A catalytic cracking regenerated flue gas sulfur transfer additive and its preparation method

Abstract

The invention discloses a sulfur-transferring additive for regenerative flue gas in catalytic cracking and a preparation method thereof and particularly relates to a high-efficiency sulfur transferring agent adopting aluminium-magnesium spinels and hydrotalcite-like compounds as carriers. The preparation method comprises the following steps: with magnesium and aluminium as active components, adopting a coprecipitation method to prepare the aluminium-magnesium spinels (MgAl2O4); with manganese, magnesium and aluminium as the active components, adopting the coprecipitation method to prepare zinc-magnesium-aluminium hydrotalcites (MnMgAl-LDH); with rare-earth cerium as the active component and copper as a desorbing active component, adding aluminum sol to form uniform slurry, spraying, forming, drying and roasting to obtain the sulfur-transferring additive. The sulfur-transferring additive and the preparation method disclosed by the invention have the advantages that the content of MgO in the additive is high; pseudo-boehmites are acidified, and the aluminium sol is added, so that the wear resistance of the additive is improved; the additive contains the pseudo-boehmites and the manganese-magnesium-aluminium hydrotalcites, so that the specific surface area of the additive is enlarged; and the additive does not contain harmful components such as vanadium and iron for the catalytic cracking, so that the obtained sulfur transferring agent for FCC regenerative flue gas has higher SOx removing rate and better regenerative performance.

Description

technical field [0001] The invention relates to a catalytic cracking regenerated flue gas sulfur transfer additive and a preparation method thereof, in particular to a high-efficiency sulfur transfer agent with aluminum-magnesium spinel and a hydrotalcite-like compound as a carrier and a preparation method thereof. Background technique [0002] Fluid catalytic cracking (FCC) is the main secondary processing process of light oil products in refineries. While producing a large amount of high-quality light oil products, a certain amount of SOx will be emitted from the regeneration flue gas. It will pollute the environment and cause corrosion of the device. It is estimated that the SOx emission in the FCC regeneration flue gas accounts for about 6%-7% of the SOx emission in the air. The main methods to reduce SOx emissions in FCC regenerators are: 1. flue gas scrubbing; 2. raw oil hydrogenation; 3. using sulfur transfer agent. Since the use of sulfur transfer agent requires al...

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Problems solved by technology

[0004] In the technology disclosed in the above-mentioned patents, although the liquid sulfur transfer aid is simple to prepare and easy to use, in recent years, the increasingly heavy and inferior quality of catalytic cracking raw materials has increased the amount of heavy metal deposition on the catalytic cracking balancer. Depositing a certain amount of liquid sulfur transfer additive active metal on the balancer will often aggravate the metal poisoning of the catalyst, resulting in a decrease in catalyst activity and poor selectivity, and 50-60% of the sulfur transfer activity is difficult to meet the increasingly stringent environmental protection requirements Require

In solid sulfur transfer aids, whether it is the early alumina carrier loaded active components, or the more popular aluminum-magnesium spinel or hydrotalcite-like carrier loaded active metals in recent years, there are complex preparation processes, MgO content and Low specific surface area of ​​additives, containing metals that are toxic to catalytic cracking catalysts, such as alkali metals and transition metal vanadium, etc.

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