By XiaoZhi Lim
ACS Central Science
A narrow tower two stories high sits behind chemical engineer S. Venkata Mohan’s lab at the Council of Scientific and Industrial Research-Indian Institute of Chemical Technology. Every other day for six months in 2017, he and his team fed this “beast.” They collected food waste from the institute’s cafeteria, ground it up, filtered out large particles, drained the oils, and added it to the tower, which contains containing an anaerobic digester filled with a soup of waste and bacteria. Munching on the leftover lunch, those microorganisms didn’t produce a conventional biogas, the typical output of digesters. With some scientific innovation from Mohan and his team, the microbes instead produced a gas rich in hydrogen. Building on the beast’s ability to pump out 5 kg of hydrogen per day, Mohan is now in talks with Indian officials to build similar plants 10 times as large to treat municipal waste in Hyderabad and Mumbai.
Mohan is among a small group of researchers around the world who are finding that various organic waste streams—such as food waste, agricultural waste, and wastewater—can be viable sources of hydrogen gas. These researchers seek to generate hydrogen, a fuel that does not produce greenhouse gases when burned, while simultaneously dealing with a growing waste problem. In some cases, these methods enjoy a bonus of producing valuable carbon-based products instead of climate-warming carbon dioxide.
Continue reading at ACS Central Science. Originally published on February 20, 2019.