CBM – travelling a fine line

According to the World Coal Association (WCA) there is enough coal, around 847bnt of proved reserves globally, to last approximately 118 years at the current rate of production. Coal bed methane (CBM) gas, a valuable energy source, while not suitable for extraction from every coal seam, is rapidly becoming an option for energy companies. However, like most other energy sources CBM has advantages, disadvantages and challenges, which technology may or may not be able to address successfully.

At the University of Alberta in Edmonton, researchers are working on a project that kicked off in the summer of 2011 to study anaerobic bacteria responsible for making methane gas. The study is part of a larger three-year project supported by a CAD1.92m grant from Carbon Management Canada (CMC) and CAD150,000 from industry partner EnCana Corp. The 15-member team is lead by Sushanta Mitra, associate professor of mechanical engineering and director of the micro- and nano-scale transport laboratory at the National Institute for Nanotechnology. “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,” said Prof Mitra in a statement.

Progress is ongoing, “We are studying the methanogenesis process, part of the metabolic cycle of the micro-organisms,” he told reporters from the Edmonton Journal. The university team says that they aim to identify the micro-organisms in coal seams and work out what chemicals can be added to existing bacteria to make them produce more methane as well as how fluid moves through coal. Once this is done, the plan is, in cooperation with EnCana, to run field tests and to develop sensors, “Our goal is to have full-sized field testing underway on an underground coal seam in Alberta by 2015,” he added. According to Energy Alberta, the Canadian province has around 37bnt of coal that can still be mined and possibly trillions of tonnes of coal that cannot with today’s technology. Coal provided some 59% of Alberta’s fuel for energy in 2008. Should Mitra and his team be successful then the CMC estimates that Canada’s net carbon dioxide emissions could be cut by 25% as deep unmineable coal energy is unlocked.

Multidisciplinary team

Some of Mitra’s team members are studying the best environmental conditions for bioconversion and the biochemical pathways that microbes use to degrade coal and have employed DNA analysis to identify which microbial species are at play. CMC also says that the team has been using-high resolution microscopy to examine the pore structure of coal as well as the microbial-coal interface. Aside from the University of Alberta, Alberta Innovates – Technology Futures, the University of Western Ontario, New Paradigm Engineering and the University of Arizona are all taking part in the project. The Scientific Director of CMC and investigator on the coal bioconversion project, Steve Larter, said in a statement that an interdisciplinary approach is crucial 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,” said Larter. “We’re trying to build an orchestra.”

Safeguarding resources

CBM is potentially a very big thing in Alberta and the provincial government established an advisory committee (MAC) in 2003 and new legislation, Bill 26 – Mines and Minerals (Coalbed Methane) Act, came into law in 2010.
The Alberta scientists are not the only ones working on how to make more CBM from deep coal seams from studying methanogenesis but they do say that they are the only ones currently working with nanotechnology and Prof Mitra said that the team expects to publish some “interesting research.”

Across the border from Alberta, in the US state of Wyoming, CBM methane farming techniques has got state regulators looking at proposed rules in response to suggestions from the US Environmental Protection Agency (EPA). Like almost any other process to harvest and use fossil fuels, there are concerns and more may emerge as new technology is deployed.

Methane farming, as it is known, is a technique where coal consuming microbes are introduced to old CBM wells so that a slow, steady rate of production can be achieved. The EPA has been tracking this activity to ensure that groundwater will not be contaminated and recently contacted the Wyoming Oil and Gas Conservation Commission (WOGCC) saying that the commission should adopt a uniform standard across the state. The WOGCC said that it had already been looking at methane farming in the Powder River Basin to ensure that practices met with EPA Class V standard that dictates that water from aquifers must remain safe to drink. In the meantime, following the latest contact from the EPA the WOGCC has said that after talking to the EPA that it would be looking at how to adopt the new proposals, “We decided that we needed to have more time,” Wyoming Oil and Gas Supervisor, Tom Doll told the Billings Gazette. The next meeting of WOGCC is on 20 September 2011.

Taking the time to do the studies and due diligence on CBM extraction makes sense. Aside from water contamination issues associated with CBM concerns have also been raised by coal mining companies and owners of coal resources that minable coal resources might be damaged by methane farming especially if there are scientific knowledge gaps or unexpected turns of events far underground and the process can’t be controlled. CBM is a significant energy option worldwide but like others in the unconventional stable such as shale gas, shale oil, underground coal gasification and coal to liquids, there are real and difficult issues to be considered. However, until renewables are able to take up more of the energy strain, and that day could still be decades away, we have to make the best of what we have without damaging other vital resources, such as water. This means travelling somewhat of a fine line indeed.