Resources, properties and utilization of tar

Demand for natural resources and energy, is increasing every day due to the rapid expansion of population and urbanization. Higher effective utilization such as reduction, reuse and recycle of the existing natural resources including waste becomes an important reason for the limited nature resource for change. Tar is an unavoidable waste or a by-product during biomass thermal conversion process (0.1-20% in biomass gasification, main product in biomass pyrolysis) or fossil thermal conversion (coal gasification, or liquefaction), whose utilization has an important influence on the efficiency of energy resource. Tar as resource and energy is reviewed in this study. The sources, properties and utilization styles of tar are summarized in detail, and some main companies related to tar production and handling are also introduced. (C) 2010 Elsevier B.V. All rights reserved.