This paper provides an updated review on fast pyrolysis of biomass for production of a liquid usually referred to as bio-oil. The technology of fast pyrolysis is described including the major reaction systems. The primary liquid product is characterised by reference to the many properties that impact on its use. These properties have caused increasingly extensive research to be undertaken to address properties that need modification and this area is reviewed in terms of physical, catalytic and chemical upgrading. Of particular note is the increasing diversity of methods and catalysts and particularly the complexity and sophistication of multi-functional catalyst systems. It is also important to see more companies involved in this technology area and increased take-up of evolving upgrading processes. © 2011 Elsevier Ltd.

Review of fast pyrolysis of biomass and product upgrading

http://ehsan13967.persiangig.com/document/pyrolysis7.pdf

An overview of fast pyrolysis of biomass

Principles and practice of biomass fast pyrolysis processes for liquids

Catalytic pyrolysis of biomass for biofuels production

Comparison of products from the pyrolysis and catalytic pyrolysis of rice husks

The Liquefaction Group of the lEA Biomass Agreement has carefully studied and analyzed a thermochemical conversion process under development at the National Renewable Energy Laboratory (NREL, formerly the Solar Energy Research Institute). This process converts biomass to an aromatic gasoline product. Biomass is subjected to very rapid pyrolysis in a vortex reactor to maximize the formation of oil vapors. After the char is removed from the process stream, the oil vapors are immediately sent to a catalytic cracking reactor with ZSM-5 zeolite catalyst to form a mixture of aromatic gasoline and gaseous olefins. Subsequent processing recovers byproduct gaseous olefms and converts them to aromatic gasoline. The small amount of toxic benzene formed as an intermediate compound is alkylated to extinction to form relatively benign compounds with a higher octane, such as cumene. The narrow boiling range desired for tomorrow’s reformulated gasolines is maintained by recycling both the volatile light ends and the difficult-to-bum heavy ends to extinction. A gasoline with a very high blending octane is the primary product. It is expected that this product will command a premium price. The process features state-of-the-art energy-saving and waste-management techniques. Using a consistent and well documented approach, the technoeconomics of this process were determined for both a “present” case and a “potential” case. The difference between the product costs for these two cases serves as an incentive for further research and development (R&D).

D. C. Elliott

Papers

IEA Technoeconomic Analysis of the Thermochemical Conversion of Biomass to Gasoline by the NREL Process