Evaluating the carbon footprint of sulphur recovery unit: A comprehensive analysis

Abstract

Desulphurising of oil-based fuels and industrial gases is a widespread practice. The combustion process in the sulphur recovery unit (SRU) involves the reaction of H2S with oxygen to produce SO2, which is then converted to elemental sulphur through a series of catalytic reactions. Oxygen enrichment is a technique used to enhance the performance and efficiency of the SRU. By introducing a higher concentration of oxygen into the combustion process, the overall combustion reaction can be optimized, resulting in an increased sulphur recovery from sour gas and reduced emissions of sulphur compounds. The present study analyses the gate-to-gate comparative environmental impact of air versus oxygen-enriched air used for combustion to recover 1.0-ton sulphur using GaBi software (8.5.0.79 version). The primary data was collected from the literature. The GaBi Indian extension database is used for the secondary data source. The results are reported using midpoint impact assessment methods CML 2001. The global warming potential for oxygen-enriched SRU is 232 kg CO2 eq. compared to 276 kg CO2 eq. for air-enriched SRU. Similarly, the potential for abiotic depletion (elements + fossil), acidification, eutrophication, human toxicity, freshwater aquatic ecotoxicity, marine aquatic ecotoxicity, photochemical ozone creation and terrestric ecotoxicity are higher for air-based SRU than oxygen-enriched SRU. The analysis concludes that oxygen enrichment technology is a highly effective way to reduce the environmental impact of the SRU.