ENGINEERING JOURNAL CHIANG MAI UNIVERSITY

Volume 27, No. 02, Month AUGUST, Year 2020, Pages 121 - 150

Biomass torrefaction technology for producing high quality solid biofuels

Pumin Kongto, Arkom Palamanit, Sumate Chaiprapat and Nakorn Tippayawong

Abstract Download PDF

The conversion processes of biomass into biofuels or bioenergy via thermochemical process can be performed by several processes such as torrefaction, pyrolysis, gasification and combustion. The use of different biomass conversion processes provides the different biofuels or bioenergy forms, for example, solid, liquid, gas, heat and power. The criterion for selecting biomass conversion processes depend on many factors, including (1) type and property of biomass (2) target for using biofuels or bioenergy such as using as fuel for heat and power generation and using as vehicle fuels (3) storage and transportation (4) production and conversion cost and (5) environmental impacts and social acceptance. For the torrefaction process, it is the process used to improve the biomass property by using heat at the temperature range of 200-300°C under absence or controlled oxygen conditions. With this process, the moisture and light volatile will be removed, resulting in torrefied biomass with higher heating value and energy density. The torrefied biomass also has better property such as low moisture and water absorbability and low biological activity during storage. With a better property of torrefied biomass, the industry and power sectors have more increasingly interested in torrefied biomass for using as fuel or co-firing with coal in heat and power generation. However, production of torrefied biomass with a good property depends on several factors such as type and property of biomass, operating parameters and types of reactor. Therefore, this review article presents biomass torrefaction technology. The detail of this article covers the definition, torrefaction technology, types of torrefaction processes, effects of operating parameters on quality and quantity of torrefied biomass, the physiochemical property of torrefied biomass, advantages and disadvantages of torrefied biomass, as well as the use of torrefied biomass. This review article will be a guideline for the readers who interest in biomass torrefaction technology for sustainable development and application in the future.

Keywords

Biomass, Biomass conversion, Torrefaction, Torrefied biomass, Solid biofuel.

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