Center reports significant progress in study of carbon capture technologies 

 

BY ROSE RAGSDALE FOR GREENING OF OIL

Research into capture and storage of carbon dioxide, the world’s most common greenhouse gas, will continue for another five years at the Co-operative Research Centre for Greenhouse Gas Technologies in southern Australia thanks to the extension of funding of the center until 2015.

CO2CRC is one of the world’s leading collaborative research organizations focused on CCS. Led by the Australian government, it counts most of the world’s largest resource companies as members, including Rio Tinto, BHP Billiton, Anglo American, BP, ChevronTexaco, Shell and ConocoPhillips, as well as leading government and university research institutions such as the Lawrence Berkeley National Laboratory in California and the Alberta Research Council in Canada. The center, which received at least A$20 million in support from the Australian government in 2009, has been studying ways to reduce carbon dioxide emissions since 2003. Its researchers are testing applications along the full chain of capture, transport and geological storage of carbon dioxide aimed at overcoming major technical obstacles to large-scale deployment.

Next five years crucial for CCS

Fossil fuels, a leading source of CO2 emissions, currently supply 85 percent of the world’s energy and will continue to be heavily used for many years to come, predicts the International Energy Agency, despite the urgent need to reduce levels of carbon dioxide in the atmosphere.

As a result, carbon capture and storage will become increasingly important in addressing climate change, along with energy efficiency, less carbon-intensive fuels, natural carbon sinks and renewable energy.

“The next five years will be crucial for the global development of CCS as commercial projects begin to come on-stream, both here, through the Federal Government’s CCS Flagship initiative, and overseas,” said Dr. Peter Cook, chief executive of CO2CRC.

“Re-funding is an acknowledgement of the scientific excellence the CRC has brought together, here in Australia and around the globe,” he said July 1.

CO2CRC’s research will play a key role in supporting projects worldwide by helping to identify and effectively use CO2 storage options, reduce the cost of CO2 capture and address public concern about the technology, Cook predicted.

In recent months the center launched a CCS atlas of New South Wales. It also hit the two-year milestone for demonstrating secure storage of 65,000 metric tons of CO2 deep underground beneath about 500 meters of impermeable rock at the A$50 million Otway Basin Project in southwestern Victoria, Australia’s first CO2 storage project.

“We compress the CO2 gas into a liquid and inject it into porous rocks below nonporous strata, trapping it deep underground,” Cook said.

The renewed funding for CO2CRC includes support for a second stage of applied Otway Project research into CO2 storage in saline aquifers and monitoring, as well as continuing work at CO2 capture demonstrations.

Progress in carbon capture tests

CO2CRC’s capture projects, meanwhile, are perhaps its most intriguing work.

Center researchers are working to develop the most cost-effective methods for removing CO2 from the emissions of coal and gas-fired power plants.

Separate trials in Victoria are being conducted in projects at International Power Australia’s Hazelwood power station and at the HRL Mulgrave gasifier site. The pilot projects were launched in 2009. By investigating solvent, membrane and adsorbent systems and evaluating the cost-effectiveness of hydrate formation and cryogenic distillation systems in the removal of carbon dioxide from a range of applications, CO2CRC aims to establish the most cost-effective systems for post-combustion and pre-combustion CO2 capture applications.

Solvents are the current technology widely used for gas separation but membranes and adsorbents have potential advantages in reduced running costs, reduced capital costs or lower environmental impact.

The scientists also are studying process improvements, including energy integration, which CO2CRC studies have shown could reduce the cost of CO2 capture by 25 percent. Capture costs can be as much as 80 percent of the total costs of a CCS system.

CO2CRC said the two sets of trials are showing that the cost of carbon dioxide capture can be reduced and therefore make a substantial difference to overall CCS costs.

For example, membranes similar to high-tech cling wrap can “sieve out” carbon dioxide from waste gases. Developed by Melbourne University chemical engineer Colin Scholes, a CO2CRC research fellow, the membranes can be fitted to existing power plant chimneys where they capture CO2 for removal and storage.

Scholes, who presented his work for the first time in public in June through Fresh Science, a communication boot camp for early-career scientists in Australia, said the membranes are currently being tested on brown coal power stations in Victoria’s La Trobe Valley. 
“The membrane material is specifically designed to separate CO2 from other molecules,” Scholes said. “It acts like a filter and is much more efficient than existing technology. We are hoping these membranes will become an important part of a carbon capture and storage strategy (that) will cut emissions from power stations by up to 90 percent.”

Not only are the new membranes efficient, they are also relatively cheap to produce. “And cheaper systems mean power generators can put them in place much sooner,” Scholes said.

Another crucial aspect of the membranes has been their toughness – a power station chimney is not a friendly environment. “Trials with real flue gas have been essential for the development of material robust enough to handle industrial conditions,” he added.

Other capture technology success

The CO2CRC capture demonstration projects at the Hazelwood power station and the Mulgrave gasifier site are progressing, with test programs at both continuing successfully.

Center researchers said some minor modifications will be undertaken in two of the six rigs this summer. In particular, the commercial solvent used in International Power’s 28-meter capture plant, the largest in Australia, has been replaced with CO2CRC’s UNO solvent and is awaiting clearance for startup.

Researchers say this test will provide very useful data on the commercial application of the potassium carbonate-based solvent, which the center developed and patented.

Lab tests of the UNO solvent suggest advantages in efficiency, cost savings and environmental benefits. Through this trial, the potential advantages are being investigated at an industrially significant scale using plant flue gas.

Part of CO2CRC’s H3 Capture Project at the Hazelwood power station also is testing the UNO solvent in a gas-liquid membrane contactor system, using the novel membranes developed at the center.

CO2CRC also is working with HRL Developments Pty Ltd., an Australia-based public company that developed a new technology called IDGCC, which integrates the drying of wet coal with a gasification combined cycle process for power generation. Center researchers say the HRL technology is particularly suited for combustion of the abundant, high-moisture brown coal available in Victoria and is well suited for pre-combustion carbon capture for sequestration.  

Links of interest

CO2CRC - Leaders in research into Carbon Capture and Storage

CO2CRC research 

Science news from Australia and New Zealand 

Long-term effectiveness and consequences of carbon dioxide sequestration

Contact Rose Ragsdale at roseragsdale@live.com