The economic analysis undertaken in this report puts the process technology into fourmajorproduction stages: cultivation, dewatering, extraction and transesterification. The integration of these individual production stages was used to determine the total production cost of biodiesel from microalgae. To allow a greater comparability between the results of the analysis, the economic model applied a consistent approach to each production stage. This approach estimated the total production cost using a number of components, which included major equipment costs; individual fixed capital costs and fixed capital investment (FCI); annual costs; and running costs.

1.7 Major Equipment Costs

The first element necessary in estimating the total cost of each alternative unit opera­tion technology was to determine the major equipment costs of each scaled-up pro­duction option. The primary source of costing information regarding standard process equipment such as pumps, tanks and compressors was provided in Peters et al. [26], whilst similar economic studies were employed to estimate the costing of more specialised equipments such as the raceway ponds [4], HTRs [10] and ELRs [21].

In the dewatering stage, the major equipment cost of centrifuge was based on information provided in Peters et al. [26], whilst the costs of the chamber, suction and vacuum filters were each estimated as a proportion of the centrifuge cost, using the ratios reported in Mohn [20]. In the esterification stage, costing for all equip­ment was scaled-up from a study completed by Sakai et al. [29]. All major equip­ment costs were scaled to current prices using appropriate indexing from the Chemical Engineering Plant Cost Index (CEPCI).