Process Study On Crude Oil Distillation For Increasing The Yield Of Light Oil And Wax Oil

Light oil and wax oil are the backbone of Nanyang Wax Fine ChemicalPlant's(NWFCP) economy, so it is very important to increase the yield of light oil andwax oil for the survival and development of NWFCP. Distillation Unit is the mainprocess for oil to be processed further. In this thesis, chemical assistants such asdemulsifier, pour-point depressant of diesel oil, enhanced distillation agent of crude oil,demulsifier for diesel oil etc. were evaluated. The main processes of atomosphericdistillation and vacuum distillation were innovated to improve the yield of light oil andwax oil.In order to optimize the operation parameter of electric desalting to enhance theratio of desalting and dehydration, a type of demulsifier-desaulter, SH992, was selected.By using SH992, the ratio of desalting increased 4% and the ratio of dehydrationincrease 12.4%.In order to increase the diesel oil yield, a pour-point depressant of diesel oil, PCHwas selected. Although it has little effect on visbreaking, it makes the cold filterplugging point decreased by 3℃. Industrial experiment result showed that PCH had asatisfying effect on visbreaking and decreasing the cold filter plugging point, whichmakes the compound diesel oil meet the national standard.A kind of enhanced distillation agent of crude oil, GX-301 was selected to increasethe general evulsion ratio of crude oil. Laboratory and industrial experiment resultsshowed that additive GX-301 has better effect on distillation of crude oil and 120 ppmadditive GX-301 can increase the diesel oil and wax oil yield 1%.In order to resolve the problem of diesel oil emulsification after alkali washing,demulsifier for diesel oil, OA-1 was selected. After it was used, the quantity of diesel oilemulsification was significantly decreased. There is a separated layer between diesel oiland alkali sediment. The quantity of diesel oil in alkali sediment was decreased sharplyto 18.4 ppm. The quantity of alkali consumption was reduced by 40 percent and thequantity of alkali sediment was reduced by one third. The loss of diesel oil can bedecreased by 251 tons annually.The atomospheric and vacuum distillation towers were improved a lot. The sprueof oil and gas in the top of atmosphere tower was moved to the position between the20th and 21th floor. The F1 type boards of float valve tower were replaced by new typeboards Super-V1. The distributing device for stock in vacuum tower was changed totwo cutting direction and circumfluence type. New type of high effective filling,ZUPAK 250Y was used. New type of vapor and liquid distributing device was used.Three rising vapor pipes were added. All of these steps make the processing capacity ofatmosphere tower and the separating precision improved. The product quality of eachsidetrack of vacuum tower was improved. The oil yield in both atomospheric andvacuum distillation towers was improved.After the above methods were put into practice, the ratio of light oil was increased1.49% and the ratio of wax oil was increased 0.57%. The general evulsion ratio of crudeoil was increased 1.25%. This brought NWFCP profit of 2.61 million RMB every year.