Model of hydrogen sulfide using a ball-and-stick method Credit: Public domain
Scientists have discovered a new chemical process that can transform a toxic, stinky gas into clean-burning fuel.
This process is described in the American Chemical Society journal ACS Sustainable Chemical Engineering. It converts hydrogen sulfidemore often called "sewer gasoline" into hydrogen fuel. Hydrogen sulfide, which is produced from manure piles or sewer pipes, is a key byproduct in industrial activities such as refining oil and gazing and producing paper.
This study demonstrates how to make iron sulfide and molybdenum with relatively little energy.
Hydrogen sulfide smells like rotten eggs and is extremely toxic. It can corrode pipes and cause health problems for those who come in contact with it.
Lang Qin, co-author of the study and research associate in chemical engineering and biomolecular engineering at The Ohio State University, stated that hydrogen sulfide was one of the most dangerous gases in the industry and the environment. "Hydrogen sulfide is so dangerous that many researchers are trying to make it less harmful and more valuable."
This study builds on the previous work of the same research group that used chemical looping. Chemical looping involves adding metal oxide particles to high-pressure reactors to burn fuels. There is no direct contact between fuel and air. Chemical looping was first applied to coal and shale gas in order to convert fossil fuels into electricity, without releasing carbon dioxide into the atmosphere. Iron oxide was used to decompose the fossil fuels in the initial process.
Later, the researchers applied this concept to hydrogen sulfuride and created the SULGEN process that converts hydrogen sulfide to hydrogen. Qin stated that iron sulfide was not a good choice for industrial use because it is a pure chemical. Qin said that the research team is currently trying to find other cheap chemicals that can catalyze this transformation in larger quantities. This study suggests that the introduction of a small amount molybdenum to iron sulfide could be an attractive option.
This material is affordable and easy to obtain, making it a good choice for larger-scale operations.
Researchers claim that hydrogen fuel is created by converting this toxic gas to oil. This alternative oil and gas contributes significantly to climate change.
Kalyani Jangam (lead author and graduate student at Ohio State's Clean Energy Research Laboratory), said that it was too early to know if the research could replace existing hydrogen fuel production technologies. "But, what we're doing is adjusting the decomposition process to make a valuable product out of it."
The researchers discovered that molybdenum can improve the hydrogen sulfide's breakdown, separating it into two partshydrogen fuel, and sulfur.
This research is still early in scientific progress. The researchers demonstrated that the process works in the laboratory; industrial tests are expected to follow.
Qin stated that the big picture was that we wanted to solve the problem of harmful gases and that chemical looping would enable us to do that. "And here, it's possible to create this value-added hydrogen fuel in the laboratory.
Liang-Shih Fan is the senior author of this paper. He is a professor at Ohio State in chemical and biomolecular Engineering. Fan's former doctoral student Yu-Yen Chen also contributed.
See more details on photodissociation dynamics for hydrogen sulfide
More information: Kalyani Jagam et.al, Mo-Doped FeS Mediated Hydrogen Production from H2S via In Situ Cyclicsulfur Looping Scheme. ACS Sustainable Chemistry & Engineering (2021). Kalyani Jangam and colleagues, Mo-Doped FeS Mediated Hydrogen Production from H2S via In Situ Cyclic Sulfur Looping Scheme. (2021). DOI: 10.1021/acssuschemeng.1c03410
