Solvent Storage for Waste to Energy plants with Carbon Capture under CHP operation

Waste-to-Energy (WtE) has become an attractive application for carbon capture utilization and storage (CCS) due to its role in decarbonizing urban waste management and its inherent potential of achieving negative emissions. Building upon a series of modeling activities, the application of interim solvent storage (ISS) is researched with the objective of improving the heat supply ability of WtE combined heat and power (CHP) plants integrated with Post-combustion CO2 capture (PCC). This paper uses a mathematical programming-based methodology using a design-day approach to investigate the optimal operation of a WtE-CHP plant with the implementation of interim solvent storage. The results show that the usage of a load-following gas boiler is reduced as a result of implementing solvent storage thereby also lowering fossil CO2 emissions. The amount of wasted excess heat is also reduced. However, the plant with interim solvent storage has a lower annual profit as the increased capital costs of building storage tanks are higher than the savings from lower boiler heat usage and lower CO2 taxes with these results highly sensitive to the problem setting and input parameters. We observe that solvent storage is not operational during the summer design day suggesting that seasonal solvent or thermal storage may be a more useful alternative