Pilot-scale parametric evaluation of concentrated piperazine for CO2 capture at an Australian coal-fired power station

Concentrated piperazine (PZ) is a promising new solvent under consideration for post-combustion capture (PCC) of CO2. A solution of 8 molal PZ was recently evaluated at the Tarong CO2 capture pilot plant in Australia. Initial operation involved evaluation of different operating conditions at the plant to determine the minimum energy conditions for this solvent. Comparison was made to results achieved previously at the same pilot plant with 30 wt% monoethanolamine (MEA). Regeneration energy requirements achieved with concentrated PZ were consistently lower than those achieved with MEA. The lowest regeneration energy for PZ at the pilot plant (2.9 MJ/kgCO(2)) was roughly 15% lower than the best result predicted for MEA. Inter-cooling located at the center of the absorber column was also evaluated for the concentrated PZ solvent. The benefit of inter-cooling was found to depend on the operating conditions of the plant, with operation at higher liquid-to-gas (L/G) ratios showing a more pronounced effect. For an L/G ratio of 3.3 kg/kg, inter-cooling was found to lower the regeneration energy required for PZ by approximately 10%.