Study On The Processing Technology Of Coker Gas Oil To Produce More High-value Products

Fluid catalytic cracking(FCC)is one of the methods to lighten heavy oil,it plays an important role in the trend of heavier and inferior crude oil.In recent years,the delay of the heavy quality of coking feedstock and the adjustment of the cycle ratio by oil refining enterprises have led to the increase of the production and deterioration of the coker gas oil with high content of viscous cyclic aromatic hydrocarbons,colloid and nitride,which seriously affects the catalytic cracking reaction.It is very necessary to study the law of catalytic cracking of coking wax oil and explore suitable processing schemes.In this study,firstly,the catalytic cracking reaction of MVGO-1 mixed with common coker gas oil was experimentally carried out,and the suitable operating conditions were obtained.With the increase of the reaction severity,raw material conversion rate increases,and the yield of the target product increases,but at the same time there is a problem that the yield of dry gas and coke in the product is higher,and the selectivity of the target product decreases.The experimental results indicated that the optimum reaction temperature was 500°C,the best catalyst to oil ratio was 8.7,and the optimal residence time was 2 s.The catalytic cracking experiment of mixed heavy coker gas oil was carried out,and the influence of mixing amount on the catalytic cracking reaction of MVGO-2 was investigated.The cracking performance of MVGO-2 is worse than that of MVGO-1 under the same mixing ratio of heavy coker gas oil as common coker gas oil.However,its heavy circulating oil has better properties and can be recycled to increase production.With the increase of the mixing amount of heavy coker gas oil,the reaction conversion rate of the raw material gradually decreases,at the same time,the selectivity of the target product is obviously reduced.Finally,the processing scheme of coker gas oil was discussed from two aspects of producing more light oil and more propylene.Pure coker gas oil catalytic cracking experiment was carried out,and the effects of catalytic cracking reaction is poorer.Under the condition of the reaction temperature of 480 ~oC,residence time of 1.8 s,and catalyst to oil ratio of 9,the single-pass conversion rate was only 81.44%.The refining of heavy cycle oil makes the light oil yield increased by 7.94%,and the gasoline properties have certain to improve.While the heavy cycle oil was refining after hydrogenation,the yield of light oil was increased by 12.45percentage points,and the olefin content in gasoline was reduced by 4.19 percentage points.Compared the mixed feed separately and mixed wax MVGO-1 feed catalytic cracking reaction as a result,the coker gas oil and excellent catalytic mixture using TSRFCC technology separately feed can avoid coker gas oil and high quality raw materials in the catalyst on the problem of vicious competition,although separated from feeding the mixed feed conversion rate 0.23%lower,but the light oil yield increased by 0.64%.The effect of catalyst composition on the propane yield of mixed gas oil MVGO-1 was investigated.The yield of liquefied petroleum gas and the selectivity of propane could be improved by adjusting the propane content of ZSM-5 zeolite as the active component in FCC catalyst properly,so as to achieve the purpose of propane yield.The experimental results show that the optimal ratio of propylene additives should be controlled around 10%.