A kind of method for extraction-extractive rectification to reduce the sulfur content of regenerated and recovered oil

Abstract

The invention relates to a method for reducing sulfur content of recycled oil through extracting-extracting rectification. The method comprises the following steps: first enabling a gasoline distillate and an extracting agent to enter an extracting tower respectively, extracting to obtain raffinate oil and a pregnant solution, enabling the raffinate oil to a supplementing refining tower, enabling steam, which is obtained after gasification of an extracting agent-containing supplementing refining agent at the bottom of the tower, to enter the bottoms of an extracting rectifying tower and a regenerating tower, enabling the pregnant solution to enter an extracting rectifying and regenerating tower after heat exchange so as to obtain extracting rectifying recycled oil, uniformly mixing the extracting rectifying recycled oil and the extracting agent in a static mixer, reflowing into the extracting rectifying and regenerating tower, and performing extracting rectification to obtain qualified extracting rectifying recycled oil; discharging or recycling other materials after regeneration and separation. By a combined method of extracting and extracting rectification, the sulfur content of a light component in the recycled oil can be reduced from 100-400[mu]g / g to about 10[mu]g / g, so that constant circulation of sulfur in the light component in the extracting tower is avoided, and the desulphurizing capacity of the extracting tower is improved.

Description

technical field [0001] The invention belongs to the technical field of petroleum refining, and in particular relates to an extraction-extraction distillation method for reducing the sulfur content of regenerated recovered oil. Background technique [0002] With the enhancement of human environmental protection awareness, people pay more and more attention to the pollution of atmospheric environment caused by harmful substances in automobile exhaust. Countries all over the world have put forward increasingly strict requirements on the composition of engine fuel, especially the sulfur content. The European Union began to implement Euro IV vehicle exhaust emission standards in 2005, requiring gasoline sulfur content to be less than 50 μg / g. On September 1, 2009, the European Union began to implement Euro V emission standards, requiring gasoline sulfur content to be less than 10 μg / g. For the strict Euro VI standard. China implemented the National III gasoline standard (GB17930...

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Problems solved by technology

[0006] Chinese patent CN103555359A proposes a method for deep desulfurization of catalytic cracked gasoline. Although this method can deeply remove sulfur compounds contained in catalytic cracked gasoline and reduce the processing ratio of hydrodesulfurization, the extracted and regenerated light components in this method Sulfur content (150-400μg / g) is high, so it cannot be directly used as a product, and has to be returned to the bottom of the extraction tower, which increases the load on the extraction tower. This part of sulfur circulates continuously in the extraction tower, reducing the desulfurization capacity

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