Agricultural Waste as Raw Materials for the Production of Activated Carbon: Can Tanzania Venture into this Business?

Abstract

Activated Carbon (AC) can be produced from a variety of carbonaceous materials. Traditionally, they are produced from coal, lignite, coconut shells and wood peat thus raising the cost of commercial activated carbons. Agricultural wastes and by-products are considered good alternative source materials for production of activated carbons because of their abundance, high carbon content and cheap availability. In this review, an extensive list of agricultural wastes and by-products from vast literature has been assessed and properties of activated carbons produced from them evaluated. The potential of Tanzanian agricultural wastes for production of activated carbons is also discussed. Among the variety of agricultural wastes studied, nut shells, stones, seed hulls/husks, plant straws/stalks, sugar cane bagasse and agro-forestry residues such as sawdust have drawn much interest. The review also reveals that indeed agricultural wastes can produce activated carbons with properties comparable to commercial ones. In this case, Tanzania stands a chance of benefitting both economically and environmentally if it utilises the agrowastes for large scale production of activated carbons.

Keywords: Activated carbons, physical activation, chemical activation, agricultural wastes.