A new absorption power cycle using ionic liquid and refrigerant under COSMO-SAC model

Abstract

The ionic liquid 1-hexyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([HMIm][Tf2N]) and a refrigerant (R-134a) were studied as working mixture for an absorption power system using waste heat resource and compared with the Organic Rankine cycle (ORC). A big amount of low-grade waste heat, which is the result of energy consumption, can be used to drive an absorption power system. The simulation methodology is based on the COSMO-SAC model and PENG-ROB model as implemented in Aspen Plus to verify the reliability of COSMO-SAC model. Desorber and absorber outlet temperatures and solution heat exchanger on the system performance were evaluated. The deviation between the COSMO-SAC and PENG-ROB model are floating between 26% to 31%. The efficiency (η) of the absorption power system is 1.75% than ORC at Td (desorber or evaporator temperature) = 100°C, and 32.02% higher at Td = 65°C with Ta (absorber or condenser temperature) = 40°C.