Increased energy content of rice husk through torrefaction to produce quality solid fuel

Energy is the main need of humans to carry out activities with better levels of life. At present, energy for daily life is provided from the processing of crude oil. The availability of crude oil in Indonesia is increasingly limited and the price tends to be expensive. This condition requires alternative energy for fuel availability for households. One alternative energy comes from biomass because biomass is a renewable energy and Indonesia has a very large amount of biomass. Utilization of biomass as an alternative energy source has some limitation due to the non-uniform biomass quality and scattered biomass sources. Due to the lack of biomass quality, biomass needs to be pre-treatment before being used for combustion or gasification process. One of biomass pre-treatment to improve the quality of biomass is torrefaction. Torrefaction is a mild pyrolysis at a temperature between 200-300°C to eliminate water content and a small amount of volatile matter from biomass. The torrefaction biomass will have high energy density and hydrophobic properties. Rice husk is one type of biomass produced from rice processing as waste. Indonesia has large amounts of rice husk waste with an energy potential equal to 7000 MW and is located in a rice mill. In this experiment, the energy content of the torrefaction rice husk was analyzed by observing the effect torrefaction temperature (200, 250 and 300°C) and duration of torrefaction (30, 45 and 60 minutes). At the high temperature of torrefaction (300°C), the rice husk has a darker color with high energy content (3465 kkal/kg) but almost 50 % of initial mass loss by torrefaction.