Heat pump assisted distillation. IX: Acceptance trials on a system for separating ethanol and water

Abstract

An experimental study has been carried out on a continuously operated pilot fractional distillation column equipped with an external heat pump. The distillation column was a 153 mm diameter stainless steel unit containing fourty‐four sieve plates. An ethanol‐water mixture was fed to the column and the heat pump working fluid was R114. The actual coefficient of performance (COP)A of the heat pump increased with an increase in the mass flow rate of the working fluid. A maximum value of 4.5 was obtained with a gross temperature lift of 45°C. The performance of two reciprocating compressors was compared. A heat pump effectiveness factor of 0.8 was achieved. A maximum relative contribution of the heat pump of 65 per cent was obtained with minimum temporary insulation. With good insulation it is estimated that the relative contribution of the heat pump should exceed 80 per cent at the design feed rate. No control problems were encountered in the experiments.

Graphic exergy analysis of processes in distillation column by energy‐utilization diagrams

“…Some works were conducted by using the concept of heat integration with other processes or even inside the process itself (Umeda et al, 1979;Linnhoff et al, 1983). By applying heat pump to distillation (Gopichand et al, 1988;Supranto et al, 1988) heat can also be recovered from the column.…”