ADVANCED SULFUR CONTROL CONCEPTS FOR HOT GAS DESULFURIZATION TECHNOLOGY

The objective of this project is to develop a hot-gas desulfurization process scheme for control of H₂S in HTHP coal gas that can be more simply and economically integrated with known regenerable sorbents in DOE/METC-sponsored work than current leading hot-gas desulfurization technologies. In addition to being more economical, the process scheme to be developed must yield an elemental sulfur byproduct. The Direct Sulfur Recovery Process (DSRP), a leading process for producing an elemental sulfur byproduct in hot-gas desulfurization systems, incurs a coal gas use penalty, because coal gas is required to reduce the SO₂ in regeneration off-gas to elemental sulfur. Alternative regeneration schemes, which avoid coal gas use and produce elemental sulfur, will be evaluated. These include (i) regeneration of sulfided sorbent using SO₂ ; (ii) partial oxidation of sulfided sorbent in an O₂ starved environment; and (iii) regeneration of sulfided sorbent using steam to produce H₂S followed by direct oxidation of H₂S to elemental sulfur. Known regenerable sorbents will be modified to improve the feasibility of the above alternative regeneration approaches. Performance characteristics of the modified sorbents and processes will be obtained through lab- and bench-scale testing. Technical and economic evaluation of the most promising processes concept(s) will be carried out