Crude oil deep drawing process method

Abstract

The invention discloses a crude oil deep drawing process method. Partial pressure reduction slag oil cyclically returns to a position in front of a pressure reduction furnace to be mixed with heavy oil at the bottom of a normal pressure distillation tower for entering a pressure reduction flash distillation tower arranged in front of the pressure reduction furnace, high-temperature hydrogen or nitrogen or overheated steam accounting for 1 percent to 3 percent of the mass of inlet materials is introduced into the tower bottom of the pressure reduction flash distillation tower, the tower top gas phase of the pressure reduction flash distillation tower is converted into a liquid phase to be used as products through heat exchange and condensing, bottom oil of the pressure reduction flash distillation tower is introduced into the pressure reduction distillation tower for pressure reduction distillation after being heated through the pressure reduction furnace, pressure reduction fraction oil is extracted out from the side line of the pressure reduction distillation tower, pressure reduction slag oil is extracted from the tower bottom of the pressure reduction distillation tower, a part of the pressure reduction slag oil is sent out of the device, and a part of the pressure reduction slag oil cyclically returns to the pressure reduction flash distillation tower for recycling. In the method, heat carried by the high-temperature cyclic pressure reduction slag oil and the steam extraction effect of the high-temperature nitrogen are sufficiently utilized, and lighter fraction in the normal bottom oil is evaporated out in the pressure reduction flash distillation tower. The yield of the pressure reduction slag oil is reduced, and in addition, the load of the pressure reduction furnace is reduced.

Description

technical field [0001] The invention belongs to the field of petroleum refining, and in particular relates to a crude oil deep drawing process. technical background [0002] Atmospheric and vacuum distillation of crude oil is the first process of petroleum refining. It divides crude oil into components with different distillation ranges by distillation to meet the process requirements of products and downstream equipment for raw materials. The conventional atmospheric and vacuum distillation process of crude oil mostly adopts the process of "two furnaces and three towers": crude oil enters the primary distillation tower (or flash tower) after pretreatment, and then enters the atmospheric distillation tower after being heated in the normal pressure furnace, and the bottom of the atmospheric distillation tower The oil is heated by the vacuum furnace and sent to the vacuum distillation tower by the vacuum transfer line to complete the atmospheric distillation and vacuum distill...

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Problems solved by technology

However, the bottom oil of the atmospheric distillation tower enters the flash tower. Since the temperature of the bottom oil of the atmospheric distillation tower is relatively low, and the vacuum degree of the flash tower in front of the furnace is relatively low, the effect of the flash vaporization of the flash tower is limited. Moreover, the gas phase at the top of the flash tower enters the vacuum distillation tower, which is equivalent to segmental feeding of the vacuum distillation tower after flash evaporation, without fundamentally changing the fractionation effect of the vacuum distillation tower

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