Efficiency Comparison of Large-Scale Standalone, Centralized, and Distributed Thermochemical Biorefineries

Abstract

We present a comparison of three strategies for the introduction of new biorefineries: standalone and centralized drop-in, which are placed within a cluster of chemical industries, and distributed drop-in, which is connected to other plants by a pipeline. The aim was to quantify the efficiencies and the production ranges to support local transition to a circular economy based on biomass usage. The products considered are biomethane (standalone) and hydrogen/biomethane and sustainable town gas (centralized drop-in and distributed drop-in). The analysis is based on a flow-sheet simulation of different process designs at the 100 MWbiomass scale and includes the following aspects: advanced drying systems, the coproduction of ethanol, and power-to-gas conversion by direct heating or water electrolysis. For the standalone plant, the chemical efficiency was in the range of 78–82.8 % LHVa.r.50 % (lower heating value of the as-received biomass with 50 % wet basis moisture), with a maximum production of 72 MWCH4, and for the centralized drop-in and distributed drop-in plants, the chemical efficiency was in the range of 82.8–98.5 % LHVa.r.50 % with maximum production levels of 85.6 MWSTG and 22.5 MWH2 /51 MWCH4, respectively. It is concluded that standalone plants offer no substantial advantages over distributed drop-in or centralized drop-in plants unless methane is the desired product.