Pilot‐scale evaluation of concentrated piperazine for CO 2 capture at an Australian coal‐fired power station: duration experiments

Duration operation was completed as the final stage of evaluating concentrated piperazine as a CO 2 capture solvent at the Tarong pilot plant. For the duration tests, a single operating set‐point was maintained for an extended period of time. The purpose of the duration tests was to monitor the formation of degradation products and the robustness of the solvent. Two duration tests were conducted that differed only in the regeneration temperature used (125 or 155 °C). Four hundred twenty‐five hours of operation were achieved on the solvent with a regeneration temperature of 125 °C. This was followed by a further 421 h of operation with a regeneration temperature of 155 °C, giving a total operating time on the solvent of 1700 h by the end of the project. For the duration experiments, roughly 500 tonnes of flue gas was treated, and approximately 70 tonnes of CO 2 captured. The heat stable salt (HSS) measured in highest concentration was formate, with the rate of formation increasing with regeneration temperature. The effect of pre‐treatment could be seen with sulfate concentration in the solvent increasing sharply when caustic supply to the pre‐treatment column was interrupted. Despite the formation of degradation products in the solvent regeneration energy requirements were not notably effected. For operation up to 1700 h on a real coal flue gas, no loss of plant performance was observed. © 2015 Society of Chemical Industry and John Wiley & Sons, Ltd