Exergy and thermoeconomic analysis of cream pasteurisation plant

Cream is a milk derivative comparatively rich in fat, present in the form of emulsion of fat in skimmed milk, and acquired by physical extraction from raw milk with the help of centrifugal separator. The cream with variable fat content (10–40%) is commonly employed as an ingredient to traditional or modern desserts. It is also used in the production of value-added milk products such as butter and ghee apart from regular cooking applications. The pasteurisation, being an important safety requirement of milk food products, is usually materialised by heating the milk cream at a temperature of 90 °C for a period of one second. In the current work, thermodynamic and thermoeconomic derivatives in combination with all available constraints have been determined for high temperature short-time cream pasteurisation plant. The energy and exergy efficiency of cream pasteurisation plant was determined to be 86.88% and 66.11%, respectively. The cumulative value of energy destruction and exergy demolition in subunits of cream pasteurisation plant was estimated to be 93.88 kW and 11.39 kW, respectively, which mainly ascribed to complete enzymatic denaturation of fluid cream. The overall operating cost rate of complete cream pasteurisation plant was calculated as 1649.10 Rs./H, 22.02% portion of which was associated with electrical energy consumption. Further, the cost rate of exergy degradation for chilling and cooling activities was reported as 617.57 Rs./H and 357.55 Rs./H, respectively. The exergoeconomic factors of heating (14.75%) and chilling activity (0.82%) articulated that capital investment was dominant in the former while thermal degradations were enunciated most flagrant in latter.