Absorption equipment for energy savings: A case study in Sicily

This paper considers a feasibility study on the recovery of the reject heat available from an electric utility with two units operating with 120-MW gas turbines; these units have a heat recovery system that feeds the district heating pipeline of an industrial consortium. Thus, feeding the expeller of the absorption equipment installed in a cooling plant for foodstuff stocking represents an opportunity for the feasibility study. This plant operates at both 0 °C and −18 °C. The feasibility study covers two aspects: (1) the technical feasibility of a suitable absorption cooling plant that uses two separate pieces of absorption equipment working with the pair ammonia–water and (2) the relevant economic venture analysis. The feasibility study pertains to both the optimal design of the absorption equipment and the energetic and exergetic analysis of the plant; moreover, the same type of analysis was performed for a reference case pertaining to a two-stage reciprocating compression refrigerating plant. An economic analysis of the venture demonstrated that the expected time of return on the differential investment is less than 4 years and that the specific investment costs expected given the differential costs between the two alternative options are 11.28 €/toe of primary energy savings and 15.84 c€/t(CO2,eq) of reduced greenhouse gas emissions.