Energy and exergy analysis for cryogenic process design/retrofit

While the oil price has been decreasing dramatically, downstream petrochemical industries using by-products from upstream process such as methane, ethane, and others are still growing due to demand of domestic products e.g., plastic and resin. The downstream process like LNG production or Gas separation processes needs refrigeration system for cooling the natural gas to reach the proper condition which requires high energy consumption of compressor work, evaporator and condenser. To gain more benefit, reduction of utilities are the main goal. For this purpose, exergy analysis has been applied with pinch analysis called Extended Pinch Analysis and Design (ExPAnD) (Aspelund et al., 2007) to reduce that work by adjusting the pressure and temperature. Besides that, graphical and mathematical models have been used to identify efficient condition by using the exergetic temperature concept (MarmolejoCorrea et al., 2012) which is the energy quality parameter. This parameter can be used to conduct the T-ET - (E) over dot(T) diagram (Exergetic composite curves) defining the utility consumption that should be reduced by exergy target.