In contemporary times, cassava is being recognized as an important source of biofuel. Research efforts aimed at investigating the potential of this sturdy crop for the production of biogas and bioethanol are currently in progress.

1.1 Global production of cassava

As observed by Adelekan (2012), Cassava (Manihot esculenta Cranz) is a very important crop grown for food and industrial purposes in several parts of the tropics. Nigeria, with a 2006 production of 49 million tonnes of cassava is the largest producer of the crop in the world (National Planning Commission, 2009). Other countries which grow significant quantities of the crop include Brazil, Congo Democratic Republic, Thailand, Indonesia, Ghana and China. A handful of other countries also grow the crop but at much lower production quantities. According to IFAD/FAO (2000) report, cassava is the fourth most important staple crop in the world after rice, wheat and maize. The present annual global production of cassava is estimated at 160 million tonnes. This huge production also results into the discharge of significant cassava-derived solid wastes and liquid wastes into the environment especially during processing. Cassava peels constitute 10-20% by mass of each tuber. Cassava tuber contains 25-30% dry matter by mass, the major portion of which is made up of carbohydrates in the form of starch and sugars. The tuber also contains 70-75% moisture. The ongoing encouragement of cassava cultivation by Governments in Nigeria, Thailand, China and other countries is gradually raising the profile of the crop as a significant cash crop. With increased crop production is also an associated increased production of peels and other cassava-derived wastes. This constitutes an enhanced risk of pollution of the environment. There is therefore a pungent need to find an alternative productive use of the peels. One area of possibility is to investigate the potential of cassava peels for the production of biogas. Finding such an important use for the peel would make it less burdensome on the environment as a pollutant and contribute towards enhancing energy security in the cassava-producing regions.