Energy Conversion and Management: X (Aug 2022)
Energy and exergy studies of a Sulphur recovery unit in normal and optimized cases: A real starting up plant
Abstract
Sulphur recovery units produce Sulphur from H2S gas to prevent any acidic gas emission against environmental regulation. A refinery plant in the middle east that started its official production in 2020 has an SRU plant to do this role. The plant was simulated and optimized using a special package for Sulphur in HYSYS named SULSIM. While energy is transformed into other forms, exergy is destructed in an irreversible process. A complete exergy study was conducted on different plant equipment to calculate the exergy destruction, the exergy efficiency and the percentage share of destruction. The study included the normal case, optimized case and a comparison between both cases. The thermal reactor has the highest destruction rate of 39551.79 kW, with a percentage share of 56.481% of total destruction. Then catalytic reactor1 with a destruction rate of 14000.22 kW and 19.993 percentage share. In general, the reactors participated with 88.88%, the reactors with the addition of the waste heat boiler shared with 97.07% of total destruction. The destruction distribution was approximately the same in optimized conditions. The total destruction rate of equipment was 70026.31 kW and 70301.72 in normal and optimized conditions respectively. Although from an energy point of view optimized conditions were better, the destruction exergy rate exceeds the normal conditions by 275.41 kW. In optimized conditions, some equipment destruction rate exceeds their values in normal conditions. From the energy point of view, 1.04 ton/h of steam was decreased in the optimized conditions saving 69247.03 $/year. The calculated destructed value from SULSIM for “Amine & Regenerator” is −115.56 kW, which is incorrect; the correct value is 2404.85 kW, which was calculated using standard HYSYS V.11.
