Xylene addition effects to H₂S combustion under Claus condition

Experimental results are presented on the combustion of H₂S and mixtures of H₂S and xylene at an equivalence ratio of three (Claus condition). The H₂S mole fraction decreased along longitudinal central axis of the reactor to a minimum value. The SO₂ mole fraction increased to a maximum value, which subsequently decomposed due to the formation of elemental sulfur, which is favorable under Claus condition. In contrast, mixtures of H₂S and trace amounts of xylene (0.5%, 1% and 2%) favored the formation of H₂ and increased the amounts of H₂S at reactor exit. Xylene addition reduced the maximum mole fraction of SO₂, and resulted to the formation of CH₄ and CO. The formed SO₂ decomposed faster to yield COS and CS₂ from its reaction with CH₄ and CO. The formation of CH₄, CO, COS and CS₂ poses severe impact on sulfur capture efficiency from acid gases. These results reveal a direct impact on the Claus reactor performance with trace amount of xylene present in H₂S thermal processing.