Energy Properties and Fuel Potentials of Mbeya Rice Husk as Source of Energy

Abstract

Rice husk is an agricultural waste generated in massive quantities from rice-processing units worldwide. With no valuable use, it is a waste material that creates environmental and disposal problems. However, the rice husks can be used as alternative fuel in industrial sectors; building and construction industry; animal fodder; and fertilizer. Rice husk can be converted into biofuels using different treatment and production methods such as: thermochemical conversion, biochemical conversion and chemical treatment. The study evaluated the possibilities of using rice husks as an alternative source of energy for commercial and domestic applications such as in cement production processes and for public institutions in Mbeya City. Therefore, the study investigated the energy potential and the fuel properties of rice husks widely disposed at Mwanjelwa and Mbalizi milling machines. Different samples of rice husks originating from Mbeya have been analysed related to their energy content values. Sampling of the rice husks was done according to EN 14778 and ensured proper conditions whereby only dry husks were considered from milling machines outlets. The samples were then packed in plastic bags. The following analyses were carried out: Water content, ash content, lower and higher calorific value, elementary components and other organic compounds. Thus, the organic matter assessed here contains roughly 36% carbon, 4% hydrogen and 32 % oxygen. Additionally, the rice residues contain 0.6 % Nitrogen, 0.2 % Sulphur and 0.1 % Chlorine. Furthermore, the rice husk from Mbeya City has lower calorific value ranging from 13.40MJ/kgdb to14.34 MJ/kgdb which indicates that they are suitable for various thermal applications. Therefore, results indicated that rice husks from Mbeya City has the potential to replace firewood and charcoal for cooking in public institutions, hence minimizing environmental challenges. Also, it could partially replace coal at Mbeya Cement Rotary Kiln System hence improving energy use and CO2 emissions to environment