Biorefineries : a method to compare process alternatives using different economic scenarios

Abstract

A general overview on biorefineries and cost estimation methods is presented to provide background knowledge needed to create software focused on comparing different biorefinery configurations. The software is implemented in Microsoft Excel 2003 and can account for the capital cost, operating cost and utility requirements of different process operations based on their operating scale. To facilitate consistency in estimating capital costs an equipment factored capital cost method is implemented based on the Guthrie method. Factors used determine the capital cost includes: <ul> <li> purchased equipment cost</li><li> paterials of construction</li><li> operating pressure</li><li> time index factors</li> </ul> The program also includes a custom search algorithm that cycles through the processes to give candidates, based on feasibility equations, of single product focused configurations that can be further customised for analysis. With the program’s focus on comparing alternatives hypothetical processes are created that give the same product but use different possessing routes and starting materials. The solver was used to calculate the candidate configurations and then manually configured to evaluate energy production from side products. The program’s functionality and purpose was then shown by altering costs to give results for a different techno-economic scenario.