Verification of proper operation of dry acid gas removal process on syngas derived by O2/CO2-blown gasifier

Abstract

Dry syngas purification process was demonstrated on the bench scale test facility comprised of halide removal unit and sulfur removal unit with three fixed bed reactors in which regenerable honeycomb sorbents were installed. The first-ever test of the facility aims to verify the resistance of the zinc ferrite desulfurization sorbent to the carbon deposition in actual syngas condition and proper operation of the cyclic run of the three-reactors system. The test was so challenging that the sulfur removal sorbent was exposed to the severe condition for carbon deposition in the actual syngas derived from oxygen/carbon dioxide blown coal gasifier. The process was operated at 450 °C and 0.98 MPa abs. under the duration of reactor switching of sulfur removal unit of 1 hr for the initial cyclic operation. The dry syngas purification process exhibited sufficient performance of halide and sulfur removal that was evaluated with gas analytical instruments and chemical analysis of the spent sorbent. The sulfur removal unit was operated for the initial cycle of sulfidation, regeneration, and reduction steps without any detrimental effect of carbon deposition. This result encouraged that the process is ready to perform the proper operation in the actual syngas condition during the longer duration of multiple cyclic operation of the bench scale test facility.