2.1.2 Functional unit One kilometer driven by new passenger cars was used as functional unit to compare ethanol (in the form of gasohol) and gasoline.
2.2 Data collection 2.2.1 Cassava farming cost The Thai government has recently approved the construction of 6 CE plants in the north-eastern region with a total output of 1.35 million litres (ML) per day in 2007-2008 [7]. Of this output, 0.75 ML would be contributed by 2 CE plants located in Nakhon Ratchasima which is the top cassava-producing province in Thailand [8]. Cassava farming cost was collected on-site in this province. The cost is an aggregation of various cost components which can be categorized into five groups as follows. 1) Land preparation by tractor. Included in this item are cost of fuel, hiring tractor and driver. 2) Planting activity, including cost of planting materials (cassava stems) 3) Chemical (fertilizers and herbicides) and application 4) Harvesting 5) Transportation of chemicals and harvest
2.2.2 Cassava processing cost Data were obtained through personal interview with the manager of a typical cassava-drying floor in Thailand [5]. The magnitude of cassava processing cost is contributed mainly by 1) fuel use for tractor operation, and 2) manual packing.
2.2.3 Ethanol conversion/distribution cost The detailed cost breakdown for ethanol production from cassava was adapted from the 2003 cost estimate prepared by the research team in the Cassava and Starch Technology Research Unit (CSTRU), Bangkok, Thailand [9]. The estimate was done based on a production scale of 100,000 L – 200,000 L of anhydrous ethanol per day. Up to this point, the cost of ethanol