Essential basics on biomass torrefaction, densification and utilization

Abstract

Torrefaction and densification are crucial steps in upgrading biomass as feed-stock for energy generation and metallurgical applications. This paperattempts to discuss essential basics on biomass torrefaction and densification,which can propel developing nation to take full advantage of them. The mostpromising clean energy sources that have found applications in various areasare biomass materials, that is, both the lignocellulosic and non-lignocellulosi c.However, high moisture contents, low energy density, hydrophilic nature, poorstorage and handling properties are the major drawbacks limiting its useful-ness. Therefore, torrefaction as one of the major thermal pre-treatment pro-cesses to upgrade biomass in terms of improved energy density, hydrophobic,moisture content and grindability has been discussed. The influence of temper-ature, residence time, particle sizes and gas flow rates on the properties of tor-refied biomass has also been discussed. The advantages and disadvantages ofvarious torrefaction technologies have also been highlighted. The possibleareas of application of torrefied biomass especially densification into pelletsand briquettes alongside the equipment required for it have been reviewed inthis paper. The torrefied biomass can be deployed in the metallurgical indus-tries as reducing agent in the development of sponge iron from iron ores ofvarious grade including lean ones. The information gathered in this paperfrom peer-reviewed articles will reduce the burden of seeking to understandthe preliminaries of torrefaction process and its importance