A kind of method of fcc waste catalyst demetallization reactivation

Abstract

A demetalization and reactivation method of an FCC dead catalyst is characterized by comprising the following steps that (a) the FCC dead catalyst and a halogen-containing small molecule make contact with each other to have a demetalization reaction; (b) an FCC dead catalyst reaction product obtained in the step (a) is washed with water and filtered, a filter cake serves as a demetalized FCC catalyst, filtrate containing rare earth is extracted to recycle the rare earth, and refined liquid containing the rare earth is obtained; and (c) the demetalized FCC catalyst obtained in the step (b) is activated by the refined liquid containing the rare earth and then dried, and the demetalized and reactivated FCC catalyst is obtained. The demetalization and reactivation method of the FCC dead catalyst is simple in procedure, high in demetalization rate and free of ammonia nitrogen and organic acid emission, and the catalyzing performance of the demetalized and reactivated FCC catalyst is improved remarkably.

Description

technical field [0001] The invention relates to the field of catalyst activation, and more specifically relates to a method for realizing the demetallization and reactivation of FCC waste catalysts with a short process, no ammonia nitrogen and organic acid emissions, and a high rate of impurity metal removal, and belongs to the research field of comprehensive utilization of industrial solid waste. technical background [0002] As we all know, fluid catalytic cracking (FCC) is the most important secondary processing process in the petroleum refining industry and an important pillar of the national economy. my country's daily demand for 80% of gasoline, 30% to 40% of diesel, and 40% of propylene Both come from the FCC. The annual consumption of catalytic cracking catalysts in the world is about 350,000 tons, and my country's oil refining industry consumes about 70,000 tons of FCC catalysts each year, ranking second in the world. On the other hand, with the heavy and inferior q...

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Problems solved by technology

The process flow of this method is relatively simple, without high-temperature oxidation and chlorination steps, but it will produce sulfur-containing and strong oxidizing wastewater

[0010] CN1050402A uses chemical method and passivation method to jointly improve the process of catalyst performance in catalytic cracking operation: the cracking catalyst of metal contamination is chelated with citric acid to form a chelate, and after filtration, the chelate is separated from the catalyst, washed, and ammonium salt Aqueous solution treatment to further remove sodium and nickel on the catalyst to obtain a demetallization catalyst, then saturated impregnate the demetallization catalyst with a passivating agent solution, and then convert the remaining nickel on the demetallization catalyst into a harmless form through roasting, The disadvantage is that the removal rate of heavy metals such as vanadium and nickel is low, and waste water and waste gas containing ammonia nitrogen will also be produced.

[0011] The method of CN1191772A comprises uniformly mixing the deactivated catalyst and ammonium salt according to the weight ratio of ammonium salt:catalyst=0.02~1.2:1, roasting the obtained mixture at 150-600°C for more than 20min, and roasting the obtained roasted product at the liquid-solid weight ratio At least 5.0, pH 1.8 to less than 6.0, and temperature between room temperature and 90°C, wash with water slurry for 5-60 minutes, then filter and dry, but this method has disadvantages such as low heavy metal removal rate and discharge of ammonia nitrogen wastewater and waste gas.

[0022] CN102125872A uses FCC waste catalyst as raw material, adopts in-situ crystallization process to synthesize porous microsphere material containing NaY zeolite, this method will reintroduce metal impurities such as vanadium, nickel, iron and so on in the waste catalyst into the product, causing secondary pollution

[0032] It can be seen that the silicon tetrachloride used in the resurrection of FCC waste catalysts in the prior art CN104801353A, CN104815703A, CN104815704, CN104815705, and CN104841495A is a continuation of the traditional thinking - silicon tetrachloride is used for molecular sieve gas-phase reduction of sodium, dealumination and silicon supplementation , and silicon tetrachloride decomposes with water to generate silica gel and a large amount of hydrochloric acid. Silica gel can easily block the molecular sieve and catalyst pores, while hydrochloric acid can greatly damage the molecular sieve and carrier in the catalyst. Therefore, the spent catalyst needs to be pre-roasted and fully dehydrated before the reaction; The active elements removed from the catalyst in the process-rare earth oxides did not give a recycling method, but the method of adding rare earths alone was used to supplement the active elements lost in the reaction and pickling process; the pH of the slurry was low during pickling (pH=3.3-4.5), and a too low pH value will destroy the skeleton structure of the molecular sieve in the catalyst, thereby affecting the activity of the catalyst; and the use of organic acids or ammonium salts to treat the catalyst will cause excessive COD or ammonia nitrogen emissions in the waste liquid.

It can be seen from the implementation effect that the prior art CN104801353A, CN104815703A, CN104815704, CN104815705, CN104841495A have poor removal effect and low removal rate of harmful metals, especially vanadium and calcium

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