Researchers at The Ohio State University have found a way to turn hydrogen sulfide, commonly known as sewer gas, into a hydrogen fuel. Hydrogen sulfide is emitted from manure piles and sewer pipes and is a key byproduct of industrial activities including refining oil and gas, producing paper and mining.
Hydrogen sulfide not only has a rotten smell, but is also highly toxic. “Hydrogen sulfide is one of the most harmful gases in industry and to the environment,” said Lang Qin, a co-author on the study. “And because the gas is so harmful, a number of researchers want to turn hydrogen sulfide into something that is not so harmful, preferably valuable.”
The study is based on previous work by the same research team, in which they first used chemical looping on coal and shale gas to convert fossil fuels into electricity without emitting CO2 into the atmosphere. The initial process used iron oxide to break down the fossil fuels.
The researchers later applied the concept to hydrogen sulfide and invented the SULGEN process, which converts hydrogen sulfide into hydrogen. The study shows that introducing a trace amount of molybdenum into iron sulfide might be an inexpensive and easy to obtain option that could catalyze that transformation in higher quantities.
Transforming this toxic gas into hydrogen fuel could create an alternative oil and gas, which are major contributors to climate change. “It is too soon to tell if our research can replace any of the hydrogen fuel production technologies that are out there,” said Kalyani Jangam, lead author of the study, “But what we are doing is adjusting this decomposition process and making a valuable product from that.”
The researchers found that molybdenum improves the breakdown of hydrogen sulfide into hydrogen fuel and sulfur. However, the work is still to be reproduced outside of the lab, with tests at the industrial level forthcoming.
“The big picture is we want to solve the harmful gas issue, and we thought that our chemical looping process would allow that,” Qin said. “And here, we have found a way to do it in the lab that creates this value-added hydrogen fuel.”
