Waste heat recovery in biomass gasification via a high-temperature heat pump for power generation

Bioenergy is now an essential part of sustainable energy systems. In order to unlock the full potential of biomass resources, this research aims to develop a framework for biomass-to-power systems, benefiting from advanced technologies in heat integration and heat upgrading, particularly high-temperature heat pumps (HTHPs). The framework provides an opportunity to explore the performance of biomass-to-power systems utilising a wide range of biomass types as well as various operational conditions. A reduced-order model (ROM) is developed using the proposed model, which provides a reliable estimate of the power capacity and system efficiency for power generation. The investigation also identifies the contribution of the HTHP to energy efficiency and discusses its role in different scenarios. The present study reveals that biomass-to-power systems using gas engines achieve efficiencies ranging from 16% to 30%, and the sensitivity analysis shows that efficiency is highly influenced by the feed type and gasification temperature and the load of HTHP. The integration of the HTHP minimises the use of syngas for preheating the gasifier, thereby allowing more power to be delivered by the system. Despite the limited heat-delivery temperature of the HTHP and its consumption of about 5% of the gas-engine power output, it improves the overall power generation efficiency of the system by about 2%. • HTHP integration boosts net efficiency of bioenergy power generation by ~2%. • Up to ~5% of engine power to HTHP is thermodynamically feasible and beneficial. • Biomass-to-power efficiencies of 16–29% demonstrated across six typical biomass feedstocks. • Reduced-order model accurately predicts efficiency across wide feedstocks and operating ranges.