Chemical looping with oxygen uncoupling of hydrochar in a combined cycle for renewable and low-emission power generation

Abstract

This work is concerned with design and analysis of a renewable power generation process featured with fast speed of biomass processing, low NOx and SOx emissions and ease of carbon capture. It is based on chemical looping with oxygen uncoupling (CLOU) of hydrochar derived from hydrothermal carbonization (HTC) of biomass. An air reactor and a fuel reactor employing CuO/Cu2O redox reactions are integrated with a combined Brayton and Rankine cycle to generate power. The design simulation is conducted using Aspen Plus V11. By implementing multiple-stage intercooled compression and multiple-stage reheat expansion in the Brayton cycle and multi-pressure steam generation in the Rankine cycle, an overall thermal efficiency of 35.3% on HHV basis without carbon capture (or 32.4% with carbon capture) is obtained.