Physical and Thermochemical Properties of Rice Husk

Rice husk a major by-product of the rice milling industry, is one of the most commonly available lignocellulosic materials that can be converted to different types of fuels and chemical feedstocks through a variety of thermochemical conversion processes. Proper understanding of the physical and thermochemical properties of rice husk is necessary for the design of thermochemical conversion systems. This study provides information on moisture content, bulk density, particle size, heating values, proximate analysis, ultimate analysis, ash composition, and ash fusibility characteristics for six rice husk varieties. The moisture content ranged from 8·68 to 10·44%, and the bulk density ranged from 86 to 114 kg./ m3. The results showed excessive volatile release of over 60%, high ash content ranging from 15·30 to 24·60% (dry weight basis), and high silica content of the ash ranging from 90 to 97%. The lower heating values ranged from 13·24 to 16·20 MJ / kg (dry weight basis). The ash fusion temperatures of all the varieties were found to be over 1600°C. The differences in varietal characteristics have significant effects on the chemical properties of rice husk.