Jamaica Biofuels Report - Ministry of Energy

purchased in some form from elsewhere. Because of these and other factors, as the tableindicates, the cost of ethanol from cassava is generally higher than from sugar cane. However, itdoes offer a possible way to extend the operational use of a distillery to full year.Petrobras invested in a cassava mill during the period of 1978 to 1983, but Brazilian experiencewith ethanol from cassava since then is limited. Although there is room, in all likelihood, forincreased productivity, as has occurred with cane in the past, the average yield of cassava inBrazil is only 20 t/ha. Also, according to Felipe and Alves (2007), it is very difficult to averagemore than 20% starch in cassava over a season. At those rates, about 100 L of ethanol could beproduced annually per hectare under pilot and laboratory conditions.New varieties of cassava are being developed, and while it is worth more as food, someprocessing residues could be used economically to produce ethanol. Before cassava can beconsidered for commercial application in Jamaica a number of challenging issues need to beevaluated by local field trials and a number of other factors taken into account:• Cassava can be produced in a wide range of soil types and conditions, but like any othercrop, it responds positively to better practices. Sandy soils are better than loam soilsbecause of the development of the rhizomes with less soil resistance. It is a robust cropcapable to produce even in quite low technology conditions.• Experience growing cassava in similar conditions to Jamaica involves food production ona small scale, so it has to be tested under local conditions.• Preprocessing requirements, such as enzymatic or acid hydrolysis to break down thestarch into fermentable sugars before it can be fermented and fed to a distillerydesigned primarily for sugar cane, with some process adjustments• Supplemental fuel requirements for processing. While above ground parts of the plantcould theoretically supply some fuel, these are likely to be needed to provide naturalhumus for the restoration of the soil.• Storage requirements and seasonal factors for year-round continuous processing.Cassava may have an application in Jamaica as a crop that can be stored in piles or asdried chips to provide feedstock when sugar cane is out of season.2.3 BiodieselCastor• CharacteristicsCastor is a perennial plant that grows wild in many locations and is well adapted to poor soils,so it commonly appears as a weed among other crops. As such, the economical growth of thiscrop often needs more care than most farmers are willing to provide for the attainable return.For success, it needs a suitable fertilization program, proper soil preparation, weed control andother good practices.19