Patent ID: 7754068
Filing Date: 2010-07-13
Classification: C10G

Abstract:
1. A process for the selective hydrodesulfurization of naphtha streams containing olefins and organosulfur compounds, said process including: a) contacting said naphtha feed containing olefin content in the range of 20 to 50 mass % and sulfur in the range of 200 to 7,000 mg/kg in a first reaction stage, under hydrodesulfurization conditions comprising temperature from 200 to 420° C., pressure from 0.5 to 5.0 MPag, and space velocity LHSV between 1 to 20 h b) removing H c) directing said naphtha obtained in step b) towards a second reaction stage, in a reactor charged with a hydrorefining sulfided catalyst, under hydrodesulfurization conditions similar to those of the first stage, and contacting said partially hydrodesulfurized naphtha with a stream which is a mixture of H wherein said process comprises: (i) in the said first reaction stage: the said hydrorefining catalyst is made up of a more active catalyst for HDS while the H (ii) in the said second reaction stage: the said hydrorefining catalyst is made up of a less active catalyst for HDS, said second stage catalyst being distinct from the said first stage catalyst, and the H (iii) the said first reaction stage catalyst is more active towards HDS than the said second reaction stage catalyst since said first reaction stage catalyst requires, for obtaining the same sulfur conversion and same hydrorefining conditions, lower temperature than the said second reaction stage catalyst for obtaining the same sulfur content when processing the same naphtha feed, whereby a hydrodesulfurized naphtha of improved selectivity relative to the state-of-the-art technique is recovered at the end of the said process, wherein the mole ratio, H