Techno-economic assessment of carbonate looping for cost-effective CO2 capture in waste incineration

Waste incineration and waste-to-energy (WtE) plants play a key role in waste management worldwide. To avoid the high amounts of CO2 emissions associated with waste incineration, cost-effective capture solutions are required. Nevertheless, most capture processes entail high economic penalties, making them unprofitable under current carbon taxes. In this work, we compare two concepts for capturing CO2 emissions using carbonate looping (also known as calcium looping, CaL) technology. One concept involves retrofitting the capture facility at the back end. The other is a novel integration concept that uses pretreated waste to fire the calciner, replacing one incineration line. The CaL concepts are analyzed for retrofitting a German WtE plant, which treats 200 kt of waste per year. We performed a techno-economic assessment that includes process modeling using the software Aspen Plus. The process simulations were supported using reactor models validated with pilot plant data. The calculated mass and energy balances were used to dimension components and calculate economic indicators, including a sensitivity analysis. We obtained CO2 avoidance costs (CAC) of ca. 140 €/tCO2,av for the tail-end concept, in agreement with previous studies. On the other hand, the integrated concept has CAC of 27 €/tCO2,av, including compression but excluding transport and storage, making it competitive with the current price of CO2 certificates in the European Union. To the best of our knowledge, this is the lowest value reported in the scientific literature for CO2 capture from waste incineration plants to date.