Achieving net-zero CO2 emissions from indirect co-combustion of biomass and natural gas with carbon capture using a novel amine blend

Abstract

The application of indirect co-combustion of biomass (in the form of producer gas) and natural gas with CCS technology has been identified as an alternative approach for electricity generation while achieving net zero CO2 emissions. Using the benchmark 5 M MEA (as a basis) and LCA methodology, it was identified that to achieve net-zero CO2 emissions, 14.5 % producer gas (energy basis) is required. Different amine blends were developed and assessed against 5 M MEA. The best performing solvent was 4 M (2:2) AMP: 1-(2HE) PRLD with CO2 absorption and desorption parameter of 4.5 % and 1667 % higher than 5 M MEA at absorption and desorption temperatures of 40 °C and 90 °C, respectively. At the desorption temperature of 110 °C, the lean loading of this optimum solvent and 5 M MEA were 0.02 and 0.24 mol CO2/mol of amine, respectively implying a higher cyclic capacity. The CO2 removal efficiency of the final solvent at 110 °C was 31 % higher than that for 5 M MEA. Finally, Using this optimum solvent as the absorbent for CO2 capture and applying the increased CO2 removal efficiency to the LCA data, it was determined that 8.2 % of producer gas, on energy basis, is sufficient for achieving net-zero CO2 emissions. Thus, using a solvent with a better absorption and desorption parameter allows for a reduction in the volume of biomass required for achieving net-zero CO2 emissions. If the ratio of biomass volume requirement for 5 M MEA is maintained in the scenario where the optimum solvent is used, negative CO2 emissions will be achieved.