... hydrocarbon-based large-scale ammonia plants is sensitive to sulfur compounds and prone to be poisoned and deterioration in activity ... on attrition ,%max3.0Thiophene conversion,%min604. Operation ConditionOrganic sulfur in gases or oil, ppm100-200H2 to oil volume ... in hydrogenated gas, ppmmax100Arsenic in feed oil, ppbmax100Organic sulfur in effluent gas or oil, ppmmax0.1The hydrogenation reactions ...