Comparative techno-economic and exergetic analysis of gasification technologies

Abstract

Nowadays, the use of lignocellulosic materials to produce biofuels/electricity is a field of ever growing importance. Two options of the interesting residual biomass are sugarcane bagasse and straw. A technological pathway for the conversion of biomass is the thermochemical route. Hence, biomass gasification represents a promising technology within this route for power generation and large scale production of a variety of biofuels (e.g. Methanol, Dimethylether, Fischer-Tropsch fuels, Hydrogen, and Synthetic Natural Gas). In this work, the technoeconomic and exergy analysis of the thermochemical routes integrated into a Combined Cycle are presented. The lignocellulosic gasification process uses fluidized-bed (circulating and dual bed) systems, with subsequent conversion of the synthesis gas (syngas). The process simulations were carried out using Aspen Plus® software, including biomass drying and gasification, syngas cleaning, conditioning, separation of synthesis products, and heat recovery. From the techno-economic assessment, the DFB-LCM model has the lowest total cost of investment, which represents a 40% less concerning the CFB-SCB system. In addition, the DFB-LCM model shows the lowest exergy destruction rate; as a consequence, the higher the exergy efficiency of the overall systems. Hence, the DFB-LCM model could represent a competitive application for the agro-industrial sector to explore the contribution/potential of lignocellulosic materials on carbon-neutral systems by converting syngas into electricity.