Post-combustion CO₂ capture in waste incineration plants

Every European produces about 500 kg of waste each year. While some of this waste can be reused or recycled, 40% ends up in landfills or is incinerated. Waste incineration offers several advantages over landfilling: significant volume reduction, recovery of remaining energy, straightforward treatment of hazardous materials, and suitability for highly urbanized areas. For these reasons, despite the increasing spread of renewable energy sources, the number of waste incineration plants (WIPs) is expected to continue rising due to ongoing growth in global waste generation. However, waste incineration in WIPs currently produces about one ton of CO₂ per ton of treated waste. In Europe, this amounts to roughly 100 million tons of CO₂ per year—more than 3% of total European greenhouse gas emissions. The only way to avoid CO₂ emissions from WIPs is to capture it before it is released. The captured CO₂ can either be stored underground or reused (e.g., for the production of chemicals). Due to the share of biogenic carbon in residual waste, capturing and geologically storing CO₂ from WIPs can even result in net-negative emissions, also known as Carbon Dioxide Removal (CDR). There are three strategies for CO₂ capture in WIPs, depending on their integration with the combustion process: pre-combustion, oxy-fuel combustion, and post-combustion. Pre-combustion technologies separate CO₂ through a gasification step followed by CO₂ capture. In oxy-fuel combustion, waste is burned with pure oxygen to avoid high nitrogen concentrations in the flue gas. Finally, post-combustion systems capture CO₂ from flue gases after combustion. The main advantage of post-combustion capture is that, unlike the other technologies, it allows retrofitting existing plants without major modifications to the upstream process. The costs of these technologies depend heavily on the type and degree of integration as well as plant size. In this work, we explain the main post-combustion technologies available for CO₂ capture in WIPs. We present their advantages and disadvantages and provide recommendations for further research to reduce costs. Amine-based systems have been tested in a few WIP facilities, but their high energy demand makes their economic viability challenging. On the other hand, carbonate looping technology can achieve the lowest CO₂ avoidance costs, but it still requires further validation. If the system performs as expected in planned pilot trials at existing WIPs, CaL could become the standard technology for retrofitting CO₂ capture in waste incineration plants.