Study: Huge potential for carbon storage in China

Oct 14, 2009 - Elaine Kurtenbach - The Associated Press

SHANGHAI - China has ample potential capacity to store carbon dioxide from burning coal underground and offshore, an international team of scientists say in a report released Wednesday that suggests the option may be less costly than expected.

A largely untested technology known as carbon capture and sequestration involves capturing carbon dioxide emitted from burning coal and other fossil fuels and storing it in rock formations deep underground. The aim: to reduce emissions of greenhouse gases that contribute to climate change.

The group of researchers affiliated with Pacific Northwest National Laboratory, in Richland, Washington, say their studies of China's geologic conditions show the country has enough storage capacity for carbon dioxide to meet potential demand for more than a century.

Most locations, they said, are within 100 miles (160 kilometers) of major sources of carbon dioxide emissions such as coal-burning power plants - a fact that could help keep costs lower than expected.

"In dealing with climate change, the more options we have, the better. This is a first step that we hope can stimulate more efforts in this area," Robert T. Dahowski, of the laboratory, which is affiliated with the U.S. Department of Energy, told The Associated Press in a phone interview.

"Carbon capture and storage is a very important part of the portfolio of options to be considered," he said.

Regardless of the geologic potential for carbon capture, the technology is still in its early stages, with many questions yet to be answered, experts caution.

"All work now is just at the experimental level. No one can guarantee there would be no leaks of the carbon dioxide or other environmental damage," said Zheng Hongbo, a geologist who heads the School of Earth Science and Engineering at eastern China's Nanjing University.

"It's a long way from the lab to the commercial market," said Zheng, who is working on a project that would involve converting the carbon dioxide, through chemical processes, into a more stable form for storage.

Dahowski acknowledged that many questions remain. But for China, with its heavy reliance on domestically abundant but heavily polluting coal to generate electricity, carbon capture is likely to be an important component of future energy policy, he said.

China is the world's second-biggest energy consumer after the United States and the biggest producer of gases that scientists say are changing the climate, though its emissions are lower on a per capita basis due to its huge population of 1.3 billion.

Ahead of a global climate summit in Copenhagen in December, Chinese President Hu Jintao promised in a Sept. 22 speech at the United Nations to make "substantial reductions in China's carbon dioxide emissions per unit of economic output.

The U.S. Energy Department, which helped support the research study released Wednesday, is considering as many as seven projects that would capture and put into the ground at least 1 million tons of carbon dioxide a year.

Working with researchers at the government-affiliated Chinese Academy of Sciences, the Pacific Northwest National Laboratory team surveyed potential deep geological formations underground and offshore. The researchers mapped locations of key sources of carbon dioxide emissions; studied the needs for pipelines to connect them with storage locations; and evaluated the likely costs of pumping those gases to the possible storage sites.

In some cases, the report says, costs of storing the carbon dioxide underground would be outweighed by profits from recovery of not-yet-recovered gas and oil in partially depleted reserves, it said.

The study, which took five years to complete, focused on 1,623 major sources of carbon dioxide emissions, including 629 coal- and oil-fired power plants accounting for nearly three-quarters of all stationary emissions of the gas.

Other major sources include hundreds of cement and ammonia factories, iron and steel mills and refineries.

Such facilities emit more than 3.8 billion metric tons of carbon dioxide a year, mostly from burning coal, the report said.

Developing ways to capture those emissions is a priority, said Huang Bin, an expert working on a carbon capture and sequestration program affiliated with China Huaneng Group, one of the country's major power companies.

"Ultimately, it's the trend and it's the responsible thing to do, but China has a long way to go," he said.

China Huaneng has installed equipment to capture carbon dioxide from a coal-fired power station in Beijing, and another, able to capture about 100,000 tons of carbon dioxide a year, in Shanghai.

For now, though, the carbon dioxide is being refined for use by the food and beverage industry, Huang said.

Associated Press researcher Ji Chen contributed to this report.