Researchers harness greenhouse gases with good microbes, chemistry and attitude

Microbes that convert coal into natural gas; the formation of icy carbon dioxide-hydrates; and public perceptions of carbon capture and storage are three areas of investigation that University of Calgary researchers are pursuing to address the problem of upstream greenhouse gas emissions.

Steve Larter, Mehran Pooladi-Darvish and Edna Einsiedel are each working on innovative research projects that are receiving funding from Carbon Management Canada (CMC), a Network of Centres of Excellence that supports game-changing research to eliminate carbon emissions from the fossil energy industry. The 2011 round of CMC funding will see $10 million awarded to Canadian university researchers working on 18 projects. The coal bioconversion project is supported by a $1.92 million grant from CMC and $150,000 from industry partner, Encana. Another $660,000 from CMC will go to two University of Calgary-led projects: a novel method to store carbon dioxide (CO₂) as a semi-solid gas hydrate ($310,000) and an assessment of attitudes towards carbon capture and storage ($350,000). The decision to fund the projects was made after a rigorous, international peer-review process.

University of Calgary geoscientist Steve Larter is the Scientific Director of CMC and an investigator in an ambitious project to coax communities of microorganisms to convert coal into natural gas, or methane, right in the ground. The methane produced from bioconversion could then be collected for use as a clean-burning fuel.

“What we’re trying to do is decarbonize the use of fossil fuels,” said Larter. “Fossil fuels are not going to go away very quickly, for practical, economic and other reasons, and yet we’ve got to stop emitting all this CO₂ to the atmosphere.”

There are some 50 coal-fired power plants in Canada. Each emits roughly 3 million tons of CO₂ a year. If made economically viable, the bioconversion method could potentially reduce Canada’s net CO₂ emissions by 25 per cent while allowing access to the energy stored in deep, unmineable coal.

Larter and 14 others will work together to investigate bioconversion at the nano-scale through to lab and field scales. Sushanta Mitra, a professor of mechanical engineering at the University of Alberta, is leading the collaboration.

“The challenge is that our understanding of the process is currently confounded by the complexity and variability of coal, the inaccessibility of many coal seams and their associated microbiota, and the lack of knowledge of basic biodegradation systematics and reactant transport in coal,” explained Mitra.

Some team members will study the best environmental conditions for bioconversion and the biochemical pathways that microbes use to degrade coal. DNA analysis will identify which microbial species are at play. The researchers will also use high resolution microscopy to examine the pore structure of coal as well as the microbial-coal interface.

Engineers on the team will design sensors to monitor microbial activity and, using lab experiments and computer modeling, will investigate how nutrients and methane flow through coal. Other contributors will create a plan for a field-scale bioconversion system.

Participating in the three-year study are investigators with the University of Calgary, the University of Alberta, Alberta Innovates - Technology Futures, the University of Western Ontario, New Paradigm Engineering Ltd. and the University of Arizona.

Larter noted that an interdisciplinary approach is critical to the project’s success.

“The problem can’t be solved by a really good geochemist, or just a really good microbiologist, or just a very good engineer,” he said. “We’re trying to build an orchestra.”

In another CMC-funded project, chemical and petroleum engineering professors Mehran Pooladi-Darvish, Hassan Hassanzadeh and their team at the University of Calgary’s Schulich School of Engineering will study a novel method to store CO₂ as a semi-solid hydrate in depleted gas pools. The experimental method could make it possible to securely store CO₂ emissions associated with oil sands in northeast Alberta without the need for long distance transfer.

Gas hydrates occur in nature, typically as molecules of methane (natural gas) locked in water crystals that are buried beneath permafrost or in deep ocean sediments. The University of Calgary method, initiated by Pooladi-Darvish and Olga Zatsepina, would trap CO₂ along with methane as icy gas hydrates in spent gas pools. Because solids take up less room than gases, the gas hydrate storage capacity of depleted gas reservoirs is vast.

The new technology for secure storage of CO₂ as solid hydrates stands in contrast to carbon storage in aquifers, which retain CO₂ in a buoyant form.

The plan for the two-year project is to not only demonstrate CO₂-hydrate formation, but also to assess the potential storage capacity of depleted reservoirs and design a pilot study for an actual site. To accomplish this feat, the Pooladi-Darvish and Hassanzadeh will collaborate with an earth science expert at Simon Fraser University and a chemical engineer at the University of British Columbia.

In addition to supporting greenhouse gas-reducing innovation, CMC is also funding social science research to inform policy-makers and industry preparing to put new technologies into action.

“The big problem, especially in the Western world, is that the public doesn’t like things near them,” explained Larter. “This human side of technology deployment is one of the issues that we have to understand and address.”

University of Calgary communication studies professor Edna Einsiedel is leading an investigation into stakeholder and public attitudes towards greenhouse gas-mitigating technologies. In collaboration with researchers at Ontario’s Trent University, the University of Victoria and the Pembina Institute, Einsiedel will compare views on energy technologies in four Canadian provinces.

The team hopes to find out how and why people make the judgments they do about given technologies, including hydroelectric power and wind power in Ontario, and carbon capture and storage in Alberta. People typically raise questions, from “What is the purpose of this technology?” to “Who benefits?” and “How do we ensure this technology is safe?”

In particular, PhD student Amanda Boyd will interview members of communities where carbon capture and storage facilities already exist or are planned, and where there are no such facilities.

Einsiedel noted that public engagement is a critical part of transparency and accountability, not only in government, but also in the investment community, who must answer to shareholders and the general public.

“Understanding how public values and preferences can contribute to shaping a technology is just as important,” she said. “The scientific solution is only half the answer,” she stressed, adding “You might build a great mouse trap, but if nobody wants to use it, then what good is that?”

Provided by University of Calgary