Preparation Of Molecular Sieve Supported Solid Desulfurizing Agent And Its Performance Research

With the improvement of people's living standard,the demand for oil is dramatically raising.However,the quality of crude oil being processed by refineries has gone from bad to worse and the content of heavy crude oil and high-sulfur crude oil is increasing in recent years.As we all know,sulfides can lead to the corrosion of equipment,and it may also cause the poisoning of catalysts in the refining process.Therefore,the pre-desulfurization can benefit a lot to the equipment protection and the environment and this research has a very good prospects for development.The middle Saudi Arab crudes were used as feedstock in this thesis,and the simple adsorption desulfurization techniques were adopted in the process of pre-desulfurization.The NaY and 13 X zeolites were used as carriers,which were loaded with transition metals by ion-exchange method,such as Cu²⁺?Zn²⁺?Co²⁺ and so on.Moreover,the best preparation conditions of desulfurization adsorbents and proper reaction conditions were investigated,and the regeneration performance of the best desulfurization adsorbent was also studied.At first,NaY zeolite sieve was used as carrier and copper nitrate as the modified substances.And the best preparation conditions for desulfurizer and desulfurization conditions were determined.The best preparation conditions was that the ion exchange concentration was 0.8mol/L and temperature was 90?.At the same time,the best desulfurization conditions was that the reaction temperature was 40? and time was 2 hours.And the highest desulfurization rate was 40.05%.After that,13 X zeolite sieve was taken as carrier.Cu?NO₃?₂ and Zn?NO₃?-2 was used as the modified substance,respectively.And the best desulfurization rate is 41.01% and 39.02%,respectively.In order to study the association between transition metals and zeolite sieve,the matching experiments were carried out.The results showed that 13X?Zn?was the best desulfurization adsorbent.And the best conditions were as follows: ion exchange concentration was 0.6mol/L and temperature was 45?,and the desulfurizer was exchanged twice.What is more,the best desulfurization conditions were as follows: the reaction temperature was 40? and time was 2 hours.Then the regenerability of 13X?Zn?was investigated.Moreover,solvent and calcination methods were adopted in this paper and the highest desulfurization was 18.56% and 33.15%,respectively.The results also showed that the rate of desulfurization gradually decreased with the increase of regeneration time of catalyst.In the end,the molecular sieve was characterized by XRF,XRD,SEM and other characterization techniques.The sulfur content was determined and sulfur compounds were characterized before and after desulfurization simultaneously.Based on the above,the mechanism of desulfurization was studied.