Computer-aided Molecular Design of ORC Working Fluids using PC-SAFT

Organic Rankine Cycles (ORCs) are used for the transformation of low-temperature heat to power. The key design variables are the process settings and the working fluid. This paper presents a holistic method for the computer-aided molecular design (CAMD) of ORC working fluids. The basis for the design is a novel approach allowing for the simultaneous optimization of the working fluid and the process by exploiting the molecular picture underlying PC-SAFT. The simultaneous design yields a target for a hypothetical working fluid and optimal process settings from one optimization problem. The hypothetical target fluid forms the basis for the CAMD method. For this purpose, a group contribution (GC) method is developed for the prediction of PC-SAFT pure component parameters. Thereby, a holistic design of novel working fluids and optimal processes is achieved.