Reforming reactions of acetic acid on nickel catalysts over a wide temperature range

Abstract

Catalytic steam reforming of bio-oil, a liquid derived from pyrolysis of biomass, may be a viable process of renewable hydrogen production. Acetic acid is one of the major constituents of bio-oil, and for this reason, it is used as a model compound to study its reaction network under steam reforming conditions over Al 2O 3 and La 2O 3, and Ni catalyst supported on La 2O 3/Al 2O 3 carrier, employing transient and steady-state techniques. It is found that acetic acid interacts strongly with the Al 2O 3 carrier and less strongly with La 2O 3. Decomposition reactions as well as the ketonization reaction take place, especially at intermediate temperatures. In the presence of Ni, catalytic activity is shifted toward lower temperatures. Nickel promotes steam reforming reactions and retards the rate of carbon deposition onto the catalyst surface. It is also found that carbon formation is affected by reaction temperature, the HAc/H 2O ratio and catalyst composition. Carbon deposition is favoured at low reaction temperatures and at high HAc/H 2O ratio.