that want to continue to rely on coal for decades.
“Does it help with acid rain? Yes,” said Allen Hershkowitz, a specialist in Appalachian coal fields at the Natural Resources Defense Council, an environmental group based in New York. “It hurts us when it comes to global warming.”
Coal remains a particularly dirty form of electricity generation when it comes to producing climate-changing gases.
The global warming calculus for coal blending is less clear. Blending makes it easier to feed a power plant with exactly the right coal mixture at which its boilers work most efficiently. This means the plant can burn less coal and emit less greenhouse gas. How much less — and how does that improvement compare with switching to other fuels — varies a lot depending on the power plant and the coal it burns without blending. Better operating efficiency at the power plant helps offset the cost of blending, which can add up to 4 percent to the price tag of the coal.
China does not just have an ancient civilization; it also has a lot of very old coal. Much of it has been tightly compressed over millions of years. That has pluses and minuses.
Chinese coal releases a lot of heat when burned and has very little moisture left, two very desirable features, according to coal traders. But Chinese coal deposits also contain a lot of sulfur as well as so-called fly ash — dust that is not combustible and contributes to particulate air pollution.
China also has some deposits of young coal which has fairly low heat content and requires blending before it can be burned.
China has the third-largest coal reserves, after the United States and Russia, and consumes more coal than any other country. It accounted for nearly half the 7.3 billion metric tons burned around the world last year.
Four-fifths of China’s reserves, however, do not comply with the country’s standards for industrial use, according to the government-run China Coal Research Institute. Complicating matters, the China’s environmental regulators have signaled plans to reduce further the allowable levels of sulfur.
China led the world last year in clean energy investments, with $54.4 billion, according to a study by the Pew Charitable Trusts. But coal is still China’s dominant energy source, accounting for 73 percent of electricity capacity.
Because coal-fired plants run day and night — while alternatives like wind turbines and hydroelectric dams only run when enough wind or water is available — coal accounted for 83 percent of electricity generation last year.
China has led the world in recent years in the construction of high-efficiency coal-fired power plants. These plants heat water to higher temperatures and pressures than earlier designs, so that less coal is burned to produce the same kilowatt-hours of electricity. But the newer power plants need coal of a precise makeup, making it even harder for China to rely exclusively on domestic coal fields.
To meet the needs of the new plants, China has gone on a twin binge of importing coal and buying coal mines abroad. Wood Mackenzie, the global energy consulting company, predicts that Indonesia will be the world’s fastest-growing exporter of coal in the next five years because of Chinese demand.
While coal blending facilities may provide a short-term environmental benefit, they also make it possible for countries like China to plan on consuming a lot more coal for decades into the future.
People have been blending coal for more than a century, often in surprisingly simple ways. Richard Elman, the chairman of the Noble Group, one of the world’s largest commodity companies, is skeptical of newer blending technologies. He says bulldozers have been roughly mixing different grades of coal at power plants and mines for years.
A single coal mine may have different qualities of coal in different seams, and will often stir them together with bulldozers before shipment so as to provide a mixture that better meets the customer’s specifications, he said.
In the United States, big engineering companies like Bechtel and the Roberts & Schaefer subsidiary of KBR have been designing elaborate systems of conveyer belts that take coal arriving by rail and barge and distribute it to various stockpiles, blending it along the way.
The most elaborate approach, developed in Europe and put into effect here, is to build a series of silos, each containing a different grade of coal. A large conveyor belt and scales are mounted underneath the silos. Coal from each silo is sprinkled onto the conveyor belt, and then the mixture is dropped into rail cars, ships or a storage yard.
“It’s not easy for this new technology to be accepted, so I’m using my network because I believe this would be good for the country,” said Li Anqing, the retired top administrator of Lianyungang’s big coal port, who is now the general manager of the operation here.
Bob Williams Jr., the vice president for sales and marketing at Roberts & Schaefer, said that using specially built silos for blending coal is an unusually expensive approach, and would barely be considered except at large coal ports. But Mr. Au said that the blending cost per ton using silos, about $5, had not changed for the last several years.
By contrast, coal prices have doubled in the past five years, to $130 a ton in China for coal with high heat content. So blending costs have halved as a percentage of the overall cost of coal. Those reductions in relative costs, combined with tighter regulations in China aimed at reducing acid rain, have increased its attractiveness.
“Blending didn’t make sense prior to 2003 as prices of coal were low,” Mr. Au said. But now, Petrocom is making plans for dozens of coal-blending facilities in China, to accommodate a flood of imports that could last for decades.
