EA043359B1 - METHOD FOR ADDITIONAL PROCESSING OF ZEOLITE - Google Patents

Description

Field of technology

The present invention generally relates to a method for performing controlled sequential alkali or acid treatments on zeolites to obtain improved physicochemical and catalytic properties while particle and crystal size are not negatively affected. Accordingly, the zeolites thus obtained can be easily recovered from the alkaline solution.

Prerequisites for creating an invention

Zeolites are microporous structures based on aluminosilicate oxide, which are characterized by clearly defined porous structures due to their high degree of crystallinity. Crystalline aluminosilicate zeolites can be of natural or synthetic origin. In protic form, crystalline aluminosilicate zeolites are generally represented by the formula H _x Al _x Si1_ _x O2, where H represents the (exchangeable) proton that balances the electrovalency of the tetrahedron. The number of protons capable of exchange is called cation exchange capacity (CEC). The exact type of aluminosilicate zeolite structure is usually determined by the specific molar ratio of silicon to aluminum (Si/Al) and the pore sizes of the cell structure. The size of micropores (usually in the range of 0.4-1 nm) can be specified as the number of T-atoms with the smallest diameter, so-called ring members (MR). Using this definition, the most common industrial zeolites include 8 MR, 10 MR, or 12 MR micropores. Zeolite structure can also be produced, in addition to silica and alumina, using phosphates, which form a class of crystalline microporous silicoaluminophosphates (SAPO). In addition, if silica is absent, crystalline microporous aluminophosphates (AlPO) are formed. SAPO and AlPO, like zeolites, have unique porous and acidic properties, making them widely used in industry for catalysis, adsorption and ion exchange.

Recently, multilevel (mesoporous) zeolites, SAPO and AlPO have received considerable attention due to their potential advantages in catalysis due to their high external surface area, reduced diffusion path lengths and exposed active sites. The formation of a secondary mesopore network (typically in the 2-50 nm range) results in significant changes in material properties that affect the performance of zeolites in traditional applications such as catalysis and separations. The number of available active sites increases rapidly with increasing material porosity. In addition, multiscale zeolite crystals exhibit reduced diffusion path lengths compared to conventional microporous zeolites, AlPO or SAPO. Accordingly, these materials have achieved excellent performance in many catalytic reactions such as cracking, alkylation and isomerization.

Multilevel zeolites can be prepared using a wide range of bottom-up and top-down procedures. Bottom-up procedures involve modifying the hydrothermal synthesis of zeolites, for example by using organic matrices or by extending the crystallization time. However, the most interesting option from an industrial point of view is the (downstream) postsynthetic modification of conventional commercially available microporous zeolites. The key treatment in the latter category is the use of a base treatment, called desilication. This approach involves bringing zeolites into contact in alkaline aqueous solutions to produce multilevel zeolites by removing part of the solid to produce intracrystalline or intercrystalline mesopores. Base treatments can transform virtually any conventional zeolite into its improved multi-level analogue. Additionally, in the case of SAPO and AlPO, base treatments provide an improved catalytic analogue.

In addition to the purpose of forming mesopores, resulting in the formation of multi-level crystalline materials, alkali treatments can also be carried out to wash out unwanted phases from two-phase materials. For example, NaOH leaching can be used to remove unwanted ZSM-5 impurities from ZSM-22 zeolites. In addition, base leaching can be used to selectively leach elements from materials containing a wide range of elements. For example, when applied to zeolites, base leaching is selective for silicon. In turn, when applied to SAPO, base leaching is most selective for phosphorus. Thus, base treatments make it possible to regulate, in addition to (meso)porosity, other physicochemical properties of the resulting material, such as bulk composition, distribution of elements in crystals and acidity.

Base treatments are carried out by directly adding the zeolite to an aqueous base solution, usually at a high pH (>12), and therefore a high base concentration (eg, >0.1 M NaOH) and allowing the solid to react with the base, typically within 30 minutes. This procedure is followed by filtration, usually performed by filtration with a Buchner funnel. For 10 MR zeolites, e.g. framework topologies such as MFI, FER, TON, only an inorganic base (usually NaOH) is usually sufficient for alkali treatment. However, in the case of 12 MR zeolites, such as zeolites with FAU or BEA topology, it may be necessary to add organic

- 1 043359 substances such as tetrapropylammonium bromide (TRABr) or diethylamine to the alkali solution to maintain the characteristic properties of the zeolite, such as crystallinity, acidity and microporosity.

SAPO and AlPO are generally more sensitive than zeolites, requiring the use of (inorganic) salt-free alkali solutions derived from amines or TPAOH to produce improved solids.

Alkali (base) treatments are often carried out as one treatment in a sequence of postsynthetic modifications. For example, to obtain multi-level zeolite Y with improved catalytic properties, a sequence of 3 sequential acid-base-acid treatments can be performed. Alternatively, in the case of clinoptilolite (a natural zeolite), a sequence of 6 consecutive treatments (4 times acid, base, acid) has been reported. Additionally, two treatments (base-acid) were reported for ZSM-5 and ZSM-22. After each individual treatment, a filtration and drying step is necessary. In general, acid treatments result in the removal of Al (while base leaching usually results in selective leaching of Si), and their effect on the zeolite tends to differ markedly from that of a base treatment. For example, acid treatment prior to base treatment effectively removes aluminum from the zeolite framework, increasing the efficiency of subsequent base treatment. In turn, acid treatment, which is carried out after base treatment, has been described as a mild acid wash, and is aimed primarily at removing Al residues from the external surface. These Al residues were formed during alkali pretreatment. Therefore, the effectiveness of acid washing is closely related to the effectiveness of the previous alkali treatment. Acid treatments performed before and after alkali treatment are usually performed in a similar manner to alkali treatment: the zeolite is added directly to an aqueous acid solution, usually low pH (<4), followed by filtration, usually performed by Buchner funnel filtration. However, the effect of the acid is fundamentally different (removal of mainly Al instead of mainly Si in the case of a base). For example, acid treatments performed before or after alkali treatments often take significantly longer (usually 1 hour or longer).

In addition to the above-mentioned advantages of base leaching, there are several serious disadvantages of base leaching that need to be noted. First, organic matter should be avoided in most cases because it must be removed by combustion. This method not only leads to the destruction of expensive organic substances, but it also requires careful care of the resulting combustion products, which in itself is an expensive procedure. Simple amines such as diethylamine, used as a base for leaching zeolites 12 MR (beta and USY), AlPO and SAPO, can be easily recovered due to their high volatility, which increases their industrial attractiveness. However, the use of tetraalkylammonium (TAA) cations such as TRABr and cetyltrimethylammonium bromide (CTABr) are preferably avoided because they are more expensive and must be removed by thermal treatment, resulting in the formation of undesirable streams such as CO ₂ , NO _x , H ₂ O and/or explosive organic substances. Therefore, it is extremely important to reduce the use of organic substances, especially TAA.

Second, base-leached zeolites (with or without additional acid treatments) are reported to typically exhibit greatly enhanced mesoporosity values even under optimal conditions with organic molecules. However, more often than not, they can also exhibit undesirable cases of reduced zeolite properties. Common examples of this are crystallinity, Brønsted acidity and microporosity. These reductions have been reported for most multilevel or mesoporous zeolites prepared by alkali treatment or sequential acid and alkali treatments, as shown in Table 1. And the examples section.

An important recent development has been the realization that, in addition to the degree of secondary porosity, the quality of the pores is also critical. It has been observed that especially in zeolites with high silica content (Si/Al>about 10), base leaching can lead to the formation of mesopores that are (partially) cavitated. In this case, the greater the cavitation, the less the catalytic benefits. Therefore, at constant surface or volume of mesopores, the least degree of cavitation of mesopores is desirable.

Finally, base treatment can result in a noticeable reduction in zeolite crystal size. This decrease is associated with fragmentation, which can lead to the formation of fragments with a size in the range of 5-100 nm. They are colloidally stable particles that are very difficult to separate using conventional filtration methods using porous filter membranes and require expensive industrial separation methods such as high-speed industrial centrifuges. Accordingly, zeolite suspensions after base leaching are often extremely difficult to filter, as shown in Table 1. And the examples section.

It is therefore desirable to provide a more efficient process that provides the same effect (increased mesoporosity) but produces solids with higher zeolite properties, reduced cavitation, reduced organic additives and/or retained size. crystals. Moreover, such an improved process preferably has similar or reduced numbers of steps involved, total process time, and amount of wastewater produced. The resulting materials may have improved properties for the production of technical catalysts or for use in catalysis, adsorption or ion exchange processes.

Brief description of the invention

In accordance with the purpose of the present invention, which is implemented and broadly described herein, the present invention broadly relates to a method for performing sequential acid and alkali treatment of zeolites having improved physicochemical (zeolite) and catalytic properties. These improved properties may combine increased mesoporosity with higher Bronsted acidity, higher microporosity, higher mesoporosity, higher crystallinity, and/or combinations thereof.

In one aspect, the present invention relates to a method for producing a treated zeolite with a faujasite topology with a mesopore volume of 0.05 ml/g or more and a unit cell size of not more than 24.70 A, where the method consists of two or three separate treatments that are separated by a separation step solid, wherein at least one of the treatments is a base treatment, which comprises the steps

a) providing zeolite in an amount of ms;

b) providing the total amount of base mb, _total ; And

c) bringing the zeolite into contact with an amount of base m _b (t) in an aqueous solution at a temperature of from room temperature to 100°C and a pH of at least 10 to at most 14 and causing them to react, where the base is continuously added to the zeolite for time period At for the total amount of base mb, _total , wherein the time period At is at least 15 s; and at least one of the treatments is an acid treatment, which comprises the steps

d) providing zeolite in an amount of ms;

e) providing the total amount of acid ma, _total ; And

f) bringing the zeolite into contact with an amount of acid m _a (t) in an aqueous solution with a temperature of from room temperature to 100°C and a pH of from at least 0 to at most 5 and causing them to react, where the acid is continuously added to the zeolite for time period At for the total amount of acid ma, _total , wherein the time period At is at least 15 minutes;

thus obtaining a treated zeolite, where depending on the order of the treatments m _s means either an untreated zeolite or a zeolite obtained as a result of a previously performed treatment in accordance with step c) or step f), and where the maximum amount of base m _b , _max . for m _b (t) brought into contact with the zeolite ms at any time t in step c) is less than mb, total/ms, with mb, _max . is no more than 0.25χmb,tot., and where the total amount of base mb, _tot . presented in the form of solid alkali or alkaline solution, and where the maximum amount of acid is ma _max . for m _a (t) brought into contact with the zeolite ms at any time t at stage f), less than ma, total/ms, with ma, _max . is no more than 0.25xm _a , total, and where is the total amount of acid ma, _total . presented in the form of a solid acid or an acid solution.

In some preferred embodiments, the zeolite is treated with a base followed by solid separation followed by treatment with an acid.

In some preferred embodiments, the zeolite is treated with an acid followed by solid separation, followed by treatment with a base.

In some preferred embodiments, the maximum amount of base mb, max. for m _b (t) at any time t at stage c) is no more than 0.10xm _b , _total ..

In some preferred embodiments, the maximum amount of acid ma, _max . for m _a (t) at any time t at stage f) is no more than 0.10xm _a , _total ..

In some preferred embodiments, step a) comprises a') providing an amount of zeolite ms suspended in water; and step d) involves d') providing the zeolite in an amount ms suspended in water.

In some preferred embodiments, the base is an inorganic base from the group consisting of NH ₄ OH, NaOH, KOH and LiOH, or the base is an organic base such as tetrapropylammonium hydroxide, diethylamine, dipropylamine, tetrabutylammonium hydroxide and tetraethylammonium hydroxide or combinations thereof.

- 3 043359

In some preferred embodiments, the acid treatment is carried out using an inorganic acid selected from the group consisting of HCl, HNO ₃ , H2SO ₄ , H ₃ PO ₄ , H ₃ BO ₃ , or the acid treatment is carried out using an organic acid selected from the group consisting of oxalic acid, citric acid, acetic acid, benzoic acid, formic acid, ethylenediaminetetraacetic acid (H4EDTA), disodium ethylenediaminetetraacetic acid (Na2H2EDTA) or any combination thereof.

In some preferred embodiments, the method comprises a base treatment comprising a number of base additions per treatment (x) that are not separated by a solids separation step, such as a filtration step, and an amount of base added per addition ( _mb , i, where 1=1. ..x) is characterized in that x is not equal to 1, preferably x is at least 2, preferably at least 3, preferably at least 4.

In some preferred embodiments, the method involves an acid treatment comprising a number of acid additions per treatment (x) that are not separated by a solids separation step, such as a filtration step, and the amount of base added per addition (ma, i, where i=1_x) is characterized in that x is not equal to 1, preferably x is at least 2, preferably at least 3, preferably at least 4.

In some preferred embodiments, the number of treatments is 2, the untreated zeolite is faujasite with a unit cell size in the range of 24.70 to 24.50 A, and the base treatment comprising steps a), b) and c) is performed after the acid treatment , including stages d), e) and f).

In some preferred embodiments, the number of treatments is 2, the untreated zeolite is faujasite with a unit cell size ranging from 24.375 to 24.300 A, and the acid treatment comprising steps d), e) and f) is performed after the base treatment comprising steps a ), b) and c).

In some preferred embodiments, the number of treatments is 3, the untreated zeolite is faujasite with a unit cell size in the range of 24.70 to 24.50 A, and the base treatment comprising steps a), b) and c) is performed before the acid treatment and after another acid treatment, each acid treatment comprising steps d), e) and f).

In some preferred embodiments, the rate of addition of the amount of base over time is no more than 3.0 mmol-g'-min, preferably no more than 1.0 mmol- ^gAmin'1 , preferably no more than 0.5 mmol- ^gAmin'1 .

In some preferred embodiments, the rate of addition of the amount of acid over time is no more than 1.0 mmol- ^g'1 - ^min'1 , preferably no more than 0.1 mmol- ^g'1 - ^min'1 , preferably no more than 0.01 mmol-g' ¹ -min' ¹ .

In one aspect, the present invention relates to a zeolite with a faujasite topology, prepared in accordance with a method according to any of the aspects and embodiments described herein, with a unit cell size ranging from 24.375 to 24.300 A, with a mesopore volume of at least 0. 30 ml/g and one or more of the following:

a Bronsted acidity of at least 450 µmol g' ¹ measured with pyridine;

a crystallinity of at least 75% relative to the NaY zeolite standard and at least 90% relative to the NIST alumina reference standard (SRM 676).

In one aspect, the present invention relates to a zeolite with a faujasite topology, prepared in accordance with the method of any of the aspects and embodiments described herein, with a unit cell size of from 24.60 to 24.40 A, with a volume atomic ratio Si/ Al greater than 7.5, with a mesopore volume of at least 0.30 ml/g and a micropore volume of at least 0.20 ml/g.

Brief description of graphic materials

The present invention will be better understood from the detailed description set forth herein below and the accompanying drawings, which are provided by way of illustration only and are therefore not limiting to the present invention, and wherein the drawing shows a general overview of a method for exposing a porous solid to substances to a series of acid or base treatments. Typically, in a fixed volume of water, each treatment is performed by first adding a base or acid to the reactor, after which the porous solid is added and the reaction proceeds with vigorous mechanical stirring. The drawing, however, shows several additions during each individual treatment.

In the drawing, x represents the number of base or acid additions per reaction, m _b and ma are the number of base or acid added per addition, respectively, y is the number of solid additions per reaction (always equal to 1), and

- 4 043359 ms is the amount of solid added per addition, and z represents the number of treatments.

In the prior art, the values of x and y per processing are 1. In additional embodiments in this detailed description, the values of y and ms are not changed. In the present invention, x is not equal to one (preferably x>2) for at least two separate sequential treatments (z>2), in which at least one treatment is an alkali treatment, and in which at least one treatment is a acid.

Detailed Description of Embodiments of the Present Invention

The following terms are presented solely to facilitate the understanding of the present invention.

The term room temperature as used herein means a temperature in the range of 12 to 30°C, preferably in the range of 16 to 28°C, more preferably in the range of 17 to 25°C, and most preferably in the range of about 20 to 23° C.

The term molecular sieve as used herein means a solid with pores the size of molecules. It includes, but is not limited to, microporous and mesoporous materials, AlPO and (synthetic) zeolites, cross-linked or non-cross-linked clays, clathrasyls, clathrates, carbon molecular sieves, mesoporous silica, aluminosilicate (e.g. type MCM-41 with ordered pore system), microporous titanosilicates, such as ETS-10, urea and related base materials, porous metal oxides. Molecular sieves can be characterized by a multimodal pore size distribution, also called ordered ultramicropores (typically less than 0.7 nm), supermicropores (typically in the range of about 0.7-2 nm), or mesopores (typically in the range of about 2 to 50 nm). A particular type of molecular sieve contemplated by the present invention are silicon molecular sieves, more particularly silicon zeogrides, zeolites and/or amorphous microporous silicon materials. Among the solids known today, those that have uniform channels, such as zeolites represented by porous crystalline aluminum silicates and porous crystalline aluminum phosphates (AlPO), are defined as molecular sieves because they selectively adsorb molecules smaller than the inlet size. channel, or they allow molecules to pass through the channel. From a crystallographic point of view, zeolites are completely crystalline substances in which atoms and channels are arranged in complete regularity. These fully crystalline molecular sieves are obtained naturally or synthesized through hydrothermal reactions. The number of fully crystalline molecular sieves obtained or synthesized to date amounts to several hundred types. They play an important role as catalysts or supports in the modern chemical industry due to their characteristics including selective adsorption, acidity and ion exchange capacity. Molecular sieves, both natural and synthetic, contain a wide range of crystalline silicates containing positive ions. These silicates can be described as a rigid three-dimensional framework of SiO ₄ and an oxide of an element of group 13 of the periodic table, for example AlO ₄ , in which the tetrahedra are cross-linked through shared oxygen atoms, resulting in the ratio of all group 13 atoms and group 14 atoms, such as silicon, and atoms oxygen is 1:2. Crystalline microporous silica polymorphs are the composite end members of these families of composite materials. These silicon molecular sieves do not have cation exchange capacity.

A zeolite can be defined as a crystalline material whose chemical composition consists essentially of aluminum, silicon and oxygen. Typically, zeolites are described as aluminosilicates with a three-dimensional framework and molecular-sized pores. Zeolites, both natural and synthetic, have been demonstrated in the past to have catalytic properties for various types of hydrocarbon conversion. Certain zeolite materials are ordered porous crystalline aluminosilicates having a defined crystal structure, determined by X-ray diffraction, in which there are a large number of smaller cavities that may be connected by a series of even smaller channels or holes. These cavities and pores are of uniform size within a given zeolite material. Because the dimensions of these pores are such that they accept molecules of a certain size for adsorption and do not accept molecules of larger sizes, these materials are known as molecular sieves and are used in a variety of ways to exploit these properties. The term zeolite, as used in the present invention, can also mean any member of the group consisting of structured aluminosilicate minerals containing cations such as sodium and calcium or, less commonly, barium, beryllium, lithium, potassium, magnesium and strontium; which are characterized by the formula H _x Al _x Si1_ _x O ₂ , where H can be replaced by any other monovalent cation or (if x, which refers to H, is a multiple of valency) by a multivalent cation. The term zeolite also refers to an open tetrahedral framework structure capable of ion exchange and freely held moles.

- 5 043359 water coolers that allow reversible dehydration. The term zeolite also includes zeolite-related materials, or zeotypes, which are obtained by replacing Si ⁴⁺ or Al ³⁺ with other elements, as in the case of aluminophosphates (for example, MeAPO, SAPO, ElAPO, MeAPSO and ElAPSO), gallophosphates, zinc phosphates, titanosilicates etc. The zeolite may be a crystalline porous material with a framework structure, as described in US 2013/0118954, or as presented in the IZA Structure Commission database of zeolite structure types, where the following structure types (from which the frame density can also be determined) defined by the International Association for zeolites, such as type ABW, type ACO, type AEI, type AEL, type AEN, type AET, type AFG AFI, type AFN, type AFO, type AFR, type AFS, type AFT, type AFX, type AFY, type ANT, type ANA, type APC, type APD, type AST, type ASV, type ATN, type ATO, type ATS, type ATT, type ATV, type AWO, type AWW, type VST, type BEA, type VES, type BIK, type BOG , VRN type, BRE type, CAN type, CAS type, CDO type, CFI type, CGF type, CGS type, SNA type, CHI type, CLO type, CON type, CZP type, DAC type, DDR type, DFO type, type DFT, DOH type, DON type, EAB type, EDI type, EMT type, EON type, EPI type, ERI type, ESV type, ETR type, EUO type, EZT type, FAR type, FAU type, FER type, FRA type, GIS type, GIU type, GME type, GON type, GOO type, HEU type, IFR type, IHW type, IMF type, ISV type, ITE type, ITH type, ITW type, IWR type, IWV type, IWW type, JBW type , KFI type, LAU type, LEV type, LIO type, LIT type, LOS type, LOV type, LTA type, LTL type, LTN type, MAR type, MAZ type, MEI type, MEL type, MER type, MER type, type MFI, MFS type, MON type, MOR type, MOZ type, MSE type, MSO type, MTF type, MTN type, MTT type, MTW type, MWW type, NAB type, NAT type, NES type, NON type, NPO type, NSI type, OBW type, OFF type, OSI type, OSO type, OWE type, PAR type, PAU type, PHI type, PON type, RHO type, RON type, RRO type, RSN type, RTE type, RTH type, RUT type , type RWR, type RWY, type SAO, type SAS, type SAT, type SAV, type SBE, type SBN, type SBS, type SBT, type SFE, type SFF, type SFG, type SFH, type SFN, type SFO, type SGT, SIV type, SOD type, SOS type, SSF type, SSY type, STF type, STI type, STO type, STT type, SZR type, TER type, TNO type, TOL type, TON type, TSC type, TUN type, UEI type, UFI type, UOZ type, USI type, UTL type, VET type, VFI type, VNI type, VSV type, WEI type, WEN type, YUG type and ZON type. The term zeolite also includes zeolite-related materials or zeotypes that are produced by replacing Si ⁴⁺ or Al ³⁺ with other elements, as in the case of aluminophosphates (e.g. MeAPO, AlPO, SAPO, ElAPO, MeAPSO and ElAPSO), gallophosphates, zinc phosphates , titanosilicates, etc. Typically, porous substances are classified according to pore size, for example, those with pore sizes less than 2 nm are classified as microporous substances, 2 to 50 nm are classified as mesoporous substances, and more than 50 nm are classified as macroporous substances. Non-zeolitic mesoporous silica species, such as MCM-41 and SBA-15, can exhibit significant microporosity. This type of microporosity, however, is disordered and not clearly expressed, and should not be considered zeolitic. Microporosity, as defined in embodiments herein, is derived primarily from zeolite micropores associated with framework topologies. For example, for USY zeolites with faujasite topology, microporosity is formed from clearly defined micropores of 0.74 nm, for beta zeolite with BEA topology, microporosity comes from clearly defined pores of 0.6 nm, and for ZSM-5 zeolite with MFI topology, microporosity comes from clearly pronounced pores 0.55 nm. Among porous substances, those substances that have uniform channels, such as zeolite, are defined as molecular sieves. Up to now, up to hundreds of types of substances have been discovered and synthesized. Zeolites play an important role as catalysts or carriers in the modern chemical industry due to their characteristics including selective adsorption, acidity and ion exchange capacity.

A number of ordered mesoporous materials, including MCM-41 and MCM-48, are described in US Patent Nos. 5,057,296 and 5,102,643. These ordered materials are characterized by a structure in which mesopores, uniform in size, are arranged in a regular manner. MCM-41 has a uniform structure exhibiting a hexagonal arrangement of straight mesopores, such as a honeycomb, and is characterized by a specific surface area of about 1000 m ² /g, measured using the BET (nitrogen adsorption) method. Existing molecular sieves have been prepared using inorganic or organic cations as templates, whereas these ordered mesoporous materials are synthesized by liquid crystal matrix using surfactants as templates. These ordered mesoporous materials have the advantage that their pore sizes can be adjusted in the range from 1.6 to 10 nm by adjusting the types of surfactants or the synthesis conditions used in the production method. Ordered mesoporous materials, designated SBA-1, -2 and -3, were described in Science (1995), 268:1324. Their channels are regularly arranged, while the constituent atoms exhibit an arrangement similar to amorphous silica. Ordered mesoporous materials have regularly spaced channels larger than those of existing zeolites, which allows them to be used in reactions of adsorption, release, or catalytic transformation of relatively large molecules.

In general, the present invention relates to a method for producing unique inorganic solids by applying a sequence of controlled acid and alkali treatments to existing inorganic porous solids, e.g.

- 6 043359 solids, without negatively affecting particle or crystal size, and to obtain a final solid product with improved physicochemical and catalytic properties. The method of the present invention can provide solids that are easily recovered from the alkaline solution after treatment. In a specific embodiment, the method involves the use of sequences of acid and base treatments, in which each treatment includes stepwise bringing the base or acid into contact with the porous solid, thereby achieving improved physicochemical properties. In addition to improved physicochemical properties, improved catalytic properties and improved filtration characteristics, the present invention can provide reduction in the amount of organic matter that is often used to maintain microporosity, crystallinity and acidity in alkali or acid leaching.

As used herein, the term framework Al means tetrahedrally coordinated Al. Solid properties can be assessed using nitrogen adsorption at 77 K, as this is a well-known technique for quantifying zeotype-specific properties (relating to crystalline microporous solids) as well as the degree of mesoporosity in the solid. The measure that is derived from the nitrogen isotherm is the total surface area (S _BET ). The latter is obtained by applying the BET model, and it gives an idea of the total porosity (micropores and mesopores) of solids. Zeotype-specific properties can be studied using microporosity (V _mUk p ₀ ), which is obtained by constructing a t-graph of the adsorption branch of the isotherm, preferably plotted over a thickness range of 0.35-0.50 nm. Since the active sites (Brønsted sites, described below) are located in micropores, it is preferable that after post-synthetic modification using acid and base treatments, the micropore volume remains as close as possible to that of the original zeolite.

Nitrogen sorption measurements were performed using a Micromeritics TriStar 3000 instrument controlled by TriStar 3000 software (Micromeritics) version 6.03. Before the sorption experiment, the samples were degassed overnight in a flow of N2 when heated to 300°C (5°C-min ^-1 ). The t-plot method as described in Microporous Mesoporous Mater, 2003, 60, 1-17 was used to distinguish micro- and mesopores (thickness range=0.35-0.50 nm, using Harkins and Jura thickness equation, and coefficient density conversion=0.0015468). To accurately compare microporosity obtained from a t-plot between solids, it is preferable to use the same t-plot method, thickness range, and thickness equation. For example, if the t-plot is applied over a narrow range at high relative pressures (eg, p/p ₀ =0.30-0.35), the resulting microporosity may be an overestimation. The t-plot method also provides the outer surface (called S _meso ), which is used as an indicator of the degree of secondary porosity. The total pore volume (V _nO p) was determined at relative pressure (p/p0=0.98). The volume of mesopores (Vmeso) was determined as Vmeso=Vnop-Vmicro.

In case the inorganic porous solids are crystalline, zeolites, SAPO, AlPO, the retention of characteristic properties can be tested using X-ray diffraction (XRD). This technique provides a topology-specific reflectogram. Relative crystallinity, indicative of overall zeotype-specific properties, can be estimated by combining multiple characteristic peaks using methods such as those described in ASTM D3906 (for faujasite zeolites), ASTM 5758 (for ZSM-5 zeolites), ASTM WK9245 (for mordenite zeolites) and ASTM D5357 (for NaA zeolites). It is preferable if the acid and alkali treated sample has as high a degree of crystallinity as possible compared to the original crystalline inorganic solid. For faujasites, relative crystallinity is compared to the industry standard NaY zeolite provided by Zeolyst (supplier code CBV 100). In addition, the relative crystallinity of the zeolites is quantified by comparison with the NIST alumina reference standard (SRM 676). This is achieved by comparing the 25.7° 2-theta peak area of the NIST standard with the 15.7° 2-theta peak area for FAU zeolites, or the 7.7° 2-theta peak area for FAU zeolites. theta for zeolites with BEA topology, or with peak areas ranging from 23.1 to 24.3° 2-theta for ZSM-5 zeolites. XRD is also a useful characterization technique because it can determine the unit cell size. Particularly in the case of faujasites, the unit cell size is important because it indicates the composition (Si/Al atomic ratio) of the framework. The unit cell size is determined using conventional methods specified in ASTM 3942. X-ray diffraction was measured on a Siemens D5000 diffractometer with Bragg-Brentano geometry and Cu Ka radiation with a Ni filter (λ=0.1541 nm). Data were recorded over a range of 5–50° of 2-theta angle with an angular step size of 0.05° and a counting time of 8 s per step.

Most applications of inorganic porous solids described in this

- 7 043359 document provide for acid-catalyzed transformations. In this case, the type and amount of acid site are critical. Fourier transform infrared spectroscopy (FTIR) of pyridine adsorbed on solids is commonly used to quantitatively monitor the acidity properties of solids. This method quantifies the number of strong Brønsted sites (B) and weaker Lewis acid sites (L) present in a solid. In catalytic applications of zeolites and SAPO in particular, the number of Brønsted acid sites is key to their efficient operation. Although the primary purpose of modification through combinations of alkali and acid treatments is often to improve porosity, it is critical that subsequent post-synthetic modifications, in particular, maintain the density of the Brønsted sites.

FTIR measurements of pyridine were performed using a Nicolet 6700 spectrometer equipped with a DTGS detector. The samples were pressed into individual plates and degassed at 400°C for 1 h in vacuo before measurements. After evacuation, the samples were exposed to 4-5 pulses of pyridine at least 25 mbar at 50°C for 1 min (until saturation), after which the system was heated to 150°C for 40 min, followed by obtaining spectra at the same temperature. The absorption bands at 1550 and 1450 cm ^-1 corresponded to the number of Brønsted and Lewis acid sites, respectively. The applied attenuation coefficients were determined by Emeis, J. Catal., 1993, 141, 347-354.

The catalytic properties were monitored for α-pinene isomerization because it represents a suitable model reaction in which both the function of zeotype-specific properties and the function of the external surface are examined. In this reaction, activity (A) means the degree of conversion, and productivity (P) represents the yield of useful products (limonene, camphene, α-terpinene, γ-terpinene, terpinoline, p-cymene).

Experimental catalysis. α-pinene isomerization reactions were carried out in a 50 cm ³ Parr reactor with a sampling device at 150°C in a nitrogen atmosphere of 6-8 bar with a stirring speed of 750 rpm. A mixture of substrate (20 g; α-pinene) and catalyst (0.05 g) was heated to 100°C, after which the first liquid sample was taken. The reaction mixture was then further heated to 150°C and additional samples were taken 10, 30 and 60 min after the first sample. The samples were then analyzed on a gas chromatograph (HP 5890, Hewlett Packard) equipped with an HP1 column and flame ionization detector (FID). Tetradecane was used as an external standard. Unidentified products were analyzed by GC-MS (6890N, Agilent Technologies). The activity of the samples was determined using the slope of the linear part of the graph of α-pinene conversion versus contact time.

Alkylation of toluene with benzyl alcohol was carried out by mixing 0.0125 g of catalyst with 4.98 ml (47 mmol) toluene (Fisher), 0.062 ml (0.6 mmol) benzyl alcohol (Sigma Aldrich) and 0.048 ml (0.3 mmol )propylcyclohexane (TCI Europe) as internal standard. The catalyst powder was pre-dried for 2 h at 300°C (temperature change rate 5°Cmin'1) and the reaction was carried out in closed Schott bottles (Duran) for 1 h with stirring at 120°C. The reaction mixture was analyzed using gas chromatography (Agilent 6850 series).

According to a first aspect, the present invention relates to a process for producing a treated inorganic porous solid, the method comprising at least two separate treatments (z>2) which are separated by a solid separation step, such as a filtration step, wherein at least at least one of the treatments z involves the stages

a) providing an amount of inorganic porous solid m _s ;

b) providing the total amount of base mb, _total ; And

c) bringing the inorganic porous solid into contact with an amount of base m _b (t) and causing them to react for a period of time At for the total amount of base mb, _total ;

thereby obtaining a treated inorganic porous solid; and at least one of the treatments z comprises the steps

d) providing an amount of inorganic porous solid m _s ;

e) providing the total amount of acid m _a , _total ; And

f) bringing the inorganic porous solid into contact with an amount of acid m _a (t) and allowing them to react for a period of time At for the total amount of acid m _a , _total ;

thereby obtaining a treated inorganic porous solid, wherein the maximum amount of base mb, _max . for m _b (t) brought into contact with the inorganic porous solid ms at any time t in step c) is less than mb, total/ms, and where the maximum amount of acid m _a , _max . for m _a (t) brought into contact with the inorganic porous solid ms at any time t in step c) is less than mb, total/ms.

The total amount of base may be in the form of a solid alkali or an alkaline

- 8 043359 solution, preferably an alkaline solution. Likewise, the total amount of acid may be in the form of a solid acid or an acid solution.

In some embodiments, the method involves stepwise contacting the solid with a base or acid for treatment, thereby substantially preventing fragmentation. The result can be particle and crystal pore sizes similar to those of the original solid. In addition to superior physicochemical properties, superior catalytic properties and improved filtration performance, the present invention provides the ability to reduce the amount of organic matter required to maintain microporosity and crystallinity during alkali leaching.

In some preferred embodiments, the maximum amount of base mb, _max . for mb(t) at any time t at stage c) is no more than 0.5xmb, total, preferably no more than 0.25xmb, total, preferably no more than 0.10xmb, _total ..

In some preferred embodiments, the maximum amount of acid ma, max. for m _a (t) at any time t at stage f) is no more than 0.5xm _a , total, preferably no more than 0.25xm _{a, total.} , preferably no more than 0.10xm _{a, total.} .

In some preferred embodiments, the inorganic porous solid includes molecular sieves such as zeolite or SAPO.

In some embodiments, the inorganic porous solid is a zeolite material, preferably with a structure of the type MWW, BEA, MFI, CHA, MOR, MTW, RUB, LEV, FER, MEL, RTH AEL, AFI, CHA, DON, EMT, CFI, CLO , TON, FER, ERI, MEL, MTW, MWW, HEU, EUO, RHO, LTL, LTA, MAZ and most preferably MOR, MFI, BEA, FAU topologies, wherein the zeolite material is characterized by mesoporosity after processing. A given method or process can start with crystalline silicates, particularly those having a zeolite structure, which are subjected to acid and alkali treatments, and a new material with zeolite properties and mesoporosity can be obtained without high-speed commercial centrifuges or without performing filtration steps between treatment sequences. Thus, these mesoporosity zeolite materials can be produced in an environmentally and economically beneficial manner.

In some embodiments, the method or process may start with an amorphous silicate, such as fumed silica, and/or ordered silica species, such as MCM-41 or SBA-15.

In some preferred embodiments, step a) comprises a') providing an amount of ms of inorganic porous solid suspended in a solution, preferably water; and step d) involves d') providing an amount of ms of inorganic porous solid suspended in a solution, preferably water.

The preferred solvent for the alkali treatment (step c) is water. In some embodiments, other solvents are used, such as alcohols (methanol, ethanol, or isopropanol). Typical solutions for performing base treatments are solutions in water with a pH that ranges from at least 10 to no more than 14, corresponding to a NaOH concentration of 0.0001 to 1 M. Solid to liquid ratio (inorganic porous solid to liquid base) can vary from very low - 1 g-l' ¹ - to very high - 100 g-l' ¹ , but in the examples it is usually chosen to be 33 g-l' ¹ . The temperature may range from at least room temperature to at most 100°C, preferably from at least 50°C to at most 70°C.

Preferred bases for preparing the alkaline solution are inorganic hydroxides such as NaOH, LiOH, KOH, RbOH, CsOH, Mg(OH) ₂ , Ca(OH) ₂ , Sr(OH) ₂ or Ba(OH) ₂ . In some embodiments, non-hydroxide inorganic alkali sources may be used, such as Na ₂ CO ₃ , NH ₃ , butyllithium (nC ₄ H ₉ Li) and sodium hydride (NaH). In other embodiments, organic bases such as tetrapropylammonium hydroxide, diethylamine, dipropylamine, tetrabutylammonium hydroxide and tetraethylammonium hydroxide may be used.

The preferred solvent for acid treatment (step f) is water. Typical solutions for performing acid treatment are solutions in water with a pH that ranges from 0 to 5, corresponding to an HCl concentration of 1 to 0.00001 M. The solid to liquid ratio (inorganic porous solid to liquid acid) can vary from very low - 1 g-l' ¹ - to very high - 100 g-l' ¹ , but in the examples it is usually chosen as equal to 66 g-l' ¹ . The temperature may range from at least room temperature to at most 100°C, preferably at least 70°C.

Preferred acids for preparing acid solutions are mineral acids from the group consisting of HCl, HNO ₃ , H ₂ SO ₄ , H ₃ PO ₄ , H ₃ BO ₃ . In some embodiments, organic acids from the group of sulfonic acids, such as methanesulfonic acid, may be used.

- 9 043359 acid, ethanesulfonic acid, benzenesulfonic acid and p-toluenesulfonic acid. In some embodiments, organic acids from the carboxylic acid group may be used, such as acetic acid, citric acid, formic acid, gluconic acid, lactic acid, oxalic acid, tartaric acid. In another embodiment, organic acids from the group of aminopolycarboxylic acids can be used, such as ethylenediaminetetraacetic acid (EDTA), iminodiacetic acid (IDA) and 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA) . In other embodiments, only a portion of the carboxylic groups in organic acids may be in the protic (acidic) form, such as Na2H2EDTA.

In some embodiments, the base is added in several separate steps. The inorganic porous solid is not separated between these steps. In some preferred embodiments, the method involves a number of base additions per treatment (x) that are not separated by a solids separation step, and the amount of base added per addition (mb,i, where 1=1...x) is characterized in that x is not equals 1, preferably x equals at least 2, preferably at least 3, preferably at least 4.

In some embodiments, the acid is added in several separate steps. The inorganic porous solid is not separated between these steps. In some preferred embodiments, the method involves a number of acid additions per treatment (x) that are not separated by a solids separation step, and the amount of acid added per addition (mb,i, where 1=1...x) is characterized in that x is not equals 1, preferably x equals at least 2, preferably at least 3, preferably at least 4.

In some preferred embodiments, z is equal to 2, and this involves one acid treatment and one base treatment. This means that two separate treatments are performed, each accompanied by a solids separation step, preferably a filtration step. During one of these treatments, the base is added in several stages (x^1) or stepwise. During the other of the two treatments, acid is added in several stages (x^1) or stepwise. The order of performing the acid and alkali treatment in the case of z=2 may be either base-acid or acid-base.

In some preferred embodiments, z is equal to 3 and includes two acid treatments and one base treatment. This means that three separate treatments are performed, each accompanied by a solids separation step, preferably a filtration step. During one of these treatments, the base is added in several stages (x^1) or stepwise. During the other two treatments, acid is added in several stages (x^1) or stepwise. The order of these three treatments in the case of z=3 is preferably acid-base-acid.

In some embodiments, the base is added in stages or continuously. The inorganic porous solid is not separated during this stepwise addition. In some preferred embodiments, the rate of addition of the amount of base over time is no more than 3.0 mmol-g-1- ^min'1 , preferably no more than 1.0 mmol-g-1- ^min'1 , preferably no more than 0.5 mmol-g'-min' ¹ .

The rate at which the amount of base is added over time may depend on the treatment used. However, solids of very good quality can be obtained by keeping this value below 3.0 mmol base per gram of zeolite per minute (mmol-g-1-min'1 ⁾ , preferably below 1.0 mmol-S- ^min'1 and most preferably less than 0.5 mmol-C-min' ¹ .

In some preferred embodiments, the base is continuously added to the inorganic porous solid over a period of time At, wherein the time period At for adding the total amount mb, _total . is at least 15 s, preferably at least 30 s, for example at least 60 s, for example at least 2 min, for example at least 4 min, for example at least 8 min, for example at least 15 min, for example approximately 30 min. In some embodiments, At is at least 8 minutes and no more than 60 minutes, preferably at least 15 minutes and no more than 45 minutes, such as about 30 minutes.

In some embodiments, the acid is added in stages or continuously. The inorganic porous solid is not separated during this stepwise addition. In some preferred embodiments, the rate of addition of the amount of acid over time is no more than 1.0 mmol-g'- ^min'1 , preferably no more than 0.1 mmol-g'- ^min'1 , preferably no more than 0.01 mmol- C-min' ¹ .

The rate at which the amount of acid is added over time may depend on the treatment used. However, solids of very good quality can be obtained by keeping this value below 1.0 mmol acid per gram of zeolite per minute (mmol-g'- ^min'1 ), preferably below 0.1 mmol-g-1-min' ¹ and most preferably less than 0.01 mmol-g-1- ^min'1 .

In some preferred embodiments, the acid is continuously added to the inorganic porous solid over a period of time At, wherein the time period At for

- 10 043359 adding the total number of m _a , _total . is at least 15 minutes, preferably at least 30 minutes, for example at least 60 minutes, for example at least 4 hours, for example at least 8 hours, for example at least 16 hours, for example at least 36 hours, for example approximately

h. In some embodiments, At is at least 2 hours and no more than 12 hours, preferably at least 3 hours and no more than 9 hours, such as about 6 hours.

In some embodiments, additives may be added, similar to adding base in the manner described above, in a similar stepwise manner. Such additives can be common salts such as NaCl and KBr, as well as metal salts such as Al(NO ₃ ) ₃ and Ga(NO ₃ ) ₃ , and organic compounds such as TRABr and DEA.

The impact of the present invention compared to the prior art may depend on the nature of the samples. Among other things, the density of the zeolite framework topology may have the greatest influence. In this case, lower topological density provides a greater advantage. Therefore, the benefits for zeolites with the FAU framework (density 13.3 T atoms/1000 A ³ ) exceed the benefits for zeolites with the BEA framework (density 15.3 T atoms/1000 A ³ ). Likewise, the benefits of the BEA structure may be greater compared to zeolites with the MFI framework (18.4 T-atoms/1000 A ³ ). Framework density values are related to full silicon framework density (FDSi) and can be found in the IZA database (http://www.iza-structure.org/databases/).

In addition, in the case of zeolites, the Si/Al ratio in the framework (and in the bulk) may have an influence. For example, in the case of preventing fragmentation and the associated increase in filtration time during alkali treatment, the effect is optimal if the Si/Al atomic ratio is 5 or higher, preferably 10 to 25 or higher, and most preferably 20 or higher. This is shown in table. A, where the filtration time of alkali-treated USY zeolites increases rapidly with increasing Si/Al ratio of the original zeolite.

In some embodiments, the present invention provides a method of performing sequential acid and alkali treatments on inorganic porous solids, providing improved physicochemical and catalytic properties, without negatively affecting (or only having a limited effect on) particle or crystal size. The use of the present invention provides solids that can be easily recovered from the alkaline solution after treatment. In some embodiments, the method comprises gradually bringing the solid into contact with a substrate, thereby substantially preventing fragmentation. The result is particle and crystal pore sizes similar to those of the original solid. In addition to superior physicochemical properties, superior catalytic properties and improved filtration performance, the present invention provides the ability to reduce the amount of organic matter required to maintain microporosity and crystallinity during alkali leaching.

As illustrated through various examples, the method of the present invention can be carried out using at least two treatments, including at least one acid treatment and one alkali treatment, wherein during each treatment the solid is exposed to a lower acidity (during the acid treatment ) or lower alkalinity (during base treatment) by stepwise dosing of base or acid during alkali and acid treatment, respectively, or by pumping a dilute alkaline or acid solution through a membrane containing the solid. Such treatments can produce porous solids with improved physicochemical properties and filtration times can be significantly reduced, thereby increasing the overall productivity of the leaching process.

In some embodiments, the reactor is then quenched, the solid is filtered (using a laboratory setup with a Buchner funnel) and washed. The drawing shows a general overview of a process in which base and acid treatment is typically carried out by first adding a base or acid to a reactor, followed by adding a porous solid, and then allowing the solid to react in a solution of the acid or base under vigorous mechanical stirring.

In the drawing, x represents the number of additions of base or acid per reaction, m _a is the amount of acid added per addition, m _b is the amount of base added per addition, y is the number of solid additions per reaction, m _s is the amount of solid added per addition, and z represents the number of treatments.

In the prior art, the values of x and y per treatment are typically equal to 1. In additional embodiments in this detailed description, the values of y and m _s are not changed.

In order to highlight the value of the present invention, it is necessary to describe the state of the art for experimental procedures for acid and alkali leaching of solids. In the prior art, a fixed amount of porous solid (typically 10-100 g L ^-1 ) is brought into contact with an aqueous solution of a fixed alkalinity or acidity. This is achieved by directly immersing the solid in a heated solution, allowing it to react and being recovered by filtration. Carrying out individual acid treatments in a stepwise manner is known in the art, which can be achieved using a pump or Soxhlet reactor. However, graded acid treatments have never been combined in any way with graded base treatments to be effective, as the inventors have surprisingly discovered.

Alkali treatments are usually carried out in NaOH or KOH solutions (usually 0.2 M) at about 70°C for 30 minutes. Acid treatments are typically performed using either mineral (eg HCl or HNO3) or organic acids (eg citric acid or _H4EDTA ). The concentration often depends on the purpose of the acid treatment: if dealumination of the framework is the target, then stronger concentration values (eg 2 M HCl) can often be used. In comparison, removal of Al residues after alkali treatment is usually performed using a much milder treatment (using 0.1 M HCl).

In some embodiments of the present invention, the acid or base is added in a solid or highly concentrated form slowly during the course of processing. The present inventors have discovered that this can be easily achieved using a pump such as a syringe or peristaltic pump. On a larger scale, industrial pumps or solid dispersants can be used. In particular, this embodiment significantly increases the effectiveness of using TRABr or DEA to maintain the characteristic properties of the zeolite during processing.

In some embodiments, the method involves contacting a solid in a stepwise manner with an acid and a base using a continuous configuration. In this configuration, a porous solid can be positioned on a membrane and a (dilute) acidic or basic solution is brought into contact with it by passing them through the solid-coated membrane. On a laboratory scale, such an experiment can be performed using a continuous microfiltration unit. This configuration bears no resemblance to known flow synthesis, since in this work the base is pumped along with the solid, which provides a reaction with it similar to that in a plug flow, which provides the same materials as in the batch reactor used in prior art. However, if a flow plant is used, the acid and base are added in stages in the flow, the solid and base no longer react as they would in a batch reactor. Instead, it operates as described for the method of the present invention: the solid is brought into contact with an acid or base in stages, which provides solids with improved properties. In addition, the base or acid may be contacted with the zeolite in a continuous stirred tank reactor or any other configuration that allows the solids to be treated with acids or bases in a stepwise or incremental manner.

In a second aspect, the present invention relates to an inorganic porous solid obtained using the method in accordance with the first aspect or any embodiment thereof. Preferred embodiments of these treated inorganic porous solids are defined above.

In a third aspect, the present invention relates to a zeolite with a faujasite topology, preferably produced in accordance with the method according to the first aspect or any embodiment thereof, with a unit cell size in the range of 24.375 to 24.300 A, with a mesopore volume of at least 0.30 ml/g. Typically, the unit cell becomes smaller as Al is removed from the framework. This type of zeolite is commonly called USY zeolite.

In some preferred embodiments, the zeolite according to the third aspect has a Brønsted acidity of at least 400 ^µmol'1 measured with pyridine; preferably 425 ^μmolyg'1 or higher, and most preferably 500 ^μmolyg'1 or higher, measured with pyridine.

In some preferred embodiments, the zeolite according to the third aspect has a crystallinity of at least 70%, preferably 75% or greater, and most preferably 80% or greater relative to standard NaY zeolite, and at least 80%, preferably 90% or greater and most preferably 100% or higher compared to the NIST alumina reference standard (SRM 676).

In some preferred embodiments, the zeolite according to the third aspect has a microporosity of at least 0.18 ^mlt'1 , preferably 0.21 ^mlt'1 or greater, and most preferably ^0.24 mlt'1 or greater.

In a fourth aspect, the present invention relates to a zeolite with a faujasite topology, preferably prepared in accordance with the process according to the first aspect or any embodiment thereof, with a unit cell size in the range of 24.60 to 24.40 A, preferably with a mesopore volume of at least 0.30 ml-g ^-1 . This type of zeolite is commonly called Y zeolite.

In some preferred embodiments, the zeolite according to the fourth aspect has a volume Si/Al atomic ratio of at least 5, preferably 6 or higher, and more preferably 7 or higher.

In some preferred embodiments, the zeolite according to the fourth aspect has a micropore volume of at least 0.18 ml-g ^-1 , preferably 0.20 ml-g ^-1 or greater, and most preferably 0.22 ml-g ^-1 or greater .

In some preferred embodiments, the zeolite of the fourth aspect has a crystallinity of at least 60%, preferably 70% or greater, and most preferably 80% or greater, relative to standard NaY zeolite.

For large scale industrial applications, zeolite powders (described in the examples) typically require conversion into industrial catalysts. Engineered catalysts are typically designed to provide the necessary mechanical strength and chemical stability to withstand the rigors of industrial catalytic installations. Conversion of zeolite powder into a commercial catalyst is preferably accomplished by mixing the zeolite with several other ingredients (such as fillers, pyrogens, binders, lubricants, etc.) and then molding into macroscopic shapes. The resulting technical catalysts can be multicomponent products with dimensions ranging from micrometer to centimeter.

In a sixth aspect, the present invention relates to a method for producing a technical catalyst, the method comprising the steps of producing a treated inorganic porous solid in accordance with the first aspect of the present invention and preferred embodiments thereof;

adding one or more additional ingredients to form a mixture, wherein the one or more additional ingredients is selected from the group consisting of fillers, pyrogens, binders, lubricants, and combinations thereof; and molding the mixture into a macroscopic shape to produce a technical catalyst, preferably wherein the macroscopic shape has a minimum size of less than 1 µm to no more than 10 cm.

The present inventors have found that the solids described above, in particular the substances of the second, third, fourth and fifth aspects, as well as their preferred embodiments, are ideal intermediates for preparing the technical catalyst described above.

In a seventh aspect, the present invention relates to the use of a treated inorganic porous solid in accordance with any of the aspects described herein, or produced by a method in accordance with any of the aspects and embodiments thereof, in catalysis, adsorption or ion exchange processes. Preferred embodiments of this application are defined above.

Some embodiments of the present invention are set forth below. These embodiments can also be combined with any of the embodiments described above.

In some embodiments, the present invention relates to a method for alkaline leaching of a porous solid, the method comprising a series of acid and base treatments (z) and characterized by the number of acid or base additions per reaction (x), the amount of base added per addition (m _b ) , the number of solids added per reaction (y), the amount of solid added per addition (ms), where x and z do not equal 1.

In some embodiments, the method is designed based on control x such that although the porous solid is exposed to the same total amount of acid or base, or the same total amount of acid or base is brought into contact with the porous solid (which is preferred to achieve the desired effect of base or acid leaching), alkali or acid leaching is less profound than normal exposure of a porous solid to the same amount of acid or base. A typical treatment may be a base-acid sequential treatment where the alkali treatment would involve treating the porous solid at 10-100 g-L ^-1 in aqueous solution coming into contact with a fixed alkalinity of 0.1 to 0.2 M NaOH, typically for approximately 20 to 40 minutes. This conventional treatment may be followed by a conventional acid treatment at 10-100 g-l ^-1 in a fixed acidity aqueous solution at 0.1-0.3 M HCl, typically for about 4-8 hours. Alternatively, the conventional treatment may represent an acid-base sequence where the conventional base treatment described immediately above is performed after the acid treatment at 10-100 g- ¹ in 0.15 M aqueous H4EDTA solution typically for about 4-8 hours.

In some embodiments, the method is designed such that although the porous solid is exposed to the same total amount of acid or base by controlling x, fragmentation of the components of the porous solid does not occur.

In some embodiments, the method comprises alkali leaching of the porous solid at 5-60 g-L, preferably 20 to 40 g-L ^-1 , wherein the method involves subjecting the porous solid to a treatment regimen involving multiple reactions under mild conditions in the presence of NaOH at a temperature of from 40 to 70°C, preferably at a temperature of from 60 to 75°C, and the reaction time is from 10 to 50 minutes, preferably from 20 to 40 minutes, and the treatment mode involves treating z with NaOH in an amount of mb for producing the same amount of NaOH that is consumed as a single treatment with NaOH in an amount of 0.15 to 0.25 M, and further includes acid leaching of the porous solid at 5-100 g- ¹ , preferably 50 to 80 g-l ^-1 , wherein the method involves subjecting the porous solid to a treatment regimen involving several reactions under mild conditions in the presence of HCl at a temperature of from 40 to 100°C, preferably at a temperature above 80°C, and the reaction time is from 1 to 10 hours, preferably 2 to 8 hours, wherein the treatment regime involves treating z with HCl in an amount of ma to obtain the same amount of HCl that is consumed as one treatment with NaOH in an amount of 0.05 to 0.35 M .

In some embodiments, the porous solid is a silicate-based porous solid.

In some embodiments, the silicate-based solid is a material with a topology selected from the group consisting of MWW, BEA, MFI, CHA, MOR, MTW, RUB, LEV, FER, MEL, RTH, AEL, AFI, CHA, DON, EMT, CFI, CLO, TON, FER, ERI, MEL, MTW, MWW, HEU, EUO, RHO, LTL, LTA and MAZ.

In some embodiments, the silicate-based solid is a material with a topology selected from the group consisting of MOR, MFI, BEA and FAU.

In some embodiments, the silicate-based solid is a porous crystalline silicate.

In some embodiments, the silicate-based solid is a porous crystalline silicate characterized by a zeolite structure.

In some embodiments, the silicate-based solid is amorphous, such as fumed silica or silica gel. In some embodiments, the porous solid is an amorphous aluminosilicate.

In some embodiments, the silicate-based solid is a porous ordered silicate (eg, MCM-41 or SBA-15).

In some embodiments, the porous solid is an ordered aluminosilicate (eg, MCM-41).

In some embodiments, the porous solid is a porous amorphous (silico)aluminophosphate.

In some embodiments, the porous solid is a porous crystalline (silico)aluminophosphate (eg, AlPO-5, SAPO-11, SAPO-34).

The efficiency of the base-acid leaching process is further enhanced (in terms of the mesoporosity generated and the retained crystallinity, microporosity and acidity in the resulting zeolites) by adding salts to the acid or base solution. These salts may contain cations selected from the group of ammonium, primary, secondary and tertiary amines, quaternary alkyl ammonium ions and metal cations of groups I, II and III of the periodic system. Salts include anions selected from the group consisting of chloride, bromide, nitrate, phosphate, sulfate, acetate, citrate, oxalate, tartrate, formate, malonate and succinate anions.

The beneficial effect of salt is achieved by adding salt during one or more acid or base treatments. The effect of salt may be more enhanced after subsequent treatment at a different pH. This implies that the presence of salt may influence the effectiveness of the treatment in which it is applied, as well as the effectiveness of the subsequent treatment. For clarity, the beneficial effect in subsequent processing should not be attributed to salts that may have remained in a solid state during incomplete washing, since the bulk (>95%) of the salt is usually removed in the washing step after the first treatment. Instead, several local changes in the solid may have occurred that are difficult to observe directly after the salt treatment. These local changes are likely to be preferentially reversed by subsequent second treatments (often performed at different pH values, eg acid after alkali and vice versa).

For example, in the case of two treatments (z=2, acid-base), if the acid treatment is followed by a base treatment, the beneficial effect of adding salt during the first acid treatment becomes more pronounced after the second base treatment (the latter performed in the absence of additional salts). As another example, in the case of 2 treatments (z=2, base-acid), if a base treatment is followed by an acid treatment, then the presence of salt during the base treatment greatly affects the effectiveness of the next acid treatment, even if there is a salt during the last acid treatment absent.

Examples

Comparative example 1.

Base treatments were carried out at 65°C for 30 min in a round bottom flask with a stirrer. Accordingly, 3.3 g of USY (CBV712 from Zeolyst) was suspended in 90 ml of water, and base (G) was added stepwise over 30 minutes at a rate of 0.2 mmol NaOH per gram of zeolite feed per minute. using a 2 M NaOH stock solution. After the reaction, the solid was isolated from the suspension using Buchner funnel filtration.

Comparative example 2.

After base treatment as described in Example 1, a few grams of the resulting sample was subjected to 3 ion exchange procedures in 250 ml of water supplemented with NH ₄ NO ₃ (0.8 g per gram of zeolite), followed by filtration, drying at 60°C for overnight and calcination at 550°C for 5 hours.

Comparative example 3.

After base treatment as described in Example 1, a few grams were post-acid treated using 67 grams of zeolite per liter of 0.22 M HCl solution at 95° C. for 6 hours in a round bottom flask with a stirrer. In this example, the zeolite was brought into contact with the acid with the entire amount (D) at once, that is, not in a stepwise manner. After the reaction, the solid was isolated from the suspension using Buchner funnel filtration and subjected to 3 ion exchange procedures in 250 ml of water supplemented with NH4NO3 (0.8 g per gram of zeolite), followed by filtration, drying at 60°C overnight and calcination at 550°C for 5 hours.

Comparative example 4.

After base treatment as described in Example 1, a few grams were subjected to further acid treatment using 67 g of zeolite per liter of 0.44 M HCl solution at 95° C. for 6 hours in a round bottom flask with a stirrer. After the reaction, the solid was isolated from the suspension using Buchner funnel filtration and subjected to 3 ion exchange procedures in 250 ml of water supplemented with NH4NO3 (0.8 g per gram of zeolite), followed by filtration, drying at 60°C overnight and calcination at 550°C for 5 hours.

Example 5.

After base treatment as described in Example 1, acid treatments of the present invention were carried out at 95°C for 6 hours in a round bottom flask with a stirrer. Accordingly, 2.7 g of base-treated USY was suspended in 40 ml of water, and acid was added stepwise over 6 hours at a rate of 0.55 mmol HCl per gram of zeolite stock per hour using 3.14 M HCl stock solution. After the reaction, the solid was isolated from the suspension using Buchner funnel filtration and subjected to 3 ion exchange procedures in 250 ml of water supplemented with NH4NO3 (0.8 g per gram of zeolite), followed by filtration, drying at 60°C overnight and calcination at 550°C for 5 hours. As shown in table. B, the characteristic properties (microporosity, Brønsted acidity, crystallinity), secondary porosity (mesoporosity) and catalytic properties of this sample are significantly superior to those of a sample obtained by standard acid treatment using the same amount of acid per gram of zeolite (Example 3) . This accordingly clearly demonstrates the advantages of staging both base and acid treatments.

Example 6.

After base treatment as described in Example 1, acid treatments of the present invention were carried out at 95°C for 6 hours in a round bottom flask with a stirrer. Accordingly, 2.7 g of base-treated USY was suspended in 40 ml of water, and acid was added stepwise over 6 hours at a rate of 1.1 mmol HCl per gram of zeolite stock per hour using 3.14 M HCl stock solution. After the reaction, the solid was isolated from the suspension using Buchner funnel filtration and subjected to 3 ion exchange procedures in 250 ml of water supplemented with NH4NO3 (0.8 g per gram of zeolite), followed by filtration, drying overnight and calcination at 550°C for 5 hours. As shown in table. B, the characteristic properties (microporosity, Brønsted acidity, crystallinity), secondary porosity (mesoporosity) and catalytic properties of this sample significantly exceed those of a sample obtained by standard acid treatment using the same amount of acid per gram of zeolite (Example 4) . This accordingly clearly demonstrates the advantages of staging both base and acid treatments.

In table B shows the crystallinity, porosity, acidity and catalytic properties of conventional base-treated and base-acid treated USY zeolites. _________________________________________________________ Table B

No. example Base (first treatment) total/ (g g' ¹ ) Acid (second treatment) ^a,tot/ (g g' ¹ ) V ^a g meso -1 ML G Vmicro mlg ¹ Krist? % Acidity ⁰ µmol g ¹ A ^e -1 USY ^h 0.18 0.25 100 270 15 z, z 2 0.24(G) ^s - 0.31 (+72%) ^f 0.24 (-4%) 61 (-39%) 313 (+16%) 264 2.2 3 0.24(G) 0.12(D) 0.35 (+94%) 0.22 (-12%) 63 (-37%) 325 (+19%) 540 2.2 4 0.24(G) 0.24(D) 0.36 (+100%) 0.20 (-20%) 67 (-33%) 267 (-1%) 431 z, z 5 0.24(G) 0.12(G) 0.38 (+111%) 0.25 (0%) 85 (-15%) 427 (+58%) 570 4.1 6 0.24(G) 0.24(G) 0.35 (+94%) 0.26 (+4%) 81 (-19%) 494 (+83%) 574 3.3

^a Nitrogen adsorption.

^b XRD compared to the original USY zeolite (regular).

^with Pyridine.

^d Catalyst productivity in the conversion of α-pinene in grams of useful products formed (limonene, camphene, α-terpinene, γ-terpinene, terpinoline, p-cymene) per gram of catalysts per hour.

^e Catalyst productivity for the alkylation of toluene with benzyl alcohol, expressed in g of benzyl alcohol converted per gram of catalyst per hour.

^f Values in parentheses indicate the induced change compared to the original conventional USY zeolite.

^g Letters in parentheses in the Base and Acid columns indicate whether the treatment was carried out in a stepwise manner (G) or in a non-stepwise manner adding all at once (D).

^h Commercial USY provided by Zeolyst (CBV 712).

Comparative example 7.

Several grams of commercial NaY zeolite (CBV 100 from Zeolyst) were acid treated using 67 g of zeolite per liter of 0.15 M H ₄ EDTA at reflux for 6 hours in a round bottom flask with a stirrer. After the reaction, the solid was isolated from the suspension using Buchner funnel filtration, washed and dried.

Comparative example 8.

Several grams of commercial NaY zeolite (CBV100 from Zeolyst) were acid treated using 67 g of zeolite per liter by adding an equivalent amount of H ₄ EDTA as in Example 7 as a solid in ten doses evenly distributed over 6- hourly processing, under reflux in a round-bottomed flask with a stirrer. After the reaction, the solid was isolated from the suspension using Buchner funnel filtration, washed and dried.

Comparative example 9.

The solid obtained in Example 7 was post-treated with a base. It was performed at 65°C for 30 min in a round bottom flask with a stirrer. Accordingly, 1.66 g of the solid was suspended in 45 ml of water, and base was added stepwise over 30 minutes at a rate of 0.2 mmol NaOH per gram of starting zeolite per minute. using a 2 M NaOH stock solution. After the reaction, the solid was isolated from the suspension using Buchner funnel filtration, washing and drying.

Example 10.

The solid obtained in Example 8 was post-treated with a base. It was performed at 65°C for 30 min in a round bottom flask with a stirrer. Accordingly, 1.66 g of the solid was suspended in 45 ml of water, and base was added stepwise over 30 minutes at a rate of 0.2 mmol NaOH per gram of starting zeolite per minute. using a 2 M NaOH stock solution. After the reaction, the solid was isolated from the suspension using Buchner funnel filtration, washing and drying. As shown in table. C, the characteristic properties (microporosity and crystallinity) and secondary porosity (mesoporosity) of this sample are significantly greater than those of a sample obtained by standard acid treatment using the same amount of acid per gram of zeolite (Example 9). This, therefore, clearly demonstrates the advantages of performing stepwise treatment with both acid and base.

In table C demonstrates the porosity and crystallinity of commercial, acid-treated, and base- and acid-treated Y zeolites.

Table C

No. example Acid (first treatment) ^a,tot/ (g g' ¹ ) Base (second treatment) ^b,total/ m _s (g g' ¹ ) V ^a ' meso ml g ¹ V ^a E micro ml g ¹ Crystallinity ^% Si/Al ^c mol mol ¹ NaY ^e 0.01 0.33 100 2.6 7 0.66(D) ^d SI 0.21 32 8 0.66(G) 0.09 0.29 46 9 0.66(D) 0.24(G) 0.41 0.15 25 10 0.66(G) 0.24(G) 0.52 0.23 78

^a Nitrogen adsorption.

^b XRD compared to parent zeolite Y (commercial).

^c ICP-OES.

^d Letters in parentheses in the Acid and Base columns indicate whether the treatment was carried out in a stepwise manner (G) or in a non-stepwise manner adding all at once (D).

^e Commercial NaY provided by Zeolyst (CBV 100).

Comparative Example 11: Conventional Base Leaching Techniques.

In table And the physico-chemical properties of conventional (untreated) and acid- and base-treated zeolites were demonstrated using total addition effects, such as non-step addition, of base or acid on the zeolite. Data are given relative to the original (untreated) zeolites.

Table A

Zeolite Sequence Mesopore Micropore Crystalline Acidity Time

modifications ^cost (%) ^Trueness (%) ity ^a (%) Brønsted ^a (%) filtration ^b (%) Y raw 100 100 100 100 - Y first: acid (D) ¹ second: base (D) third: acid (D) 2100 61 51 52 USY ^d raw 100 100 100 100 100 USY base (D) 259 97 54 67 200 USY-II ⁶ raw 100 100 100 100 100 USY-II base (D) 336 81 64 57 3400 USY-SH ¹ untreated 100 100 100 100 100 USY-III base (D) 296 78 76 93 4400 ZSM-5 ^s raw 100 100 100 100 100 ZSM-5 base (D) 700 57 72 84 600 beta ¹¹ raw 100 100 100 100 100 beta base (D) 313 90 61 76 500

^a Data for porosity, crystallinity, and acidity were obtained from ACS Catalysis, 2015, 5, 734.

^b Filtration times for base treatments were obtained by reproducing experiments from ACS Catalysis, 2015, 5, 734 on a 100 mL scale and filtering using a Buchner setup with No. 5 Whatman filter paper (9 cm diameter). The filtration time of untreated conventional zeolites was determined by filtering a suspension of 3.3 g of zeolite in 100 ml of distilled water using a Buchner apparatus with Whatman No. 5 filter paper (9 cm diameter).

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Claims (7)

^d CBV 712, Si/Al=6. ^e CBV 720, Si/Al=15. ^f CBV 760, Si/Al=30. ^g CBV 8014, Si/Al=40, Si/Al=6. ^h TOSOH, HSZ-940HOA, Si/Al=20. ¹ The letters D in the Sequence of Modification column indicate that the treatments were not carried out in a stepwise manner with the entire amount added at once. CLAIM 1. A method for producing a processed zeolite with a faujasite topology with a mesopore volume of 0.05 ml/g or more and a unit cell size of not more than 24.70 A, where the method consists of two or three separate treatments that are separated by a solid separation step, wherein at least one of the treatments is a base treatment, which comprises the steps a) providing zeolite in an amount of ms; b) providing the total amount of base mb, _total ; And c) bringing the zeolite into contact with an amount of base m _b (t) in an aqueous solution at a temperature of from room temperature to 100°C and a pH of at least 10 to at most 14 and causing them to react, where the base is continuously added to the zeolite for time period At for the total amount of base mb, _total , wherein the time period At is at least 15 s; and at least one of the treatments is an acid treatment, which comprises the steps d) providing zeolite in an amount of ms; e) providing the total amount of acid ma, _total ; And f) bringing the zeolite into contact with an amount of acid m _a (t) in an aqueous solution with a temperature of from room temperature to 100°C and a pH of from at least 0 to at most 5 and causing them to react, where the acid is continuously added to the zeolite for time period At for the total amount of acid ma, total, wherein the time period At is at least 15 minutes; thus obtaining a treated zeolite, where depending on the order of the treatments m _s means either an untreated zeolite or a zeolite obtained as a result of a previously performed treatment in accordance with step c) or step f), and where the maximum amount of base mb, _max . for m _b (t) brought into contact with the zeolite ms at any time t in step c) is less than mb, total/ms, with mb, _max . is no more than 0.25xmb, total, and where is the total number of bases mb, _total . presented in the form of solid alkali or alkaline solution, and where the maximum amount of acid is ma, _max . for m _a (t) brought into contact with the zeolite ms at any time t at stage f), less than ma, total/ms, with ma, _max . is no more than 0.25xma, total, and where is the total amount of acid ma, _total . presented in the form of a solid acid or an acid solution. 2. The method according to claim 1, wherein the zeolite is subjected to treatment with a base, followed by separation of the solid, followed by treatment with an acid. 3. The method of claim 1, wherein the zeolite is treated with an acid followed by separation of the solid, followed by treatment with a base. 4. Method according to any one of claims 1-3, where the maximum amount of base m _{b, max.} for m _b (t) at any time t in step c) is no more than 0.10xm _b , _max ., and where the maximum amount of acid ma, _max . for m _a (t) at any time t at stage f) is no more than 0.10xm _a , _total .. 5. The method according to any one of claims 1 to 3, where stage a) involves a') providing zeolite in an amount of ms suspended in water; and step d) involves d') providing the zeolite in an amount ms suspended in water. 6. The method according to any one of claims 1 to 5, where the base is an inorganic base from the group consisting of NH4OH, NaOH, KOH and LiOH, or where the base is an organic base such as tetrapropylammonium hydroxide, diethylamine, dipropylamine, tetrabutylammonium hydroxide and tetraethylammonium hydroxide or combinations thereof. 7. Method according to any one of claims 1-5, -