Heavy inferior crude oil inorganic salt organic acid organic metal compound combined removal process

Abstract

The invention relates to a heavy inferior crude oil inorganic salt organic acid organic metal compound combined removal process and belongs to the technical field of heavy inferior crude oil treatment. The heavy inferior crude oil inorganic salt organic acid organic metal compound combined removal process is characterized in that transformation is conducted on the basis of three-stage electric desalination, the first stage realizes removal of organic metal compounds and part of inorganic salt, the second stage realizes removal of organic acid and part of inorganic salt, the third stage realizes deep removal of inorganic salt, sewage after first-stage organic metal compound and inorganic salt removal and sewage after three-stage desalination treatment are introduced into a sewage treatmentsystem, sewage after secondary-stage organic acid and inorganic salt removal is introduced into a naphthenic acid recovering system, a naphthenic acid resource is recovered, and the high emulsion phenomenon which may occur in the electric removal process is treated by a high-voltage and high-frequency pulse electric field and by an emulsion layer liquid reinjection mode.

Description

technical field [0001] The invention relates to a combined removal process of inorganic salts, organic acids, and organic metal compounds of heavy and inferior crude oil, which belongs to the technical field of heavy and inferior crude oil treatment. Background technique [0002] As domestic crude oil becomes heavy and inferior, aging and emulsification problems become more and more serious, the content of inorganic salts in crude oil and the content of organic metal compounds such as Ca, Mg, Ni, and V increase, and the acidity of crude oil increases, which will lead to a substantial increase in the degree of emulsification of crude oil, resulting in frequent A series of problems such as corrosion, blockage, and catalyst poisoning of subsequent equipment such as decompression and catalytic cracking have seriously affected the long-term safe and stable operation of refinery units. [0003] At present, heavy oil can be demetalized by distillation, membrane adsorption, catalyti...

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Problems solved by technology

[0002] As domestic crude oil becomes heavy and inferior, aging and emulsification problems become more and more serious, the content of inorganic salts in crude oil and the content of organic metal compounds such as Ca, Mg, Ni, and V increase, and the acidity of crude oil increases, which will lead to a substantial increase in the degree of emulsification of crude oil, resulting in frequent A series of problems such as corrosion, blockage, and catalyst poisoning of follow-up equipment such as decompression and catalytic cracking have seriously affected the long-term safe and stable operation of refinery units

[0003] At present, heavy oil can be demetalized by distillation, membrane adsorption, catalytic hydrogenation, chelation separation and other methods. Catalytic hydrogenation and chelation separation are more suitable for industrialization. Catalytic hydrogenation can form heavy metals in crude oil with oxygen, sulfur, nitrogen, etc. The complexes or compounds are deposited on the surface of the catalyst, the demetallization rate is high but the cost is high and the catalyst is easily deactivated. Chelation separation uses chelating agents to react with metalloporphyrins and their complex compounds to form hydrophilic complexes or precipitate through electrolysis. After the desalination process, it will be discharged with desalted water, but a large amount of by-products will be produced during the reaction, which will reduce the selectivity of the reaction

[0004] High-acid crude oil refers to crude oil rich in naphthenic acid (more than 90%), fatty acids, and phenols, which can be removed by alcohol ammonia method, alkali washing, thermal decomposition, catalytic hydrogenation, extraction, adsorption separation, etc. Acid and alkali washing methods will produce a large amount of alkali residue and intensify the emulsification of crude oil. Thermal decomposition and hydrogenation will destroy naphthenic acid resources. Alcohol ammonia method and extraction require a large solvent-oil ratio to obtain better deacidification effects. It is difficult to achieve industrialization

[0005] Under the background of increasingly serious crude oil quality and inferior quality, the pretreatment of heavy and inferior crude oil has greatly increased the difficulty. At present, there is no better method for combined and centralized treatment of inorganic salts, organic acids, and organometallic compounds in crude oil.

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