Method for promoting heavy oil catalytic pyrolysis and improving propylene yield and selectivity

Abstract

The invention relates to a method for promoting heavy oil catalytic pyrolysis and improving propylene yield and selectivity. The method is mainly characterized in that one or a mixture in a small amount of methanol, ethanol, propyl alcohol, butyl alcohol and other small-molecule alcohol is fed with heavy oil, so that the conversion rate of the heavy oil can be obviously promoted, and the yield of liquefied gas and propylene can be improved. Compared with other technologies for increasing the production of propylene by heavy oil catalytic cracking or catalytic pyrolysis, the invention improves the yield and selectivity of propylene generated by catalytic pyrolysis by introducing a small amount of alcohols, thereby having the advantages of convenient implementation, obvious effect, prominent economic benefit and the like. For dry gas hydrogen-producing enterprises, the hydrogen content of the dry gas can be obviously increased after the introduction of alcohols, and therefore, the invention is beneficial to improving the hydrogen yield of a dry gas hydrogen-producing device.

Description

technical field [0001] The invention relates to a method for promoting heavy oil catalytic cracking to increase propylene yield and selectivity, which belongs to the process improvement of heavy oil catalytic cracking in petroleum processing, and the main purpose is to improve the propylene yield and selectivity. The method is to feed a small amount of methanol, ethanol, propanol, butanol and a mixture of one or more of small molecule alcohols with heavy oil during the reaction process, so that the conversion rate of heavy oil can be significantly promoted and the liquefied gas can be improved. and propylene yields. Background technique [0002] At present, propylene is mainly produced by steam cracking of naphtha. Naphtha steam cracking mainly has the following disadvantages: 1) high reaction temperature (generally above 800°C), cryogenic separation (demethanization below -100°C), large amount of water vapor (accounting for naphtha input) 50% to 100% of raw materials), so...

AI Technical Summary

Problems solved by technology

Naphtha steam cracking mainly has the following disadvantages: 1) high reaction temperature (generally above 800°C), cryogenic separation (demethanization below -100°C), large amount of water vapor (accounting for naphtha input) 50% to 100% of raw materials), so energy consumption is high; 2) the yield of high value-added products is low, and the sum of the yields of high-quality cracked naphtha ethylene and propylene can be close to 50%, and the general raw material ethylene+propylene The yield is only about 40%, while the low value-added methane yield is high, generally up to about 14%; 3) High-quality cracked naphtha resources are in short supply, and the price is high; 4) Naphtha steam cracking, the propylene / ethylene ratio Low, difficult to make large adjustments by changing operating conditions

If all the oxygen in methanol is H 2 56.25% will be removed in the form of O; if part of the oxygen is in the form of CO or CO 2 If the form is removed, the loss will be even greater

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