14 DAY TRIAL // A team of experts from the Stanford University announces the development of a new method for producing ethanol from carbon monoxide (CO) gas that is far more efficient than synthesizing this liquid fuel from crops such as corn. The approach could soon be used as a more environmentally-friendly way to obtain ethanol at a large scale.
At this point, ethanol is primarily synthesized inside high-temperature fermentation facilities, which convert chemicals in corn, sugarcane, and other crops into pure alcohol. This compound is widely used for a variety of applications, including in thermometers, as a solvent, and as a fuel. However, obtaining it from crops can be an energy-intensive process that requires a lot of work.
What the Stanford team did was develop a way of obtaining ethanol a lot easier and faster, by using a catalyst that works under normal temperature and pressure. Details of how the process works were published in the April 9 advanced online issue of the top scientific journal Nature. Stanford assistant professor of chemistry Matthew Kanan was a coauthor of the research paper.
“We have discovered the first metal catalyst that can produce appreciable amounts of ethanol from carbon monoxide at room temperature and pressure – a notoriously difficult electrochemical reaction,” the expert says. With the new advancement, it may no longer be necessary to harvest thousands of acres of lands with crops exclusively for ethanol synthesis.
In addition to allowing farmers to use this land for crops destined for human consumption, the new method would also reduce the need to use vast amounts of water and fertilizer just to produce ethanol. As a positive side-effect, the amount of nitrogen infiltration and pollution associated with excessive fertilizer use may also be reduced around the world.
According to a series of recent statistics, it may take up to 800 gallons (3,028 liters) of water to grow a bushel of corn, which in turn produces no more than 3 gallons (13.5 liters) of ethanol. The new approach, designed by Kanan and graduate student Christina Li, does away with the need to include fermentation in the synthesis process, thus eliminating many of the issues associated with ethanol production today.
“Our study demonstrates the feasibility of making ethanol by electrocatalysis. But we have a lot more work to do to make a device that is practical,” Kanan explains. At the core of the new approach lies a material called oxide-derived copper, which the team developed two years ago. The material is now being used to create novel electrodes for ethanol electrocatalysis.
“Most materials are incapable of reducing carbon monoxide and exclusively react with water. Copper is the only exception, but conventional copper is very inefficient. The oxide-derived copper produced ethanol and acetate with 57 percent faradaic efficiency. That means 57 percent of the electric current went into producing these two compounds from carbon monoxide,” Kanan explains.
“We're excited because this represents a more than 10-fold increase in efficiency over conventional copper catalysts. Our models suggest that the nanocrystalline network in the oxide-derived copper was critical for achieving these results,” the investigator concludes.