Modelling and simulation of a novel micro-scale combined feedstock biomass generation plant for grid-independent power supply

Remotely located and sparsely populated areas often do not have access to an efficient grid connection for electricity supply. However, plenty of biomass is normally available in such areas. Instead of employing island solutions such as diesel generators or large battery stacks with severe impacts on both the environment and economics of rural electrification, a micro-scale biomass plant using locally available feedstock to produce electricity and/or heat is an efficient way of not only providing those areas with competitive and reliable electricity, but also a step towards energy self-sufficiency for a large share of areas worldwide. Both wet and dry feedstock are usually available in remote areas, therefore a novel plant design combining thermochemical and biochemical treatment has been developed. The system consists of a small-scale downdraft gasifier and an anaerobic digester unit, both coupled to a gas storage system and a microturbine as the generation unit. This combined feedstock design is suitable to provide electricity down to a level of around 50 kWe, which suits a remote village or a large farm. This paper covers the modelling of the plant design in chemical engineering simulation software. Additionally, feasibility studies and results obtained from operation simulations are described and show that such a system is a feasible and an economic solution for remote power supply. Copyright (C) 2009 John Wiley & Sons, Ltd.