In Colorado, here’s the future of ethylene production as Dr. Jianping Yu sees it. “We envision some farms in the field that cover many acres. We will have cyanobacteria harvesting sunlight and C02 and then produce ethylene or ethylene derivatives,” said Yu, a research scientist in the Photobiology Group at the Energy Department’s National Renewable Energy Laboratory. “That’s pretty far from where we are now, but that’s the goal. If things work out, 10 years from now we should see some farms making petrochemical replacements.”
Ethylene already can be made without fossil fuels through the conversion of bioethanol, but that requires making bioethanol plus an additional step. Yu’s research showed ethylene could be made directly and continuously from cyanobacterium. Normally, algae convert carbon dioxide during photosynthesis into biomass or sugars. But Yu’s method redirected the cyanobacterium to use a portion of the CO2 to produce ethylene. Ethylene rises to fill the headspace of a sealed glass tube or photobioreactor and can be easily captured. Since his initial discovery in 2010, Yu has managed to increase the amount of ethylene produced in the laboratory by more than a thousand-fold, to 35 milligrams per liter per hour. His goal is to make 50 milligrams by the end of the year.