Catalytic conversion method for producing propylene and fuel oil

Abstract

The invention provides a catalytic conversion method for producing propylene and fuel oil. The method comprises the following steps: enabling raw material oil of which the paraffin content is 40-90wt% and methane to contact with a catalytic cracking catalyst under the catalytic cracking condition; separating out pyrolysis gas oil from a contacted mixture; and carrying out aromatics extraction on the pyrolysis gas oil to obtain extract oil and raffinate oil. According to the method provided by the invention, the raw material oil (for example, straight-run diesel oil), which is relatively high in paraffin content can be adopted as a raw material; low-carbon olefin, particularly propylene and fuel oil can be produced at high selectivity; the problem of shortage of petrochemical materials is solved; and the economic benefits of a refinery plant are improved.

Description

technical field [0001] The invention relates to a catalytic conversion method for producing propylene and fuel oil. Background technique [0002] Propylene is an important organic chemical raw material. According to analysis, the global demand for propylene increased by about 4.0% in 2012, about 83Mt, and the supply-demand ratio of propylene was about 1.0. In the past 10 years, the growth rate of world propylene demand has been higher than that of ethylene. It is estimated that in the next 20 years, the growth rate of world propylene demand will still exceed the growth rate of ethylene demand. At present, 61% of the world's propylene comes from the by-products of steam cracking to produce ethylene, and 34% comes from the by-products of gasoline and diesel produced by catalytic cracking units in refineries. Among them, steam cracking uses naphtha and other light oils as raw materials to produce ethylene through thermal cracking And propylene, but the yield of propylene is on...

AI Technical Summary

Problems solved by technology

[0011] From the point of view of existing technologies, the development of catalytic conversion of hydrocarbons to produce low-carbon olefins and fuel oil mainly focuses on heavy oil catalytic cracking technology. In order to increase the yield of propylene, a higher reaction temperature is used, resulting in a substantial increase in the yield of dry gas, especially methane, in the case of increasing the yield of propylene

[0012] When middle distillates such as straight-run diesel oil are used as raw materials, because the raw materials contain more paraffins, through a cracking reaction, although the yield of by-product methane in the product is higher, it still has a higher yield of olefins and gasoline fractions , and because the raw material molecules are relatively small compared to heavy oil molecules, a higher reaction temperature is required to effectively crack. problem, which makes the regenerator carbon accumulation prone to occur during the operation of the unit, which eventually leads to the deterioration of product distribution

[0013] In addition, the existing technology does not make full use of the high-octane components in gasoline and the latent content of gasoline in diesel, resulting in low gasoline yield

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