Unique CGIAR project: small farmers in decentralised cassava ethanol production

Cassava is increasingly gaining attention in the developing world as an attractive biofuel crop. The reasons are manifold: as a biofuel, cassava based ethanol has a strong energy and GHG balance. This contrasts with fuels made from crops grown in the US and the EU, the fuels of which barely have a positive energy balance and do little to reduce carbon dioxide emissions. Moreover, the plant thrives under rainfed conditions on marginal lands not suitable for other crops, requires relatively low inputs and is thus easily cultivated by small farmers. Cassava grows far away from rainforests the soils of which are not suitable for the crop, thus limiting the risk of the biofuel driving deforstation.

Some of the brightest minds in biotechnology - like Norman Borlaug, father of the Green Revolution - are working on mapping cassava's genome with the aim of improving it for fuel production (see the U.S. DOE's Joint Genome Institute and its work on cassava, as well as the work at the International Atomic Energy Agency's Plant Breeding and Genetics division, where nuclear and space breeding techniques are used to study the crop for improvement).

According to a report from the Consultative Group on International Agricultural Research (CGIAR), one of the leading global agricultural research consortia working towards strengthening the food security of people in the developing world:

"Cassava has erupted into the first decade of the third millennium as a crop that can contribute to agro-industrial and small-farmer development in the tropics. One of the most recent advances — using cassava to produce fuel alcohol — has opened multiple opportunities, not least for small farmers."

In short, cassava looks like an ideal biofuel crop and countries like Thailand and China have already taken it up to produce ethanol. In Nigeria, the Presidential Cassava Initiative is aimed at ethanol and biogas, and is expected to bring 3 million jobs.

An initiative by the International Centre for Tropical Agriculture (CIAT) in Colombia (part of the CGIAR), is now playing an active role in diversifying the use of cassava and in creating new strategies to access markets. The approach promoted by CIAT, in alliance with the Latin American and Caribbean Consortium to Support Cassava Research and Development (CLAYUCA) and with Dutch company Diligent Energy Systems, facilitates the participation of small farmers in the production of cassava as the raw material and in pre-processing activities.

Unique decentralisation approach
The initiative is unique in that cassava roots are initially transformed into ethanol at 50% concentration by the small producers, at the most local level. The alcohol is then taken to a central distillery to produce fuel alcohol (ethanol at 99.5% concentration). One of the biggest hurdles to producing fuels from biomass efficiently - transporting the bulky material over long distances - is thus overcome. Raw biomass (such as starch tubers) has a low energy content. By transforming the material into an intermediate product with a higher energy density (alcohol) at the local level, the transport costs can be greatly reduced.

The CIAT's low-tech approach to decentralisation is similar to high-tech strategies based on placing pyrolysis plants near biomass harvesting sites, aimed at producing bio-oil which is then brought to a central processing plant (more here).

Artisan-scale processing plants can easily be set up in many rural communities because of their low cost. Small distilleries have been around for a long time, but their efficiency can be greatly improved with minimal redesigns. In addition, processing by-products from the fermentation step can be used by the local farmers as feedstocks for biogas, animal feed and organic fertiliser:
bioenergy :: biofuels :: energy :: sustainability :: alcohol :: starch :: ethanol :: cassava :: poverty alleviation :: rural development :: decentralisation :: Colombia ::

To facilitate the implementation of this decentralised approach, CIAT and CLAYUCA received financial support from Colombia’s ministry of agriculture to establish in the second half of 2007, a pilot plant for processing ethanol from cassava, sweet potato and other sources of biomass. The plant’s processing capacity will be 800 liters a day. It will be located at CIAT's headquarters.

We are working to generate an innovative, decentralised process, where small farmers are given more participation and where production is oriented towards a bio-refinery concept, in which the potential of crops such as cassava and sweet potato is tapped to obtain biofuels, convert wastes into fertilisers and animal feed products, and transform liquid effluents into biogas. - Bernardo Ospina, executive director of CLAYUCA.

This endeavour aims to position cassava as an agricultural option that can help Colombian farmers improve their income and quality of life. It should also help validate sustainable and competitive options of energy and agro-industrial development currently implemented by the Colombian government.

The experience can serve as a model for other countries in Africa, Asia and Latin America that seek the sustainable development of bioenergy programs using traditional crops.

The project is not limited to biofuel production. It also aims to solve the problem of contamination from solid and liquid wastes.

The North American companies Feeco, Encap and Soil Net LLC (all from Wisconsin), the sugar refineries Mayagüez, Providencia and Riopaila, Colombia’s largest paper manufacturer (Propal), CLAYUCA and CIAT recently formed an alliance to transform the contaminating residues resulting from the manufacture of ethanol (sugar industry effluents, also known as vinasse) into competitive products, thus helping to reduce the adverse environmental impact of these residues on the region’s soil and water resources.

Vast potential
Cassava holds an enormous potential across the subtropics and the tropics. Especially in Central and West-Africa there is a vast amount highly suitbable non-forest land currently not being used.

Traditionally, cassava is grown as a subsistence crop and seen as an emergency foodstuff. It can be left in the ground for long periods of time and harvested in times of scarcity. At this subsistence level, yields remain low. Given the vast number of small farmers who grow cassava in Africa, Asia and Latin America without inputs, production from existing hectarages can be increased considerably with micro-doses of fertilizer (previous post). Besides increasing yields from existing farms, there are millions of suitable and highly suitable hectares of non-forest land available.

Some countries, like Thailand and Nigeria, have developed an industrial-scale cassava sector which serves to produce animal feeds and starch. Nigeria used to export large quantities to the EU, but new policies there which support European animal fodder producers, have closed off the market. For this reason, former president Olusegun Obasanjo launched a 'Presidential Cassava Initiative' aimed at boosting and diversifying uses for the crop. Biofuels offer an entirely new market and may revive the sector for industrial cassava (earlier post).

More information:
Consultative Group on International Agricultural Research: Fueling Cassava's Popularity - June 2007.

CIAT's Cassava Biotechnology Network.

The Consortio Latinoamericano y del Caribe de Apoyo a la Investigación y al Desarollo de la Yuca.