Car fuelled by cassava is a world first

Photo: CIATThe first vehicle completely powered by a biofuel made from cassava roots is already on the move in the department of Valle del Cauca, Colombia.

The test run is being carried out using a CIAT (International Center for Tropical Agriculture) pick-up truck. CIAT, together with Clayuca, a consortium that supports cassava research and development in Latin America and the Caribbean, recently inaugurated a pilot small-scale processing plant that produces hydrated ethanol using cassava, sugar sorghum, or sweet potato as raw material. This fuel contains 4 per cent-5 per cent water, hence its name of hydrated ethanol.

The vehicle has already covered 700 kilometers, "without feeling the change," says Bernardo Ospina, executive director of Clayuca. Ospina decided to set the example and demonstrate the effectiveness of the new technology developed in Brazil.

Any vehicle can be converted to this system by installing a kit that can be purchased in Brazil, over the Internet. The kit costs approximately USD120, is very easy to install, and allows the car to run purely on ethanol, gasoline, or on a mixture of both, in any proportion.

"A mixture of 85 per cent bio-ethanol and 15 per cent gasoline is recommended, but we are using 100 per cent bio-ethanol in this test run," said Ospina. "The device allows the motor to make adjustments in the compression rate to better use the larger amount of oxygen present in the ethanol."

Because this is a pilot project, the vehicle uses ethanol prepared by Clayuca's pilot plant at CIAT's headquarters in Cali, which has capacity to produce an average of 300 liters per day.

Bio-electricity too

The hydrated ethanol can also be used to generate bio-electricity. A stationary ethanol-operated plant can produce up to 110 and 120 volts electricity. Four liters of hydrated ethanol are needed to generate 1 hour of electric power.

The use of hydrated ethanol as vehicle fuel began to gain importance in Brazil in 2003 when flexible-fuel vehicles, locally known as Flex vehicles, were introduced to the market. These vehicles are capable of operating on any mixture of gasoline and hydrated ethanol. Estimates are that, in April 2009, Brazil's fleet of Flex vehicles, which operate with a mixture of 86 per cent bio-ethanol and 14 per cent gasoline, surpassed the 7.5 million units.

In Colombia, the current mixture is 10 per cent alcohol fuel (produced with sugarcane) and 90 per cent gasoline.

The production of hydrated ethanol at the CIAT/Clayuca pilot plant is the basis of a work methodology known as rural social bio-refineries because their low installation and operation costs can make a significant contribution to rural communities located in marginal areas that lack access to electric power systems.

The raw material used does not compete with products for human consumption because the cassava varieties used are industrial (inedible) types, developed by CIAT researchers, with high starch content. The stems of sugar sorghum and sweet potato, an Andean crop little used as food in Colombia, are also used.

The concept of a rural social bio-refinery seeks to motivate institutions to endorse the use of this technology, since the raw materials are entirely used. In addition to producing hydrated ethanol, the potential contaminating processing wastes, similar to sugar industry effluents known as vinasse, are being used to prepare nutritional blocks for livestock and fertilizers to reactivate soils.

"Any rural community that does not yet have connection to electric power can set aside 3-5 hectares to grow cassava as an energy crop and what is produced would be sufficient to provide electric power for 6 hours a day, all year round," says Ospina. The same result can be obtained with other crops such as sweet potato and sugar sorghum. "The impact potential of this approach is enormous if we consider that, according to the UN, nearly 2 billion people worldwide still don't have access to electric power."

Valle del Cauca's Governor, Juan Carlos Abadía, observed first-hand the operation of the pilot plant and expressed his interest in implementing the technology in several regions of the department. This prototype bio-refinery also attracted the attention of representatives of numerous organizations around the world that participated in Clayuca's Annual Meeting of Partners recently.