Study on impact of H_2S on diesel hydrodesulfurization

On the basis of commercial FHUDS-5 and FHDUS-6 catalysts,the process conditions of diesel hydrofining were simulated,the impact of H2S on diesel hydrodesulfurization was studied and inhibition mechanism of H2S on diesel hydrodesulfurization was discussed.The results show that,the H2S has inhibition effect on diesel hydrodesulfurization with these two catalysts.The inhibition effect of H2S with FHDUS-6 catalyst is greater than that with FHDUS-5 catalyst.In deep hydrodesulfurization reaction(less than 50 ppm sulfur(mass),the inhibition effect of H2S is not apparent,indicating that the inhibition effect of H2S on diesel hydrodesulfurization reaction decreases with increase of reaction severity.Therefore,the H2S concentration in recycle hydrogen in commercial conventional hydrodesulfurization processes units must be controlled to minimize the inhibition effect of H2S on hydrodesulfurization reaction and reduce sulfur in product diesel.