Study On Hydro-donated Hydrovisbreaking Upgrading Of Oil Sand Bitumen

With the development of exploitation technique,unconventional oil resources development and utilization ratio increased.As unconventional oil resources,Canadian oil sand bitumen is characterized by complex composition,high viscosity,high metal heteroatomic content and high carbon residue.The high viscosity brought great difficulty to transportation of the bitumen.Therefore,it is necessary to choose appropriate processes to upgrade this viscous oil.In this paper,study on visbreaking,hydrovisbreaking and hydro-donated hydrovisbreaking of Canadian oil sand bitumen were carried out,the study provided basic data for the development of hydrovisbreaking technology.The influence of reaction conditions on the products was analyzed,and suitable process conditions were screened by reference to the standard of 380# fuel oil.In the meantime,the synergistic effect of hydrogen and hydrogen donor was revealed in the hydrovisbreaking of oil sand bitumen.By visbreaking of BAR,the viscosity of the upgraded oil could be effectively reduced,.but its stability turned out to be poorer,which couldn’t satisfied the requirements of pipleline or tank transportation.However,by hydrovisbreaking of BAR,its viscosity and stability could satisfied the requirements of pipleline transportation,also the oAPI was increased.And the optimum technology condition for hydrovisbreaking was 420oC,15 min.Under this condition,the viscosity of the upgraded oil was 375.35mm~2/s,and the oAPI was improved up to 13.3.The research by modified chemical probe method showed that,the hydrogen trasnferring ability of DB was stronger than DA.And then the best blending ratio of DB was 5%.Based on hydrovisbreaking of BAR,the hydrovisbreaking of BAR with hydrogen donor DB was carried out.The results showed that the upgraded oil by hydro-donated hydrovisbreaking was better than that of hydrovisbreaking,higher oAPI and less coke yield,and its viscosity and stability could satisfied the requirements of pipleline transportation.The optimum reaction condition for hydro-donated hydrovisbreaking was 420oC,15 min.Under this condition,the viscosity of the upgraded oil was 198.48mm~2/s,and the oAPI was improved up to 15.4.At last,the synergistic action of hydrogen and hydrogen donor was researched in the hydrovisbreaking of BAR process.It turned out that hydrogen can enhance the hydrogen capacity of hydrogen donor.Meanwhile,both of them can change the reaction product distribution,reduce the heavy components,increase the activation energy,Inhibit the reaction rate,then,the BAR can react under higher severity by hydrovisbreaking with hydrogen donor DB to abtain higher quality products.