Exergy Analysis of a Process Converting Power and Biomass to a Liquid Fuel

Abstract

A power and biomass to liquid process (PBtL) via Fischer-Tropsch synthesis is exergetically analysed. Synthesis gas is generated through an entrained flow gasifier and extra hydrogen is produced through high temperature steam electrolysis in a solid oxide electrolysis cell (SOEC). The gasification section of the process has the highest exergy destruction rate, followed by the Fischer-Tropsch and SOEC sections. To improve the process, the focus should be on the design and operation of these sections. The plant has an overall exergetic efficiency of 69 %, evaluated as the ratio of the exergy of the products to the exergy of the biomass and electricity supplied to the process.