A Cheaper Option to Turn Carbon Dioxide Into Synthetic Fuel

Carbon capture and storage has been a political buzzword for years, even though it remains expensive and largely elusive on a commercial scale.

The first part of the equation, capturing carbon dioxide from power plants and other large emitters of carbon pollution, is the relatively easy part. The problem has been what to do with it. Injecting it underground is expensive, and turning it into fuel takes a lot of energy and often involves rare or toxic chemicals.

Researchers at the University of Delaware have taken a different approach, using an inexpensive catalyst that relies on electricity from solar energy to convert carbon dioxide (CO₂) into carbon monoxide (CO) that can be used for a range of industrial applications, including liquid fuel.

Gold and silver have traditionally been used as the catalyst to convert CO₂ into CO, but Joel Rosenthal, a chemist at the University of Delaware, found that the metal bismuth works just as well, if not better. “Despite its low cost, bismuth has been virtually ignored as a cathode material for CO₂ electrolysis,” Rosenthal wrote in a study that appeared in the June 19 issue of the Journal of the American Chemical Society.

An ounce of bismuth is 2000 times cheaper than an ounce of gold and found in many places as a byproduct of refining lead, tin and copper, according to Rosenthal. “Most catalysts do not selectively make one compound when combined with carbon dioxide — they make a whole slew,” Rosenthal said in a press release. “Our goal was to develop a catalyst that was extremely selective in producing carbon monoxide and to power the reaction using solar energy.”

Carbon monoxide is a valuable commodity chemical, said Rosenthal. It is used to make hydrogen gas, but also in the production of synthetic petroleum, which researchers are developing across the globe. 

Cheaply converting CO₂ to useful products that don’t require a lot of energy is an area of active research, especially as countries look to curb carbon emissions. Although the U.S. may never have a carbon tax, President Obama’s recently unveiled climate plan included provisions for the U.S. EPA to regulate greenhouse gas emissions from existing power plants, which will only increase the interest in CO₂ conversion research. Obama’s plan included $8 billion in loan guarantees for advanced fossil energy technologies, including carbon capture.

There are also many other researchers and burgeoning companies trying to find low-cost, low-energy solutions to CO₂ pollution. Skyonic, a company with a technology to turn CO₂ into baking soda, recently raised $128 million in venture capital. Researchers at the University of Texas at Arlington are converting CO₂ to liquid methanol using copper oxide nanowires and sunlight. Researchers at the University of Georgia have created a microorganism that feeds on CO₂ and can then be manipulated to make chemicals for fuels or plastics.

But for every breakthrough, there is far more work that needs to be done. University of Delaware’s Rosenthal said there are at least a dozen issues his lab needs to follow up on, which they will pursue this summer.

Source: http://spectrum.ieee.org/

International Energy Agency Doubles Down on Climate Change

The OECD's International Energy Agency (IEA), Paris, issued a report and companion materials today squarely addressing the question of what to do about the blunt fact that the world is not meeting its goals for reducing greenhouse gas emissions.

The agency's new director general, Maria van der Hoeven, framed the question in notably simple and straight-forward terms: "We recently passed a grim milestone with the concentration of carbon dioxide in the atmosphere topping 400 parts per million at the Mauna Loa Observatory in Hawaii. This is uncharted territory in the history of humans. While it does not represent a tipping point per se, that milestone is symbolic of our failure to respond adequately, and to fulfill our own national and international pledges to limit average global temperature increase to 2 degrees Celsius over the long term.

"If we continue with business as usual," van der Hoeven continued, "that rise could be 5.3 degrees Celsius, with potentially disastrous implications in terms of extreme weather events, rising sea levels, and the huge economic and social costs that these can bring. In short, we are drifting off-track, and global negotiations are not expected to yield agreement before 2015, and to be enforced after 2020."

Taking a constructive tack, the IEA proposes four ways in which countries could substantially cut emissions between now and 2020. These, the organization reasons, would make it possible—at least in principle—to eventually limit global temperature increase to 2 degrees Celsius even in the absence of any immediate international accord. Each of the four ways was selected because the IEA predicts that it would generate significant near-term emissions cuts without dampening economic growth, rely exclusively on proven technologies, and bring significant benefits besides reductions in greenhouse gas emissions.

Of the four elements in what the IEA is dubbing its "four for two" strategy, the one that brings by far the greatest benefit (accounting for half of projected near-term emissions reductions) is improved energy efficiency. Improvements in heating and cooling, appliances, and lighting could each account for about 30 percent of efficiency gains, and electric motors another 25 percent or so; interestingly, the IEA expects only 15 percent to result from gains in automotive efficiency.

The IEA's focus on potential efficiency gains is consistent with findings by U.S. energy authorities going back a decade or more, and gibes with the general consensus among experts. So too is its finding that phasing out the most inefficient coal-fired plants could bring substantial reductions, more than one-fifth of total near-term reductions. Cuts in fossil subsidies among the major oil producers could bring more than one-tenth. A little more startling, perhaps, is the IEA's conclusion that eliminating methane leakage from upstream oil and gas distribution could yield a whopping 20 percent reduction in emissions.

The IEA does not dwell, in summary materials or even in the report itself, on possible obstacles to implementation of its proposals. The summary material makes no mention, for example, of what energy economists call the efficiency paradox—that as the efficiency of any given item is improved, people use more of it, vitiating any net gains. But the body of the report seems to implicitly take such issues into account, focusing on gains achievable with standards and regulation, rather than just spontaneous technology improvement and market forces.

The agency might be faulted for taking a somewhat overly optimistic view of recent emissions trends. Van der Hoeven noted, for example, that China's 2012 increase in greenhouse gas emissions "was one of the lowest it has seen in a decade as a result of efforts in renewables deployment and efficiency gains." That statement, taken alone, is somewhat misleading when put into context with the agency's own summary points. For instance, China's 2012 increase in carbon dioxide emissions (300 megatonnes) accounted for three quarters of the whole world's net 2012 increase. It is an encouraging sign that China is considering a cap on greenhouse gas emissions in its next five-year plan, as the Financial Times reported last week, but even so, China will have a long way to go.

Still, some of the recent trends are indeed encouraging. While continued emissions reductions in Europe were largely cancelled out by post-Fukushima increases in Japan (because fossil energy replaced nuclear), U.S. emissions were down sharply and are now at levels not seen since the pre-Kyoto years of the mid-1990s. The 2012 U.S. decrease, at 200 megatonnes, was equivalent to two-thirds of China's increase. The United States, as the IAE implies, is in fact no longer the laggard in greenhouse gas reduction that it was during the first decade following adoption of the 1997 Kyoto Protocol. The country is in a position now to take a leading role in the climate diplomacy that, the IAE fervently hopes, will chart out a long-term post-2020 global strategy.

The agreement on hydroflourocarbon reduction reached by President Obama and China's President Xi this weekend is an encouraging sign. But it seems too much to call it a "breakthrough," as one environmental organization did, or to speak of its boosting the odds of a "global climate deal," as the Financial Times did today.

Source:  http://spectrum.ieee.org