PYROLYSIS-GC/MS OF BIOMASS THERMALLY PRETREATED BY TORREFACTION

摘要

Torrefaction is a low temperature thermal conversion that improves the fuel properties of biomass. Considered a mild form of pyrolysis, the slow heating of torrefaction occurs at atmospheric pressure and between the 200-300°C temperature range in the absence of oxygen.1 The torrefied product tends to be uniform with reduced moisture content and increased energy density, retaining about 70% of initial mass and up to 90% of its initial energy. Torrefied biomass is also hydrophobic and easily ground, improving its potential for storage and transport.2 In addition to production of charcoal with characteristics similar to coal hence touted as green coal, torrefaction is potentially useful as a pre-treatment for fast pyrolysis of biomass to pyrolysis oil (bio-oil).3-6 This is because any use of a fast pyrolysis feedstock that has lower oxygen content, such as torrefied biomass, would create a less oxygenated bio-oil that might be more stable than that produced from conventional pyrolysis feedstocks, and could therefore be more easily stored, transported, and upgraded to consumer-quality vehiclar fuel. Herein, we quantify the products of pyrolysis of torrefied biomass using py-GC/MS and examine the utility of torrefaction pre-treated biomass as feedstock for the production of bio-oil.