Ohio State University researchers have developed a chemical catalyst that increases hydrogen production via coal gasification without using a toxic metal common in other catalysts.
The new catalyst uses a combination of iron and aluminum (Fe-Al) with other metals (such as cobalt (Co) or copper (Cu)) to harvest hydrogen from the synthetic gas (syngas) resulting from gasification. In tests, the catalyst performed up to 25% better than a commercially available alternative.
Retrieving hydrogen from a reaction between the carbon monoxide and water in the syngas requires catalysts to boost the reaction—especially in large-scale gasification.
Currently, the most popular commercial catalyst is made from iron and the toxic metal chromium (Fe-Cr). During hydrogen production, the catalyst can release chromium as a byproduct. When the catalyst material has passed its useful lifetime, it requires expensive disposal methods.
Researchers don’t fully understand the iron-chromium mechanism. The OSU research team, led by Umit Ozkan, suspected that the chromium helps maintain the pore structure of iron during the reaction, so they looked for a metal with a similar chemical structure.
That led them to aluminum, and to other complementary metals that greatly increased hydrogen production.
The research team to date has tested the catalyst using a feed mixture similar to what is produced from coal gasification, and will next test whether their catalyst works in the presence of sulfur, since coal from Ohio and much of the American northeast is sulfur-rich.
But it seems as though the new Fe-Al catlayst should work with the syngas resulting from other feedstocks—but it would remain to be seen how well.