CO2 Storage to Produce Water in China

Part of the US China Climate Accord is to Build a Carbon-capture Plant that Creates Water

Among the many shockers in the climate deal announced last week between the United States and China was this: a plan to jointly build a coal plant in China that would store a million tons of carbon dioxide a year and make copious amounts of fresh water.

No one has ever tried to build a carbon-capture plant that creates water; it has only been modeled on computers. Its appearance as one of only a few action items in the historic climate agreement took off-guard even the experts in energy and climate issues in China.

"We haven't been told" about the project, said Jim Wood, the director of the U.S.-China Clean Energy Research Center (CERC), a sprawling consortium of companies and researchers in China and in the United States, including several U.S. national laboratories. "We're waiting to hear what [the Department of Energy] says our role will be."

The White Houseannouncementsaid that "the United States and China will undertake a major carbon capture and storage project in China that supports a long term, detailed assessment of full-scale sequestration in a suitable, secure underground geologic reservoir." Built on equal funding from the two governments and from private industry, it would inject a million tons of CO2 a year into the earth and yield 1.4 million cubic meters of fresh water.

The prospects for such a plant are unclear, given the lengthy delays that have beset other attempts to build carbon-capture plants, including those done in collaboration between the United States and China.

There is an overriding reason for U.S. government and industry to want to help out: China is building coal plants, and the United States is shutting them down.

In order for China to meet the commitment it made last week to have its carbon emissions peak by 2030, it would aid greatly to remove the greenhouse gases before they leave the smokestack. Getting in on the ground floor of these carbon capture and sequestration (CCS) projects could be a source of business for the beleaguered U.S. coal industry and its suppliers.

Kyle Ash, a climate lobbyist at Greenpeace, a consistent critic of clean coal efforts, questioned whether the water the CCS project could produce could justify its substantial hunger for both water and power.

"You have to ask yourself, why isn't this happening on its own in China?" he asked. The answer, he said, is in part that the U.S. coal industry "wants to keep coal around [and] is looking for anyplace they can invest in this and get away with it politically."

Making water from coal

How could a coal plant, and the storing of its carbon, produce water? Several projects are underway to scrub the CO2 from a coal plant's emissions and convert it to a supercritical, fluid state. If this fluid CO2 were pumped more than a mile underground, it could displace water that could then be redirected to the surface, aided by tremendous underground pressure.

How much water such a project could produce, and its quality, depends greatly on where it is located, Wood said. The water could be ready for drinking, or could be a brackish stew that needs desalination before being sent for drinking, for agriculture or, most likely, to meet the thirsty needs of a coal plant.

Water plays a tricky and controversial role in carbon capture and sequestration. Some worry that coal plants, which already use a prodigious amount of water for cooling, could use even more if the plant also attempted to capture carbon. Adding carbon capture to a coal plant can increase water usage by 35 to 95 percent, according to agovernment study.

But anotherstudyby Lawrence Livermore National Laboratory estimated that a state-of-the-art, 1-gigawatt coal plant that returns water to the surface could meet half of its water needs.

Wood, the head of CERC, estimated that the demonstration project called for in the U.S.-China climate agreement might be on the scale of tens of megawatts. That is a small start for a country that is building, on average, a 600-megawatt coal plant every week and a half,accordingto the Climate Central blog.

Water is even more critical because China is building many of its coal plants in the arid north of the country, an area that suffers from water shortages even in the absence of new users.

Many projects, few results

The new plant builds on work that has been quietly occurring between the United States and China for more than a decade. So far, there has been little to show for the effort, but there are signs that this may change.

In July, several Chinese energy giants signed on to play key roles in the development of the Texas Clean Energy Project, a $2.5 billion coal plant to be built outside Odessa, Texas. Slated to break ground next year, it would produce 200 MW of electricity and sequester 90 percent of its carbon.

The project received a $450 million grant from DOE, and part of its engineering and design is to be performed by a subsidiary of China National Petroleum Corp. Also, China Huaneng Group, the largest power generator in China, will assist in planning and operation,accordingto the Texas Clean Energy Project.

Source: E&E Publishing

Read More Related Content On This Topic - Click Here

Media

Taxonomy

• Water Supply
• Governance & Planning