To reduce the dependence on dwindling crude oil reserves, the rational design of heterogeneous catalysts for the selective conversion of syngas into valuable fuels and chemicals is considered a principal scientific and industrial target. Syngas is an important intermediate for manufacturing clean fuels and chemicals, which can be derived from a variety of carbonaceous resources such as coal, natural gas, shale gas, municipal solid waste (MSW) or lignocellulosic biomass feedstocks through gasification or reforming technologies. The use of biomass feedstock and its derivatives (biomass-derived syngas) to produce renewable energy, carbon neutral and clean fuels and chemicals is gaining increasing interests because these resources can supplement existing supplies of raw materials and have less net environmental impact. This book provides recent research on the production, emerging technologies and ecological impacts of syngas.