Technical and economic feasibility of the Isopropanol-Acetone-Hydrogen chemical heat pump based on a lab-scale prototype

Abstract

Chemical heat pump are promising alternatives in waste heat recovery applications. The present paper focuses on the technical and economic feasibility analysis of the Isopropanol-Acetone-Hydrogen Chemical Heat Pump (IAH-CHP) system. A small scale prototype of the IAH-CHP was established. Coefficient of performance (COP), exergy efficiency and entransy efficiency analysis were adopted to evaluate the performance of the IAH-CHP prototype. The stable operation is given with the waste heat temperature of 90 °C and the high-level output temperature of 160 °C. The COP, exergy efficiency and entransy efficiency of the system are up to 24.3%, 42.3% and 29.1%, respectively. Moreover, based on the detailed experimental results of the lab-scale apparatus, a 100 kWth model was built to evaluate economic feasibility of the IAH-CHP. The exergy cost and the thermoeconomic cost based on the structural theory, as well as the payback period were evaluated. The results indicate that the exergy destruction and investment cost of the distillation column is the highest, and the payback period is 5.6 year for the case of the optimal performance. The unit exergy cost of the final exergetic product is 6.56 W/W. The results proved that the IAH-CHP system is efficient in recovering the low-level waste heat.