Biodesulphurization of fossil fuels: energy, emissions and cost analysis

Abstract

In order to achieve stringent environmental and safety requirements, refineries are in search of “green” and cost-effective methods for crude oil desulphurization. Combined desulphurization technologies are being studied, including bioprocessing to upgrade fossil fuels. Using biodesulphurization (BDS), which is a biochemical process mediated by specific microorganisms, it is possible to desulphurize most of the hydrodesulphurization (HDS) recalcitrant sulphur compounds under mild operating conditions, making it a simple and eco-friendly process. In this study, two BDS process designs are compared, in terms of energy consumption, greenhouse gas emissions and operational costs by following a life cycle assessment (LCA) and life cycle cost (LCC) based methodology. The industrial HDS process is used as the reference technology for sulphur removal from fossil fuels. Different theoretical scenarios were considered and the best BDS results are scaled-up to evaluate a case study of providing ultra low sulphur diesel to an urban taxi fleet. This study exploits the potential of BDS as a cost-effective and eco-friendly alternative or complementary technology to the commonly HDS towards ultra low sulphur fuels.