CN102874838A

CN102874838A - Method for regulating composition of Y-type molecular sieve

Info

Publication number: CN102874838A
Application number: CN2012102831759A
Authority: CN
Inventors: 刘欣梅; 张新功; 魏杰; 叶红; 阎子峰
Original assignee: QINGDAO HUICHENG PETROCHEMICAL TECHNOLOGY Co Ltd; China University of Petroleum East China
Current assignee: QINGDAO HUICHENG PETROCHEMICAL TECHNOLOGY Co Ltd; China University of Petroleum East China
Priority date: 2012-08-05
Filing date: 2012-08-05
Publication date: 2013-01-16

Abstract

The invention discloses a method for regulating the composition of a Y-type molecular sieve. According to the method, Na<+> in a NaY molecular sieve and metal ions in a solution are subjected to ion exchange by an iron exchange method, so that the content of rare earth ions in the conventional rare earth Y-type molecular sieve can be reduced. The specific surface, the pore structure, and the relative crystallinity degree of the prepared modified Y molecular sieve can be regulated according to the factors such as the variety of the metal ions and the difference of synthesis conditions. The prepared modified Y molecular sieve shows a large specific surface and a large pore volume, is reasonable in acidity distribution and is suitable to be used as a catalyst for catalytic cracking. Meanwhile, the used raw materials have great economic advantages; and the process of the ion exchange method is simple and mature, and industrialization is easy to realize.

Description

The regulate and control method that a kind of Y zeolite forms

Technical field

The present invention relates to a kind of method that can reduce catalytic cracking molecular sieve catalyst content of rare earth, it is a kind of molecular sieve technology.The method is to skyrocket for current rare earth price, manages composition by metal ion in the regulatory molecule sieve with the preparation method of the Y zeolite that reduces the rare earth consumption.

Background technology

Catalytic cracking (FCC) is the most important secondary processing process of heavy oil lighting, also is the oil refining process of catalyst levels maximum.Gasoline and the 30% above diesel oil of China more than 70% all comes catalytic cracking.Super steady rare earth Y type molecular sieve (REUSY) through rare earth ion exchanged is one of main active component of catalytic cracking catalyst, because it has the stable and highly active acid characteristics of rare-earth Y molecular sieve of ultra-steady Y molecular sieve skeleton structure concurrently so that it has higher heavy oil conversion performance, gasoline selective and anti-vanadium poisoning capability in catalytic cracking process, so widespread use.

Global rare earth market value significantly rose suddenly and sharply in 2010.According to the industry data presentation, price has risen 500% for the principal element lanthanum trioxide in the light rare earths and cerium oxide.If represent with price curve, since 2011, the rare earth oxide curve almost was vertical configuration with X-coordinate, rare earth price even the situation of " quotation in a day ", " changing at sunset towards newspaper " occurred.Skyrocketing of price makes numerous enterprises take rare earth as raw materials for production at a loss as to what to do.Whole world fluid catalytic cracking (FCC) Catalyst Production merchant is making great efforts to overcome the pressure that Rare Earth Lanthanum and cerium price sharp rise and bring.And the REUSY molecular sieve in use also exists some shortcomings, the drawback that for example gasoline octane rating is low, the green coke amount is large and production cost is high.Therefore the modified Y molecular sieve of development of new structure, low cost, excellent property is imperative.

The method of modifying of Y zeolite commonly used mainly contains: ion exchange method, pickling process, hydrothermal synthesis method, microwave irradiation.Wherein ion exchange method is to use now morely, and the method for research and comparison maturation belongs to a kind of post-modification method from classification, have simple to operate, the characteristics such as product property is stable.The structure of ion-exchange modulation REUSY, the means that can pass through molecular sieve ion-exchange techniques, ion-exchange type and structure secondary modification are regulated and control the composition of REY type molecular sieve.By changing the type of ion, can obtain the Y molecular sieve of different ions modification, make it demonstrate different structure and characteristics, in order to obtain the molecular sieve of different structure and characteristics, can be by different ions be carried out composite modified examination.In addition, also can be by its structure and composition of post-modification method modulation of Y zeolite, mainly contain: high temperature hydrothermal method, organic coordination reaction method, high temperature gas-phase reaction method, ammonium silicofluoride liquid phase reaction method, alkaline purification etc., they can improve acidity, pore structure and the thermostability of molecular sieve.

In the middle of the preparation of former REUSY, all be to improve in rare earth exchanged technique, improve as far as possible the rare earth exchanged capacity, perhaps go out to send the exchange capacity that improves rare earth ion from the skeleton structure that changes the NaY molecular sieve, up to the present also do not find a kind of and rare earth ion function class seemingly, can replace rare earth ion fully or replace the ion of part rare earth ion.This research be substantially constant at molecular sieve performance or the prerequisite that increases under, manage to seek a kind of substitute fully or part replaces the preparation method of the Y zeolite of rare earth ion.

Summary of the invention

The present invention is intended to avoid above-mentioned the deficiencies in the prior art part and a kind of preparation method that can reduce the REY type molecular sieve of content of rare earth is provided, and obtains the heavy oil cracking performance good, and acid distributes rationally, the Y zeolite of good hydrothermal stability.

It is by screening suitable non-rare earth ion, adopt ion exchange method, managing to reduce the content of existing REY type molecular sieve middle-weight rare earths that the present invention solves its technical problem.Its specific implementation method is seen following steps:

(1) a certain amount of NaY molecular sieve is joined in the salts solution that contains non-rare earth ion, stirred at a certain temperature 0.5-8 hour, temperature can be controlled between room temperature and 120 ℃.

(2) with the sample drying after the ion-exchange, then hydrothermal aging is processed for some time at a certain temperature;

(3) sample with gained in (2) carries out the secondary ions exchange by the operational condition in (1), and this moment, the ion of exchange was non-rare earth ion or rare earth ion lanthanum or cerium;

(4) sample after gained secondary ions exchange in (3) was descended dry 12 hours at 100 ℃, then 300 ℃ of lower roastings 2 hours, namely get the Y zeolite that contains different ions.

Effect of the present invention is the Na in the NaY molecular sieve ⁺With contain non-rare earth ion and rare earth ion and carry out ion-exchange, the REY type molecular sieve of the low content of rare earth of preparation.Specific surface and the pore structure of the REY type molecular sieve that makes by the method can be regulated and control by the kind of ion and the condition of ion-exchange.Wherein, in the ion-exchange condition, the solid-to-liquid ratio of ion-exchange time, ion-exchange temperature, reactant etc. all produce larger impact to structure and the character of molecular sieve.Reached the molecular sieve of traditional rare earth ion exchanged in acidity with the molecular sieve of zirconium ion modification, suitable active sites of providing of catalytic cracking reaction will be provided for this.With zirconium ion Partial Replacement rare earth ion, can reduce the cost of raw material.Simultaneously, ion exchange method preparation process and preparation technology are simple, and be substantially similar with original technique, strong adaptability, and significantly reduced the production cost of REY type molecular sieve.

Description of drawings:

Fig. 1 is the XRD spectra of using the Y molecular sieve of different ions modification among the embodiment 1;

Fig. 2 is NH among the embodiment 2 ₃The desorption curve of-TPD;

Fig. 3 is the XRD spectra under the different hydrothermal aging conditions among the embodiment 3.

Embodiment:

Below in conjunction with specific examples in detail technical characterstic of the present invention is described in detail.

Embodiment 1:

This example is the molecular sieve that the ion exchange method preparation contains cobalt ion.

(1) weighing 1.5gNaY molecular sieve is transferred in the round-bottomed flask, adds the good cobalt nitrate solution 20ml of configured in advance, stirs, and constant temperature stirred 4 hours in 80 ℃ water-bath.

(2) then the sample suction filtration after the ion-exchange was placed 100 ℃ of baking ovens dry 12 hours.

(3) with dried sample at 600 ℃, roasting is 2 hours under 100% water vapour.

(4) sample with gained in (3) carries out the secondary ions exchange by the operational condition in (1);

(5) sample after gained secondary ions exchange in (4) was descended dry 12 hours at 100 ℃, then 300 ℃ of lower roastings 2 hours, namely get the Y zeolite that contains cobalt ion.

By the XRD spectra of the synthetic Y molecular sieve that contains cobalt ion of above condition as shown in Figure 1, compare with the Y molecular sieve of La ion modification with traditional usefulness Rare-Earth Ce ion, the Y molecular sieve relative crystallinity of usefulness Y ion modification is higher, and is less to the structure deteriorate of molecular sieve.

Embodiment 2:

This example is that the ion exchange method preparation contains the zirconium ion Y zeolite.Identical with the preparation method of example 1, just change cobalt nitrate solution into zirconium nitrate solution.NH by the synthetic Y zeolite that contains zirconium ion of above condition ₃The desorption curve of-TPD and has been calculated the amount of weak acid and middle strong acid as shown in Figure 2 according to opisometer.With compare with the molecular sieve of rare earth ion Ce modification, with the molecular sieve total acid content of Zr ion modification and Ce ionic species seemingly, and middle strong acid ratio slightly raises.

The sample acid distributed data of table 1 cerium ion and zirconium ion exchange

Embodiment 3:

This example is the Y molecular sieve that the ion exchange method preparation contains zirconium ion.Identical with the preparation method of example 2, just the condition of hydrothermal calcine changes to some extent.The specific surface of the sample of hydrothermal calcine and pore structure data and XRD spectra such as table 3 and shown in Figure 3 under the different condition.

After increasing the hydrothermal aging process, the degree of crystallinity of molecular sieve obviously improves, and molecular sieve is carried out first the primary ions exchange, carries out hydrothermal treatment consists again, and then carries out the secondary ions exchange, and the structure of gained sample is more excellent.

The specific surface of the sample of hydrothermal calcine and pore structure data under table 3 different condition

Embodiment 4:

This example is the rare-earth Y molecular sieve that the ion exchange method preparation contains zirconium ion.Identical with the preparation method of example 2, just the solution of for the first time clearing house employing is zirconium nitrate solution, and what adopted the clearing house for the second time is cerous nitrate solution.Record specific surface and the pore structure data are as shown in table 2.Wherein the ratio of twice exchange when the content of zirconium ion 10% the time, sample has larger specific surface and pore volume.

Sample specific surface and pore structure data after the cerium zirconium ion exchange of table 2 different ratios

The Y molecular sieve that the present invention synthesizes demonstrates the characteristic of high-ratio surface, high pore volume, and acid distributes rationally, has greatly remedied the high problem of rare earths material price that exists in the present industrial rare-earth Y molecular sieve preparation process.In addition, what deserves to be explained is that preparation technology is simple in whole preparation process, substantially similar with original preparation of molecular sieve.

Claims

1. regulate and control the method that Y zeolite forms for one kind, the method is to adopt ion exchange method, with Na in the NaY molecular sieve ⁺Carry out ion-exchange with the metal ion in the solution, to manage to reduce the content of existing rare earth Y type molecular sieve rare earth ion.It is characterized in that concrete steps are as follows:

(1) a certain amount of NaY molecular sieve is joined in the salts solution that contains non-rare earth ion, stirred at a certain temperature 0.5-8 hour, temperature can be controlled between room temperature and 120 ℃, and solid-to-liquid ratio is 0.025-0.5.

(4) sample after gained secondary ions exchange in (3) was descended dry 12 hours at 100 ℃, then at a certain temperature roasting is 2 hours, namely gets the Y zeolite that contains different ions, and maturing temperature can be regulated and control between 300 ℃～600 ℃.

2. preparation method according to claim 1 is characterized in that described non-rare earth ion is zirconium and cobalt etc.