(Graphic: Satkar J. Yonzon)

Fedorov and his student, David Damm, argued that people had got the problem by its wrong end. Once petrol burns, it is impossible to capture the carbon dioxide that rushes out of the exhaust pipes. Their solution: remove the carbon from the fuel before combustion. The result is hydrogen, which can be burned to power the vehicle, and carbon, which can be stored in the vehicle for disposal.

So, a refuelling trip serves two purposes: it fills your fuel tank, and it empties your vehicle of stored carbon to be put away safely somewhere. But Fedorov’s working prototype is far from being a commercial product. “We have shown that the method works, and now we are waiting for those with commercial interests to take it to the market,” says Fedorov.

All over the world, while scientists are working hard to develop renewable fuels, hundreds of researchers such as Fedorov are working to address another related problem. How do we store the carbon that is being burned now in fossil fuels? It is important to do so for several reasons.

No one expects scientists and engineers for some time to develop a renewable fuel that is as efficient and convenient as fossil fuels while also being as cheap. So, assuming that we use fossil fuels for the next four decades at least, we need to find ways of not increasing our carbon dioxide emissions as well. There is only one way out: find ways to capture, transport and store the carbon that we generate as waste, a process that is now known by the acronym CCS (carbon capture and storage).

CCS is not an easy process, as experts had known for a long time. The first challenge is to capture carbon dioxide cheaply. The next is to transport it to a place where it can be stored safely. And the third challenge is how to store it there. While some environmentalists question the safety of storing carbon dioxide under rocks and in oceans, the most serious challenge is to capture it first. “CCS is not a viable solution now because carbon capture is too expensive,” says Varun Rai, research fellow at the Program on Energy and Sustainable Development (PESD) in Stanford University. But the near-term future is promising to throw up some interesting answers, if the research in labs across the world is any indication.

In principle, there are several ways in which CCS could be done. Power plants, one of the major emitters of carbon dioxide, can capture the carbon dioxide that they emit, convert it into a liquid, and then transport it to storage areas such as the bottom of rocks or the deep sea floor. It is particularly important for power plants to practise CCS because new coal-based power plants are coming up at an alarming rate of one per week. Countries such as India and China, in particular, plan to use coal on a large scale for their future energy needs.

A study conducted by the Electric Power Research Institute in the US argued that it is possible to reduce — through CCS — about 350 million tonnes of carbon dioxide per year in the US alone by 2030.

Another recent study by McKinsey had reached similar conclusions. However, PESD recently calculated — by analysing all ongoing CCS projects — that even if all planned CCS projects are completed and work as planned, the world will reduce at the most 80 million tonnes of carbon dioxide a year by 2030. “Current capture technology based on amines is far too inefficient,” says Rai. A power plant that uses CCS will lose 15-20 per cent of its energy just for CCS, which is enough to make it unviable. However, there are several new methods under development.

One of the most promising is called oxy-fuel technology. The primary problem with the current capture technology is that carbon dioxide is present in the exhaust gas in low concentrations. The main reason for this is the use of air for combustion, although the only element we need for it is oxygen. Oxy-fuel technology uses pure oxygen, resulting in much more concentrated carbon dioxide in the exhaust. This technology has a few proponents; one of the main ones being the Chicago-based company Jupiter Oxygen, which has demonstrated its use for CCS.

“Oxy-fuel technology can make CCS more economically feasible,” says Sarah Forbes, senior associate of the Washington DC-based World Resources Institute. The institute has just published an exhaustive study of CCS economics, and its main message is this: CCS is imperative, and we should only be talking about how to implement it.

Different Approaches
Labs around the world are trying several different approaches. At the University of Wyoming, for example, Maciej Radosz and his colleagues at the Department of Chemical Petroleum Engineering have developed a low-cost method — using a carbon-based material — which traps 90 per cent of the carbon dioxide in the exhaust flue gas. Radosz believes — under certain assumption of prices and carbon credits — that his method can increase the cost of electricity by 30 per cent, which is far better than the 80 per cent under the present technology, but probably still not acceptable to the public.

In Norway, a project by Sintef, the largest independent research organisation in Scandinavia, is developing new materials that can bind carbon dioxide while also giving it up easily. Project leader Anders Hoff thinks that his team already has ideas to reduce the cost of CCS significantly. His team has done bench-scale experiments that validate such ideas, but they have to be proven in a large plant.

“This is long-term, what we call third-generation solvent systems for carbon dioxide capture,” says Hoff. Their immediate aim is to develop a first-generation system that is better than the current ones, and to be used in the full- sized capture systems that will be erected over the next one decade.

Most of the work is concentrated on the large power plants, which contribute 40 per cent of the carbon dioxide emissions. The smaller plants and automobile contribute the rest. The technologies for these processes are different. But some scientists are trying to combine all of them into one technology: capturing carbon dioxide from the air and not at the source. There are two systems available at the moment: one developed at the University of Calgary in Canada and the other at the University of Columbia. Neither is in commercial use yet, but University of Columbia has provided the technology to a private company in Arizona.

But, for all these processes to work in the long term, one might need to find a way to convert the captured carbon dioxide into a useful commercial product, and not just bury it somewhere. This is another line of research, and an entirely different story.

(Businessworld Issue 23-29 Dec 2008)