Technical and economic assessment of charcoal and densified fuel from water hyacinths and cotton stalks

Abstract

A study is presented on the production of charcoal and densified fuel using water hyacinths and cotton stalks as a feedstock. Both biomasses have no economic value and occur in fairly high concentrations. The circumstances of the town of Kosti in the Sudan are specifically investigated. The high water content of the water hyacinth has to be diminished by open-air drying. The high ash content of the air-dried plant material can be reduced to the cellular ash level of 12% by a combination of disintegration and screening. The air-dried water hyacinth is easily binderless-briquetted to a fuel wood substitute. The cotton stalks lend themselves to carbonization. 3.3 tons of chopped cotton stalks yield one ton of cotton-stalk charcoal and one MWh of electricity. The result of the study indicates that the process is technically feasible and economically viable. The cotton charcoal can be used in industry as a breeze or, after briquetting, as a lumpy smokeless fuel in households. A cotton-stalk carbonization plant should have a capacity of at least 15,000 t/a of charcoal.