Integration of a novel cyclonic reactor: effects on biomass torrefaction and optimisation

Torrefied bio-coal is a good alternative to coal used in various industries. Torrefaction is a key technology to develop a torrefied biocoal. Many researchers proposed different torrefaction reactor designs based on process conditions like rotary, auger, fluidised bed, and microwave. The proposed technology, novel cyclonic torrefaction reactor (NCTR), is a technically feasible method to improve the torrefaction process with continuous separation of torrefaction gas from torrefied biocoal. In NCTR design, a reverse cyclone is formed which improves uniform heating and residence time of process. NCTR is integrated with rotary reactors to improve conventional torrefaction processes. The optimum temperature for continuous torrefaction process is 290°C in NCTR and 260°C in rotary reactor. Torrefied charcoal properties were calorific value is 4921 kcal/kg, volatile matter is 17%, fixed carbon is 62.33%, ash content is 10%–11%, and moisture content 3%. Mass yield is 61%, energy yield is 93%, and process thermal efficiency is 76%. The separation efficiency of NCTR is 100% for 0.2–5 mm particle size. Thus, integration of NCTR with rotary reactor is a good alternative to the torrefaction process, which leads to maximised torrefied biocoal productivity with minimal resources.