Sustainability of cassava (Manihot esculenta Crantz) as industrial feedstock, energy and food crop in Nigeria C.N. Anyanwu a, * , C.N. Ibeto a , S.L. Ezeoha b , N.J. Ogbuagu c a National Centre for Energy Research and Development, University of Nigeria Nsukka, Nigeria b Dept. of Agric. and Bioresources Engineering, University of Nigeria Nsukka, Nigeria c Dept. of Agric. and Bioresources Engineering, Enugu State University of Science and Technology, Nigeria article info Article history: Received 28 August 2014 Accepted 28 March 2015 Available online Keywords: Cassava Garri Cassava flour Energy crop Agriculture Biofuel abstract Nigeria's cassava production surpassed 30 MMT around 1994 and has been increasing at 4.3% per annum. Cassava production targets under the government's agricultural transformation agenda program appear achievable, but it is unclear if current cassava output can satisfy growing demands. Yields need to in- crease from 12 t/ha currently to 25 t/ha by 2015 as specified in the ATAP. Cassava peels can yield 0.6 l/kg TS of biogas, which could augment primary energy needs. About 1.0  10 9 L of bioethanol could be produced annually from over 7.0 MMT of cassava peels generated, which is sufficient to execute gov- ernment's E10 program. © 2015 Elsevier Ltd. All rights reserved. 1. Introduction The Agricultural Transformation Agenda Programme (ATAP) of the Federal Government of Nigeria envisages high growth in the production of cassava - an important root crop that constitutes staple food for many homes in Sub-Saharan Africa. Recently, cas- sava has gained prominence as biofuel feedstock, notably for the production of bioethanol. It has become a major export commodity in view of its high starch content, which makes it a suitable raw material not only for bioethanol production, but also for many other industries such as pulp, textile, food and beverage, etc. Cas- sava production surpassed the 30 million metric tons (MMT) mark around 1997 and has been increasing at the rate of about 4.3% per annum since then. Currently, Nigeria produces about 48 MMT of cassava annually based on about 8% of cultivable land, out of which 29 MMT is demanded as food [21]. Through research, many varieties of cassava are now available for cultivation, but a major challenge is to improve cassava yields up from 11.7 t/ha to 22e25 t/ha by 2015 as targeted by the ATAP [8]. Expansion of cassava production has been relatively steady since 1980 with an additional push between the years 1988e1992 owing to the release of new improved varieties developed by the Inter- national Institute of Tropical Agriculture (IITA). National per capita production of cassava is put at 0.32 tons [26]. Over 800 million people world-wide depend on cassava as a regular source of energy. Per capita consumption in West Africa is more than 120 kg per annum. Cassava tuber may be processed into a variety of products, including chips, flakes, cubes, peeler, starch and flour, pellets etc, which are highly demanded in the export market. There is booming export market and the European Union (EU) Countries import over 10 million metric tons per annum. The use of cassava for com- pounding livestock feeds has also gained wide acceptance in Latin America and Asia. Apart from livestock feeds, processed cassava serves as industrial raw material for the production of adhesives, bakery products, dextrin, dextrose, glucose, lactose and sucrose. Dextrin is used as a binding agent in the paper and packaging in- dustry and adhesive in cardboard, plywood and veneer binding. Food and beverage industries use cassava products derivatives in the production of jelly caramel and chewing gum. Pharmaceutical and chemical industries also use cassava alcohol (ethanol) in the production of cosmetics and drugs. The products also find ready use in the manufacture of dry cell, textiles and school chalk etc. Cassava cubes are used mainly in the compounding of livestock feeds. Thus, there is a very high demand for cassava products in both the local and export markets. * Corresponding author. Tel.: þ234 7036706987. E-mail address: cnasofia@gmail.com (C.N. Anyanwu). Contents lists available at ScienceDirect Renewable Energy journal homepage: www.elsevier.com/locate/renene http://dx.doi.org/10.1016/j.renene.2015.03.075 0960-1481/© 2015 Elsevier Ltd. All rights reserved. Renewable Energy 81 (2015) 745e752