The Research Of The Effect Of Amphiphiles On The Wall Coking Of Heavy Oil Hydrocracking Reaction System

The effects of different amphiphiles(SDBS,CTAB,OA) on the heavy oil hydrocracking reaction of Karamay atmospheric residue was investigated using the autoclave in this thesis.The interaction mechanism of amphiphile was also studied in three aspects of the dispersed catalysts,the stability of asphaltene and the adsorption of asphaltene on the metal surface by uesing means of the mass fraction normalized absorption photometry method, element analysis and X-ray photoelectron spectroscopy analysis, etc.The results indicated that the effects of amphiphiles on the heavy hydrocracking reaction of KLAR were different.In the same reaction time,the weight of wall coking in different amphiphiles system was CTAB>blank>OA>SDBS.In the same amphiphiles system,the weight of coke on the metal surface was 35 carbon steel>Tc4 titanium alloy>316 Lstainless steel>304 stainless steel>316 stainless steel.The amphiphiles all had an optimal concentration and made the particle size of the vulcanizd catalysts become smaller.When the concentration was 500μg?g-1,the order of amphiphiles to decrease the particle size was CTAB>OA>SDBS>blank.In the certain amphiphiles system,the longer the hydrocracking reaction time, the worse the stability of asphaltene in the process.In the same reaction time,the ability of amphiphiles to stabilize the asphaltene was SDBS>blank>OA>CTAB.In the adsorption experiment of asphaltene,if the amphiphiles system was certain, the longer the hydrocracking reaction time,the easier the asphaltene adsorbed on metal surface. In the same reaction conditions,the adsorption of asphaltene on different metal surface was different.The mass of the adsorption was 35 carbon steel>Tc4 titanium alloy>316 stainless steel.If the metal was certain,the adsorption of asphaltene was CTAB>blank>OA>SDBS.We could find that the regular of the adsorption was same to the wall coking in the hydrocracking reaction.It indicated that the adsorption of asphaltene on the metal surface was an most important method to regulate the wall coking.The effect of amphiphile was related to the types and amounts of the functional groups on asphaltene surface. There were more alkaline functional groups and less acidic functional groups on the asphaltene surface of KLAR.Therefore, the anionic surfactant SDBS might use its acidic groups to have acid-base interaction with the alkaline functional groups on asphaltene surface.The amphiphile could gradually adsorb on asphaltene surface and stabilizedthe asphaltene to suppresses the adsorption of asphaltene on the surface of the metal.