Evaluation of handling and reuse approaches for the waste generated from MEA-based CO₂ capture with the consideration of regulations in the UAE

A waste slip-stream is generated from the reclaiming process of monoethanolamine (MEA) based Post-Combustion Capture (PCC). It mainly consists of MEA itself, ammonium, heat-stable salts (HSS), carbamate polymers, and water. In this study, the waste quantity and nature are characterized for Fluor's Econamine FGSM coal-fired CO₂ capture base case. Waste management options, including reuse, recycling, treatment, and disposal, are investigated due to the need for a more environmentally sound handling. Regulations, economic potential, and associated costs are also evaluated. The technical, economic, and regulation assessment suggests waste reuse for NO_x scrubbing. Moreover, a high thermal condition is deemed as an effective technique for waste destruction, leading to considerations of waste recycling into a coal burner or incineration. As a means of treatment, three secondary-biological processes covering Complete-Mix Activated Sludge (CMAS), oxidation ditch, and trickling filter are designed to meet the wastewater standards in the United Arab Emirates (UAE). From the economic point of view, the value of waste as a NO_x scrubbing agent is 6 561 600-7 348 992 USD/year. The secondary-biological treatment cost is 0.017-0.02 USD/ton of CO₂, while the cost of an on-site incinerator is 0.031 USD/ton of CO₂ captured. In conclusion, secondary biological treatment is found to be the most economical option.