Catalytic Fast Pyrolysis of Lignocellulosic Biomass to Benzene, Toluene, and Xylenes

Catalytic Fast Pyrolysis is a rapid method to depolymerize lignocellulose to its constituent components of hemicellulose, cellulose, and lignin. The pyrolysis reaction in absence of oxygen occurs at a very high heating rate to a targeted temperature of 400 to 600 °C for very short residence time. Vapors which are not condensed and are then contacted with a catalyst that is efficient to deoxygenate and aromatize the pyrolyzed biomass. One class of highly valuable material that is produced is a mixture of benzene, toluene, and xylenes. From this mixture, para-xylene is extracted for further upgrading to polyethylene terephthalate, a commodity polyester which has a demand in excess of 80 million tonnes/year. Addressed within this review is the catalytic fast pyrolysis, catalysts examined, process chemistry, challenges, and investigation of solutions.