Light hydrocarbon recycling system and method

Abstract

The invention provides a light hydrocarbon recycling system which comprises a light hydrocarbon recycling tower, an air cooler, a water cooler, a light hydrocarbon separator and a light hydrocarbon recycling device. An inlet of the air cooler is connected with an outlet at the top of the light hydrocarbon recycling tower, a temperature control executing device is arranged on the upper portion of the air cooler, an inlet of the water cooler is connected with an outlet of the air cooler, an inlet of the light hydrocarbon separator is connected with an outlet of the water cooler, a temperature control device is arranged on the light hydrocarbon separator, and an inlet of the light hydrocarbon recycling device is connected with a gas outlet of the light hydrocarbon separator. Light hydrocarbon is preliminarily separated through the light hydrocarbon recycling tower and subjected to temperature control and condensation for two times and finally reaches the light hydrocarbon separator for further separation to obtain recycled light hydrocarbon and fine white oil, so that compared with the prior art, the light hydrocarbon recycling system has the advantages that load of a distilling tower is reduced, recycling rate of light hydrocarbon is increased, device energy consumption is lowered, and product quality of the fine white oil is improved.

Description

technical field [0001] The invention relates to the technical field of oil refining, in particular to a light hydrocarbon recovery system and method. Background technique [0002] White oil refining is an ultra-deeply refined special mineral oil product. Its components are generally naphthenes and alkanes with a molecular weight of 250-400. It is a lubricating oil fraction. It is colorless, tasteless, and odorless. Thermal stability, wide range of uses. As an emerging product item, white oil is being valued by the domestic petrochemical industry. [0003] At present, domestic production of white oil is mainly produced by sulfonation of base oil, which has high cost, great environmental pollution and unstable product quality. With the development of petroleum hydrogenation technology, in the 1960s, the hydrogenation refining technology for white oil production appeared abroad. It has the characteristics of high yield, no three wastes, flexible production, and excellent pro...

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Problems solved by technology

However, in the above-mentioned process, since the low-fraction oil directly reaches the heating furnace for further heating through the heat exchanger, after entering the vacuum fractionation tower, because the low-fraction oil contains more light hydrocarbons (about 2 to 6%), it will cause vaporization When the amount of oil is increased, especially when the nature of low fraction oil becomes lighter, the content of light fraction is particularly high, which seriously affects the vacuum degree of the vacuum fractionation tower. During the processing load, due to the high vaporization volume and the high pressure of the fractionation tower, qualified products cannot be obtained and the normal processing load cannot be met.

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