Assessment of the energy and economic performance of second generation biofuel production processes using energy market scenarios

In this paper performance assessment of second generation biofuel production using energy market scenarios and system-level performance indicators is proposed. During biofuel production a number of products and services can be co-generated while import of energy services (e.g. electricity and heat) in addition to the fuel supply may also be needed. This needs to be reflected by a well-defined performance indicator enabling a comparison between different process alternatives. A marginal production perspective is proposed in this study for the definition of a general energy performance indicator, recalculating all services to primary energy on a system level. The Energy Price and Carbon Balance Scenarios (ENPAC) tool developed at Chalmers is used for the definition of the energy system background. Thereby, a scenario-specific comparison of the processes’ thermodynamic, economic and carbon footprint performance is possible. The usefulness of the approach is illustrated for production of synthetic natural gas (SNG) from biomass. The shortcomings of common performance indicators are also discussed.