Current Status in the Conversion of Lignocellulosic Biomass to Liquid (BtL) Biofuels

Abstract

Petroleum and other liquid fuels are currently the dominant source of global transportation energy. However, the rapid increase in energy demand, the extensive use of fossil fuels and the urgent need to reduce the carbon dioxide emissions (CO2) have raised concerns in the transportation sector. This brings lignocellulosic biomass into limelight to sustain the supply liquid biofuels as potential substitutes for conventional fossil fuels in the in the transportation sector. Currently, a growing number of liquid biofuels are evaluated for commercial exploitation, such as bioethanol, biodiesel, biomethanol, and reformulated gasoline components. This article reviews the existing conversion technologies and most recent developments for the production of second-generation liquid biofuels from
lignocellulosic biomass. There are two basic conversion routes for the conversion of lignocellulosic biomass to biofuels thermochemical (pyrolysis, liquefaction, torrefaction and gasification) and biochemical (fermentative pathways). Syngas fermentation has been presented as an advanced biomass conversion technology that converts syngas to higher alcohols in the presence of mesophilic and thermophilic microorganisms.