Technology

Biogas reforming by the honeycomb reactor

 By Robin Wylie

A new study has found that, using a reactor shaped like a honeycomb could enhance the performance of biogas reforming for hydrogen production, compared with the packed back reactor. The results suggest that using this “honeycomb” reactor increased hydrogen yields by 73% for biogas reforming and 41% for methane steam reforming, compared with using a packed bed reactor…

(Cover photo by Prilfish/flickr)

They say size doesn’t matter, but it seems that shape might. A study has found that a catalyzer shaped like a honeycomb could allow biogas to be converted into hydrogen more efficiently.

Engineers from Feng Chia University in Taiwan found that they could improve the efficiency of “biogas reforming” — a sustainable method of producing hydrogen (H2) — by using a honeycomb-shaped catalyzer to drive the reaction.

Industrial hydrogen is most commonly produced by chemically reacting methane gas with steam, a process which gives off hydrogen together with smaller quantities of carbon dioxide and carbon monoxide. Using biomethane to fuel this hydrogen-producing reaction — which is known as “methane steam reforming” — offers a sustainable way to produce (clean-burning) hydrogen fuel.

Catalysts are routinely used to speed up the process of methane steam reforming. In the new study, published in the International Journal of Hydrogen Energy, the Taiwanese researchers replaced a standard “packed bed” catalyzer with a honeycomb-shaped catalyzer made out of cordierite and coated with a mix of nickel and cerium oxide.

 

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BIO-Methane-GAs

They found that using the honeycomb reactor increased the yield of hydrogen by 41% during methane steam reforming. They also found that another, similar hydrogen-producing reaction, called “biogas reforming,” was improved by 73% when they used the honeycomb reactor instead of a packed bed reactor.

Honeycomb-shaped catalyzers like these have been around for decades — they have been used inside catalytic converters in motor vehicles since the 1970s. However, they have only relatively recently been explored as a means to boost hydrogen production.

The hydrogen-boosting power of the honeycomb catalyzer may be down to its highly porous nature; the greater surface area that is provided by the compartmentalized structure likely allows the hydrogen-producing reactions to occur more quickly, thereby producing more hydrogen in a given period of time.

about the author
Robin Wylie
Freelance earth/space science journalist. Currently finishing off a PhD in volcanology at University College London.