Method and apparatus for diesel acid stripping

Abstract

The invention relates to a diesel deacidification method and a device for removing naphthenic acid of diesel at low temperature, which are used for a refinery. The method is a low-temperature deacidification method which is characterized by little side effect on the environment, small amount of solvent, low volume rate of catalyst and oil, energy saving and wide application range. The technical proposal is: straight-run diesel oil and alcohol ammonia solvent are mixed in a mixer; the mixing liquid is then input, conglomerated and filtered at the upper part of a separator for conglomeration and filtration. The two-phase of oils filtered is settled down and separated at the lower part of the separator, with the upper layer being refined diesel and lower layer being alcohol ammonia solvent pregnant solution; and then the alcohol ammonia solvent pregnant solution is heated to raise the temperature through a heat exchanger and is input in a distillation tower for distillation at temperature of 100-120DEG C, and the condensed and reclaimed alcohol ammonia solvent is input in a solvent tank as regeneration alcohol ammonia solvent; and the bottom effluent of the distillation column is crude naphthenic acid. The method and the device are used for the deacidification of straight-run diesel oil in a method of alcohol and ammonia, with the advantages of low ammonia and alcohol consumption, low volume rate of catalyst and oil, energy saving, wide application range of the process, great operation flexibility, simple process and the realization of continuous operation.

Description

technical field [0001] The invention relates to a diesel oil deacidification method and device for removing naphthenic acid in diesel oil at low temperature in an oil refinery. Background technique [0002] The acidic substances contained in crude oil are collectively referred to as petroleum acids, including inorganic acids, naphthenic acids, other organic acids, phenols and mercaptans. Among them, the content of naphthenic acid accounts for about 90% of the total acidic substances, and the acidity of oil products is mainly caused by naphthenic acid. In the processing of petroleum and its distillates, naphthenic acid not only corrodes the production equipment, but also has a great impact on the quality of oil products, especially diesel oil. Naphthenic acid can reduce the stability of diesel oil, causing the diesel oil to oxidize to form colloids and sediments during storage and transportation; increase the carbon deposits in the fuel injectors and cylinder deposits, resul...

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Problems solved by technology

[0005] (2) The operating temperature is high, and ammonia is easily vaporized to generate pneumatic stirring, which leads to intensified emulsification of diesel oil;

[0006] (3) Large ethanol consumption (70%-90%), high volume ratio of solvent to oil (30%-50%), high energy consumption for solvent regeneration and large solvent loss (0.1%-2.0%), large solvent circulation, High regeneration energy consumption;

[0008] (5) The residual solvent content of refined diesel oil is high, and washing operation is required, and the solvent loss is large

This method cannot generate naphthenic acid, wasting precious resources; the oil agent has a long contact time, which is not conducive to industrialization; the second step has a high reaction temperature and high energy consumption

[0013] US4634519 uses ammonia water-methanol solvent to extract naphthenic acid. The amount of methanol is large and highly toxic. It has the greatest impact on the nervous system and blood system of the human body. Toxic reactions will occur if ingested through the digestive tract, respiratory tract or skin. Methanol vapor will damage the human body. Respiratory mucosa and vision

The yield of this method petroleum acid is low in addition, and economic benefit is poor, is unfavorable for industrial popularization and application

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