Recycling carbon dioxide is a great deal more involved than setting out separate bins for glass, aluminum, and paper. But many scientists believe that it is not only worth the effort, but a crucial endeavor. The climate change threat to the planet is now so great, they argue, that any effort to address the problem will have to include so-called "carbon negative" technologies. That means actually sucking the greenhouse gas out of the atmosphere and doing something productive with it.
The idea of capturing carbon dioxide (CO2) from coal power plants or oil facilities and storing it underground has gotten plenty of attention. Several pilot projects are operating or under construction, although a major project in West Virginia was abandoned last month due to cost concerns.
There has been less focus on the idea of actually reusing or recycling CO2. But science has long known that it’s possible to recombine carbon from CO2 with hydrogen from water to make hydrocarbons—in other words, to make familiar fuels such as gasoline. The problem, ironically, has been that the process requires a lot of energy.
Anyone who wants to create hydrocarbon fuel above ground will have to supply the energy to isolate the hydrogen and carbon atoms and put them together. "There’s no free lunch," says Hans Ziock, a technical staff member at the U.S. Department of Energy’s (DOE) Los Alamos National Laboratory, coauthor of a white paper on carbon capture from air.
"You have to put energy in to re-create the fuel," he explains. "And because re-creation is never 100 percent efficient, you end up putting more energy in than you get out." Due to the "energy penalty" of creating hydrocarbon fuel indirectly, he says, it has always made more sense for society to use the liquid fuels made directly from crude oil as long as crude oil is available. "If nature has done this for you for free, why not use it?" says Ziock.
However, in a world that is now pumping its crude oil from ultra-deep water, squeezing it from tar sands, and looking for it beneath Arctic frontiers, the time may be ripe for alternatives. Ziock says he believes the hope for greater domestic self-sufficiency for fuel alone makes research into carbon dioxide recycling worthwhile. But he warns that as a means to reduce carbon dioxide in the atmosphere, the benefits of this approach will be limited unless the energy to create the hydrocarbon fuel comes from a source other than the burning of more fossil fuel.
There are several companies working on the technology and after a selection process the technology can be licensed and put into a product that will be part of the reactor system