Don’t go running for the medicine cabinet just yet when your car runs out of gas, but a research team at the University of Delaware is working on a low cost, high efficiency carbon capture system that uses an active ingredient in Pepto-Bismol to convert carbon dioxide into carbon monoxide. The CO functions as an energy storage platform, since it can be used to make synthetic fuels including hydrogen. How efficient is the new system? It is being designed specifically to run off solar energy, which puts another twist on that solar powered “artificial leaf” concept we’ve been following for the past couple of years.
Using Pepto-Bismol For Low Cost Carbon Capture
Bismuth is also relatively cheap and abundant, and that’s the whole key to the new UDel carbon capture project. There’s nothing new about converting CO2 to CO for use in making synthetic fuels, but conventional processes are based on expensive electrocatalysts composed of gold or silver.
According to the research team, bismuth is up to 100 times cheaper than silver and 2,000 times cheaper than gold. There’s also a sustainability twofer involved in bismuth, since it can be reclaimed from lead, tin and copper refineries.
Bismuth has been of interest as an electrocatalyst since the 1970’s, when the first oil supply crisis hit the US. Naturally, as soon as the crisis faded so did federal funding, and so did the research, at least until the UDel team picked it up again.
In addition to using a low-cost catalyst, the project also differs from conventional CO2 conversion by focusing narrowly on the production of CO rather than creating a “slew” of less valuable compounds. That enabled the team to get the most bang out of its energy buck and design a catalytic system that could be powered by solar energy.
Another Kind of Solar Powered “Artificial Leaf”
The project, which is published in this month’s Journal of the American Chemical Society, basically treats the CO2 to CO conversion process as a form of energy storage, and that’s why we view it as a member of the “artificial leaf” family.
Carbon monoxide is an energy-dense precursor to a variety of synthetic liquid fuels as well as hydrogen. Setting aside those other fuels for now, let’s take a closer look at hydrogen.
CleanTechnica has been following Harvard (formerly MIT) researcher Daniel Nocera’s pursuit of a low cost “artificial leaf” consisting of a pocket-sized photoelectrochemical (PEC) cell that could be dipped in a jug of water. Unlike photovoltaic cells, which convert sunlight directly to usable electricity, PEC cells use solar energy to spark a chemical reaction that spits water into hydrogen and oxygen gas. The hydrogen can then be stored and used to run a fuel cell.
The Nocera team is aiming at the emerging market for alternative energy in undeveloped communities, so it is aiming at affordability over efficiency. Relatedly, in a recent breakthrough the team has refined its process to run on non-purified water.
More recently, we noted a new “artificial leaf” concept that could blow up the fuel cell market, a low cost silicon-based PEC proposed by the National Institute of Standards and Technology.
That brings us around to hydrogen fuel cells. As a form of vehicle energy storage, hydrogen fuel cells have been lagging somewhat behind lithium-ion batteries, especially given all the publicity surrounding Tesla’s new battery swap offer.
However, fuel cell technology for both vehicles and stationary use is poised for a mainstream breakthrough, as demonstrated by the recent interest shown in fuel cells by companies like Apple, Verizon and eBay.
Under the Obama Administration, the Department of Energy has ramped up funding for advanced fuel cell research, including a Lawrence Berkeley National Lab project involving the use of titanium dioxide to collect solar energy for splitting hydrogen from water.
Earlier this month our sister site Gas2.org reported that a team of researchers in Australia is hot on the trail of a process for splitting hydrogen from seawater, which should help resolve the fuel-vs-water conundrum, and Toyota has just announced the launch of a new fuel cell sedan for 2015.
The US Army has also teamed with GM to spearhead a major fuel cell pilot project in Hawaii that incorporates renewable energy into the hydrogen production process, and it has been testing a “green fuel cell” that can run off a combination of corn ethanol and the waste from explosives manufacturing (the corn ethanol part isn’t too exciting, but the waste reclamation aspect sure is).