Assessment of Carbon Capture Technologies for Waste-to-Energy System

Municipal solid waste is a mixture of urban and industrial waste, consisting of biodegradable fractions, such as food waste, waste wood or paper, but also fossil-based fractions, among which plastics, textiles, metals, glass and aluminum. Depending on the type of waste and recovery technique, biogas, biofuels, heat, electricity and metals, are possible value-added products. As both biogenic and fossil carbon are present among waste fractions, the reduction and capture of carbon is crucial in the deployment of sound waste management technologies. There are several physicochemical CO2 capture technologies, and they have their own benefits, challenges and limitations. Some techniques are in the development phase, and they need to be evaluated for their possible integration within waste-to-energy system. We have developed a waste-to-energy superstructure, including digestion, gasification and incineration as the main waste treatment technologies. The latter is the main contributor of CO2 emissions. The developed superstructure includes three options for CO2 capture from flue-gases: amine absorption, temperature swing adsorption and membranes. Amine absorption and membranes are considered for biogas upgradation, whereas pressure swing adsorption and membranes are evaluated for syngas upgradation. This study systematically generates and compares a number of decarbonization options for waste-to-energy system. The formulated optimization problem is a mixed integer linear programming problem, and total annual cost is considered as the performance criterion for generating decarbonizing options. For carbon capture from flue-gases, amine absorption and temperature swing adsorption found to be better options compared to membrane separation