BIOMASS TORREFACTION – A REVIEW

摘要

Torrefaction is a mild-pyrolysis (200-300 oC) process that can be employed as a pretreatment to improve fuel properties of biomass materials. The treatment can result in not only increased energy density, but also enhanced grindability, and better storage and transport characteristics for biomass fuels. Due to these promising results, torrefaction has attracted increasing research interests in the recent years. Several studies on torrefaction of biomass have been documented for heat and power applications. Substantial amounts of data on the technique are available, which need to be reviewed and analyzed for further actions in the area. This is the primary objective of the present study. Firstly, this review paper provides an introduction to the biomass torrefaction process. This is followed by a critical analysis of the experimental methods used in laboratory to carry out torrefaction under various process conditions. Later, the tested biomass materials are discussed in terms of the product yields and the evaluated product properties. An overview of the kinetic modeling studies on the topic is also included. Finally, the recommendations for future research work are provided. Reviewing the literature suggests that torrefaction is a promising technique to improve the performance of biomass for energy utilization. However, despite a number of impressive studies on the topic, a lot of information still needs to be recognized for improving the viability of the process.