A novel process to recover sulfur in aqueous phase under ambient condition.

Sulfur recovery is an important industrial process for fossil fuel clean consumption, in which HS is firstly separated from the gas stream from the hydrodesulfurization process or gasified gas of coal or biomass. Meanwhile, almost equivalent half amount of SO is produced from the boiler on-site due to the power and steam generation or the fluid catalytic cracking process in a refinery. Currently, HS is converted into elemental sulfur using Claus process, which is being used worldwide, and SO is removed from the flue gas using lime or lime water. The two sulfur removal technologies require lots of capital investment and operating cost. Here, we have developed a novel process for SO in flue gas to react with HS from the gasified gas stream, to convert them elemental sulfur by washing the flue gas and HS with liquid catalyst containing water stream, the sulfur in SO and HS is converted into elemental sulfur and floated in the washed solution pool, which can be filtered out. Here, the pilot test results of the aqueous phase ambient temperature sulfur recovery process has been described and analyzed. The system converted more than 1000 ppm of HS and 500-600 ppm of SO in the flue gas into elemental sulfur in aqueous phase at temperature below 100 °C. The flue gas was washed with our acid aqueous media, and the sulfur is formed in the aqueous acid catalyst solution and was filtered out. The sulfur powder has the same laser Raman spectra with the Claus process, with the main structure as S with high purity. [ABSTRACT FROM AUTHOR]