Bioderived Syngas to Alcohols

The catalytic synthesis of alcohols from biomass-derived syngas is an important process for utilization of this bioresource as a renewable source of energy. Although the synthesis of methanol from syngas is a mature technology, the synthesis of higher alcohols from syngas has been plagued by low yields and is yet to be commercialized. Interest in the formation of C2+ (“higher”) alcohols appears to be increasing as these compounds are finding uses as fuel additives and hydrogen carriers. Formation of these higher alcohols from syngas is fundamentally different from methanol synthesis, since both C-H bonds and C-OH bonds must be formed from the CO and CO2 in the syngas. This chapter discusses various catalyst systems that have been investigated for the formation of alcohols from bio-derived syngas. Typically, alkali doping of traditional methanol and FT synthesis catalysts is necessary to promote chain growth and increase selectivity to higher alcohols. The effect of the presence of CO2 in bio-derived syngas on alcohol synthesis is also addressed.