Process Design Of 50×10~4 T/A Shale Oil Pretreatment Unit

As a supplementary energy of oil, shale oil has a huge reserve, and its production has been increasing year by year. But the emission with nitrogen and sulfide can cause serious atmospheric pollution after shale oil combustion as marine fuel oil, because the shale oil contains non-hydrocarbons such as nitrogen, sulfur, and oxygen compounds.In this paper, the 50 × 104 t/a shale oil pretreatment unit was studied and the process schemes of feed oil pretreatment, reaction, fractionation and dry gas desulfurization were well designed.In feed oil pretreatment section, two-stage automatic backwash filter was used to remove particles of feed oil, and electrical desalting and sump were used to remove the water and metal of feed oil, at the same time, inert gas was introduced to prevent from oxidation of feed oil.In reaction section, one-stage serial hydrotreating process was selected without recycle hydrogen desulfurization; hydro-prerefining reactor and hydrofining reactor were set; the feed mixed with hydrogen before entering the furnace and reaction injection and Hot HP process were used. The hydrogen consumption, heat balance and pressure balance were calculated by PROII model.The fractionation section contains diesel stripper and fractionator. By analysis of PROII model,9 theoretical plates were used in stripper while the steam volume was 0.8t/h; 17 theoretical plates were used in fractionators,and feed temperature was 380℃ while feed position was at the tenth plate. The content of H2S in naphtha oil, diesel and hydrogenation tail oil were separately less than 10ppm,50ppm and 50ppm.In dry gas desulfurization section, absorbing tower was used. According to the AMSIM model, top operating pressure was 0.56MPa(a), operating temperature was 40℃,16 actual plates were used and the consumption of lean amine was 10t/h.Finally, the key operating conditions, process characteristics and brief process description were summarized.