BIOMASS TO HYDROGEN VIA FAST PYROLYSIS AND CATALYTIC STEAM REFORMING OF THE PYROLYSIS OIL OR ITS FRACTIONS

Pyrolysis of lignocellulosic biomass and reforming of the pyroligneous oils are being studied as a strategy for producing hydrogen. A proces s of this nature has the potential to be cost competitive with convent ional means of producing hydrogen. We propose a regionalized system of hydrogen production, where small- and medium-sized pyrolysis units (< 500 Mg/day) provide bio-oil to a central reforming unit to be catalyt ically converted to H-2 and CO2. Thermodynamic modeling of the major c onstituents of the bio-oil has shown that reforming is possible within a wide range of temperatures and steam-to-carbon ratios. In addition, screening tests aimed at catalytic reforming of model compounds to hy drogen using Ni-based catalysts have achieved essentially complete con version to Ha. Existing data on the catalytic reforming of oxygenates have been studied to guide catalyst selection. A process diagram for t he pyrolysis and reforming operations is discussed, as are initial pro duction cost estimates. A window of opportunity clearly exists if the bio-oil is first refined to yield valuable oxygenates so that only a r esidual fraction is used for hydrogen production.