Exergoeconomic Performance Assessment of a Sulfuric Acid Production Unit Using the Specific Exergy Costing Method

Abstract

In this work, an industrial sulfuric acid production unit was evaluated using exergetic and exergoeconomic analysis to determine possible improvements in its efficiency and cost effectiveness. The exergoeconomic evaluation was performed by Specific exergy costing method (SPECO). The case study process is the production of sulfuric acid from liquid sulfur by a double absorption contact. The exergy efficiency, exergy losses and exergoeconomic performance of each component in the overall plant were calculated and analyzed. The exergetic analysis, on the studied process, identifies the location, magnitude, and sources of thermodynamic inefficiencies. The obtained results indicated that the largest exergy destruction took place in the combustion stage, representing a 67 % of the total exergy losses. The exergy efficiency of the unit was around 44.7 %. Through the exergoeconomic analysis, the selling price of the produced H2SO4 as well as the total investment cost were estimated and the exergoeconomic factor of each component was quantified. The highest exergoeconomic factor, of 86 %, was observed in the recovery boiler, meaning that reducing the equipment cost of the studied process is of high importance to reduce the final product of the overall system. On the other hand, the combustion oven showed the lowest exergoeconomic factor, of 1.22 %, implying that improving its thermodynamic efficiency would be compulsory for that component.