Sugar to Hydrogen by Aqueous Catalysis
In its August 29 issue, Nature magazine published an article by a distinguished group of researchers at the Univ. of Wisconsin who have succeeded in producing hydrogen and fuel gas directly from sugars and other compounds (ethylene glycol, glycerol, etc.). The novel new process is not biological, but catalytic, and represents a key breakthrough– it is the first time anyone has successfully done catalysis of carbohydrates in the aqueous phase, and at moderate temperatures and pressures to boot. (Catalysis is always done in the vapor phase, but previous attempts with carbohydrates have always failed because reaction products clog up the catalyst.) Filed patent applications have very broad claims.
The process is called Aqueous Phase Carbohydrate Reforming (ACR), and it represents a fundamentally new route for renewable fuel gas generation from biomass. The ACR process is simple, versatile and scalable over several orders of magnitude. It can utilize safe, non-flammable feedstocks as well as renewable biomass derived feedstocks. Also, hydrogen is produced with low carbon monoxide concentrations, using a single reactor vessel.
Feedstocks are plentiful and varied. To date, best results have been obtained with methanol and ethylene glycol (storable and transportable as liquid fuels!). Glycerol, derived from the esterification of fats and oils, will be available in large quantities as a byproduct of making biodiesel fuel. A lot of attention is being given to biomass ethanol, however ethanol production relies on fermentation of glucose. Processes that break down cellulosic biomass produce a mix of higher sugars which are not readily femented. ACR is much less picky.
A near term product involves using ACR to produce a fuel gas (light alkanes) fed to an IC engine genset. As fuel cells mature, they can be wedded to ACR hydrogen production.
A company, Virent Energy Systems, has been established to commercialize the technology. They are confident that scale-up will largely be a matter of standard chemical engineering, and intend to pursue aggressive product development and licensing strategies across a wide range of applications and markets. They are looking for investment to finance cost sharing of government grants. (A small investment now will enjoy substantial leverage if an ATP award comes through. The company is optimistic.) I have a brief summary and status update from the company which I can provide on request, and a business plan is available.
Dr. Mark Daugherty, CEO
Virent Energy Systems, Madison, WI
University press release:
Paper in NATURE:
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