Thermal integration of Waste to energy plants with Post-combustion CO2 capture

Waste-to-Energy (WtE) is becoming an important application sector for carbon capture utilization and storage (CCS) implementation due to both its role in urban waste management and its inherent potential of achieving negative emissions. This study is built upon a series of modelling activities, with three representative WtE plant steam cycle configurations selected to integrate monoethanolamine (MEA) based Post-combustion CO2 Capture (PCC). Results show that there is a great potential for heat recovery from the steam cycle and the PCC process to provide heat for District Heating (DH). For WtE plants in the steam extraction and condensing configuration with PCC and heat recovery, the energy utility factor (EUF) is higher than for the scenario without PCC. Results also show that ultra-high CO2 capture requires only a marginal increase in specific reboiler duty when compared with 95% capture; and that at ultra-high CO2 capture levels, heat recovery helps to improve EUF and EEE values beyond those at 95% capture but without heat recovery.

When comparing the two CHP operation configurations with PCC integration it is important to differentiate between carbon intensities under different bases: electrical or thermal. This study found that the carbon intensity (on the basis of electricity output) with PCC is much lower under CHP configurations than that in the power-only configuration. Findings of this study could potentially increase the attractiveness of WtE-CHP plant with PCC as a climate abatement option and bring more confidence in the potential of the future implementation of carbon capture technology in the WtE sector.