HYDRODESULPHURIZATION OF NAPHTHA

Abstract

Naphtha is a brownish liquid which is a mixture of specific boiling range of hydrocarbons. It is highly flammable, has aromatic smell and is obtained from the fractionation of crude oil. Naphtha is major raw material for ethylene production around the world. It is used in the manufacture of many compounds like benzene, toluene and xylene as well as in hydrogen and ammonia production. It is also used not only as a fuel but also as a thinner to reduce the viscosity of crude oil for transportation purposes. SOx and NOx emission is destroying the environment. Hence the removal of the sulphur containing compounds from naphtha is major concern of the refineries all around the world. Sulphur present in naphtha also destroys the catalysts of cracking units and especially reforming units in industries. So its removal is essential to protect noble metal catalysts. Over the years, many processes have been developed for the removal of these compounds. The hydrodesulphurization process is chosen as suitable regarding the requirements by the industry and is studied in depth for this project. It is one of the oldest and most efficient process. Due to selectivity of catalyst towards sulphur removal, the final product has less than 1ppm sulphur. The hydrodesulphurization process is designed and optimized for this project. It is simulated using Aspen Hysys. Main focus is the design of reactor and distillation column. Research is being done on catalyst selection to ensure efficient removal of sulphur compounds. In the future, a reactive distillation scheme may be developed to integrate all plant units into one main vessel.