A Benchmark for Compact CO2 Capture Plant Designs by Monoethanolamine Solvent Testing at Technology Centre Mongstad

Technology Centre Mongstad (TCM) is a large and flexible demonstration site for post-combustion CO2 capture. It is located next to the Equinor refinery at Mongstad (Norway) which is the source of the flue gases supplied to TCM. It has been used for testing CO2 capture with MEA solvent and a compact design, providing a benchmark for compact CO2 capture technologies.. The absorber was used with its lowest possible packing height of 12m, and only one of two water washes was used (3m height). The plant was operated with a high flue gas flow rate (67,000 Sm3/h) and 35 wt% MEA with a sensitivity down to 30 wt%. The CO2 inlet concentration was 6% mimicking some industrial exhausts, small turbines with exhaust gas recycle or modern turbines with high turbine inlet temperatures. The tests demonstrated that such a low absorber can capture more than 80% of the CO2 with only a slightly higher steam demand than conventional applications with higher packing heights of 18-24m. The low absorber gave 3.9 MJ/kg CO2 for the specific reboiler duty, while previous tests at other conditions and with higher absorbers gave 3.5-3.7. Acceptable emissions were observed, while degradation was higher than earlier TCM campaigns due to the choice of running with 35 w% MEA. Overall, a benchmark has been provided for future improved compact capture technologies.