ES2703222A1 - Catalyst comprising a new molecular sieve that belongs to the ERI family and use of the catalyst (Machine-translation by Google Translate, not legally binding) - Google Patents

Abstract

Catalyst comprising a new molecular sieve that belongs to the ERI family, and use of the catalyst. Catalyst comprising a molecular sieve with the type of structure of ERI, having a molar ratio of silica to alumina of about 8 to about 100 and a crystalline morphology defined by the ratio between the dimensions rc, along yra orthogonal to the single c axis between 0.5 and 2.0, and use of the catalyst in catalytic reactions. (Machine-translation by Google Translate, not legally binding)

Description

DESCRIPTION

Catalyst comprising a new molecular sieve that belongs to the ERI family and use of the catalyst.

The present invention relates to a catalyst comprising a new molecular sieve with the ERI structure type, and the use of the catalyst in catalytic reactions.

In particular, the invention provides a catalyst comprising a crystalline zeolitic molecular sieve material belonging to the ERI structure family essentially without OFF zeolite intergrowth, with a high Si / Al ratio and a tabular to prismatic crystal morphology.

Zeolites are crystalline microporous materials formed by sharing tetrahedral TO4 corners (T = Si, Al, P, Ge, B, Ti, Sn, etc.), interconnected by oxygen atoms to form pores and cavities of uniform size and precisely defined by its crystal structure. Zeolites are also referred to as "molecular sieves" because the pores and cavities are similar in size to small molecules.This class of materials has important commercial applications as absorbers, ion exchangers and catalysts.

Zeolitic molecular sieves are classified by the International Zeolite Association (IZA) according to the rules of the IUPAC Commission on Molecular Sieve Nomenclature. Once the topology of a new structure is established, a three-letter code is assigned. This code defines the atomic structure of the structure, from which a clear X-ray diffraction pattern can be described.

The term structure type or structure topology as used herein, refers to the unique atomic structure of a specific molecular sieve, named by a three-letter code devised by the International Zeolite Association [Atlas of Zeolite Framework Types, 6th revised edition , 2007, Ch. Baerlocher, LB McCusker and D.H. Olson, ISBN: 978-0-444 53064-6].

Erionite (ERI) is an aluminosilicate zeolite of natural origin [Staples, LW and Gard, JA, Mineral. Mag., 32 , 261-281 (1959)] with a Si / Al ratio of about 3. often found as an intergrowth with OFF [Schlenker, JL, Pluth, JJ and Smith, JV, Acta Crystallogr., B33 , 3265-3268 (1977)].

Several ways have been described for preparing ERI by synthetic methods.

US Patent 2,950,952 describes the preparation of type T molecular sieve, which has been shown to be an intergrowth of ERI and OFF [J.M. Bennet et al., Nature, 1967, 214, 1005-1006. US Patent 3,699,139 describes the synthesis of ERI / OFF using trimethylbenzylammonium. US Patent 4,086,186 describes the synthesis of ZSM-34, which is also an intergrowth of ERI and OFF. US Patent 4,503,023 describes the synthesis of LZ-220, which is a slightly more siliceous form of T-type molecular sieve, and is also an intergrowth. It has also been reported that the use of DABCO (I) and DABCO (II) gives inter-growths of ERI and OFF [M. L. Ocelli et al., Zeolites, 1987, 7, 265-271].

As illustrated by the above references, the preparation of ERI typically leads to intergrowths with OFF. These intergrowths can not be considered pure ERI topologies and lead to different channel systems and cage distributions within zeolitic materials compared to pure ERI, which together will influence the properties of this class of materials.

Only a few publications refer to the synthesis of ERI essentially free of OFF inter-growth. US Patent 7,344,694 discloses the preparation of UZM-12, which is suggested to have a Si / Al ratio above 5.5 (= SiO2 / Al2O3> 11). Practically, in the examples there was no case in which the invention was carried out to achieve silica to alumina ratios (SiO2 / Al2O3) greater than 12.6. In addition, UZM-12 is prepared using a density disparity approach, in which nanocrystalline material can be obtained with crystallites of 15 to 50 nm with spherical crystalline morphologies to "rice grain." Especially, nanocrystallites are difficult to separate of the crystallization liquor.

Recently, another molecular sieve of ERI, designated SSZ-98, was disclosed in US Patents 9,409,786, 9,416,017 and in US Patent Application 2016/0001273. This material is also essentially free of OFF intergrowth.

It is claimed that SSZ-98 has a SiO2 / Al2O3 ratio between 15 and 50, with a morphology crystal like rod or sheet, and prepared using the N, N'-dimethyl-1,4-diazobicido [2.2.2] octane dication as a directing agent of the structure.

Subsequent patent applications also claim N, N-dimethylpiperidinium cations, 1,3-dicyclohexylimidazole cations, and their combination, in patent applications US 2017/0088432, 2017/0073240 and 2016/0375428, respectively.

It is commonly known in the art that the hydrothermal stability of molecular sieves of aluminosilicates becomes higher when the molar ratio of SiO2 / Al2O3 is increased. Accordingly, there is a need to increase the molar ratios of SiO2 / Al2O3 of the known ERI molecular sieve materials, in particular for applications in which hydrothermal stability is a problem. In addition, it is also commonly known in the art that crystalline morphology has a great impact on the behavior of the molecular sieve in catalytic applications. In [S. Teketel, LF Lundegaard, W. Skistad, SM Chavan, U. Olsbye, KP Lillerud, P. Beato, S. Svelle, J. Catal. 2015 , 327, 22-32] a description of the behavior of the different crystalline morphologies in zeolitic catalysis can be found. Thus, there is also a need to prepare materials with specific morphologies for specific catalytic applications.

To distinguish different crystalline morphologies, a parameter (rc / ra) is defined, which describes the relationship between the different dimensions along (rc) and orthogonal (ra) to the single c-axis of the prepared crystallites, for example determined by methods of electron microscopy (for hexagonal crystals, the single c-axis is parallel to the six-fold axis of symmetry). The morphologies of the crystallite will be described using the words sheet, tabular, prismatic, needle and rod-like. The relationship between these descriptions and the rc / ra values is defined in the Table below.

Thus, a general object of this invention is to provide an ERI crystalline molecular sieve essentially free of OFF inter-growth, with molar ratios of elevated SiO2 / Al2O3 and crystal morphologies different from what is already known.

We have found that the use of a dication of cidohexane-1,4-bis (trialkylammonium) as the directing agent of the organic structure (OSDA) results in the successful achievement of pure ERI with high silica to alumina ratios of up to 100, and with crystalline morphologies different from that of SSZ-98.

According to the above finding, the present invention is, in a first aspect, a catalyst comprising a molecular sieve with the ERI structure type, having a molar ratio of silica to alumina of about 8 to about 100 and a crystalline morphology defined by the relationship between the dimensions rc along and r orthogonal to the single c axis between 0.5 and 2.0.

The crystalline morphology of the new molecular sieve of ERI with an rc / ra ratio of between 0.5 and 2 has a prismatic to tabular crystalline morphology, as shown in Figures 2 and 4 in the drawings, which is different from a crystalline morphology similar to rods or sheet of the known ERI molecular sieve SSZ-98.

The following describes specific characteristics and embodiments of the invention.

In one embodiment, the calcined form of the ERI molecular sieve has a dust X-ray diffraction pattern, collected in Bragg-Brentano geometry with a variable divergence groove using Cu K-alpha radiation, essentially as shown in FIG. Next Table:

* The intensities of the peaks and the assignment of the letters is uncertain due to the significant overlap of the peaks.

in which the relative areas of the peaks observed in the 2-Theta interval of 7-19 degrees are shown according to: W = weak: 0-20%; M = medium: 20-40%; S = strong: 40-60% and VS = very strong: 60-100%. The values of 2-Theta are ± 0.20 °.

In a further embodiment, the molar ratio of silica to alumina is between 8 and 100, preferably between 10 and 60.

In a further embodiment, at least a portion of the aluminum and / or silicon in the molecular sieve is replaced by one or more metals selected from tin, zirconium, titanium, hafnium, germanium, boron, iron, indium and gallium.

In another embodiment, the molecular sieve further contains copper and / or iron.

The one or more metals can be introduced into and / or onto the molecular sieve product by ion exchange, impregnation, solid state procedures, and surface precipitation of the ERI molecular sieve.

A further aspect of the present invention is a method for the conversion of nitrogen oxides into nitrogen in the presence of a reducing agent, comprising the step of contacting the nitrogen oxides and the reducing agent with the catalyst according to any one of the embodiments described above.

In a specific embodiment of the method for the conversion of nitrogen oxides into nitrogen, the reducing agent comprises hydrocarbons and / or ammonia, or a precursor thereof.

In still one embodiment of the method for the conversion of nitrogen oxides into nitrogen, nitrogen oxides are contained in the exhaust of an engine.

In a further embodiment of the method for the conversion of nitrogen oxides into nitrogen, nitrogen oxides are contained in the exhaust of a gas turbine.

In another embodiment of the method for the conversion of nitrogen oxides into nitrogen, the nitrogen oxides comprise nitrous oxide.

Another aspect of the invention is a method for the selective oxidation of ammonia to nitrogen, which comprises the step of contacting the ammonia, or a gas comprising the ammonia, with the catalyst according to any one of the embodiments described above.

In one embodiment of the method for the selective oxidation of ammonia to nitrogen, the catalyst comprises an oxidation functionality or an oxidation catalyst.

In still one embodiment of the method for the selective oxidation of ammonia to nitrogen, the catalyst is disposed downstream of a selective catalytic reduction catalyst, and in which an excess of ammonia is used to reduce nitrogen oxides.

A further aspect of the invention is a method for the simultaneous oxidation of hydrocarbons and carbon monoxide and the reduction of nitrogen oxides, which comprises the step of contacting hydrocarbons, carbon monoxide and oxides of nitrogen with a catalyst according to any one of the embodiments described above.

In one embodiment of the method for the simultaneous oxidation of hydrocarbons and carbon monoxide and the reduction of nitrogen oxides, the catalyst further comprises one or more metals of the platinum group.

A further aspect of the invention is a method for the conversion of oxygenates into hydrocarbons, which comprises the step of contacting the oxygenates with a catalyst according to any one of the embodiments described above.

In one embodiment of the method for the conversion of oxygenates into hydrocarbons, the hydrocarbons produced comprise olefins.

A further aspect of the invention is a method for the partial oxidation of methane to methanol and / or dimethyl ether, which comprises the step of contacting the methane with a catalyst according to any one of the embodiments described above.

A further aspect of the invention is a method for the preparation of lower amines by reaction of ammonia with methanol with a catalyst according to any one of the embodiments described above.

The ERI molecular sieve comprised in the catalyst of the invention can be prepared by a method comprising the steps of;

i) preparing a synthesis mixture comprising at least one source of silica and at least one source of alumina, or a combined source of both silica and alumina, a source of alkali metal or alkaline earth metal (A), at least an OSDA that is a cation of cyclohexane-1,4-bis (trialkylammonium), and water in molar ratios of:

ii) subjecting the mixture to conditions capable of crystallizing the molecular sieve; Y

iii) separating the product from the molecular sieve to obtain the molecular sieve as it is synthesized.

The silica source may comprise silica, fumed silica, silicic acid, amorphous or crystalline silicates, colloidal silica, tetraalkyl orthosilicates, and mixtures thereof.

The alumina source may comprise alumina, boehmite, aluminates, and mixtures thereof.

A combined source of silica and alumina can be amorphous amorphous silica-alumina, kaolin, mesoporous materials, crystalline microporous aluminosilicates, and mixtures thereof.

OSDA is a cation of cyclohexane-1,4-bis (trialkylammonium) having the structures (R = alkyl group) as shown below.

Preferably, the OSDA is selected from the group consisting of cyclohexane-1,4-bis (trimethylammonium), cyclohexane-1,4-bis (triethylammonium), cyclohexane-1,4-bis (ethyldimethylammonium), cyclohexane-1,4- bis (diethylmethylammonium).

Currently, the most preferred OSDA is cyclohexane-1,4-bis (trimethylammonium).

The cation of OSDA is associated with anions, which may typically be hydroxide, chloride, bromide, iodide, etc., as long as they are not detrimental to the formation of the molecular sieve.

Other tetravalent elements can also be introduced into the synthesis mixture. Such elements include tin, zirconium, titanium, hafnium, germanium, and combinations thereof. Trivalent elements can also be included in the synthesis mixture, either together with aluminum or without the presence of aluminum. Such trivalent elements include boron, iron, indium, gallium, and combinations thereof. Both tetravalent and trivalent elements can be added in the form of metals, salts, oxides, sulfides, and combinations thereof.

Transition metals may be included in the synthesis mixture, either as simple salts or as complexes that protect the transition metal from precipitation under the caustic conditions dictated by the synthesis mixture. Especially, the polyamine complexes are useful for protecting transition metal ions of copper and iron during the preparation, and can also act to direct the synthesis towards specific molecular sieves (see, for example, the use of polyamines in combination with ions of copper in the patent application US 2016/271596). In such a manner, the transition metal ions can be introduced into the interior of the molecular sieve easily during crystallization.

The synthesis mixture can also contain inexpensive pore filling agents, which can aid in the preparation of more siliceous products. Such pore-filling agents may be crown (eg, 18-crown-6) ethers, simple amines (eg trimethyl- and triethylamine), and other uncharged molecules.

The crystallization of the synthesis mixture to form the new molecular sieve is carried out at elevated temperatures until the molecular sieve is formed. Hydrothermal crystallization is usually carried out in a manner to generate an autogenous pressure at temperatures of 100-200 ° C in an autoclave and for periods of time between two hours and 20 days. The synthesis mixture can be subjected to stirring during crystallization.

Once the crystallization is complete, the resulting solid molecular sieve product is separated from the remaining liquid synthesis mixture by conventional separation techniques such as decantation, filtration (in vacuo) or centrifugation. The recovered solids are then typically rinsed with water and dried using conventional methods (e.g., heating to 75-150 ° C at atmospheric pressure, vacuum drying or lyophilization, etc.), to obtain the "as synthesized" molecular sieve. The product "as synthesized" refers here to the molecular sieve after crystallization and before the elimination of the agent or agents directing the structure or other organic additives.

The typical composition of the molecular sieve, in its anhydrous state, obtained by the process according to the invention, is summarized in the Table below.

Component Wide range Preferred interval

SiO2 / Al2O3 8-100 10-60

OSDA / SO 0.01-0.6 0.02-0.2

A / SÍO2 0.01-0.6 0.02-0.2

The organic OSDA cations still retained in the molecular sieve as synthesized are removed in most cases, except that they are used in the form as synthesized, by heat treatment in the presence of oxygen. The temperature of the heat treatment should be sufficient to remove the organic molecules either by evaporation, decomposition, combustion, or a combination thereof. Typically, a temperature between 150 and 750 ° C is applied for a period of time sufficient to remove the organic molecule or molecules. A person skilled in the art will readily be able to determine a minimum temperature and time for this heat treatment. Other methods for removing the material or organic materials retained in the molecular sieve as synthesized include extraction, vacuum calcination, photolysis, or ozone treatment.

The calcined form of the molecular sieve has a dust X-ray diffraction pattern, collected in Bragg-Brentano geometry with a variable divergence groove using Cu K-alpha radiation essentially as shown in the following Table:

* The intensities of the peaks and the assignment of the etra is uncertain due to the significant overlap of the peaks.

in which the relative areas of the peaks observed in the 2-Theta interval of 7-19 degrees are shown according to: W = weak: 0-20%; M = medium: 20-40%; S = strong: 40-60% and VS = very strong: 60-100%. The values of 2-Theta are ± 0.20 °.

Usually, it is desirable to remove the remaining alkali or alkaline earth (for example Na +) ions from the molecular sieve essentially free of occluded organic molecules by ion exchange or other known methods. Ion exchange with ammonium and / or hydrogen are well-recognized methods for obtaining the NH4 form or the H form of the molecular sieve. Also, desired metal ions can be included in the ion exchange process, or they can be carried out separately. The NH 4 form of the material can also be converted to the H form by simple heat treatment, in a manner similar to that described above.

In certain cases, it may also be desirable to alter the chemical composition of the molecular sieve obtained, such as by altering the molar ratio of silica to alumina. Without being bound by any order of the post-synthetic treatments, in this case the leaching of acids can be useful (they can be used inorganic and organic using complexing agents such as EDTA, etc.), steam treatment, desilication, and combinations thereof, or other methods of demetalation.

To promote specific catalytic applications, certain metals can be introduced into the new molecular sieve to obtain a molecular sieve substituted with metal, impregnated with metal or exchanged with metal. Metal ions can be introduced by ion exchange, impregnation, solid state processes, and other known techniques. The metals can be introduced to produce essentially atomically dispersed metal ions, or they can be introduced to produce small groupings or nanoparticles with ionic or metallic character. Alternatively, the metals can be simply precipitated on the surface and in the pores of the molecular sieve. In the case of Where nanoparticles are preferred, consecutive treatment in, for example, a reducing atmosphere may be useful. In other cases, it may also be desirable to calcine the material after the introduction of metals or metal ions.

As already mentioned above, the molecular sieve according to the invention is particularly useful in heterogeneous catalytic conversion reactions, such as when the molecular sieve catalyses the reaction of molecules in gas phase or liquid phase. It can also be formulated for other commercially important non-catalytic applications, such as gas separation. The molecular sieve provided by the invention and from any of the preparation steps described above can be formed into a variety of physical forms useful for specific applications. For example, the molecular sieve may be used in the form of a powder, or it may be in the form of pellets, extruded or molded monolithic forms, for example as a fully corrugated body substrate containing the molecular sieve.

When shaping the molecular sieve, it will typically be useful to apply additional organic or inorganic components. For catalytic applications, it is particularly useful to apply a combination with alumina, silica, titania, ceria, zirconia, various spinel structures, or other oxides or combinations thereof. It can also be formulated with other active compounds such as active metals or other molecular sieves, etc.

The molecular sieve can also be employed coated on or introduced into a substrate that improves the contact area, diffusion, fluid characteristics and fluidity of the gas stream. The substrate can be a metal substrate, an extruded substrate or a corrugated substrate, the latter being formed of ceramic paper. The substrate can be designed as a continuous flow design or a flow through wall design. In the latter case, the gas flows through the walls of the substrate, and in this way can also contribute an additional filtering effect.

The molecular sieve is typically present on or in the substrate in amounts between 10 and 600 g / l, preferably 100 and 300 g / l, as calculated by the weight of the molecular sieve per volume of the total catalytic article.

The molecular sieve is coated on or in the interior of the substrate using known techniques of coating by washing. In this approach, the molecular sieve powder is suspended in a liquid medium together with binder or binders and stabilizer or stabilizers. The washing coating can then be applied on the surfaces and walls of the substrate. The wash coating also optionally contains binders based on TiO2, SiO2, Al2O3, ZrO2, CeO2, and combinations thereof.

The molecular sieve can also be applied as one or more layers on the substrate in combination with other catalytic functionalities or other zeolitic catalysts. A specific combination is a layer with an oxidation catalyst containing, for example, platinum or palladium, or combinations thereof. The molecular sieve can be additionally applied in limited areas along the direction of the gas flow of the substrate.

The molecular sieve according to the invention can be used in the catalytic conversion of nitrogen oxides, typically in the presence of oxygen. In particular, the molecular sieve can be used in the selective catalytic reduction (SCR) of nitrogen oxides with a reducing agent such as ammonia and precursors thereof, including urea or hydrocarbons. For this type of application, the molecular sieve will typically be loaded with a transition metal, such as copper or iron, or combinations thereof, using any of the methods described above, in an amount sufficient to catalyze the specific reaction.

In certain aspects of the invention, a certain amount of alkali metal or alkaline earth metal may be beneficial. See, for example, a description of the effects of alkali metals and alkaline earth metals on CHA promoted by copper in [F. Gao, Y. Wang, NM Washton, M. Kollár, J. Szanyi, CHF Peden, ACS Catal. 2015 , 5, 6780 6791]. In other aspects, it may be preferred to use the molecular sieve essentially free of alkali metal or alkaline earth metal.

The ERI molecular sieve according to the invention can be advantageously used as a catalyst in the reduction of nitrogen oxides in the exhaust from a vehicular (ie mobile) internal combustion engine. In this application, the exhaust system may comprise one or more of the following components: a diesel oxidation catalyst (DOC), a diesel particulate filter (DPF), a selective catalytic reduction catalyst (SCR), and / or an ammonia leakage catalyst (ASC). Such a system also typically contains means for measuring the reducing agent, as well as the possibility to measure hydrocarbons in the exhaust system upstream of the SCR and the DOC, respectively.

In one embodiment, the ERI catalyst is disposed downstream and / or upstream of a diesel oxidation catalyst.

In another embodiment, the ERI catalyst is disposed upstream of an ammonia leakage catalyst.

In a further embodiment, the ERI catalyst is disposed upstream and / or downstream of a diesel particulate filter.

The SCR catalyst comprises the ERI molecular sieve of the invention. The SCR catalyst may also contain other active components, such as other molecular sieves. When the SCR catalyst is located in such an exhaust system, it is exposed to elevated temperatures from the engine or during thermal regeneration of one or more of the components in the system.

In the exhaust system as described above, the SCR catalyst, comprising the ERI molecular sieve, can be located between the components of the DPF and the ASC. Another possibility is to arrange the SCR catalyst upstream of the DOC, where a certain tolerance to unburned hydrocarbons is required. The SCR functionality can also be included in the DPF, or it can be combined with the ASC in a single component with a dual function.

The ERI molecular sieve according to the invention can also be part of an ammonia leakage catalyst (ASC). The ASC catalyst is used in combination with the SCR article, and its function is to remove the excess amount of ammonia, or a precursor thereof, which is necessary in the SCR stage to remove high quantities of nitrogen oxides from the gas escape

ASC type catalysts are bifunctional catalysts. The first function is to oxidize ammonia with oxygen, which produces NOx, and the second function is the SCR of NH3, in which NOx and residual amounts of ammonia react to nitrogen.

Therefore, the ASC catalysts consist of a combination of an active component for the oxidation of ammonia by oxygen and an active component for the SCR of NH3.

The most commonly applied components for the oxidation of ammonia by oxygen are based on metals such as Pt, Pd, Rh, Ir, Ru, but for this purpose you can also use transition metal oxides or a combination of metal oxides, for example oxides of Ce, Ti, V, Cr, Mn, Fe, Co, Nb, Mo, Ta, W. When such materials are combined with the metal-charged form of the molecular sieve of the invention having SCR activity, a catalyst is obtained anti-ammonia.

The ammonia leakage catalysts based on the molecular sieve of the invention can also contain auxiliary materials, for example, and without being limited to binders, support materials for noble metal components, such as Al 2 O 3, TiO 2, SiO 2. Such combinations may have different forms, such as a mixture of the ammonia oxidation component with the active form of SCR of the molecular sieve of the invention, reactors or serial catalytic articles (see examples of US Pat. No. 4,188,364).

In particular, the ammonia leakage catalyst may be a layer coated by washing a mixture of the ammonia oxidation component with the active form of SCR of the ERI molecular sieve of the invention in a monolith, or a multilayer array coated by washing over a monolith, in which the different layers contain different amounts of the ammonia oxidation component, or of the active form of SCR of the molecular sieve of the invention, or of any combination of the ammonia oxidation component and the active form of SCR of the molecular sieve of the invention (JP3436567, EP1992409).

In another embodiment, the oxidation component of the ammonia or the active form of SCR of the ERI molecular sieve of the invention, or any combination of the oxidation component of the ammonia and the active form of SCR of the molecular sieve of the invention, is present in the walls of a monolith. This configuration can also be combined with different combinations of layers coated by washing.

Another embodiment of the ASC catalyst is a catalytic article with an inlet end of gas and a gas outlet end, wherein the outlet end contains an oxidation component of the ammonia and the active form of SCR of the molecular sieve of the invention. The input end of the catalytic article can then contain other functionalities.

The ERI molecular sieve of the invention is useful as a catalyst in the reduction of nitrogen oxides in the exhaust gas from a gas turbine using ammonia as a reducing agent. In this application, the catalyst can be arranged directly downstream of the gas turbine. It can also be exposed to large temperature fluctuations during the start-up and shut-down procedures of the gas turbine.

In certain applications, the molecular sieve catalyst is used in a gas turbine system with a single-cycle operational mode, without any heat recovery system downstream of the turbine. When placed directly after the gas turbine, the molecular sieve is able to withstand exhaust gas temperatures up to 650 ° C with a composition of the gas containing water.

Other applications of the molecular sieve of the invention are in a gas turbine exhaust treatment system, in combination with a heat recovery system such as the Heat Recovery System Generator (HRSG). In such process design, the molecular sieve catalyst is disposed between the gas turbine and the HRSG. The molecular sieve can also be arranged in several locations within the HRSG.

Still an application of the ERI molecular sieve according to the invention is the use as catalyst in combination with an oxidation catalyst for the reduction of hydrocarbons and carbon monoxide in the exhaust gas.

The oxidation catalyst, typically composed of precious metals such as Pt and Pd, can be arranged for example upstream or downstream of the molecular sieve, and both inside and outside the HRSG. Oxidation functionality can also be combined with the molecular sieve catalyst in a single catalytic unit.

The oxidation functionality can be combined directly with the molecular sieve using the molecular sieve as a support for precious metals. The precious metals can also be supported on another support material and can be physically mixed with the molecular sieve.

The molecular sieve of the invention is capable of eliminating nitrous oxide. For example, it can be arranged in combination with a nitric acid production loop in a primary, secondary or tertiary decrease assembly. In such a decreasing process, the molecular sieve can be used to remove nitrous oxide, as well as nitrogen oxides, as independent catalytic articles or combined in a single catalytic article. Nitrogen oxide can be used to facilitate the removal of nitrous oxide. Ammonia or lower hydrocarbons, including methane, can also be added as a reducing agent to further reduce nitrogen oxides and / or nitrous oxide.

The ERI molecular sieve of the invention can also be used in the conversion of oxygenated substances into various hydrocarbons. The raw material of the oxygenated substances is typically lower alcohols and ethers containing one to four carbon atoms, and / or combinations thereof. Oxygenated substances can also be carbonyl compounds such as aldehyde, ketones and carboxylic acids. Particularly suitable oxygenates are methanol, dimethyl ether, and mixtures thereof. Such oxygenated substances can be converted into hydrocarbons in the presence of the molecular sieve. In such a process, the raw material of the oxygenated substance is typically diluted, and the temperature and the space velocity are controlled to obtain the desired product range.

A further use of the molecular sieve of the invention is as a catalyst in the production of lower olefins, in particular olefins suitable for use in gasoline, or as a catalyst in the production of aromatic compounds.

In the above applications, the ERI molecular sieve is typically used in acid form, and will be extruded with binder materials or be formed into pellets together with a suitable matrix and binder materials as described above.

Other suitable active compounds, such as metals and metal ions, may also be included to change the selectivity for the desired product range.

The ERI molecular sieve according to the invention can be further used in the partial oxidation of methane to methanol or other oxygenated compounds such as dimethyl ether.

In WO11046621A1 an example of a method for the direct conversion of methane to methanol at temperatures below 300 ° C in the gas phase is provided. In such a procedure, the molecular sieve of the invention is charged with a sufficient amount of copper to carry out the conversion. Typically, the molecular sieve will be treated in an oxidizing atmosphere in which then the methane is subsequently passed over the activated molecular sieve to directly form methanol. Subsequently, the methanol can be extracted by suitable methods, and the active sites can be regenerated by another oxidative treatment.

In [K. Narsimhan, K. lyoki, K. Dinh, Y. Roman-Leshkov, ACS Cent. Sci. 2016 , 2, 424-429] describes another example in which an increase or continuous production of methanol is achieved by adding water to the stream of reactants to continuously extract methanol without having to alter the conditions between oxidative treatments and the formation of methanol.

The ERI molecular sieve of the invention can be used to separate various gases. Examples include the separation of carbon dioxide from natural gas, and lower alcohols of higher alcohols. Typically, the practical application of the molecular sieve will be as part of a membrane for this type of separation.

The ERI molecular sieve of the invention can be further used in isomerization, cracking, hydrocracking, and other reactions to improve the oil.

The ERI molecular sieve of the invention can also be used as a hydrocarbon trap, for example from cold start emissions of various engines.

In addition, the molecular sieve can be used for the preparation of small amines, such as methylamine and dimethylamine, by reaction of ammonia with methanol.

In all of the above embodiments, the ERI catalyst can be coated on a monolith or on a corrugated substrate, or it can be in the form of an extrudate.

EXAMPLES

Example 1: Synthesis of OSDA cidohexane-1,4-bis (trimethylammonium hydroxide)

A mixture of 30 ml of formic acid (89.5% by weight aqueous solution), 6.1 g of NaHCO3, 5 g of trans-1,4-diamino-monohexane (powder of 98% purity) was refluxed. 14 ml of formaldehyde (37% by weight aqueous solution) until no visible evolution of CO2 was observed. The synthesis mixture was distilled in vacuo after 50 ml of HCl (aqueous solution 2 mol / l) was added, followed by the addition of an excess of NaOH and extraction 3 times with chloroform. The chloroform portions were combined, and 8 ml of methyl iodide (99% by weight) was added, followed by mixing overnight. The solid obtained was dissolved in water and ionically exchanged to the hydroxide form, using an ion exchange resin.

Example 2: Synthesis of ERI

A mixture of 1.87 g of cyclohexane-1,4-bis (trimethylammonium hydroxide) (12.7% by weight aqueous solution), 1.7 g of KOH (10% by weight aqueous solution) was prepared, 0.48 g of distilled water and 0.94 g of amorphous silica-alumina co-precipitated (SiO2 / Al2O3 = 12). The mixture was heated in a closed autoclave lined with Teflon at 135 ° C for 7 days, and the solid product was filtered off and washed with deionized water. By X-ray powder diffraction analysis, it can be seen that the product as synthesized is pure phase ERI.

Example 3: ERI synthesis

A mixture of 1.97 g of cyclohexane-1,4-bis (trimethylammonium hydroxide) (12.7% by weight aqueous solution), 1.79 g of KOH (10% by weight aqueous solution) was prepared, 0.46 g of distilled water and 0.79 g of zeolite FAU (SiO2 / Al2O3 = 12). The mixture was heated in a closed autoclave lined with Teflon at 135 ° C for 7 days, and the solid product was filtered off and washed with deionized water.

The dry solid product had an SiO2 / Al2O3 ratio of 9.8 determined by ICP-AES analysis. By X-ray powder diffraction analysis, it is observed that the product as synthesized is pure phase ERI. The SEM analysis also reveals a Tabular to prismatic crystal morphology.

Example 4: Synthesis of ERI

A mixture of 1.95 g of cidohexane-1,4-bis (trimethylammonium hydroxide) (12.7% by weight aqueous solution), 1.77 g of KOH (10% by weight aqueous solution) was prepared, 0.5 g of distilled water and 0.79 g of amorphous silica-alumina coprecipitated (SiO2 / Al2O3 = 30). The mixture was heated in a closed autoclave lined with Teflon at 135 ° C for 7 days and the solid product was separated by filtration and washed with deionized water.

By X-ray powder diffraction analysis, it is observed that the product as synthesized is pure phase ERI. Figure 1 shows the diffractogram measured for the product as it is synthesized. The SEM analysis also reveals a tabular crystal morphology (see Figure 2).

Figure 1 represents XRPD of the molecular sieve prepared as prepared in Example 4.

Figure 2 depicts a SEM micrograph of the molecular prepared screen as prepared in Example 4.

Example 5: Synthesis of ERI

A mixture of 1.99 g of cyclohexane-1,4-bis (trimethylammonium hydroxide) (12.7% by weight aqueous solution), 1.81 g of KOH (10% by weight aqueous solution) was prepared, 0.45 g of distilled water and 0.74 g of zeolite FAU (SiO2 / Al2O3 = 30). The mixture was heated in a closed autoclave lined with Teflon at 135 ° C for 7 days, and the solid product was filtered off and washed with deionized water.

The dry solid product had an SiO2 / Al2O3 ratio of 22.0, determined by ICP-AES analysis. By X-ray powder diffraction analysis, it is observed that the product as synthesized is pure phase ERI. The diffractogram measured for the product as synthesized is shown in Figure 3. The SEM analysis also reveals a prismatic crystal morphology (see Figure 4).

Figure 3 represents XRPD of the molecular sieve prepared as prepared in Example 5.

Figure 4 represents a SEM micrograph of the molecular sieve prepared as prepared in Example 5.

Calcination of the molecular sieve as prepared dry was carried out at 550 ° C for 3 h. Then, the calcined product was ionically exchanged with Na 4 +. In Figure 5 the X-ray diffractogram measured for the calcined product is shown. In addition, the physisorption of N2 revealed a BET specific surface of multiple points of 559 m2 / g and a micropore volume of 0.19 cm 3 / g, clearly indicating the microporous nature of the prepared material.

Figure 5 represents XRPD of the calcined molecular sieve prepared in Example 5.

Claims (24)

Catalyst comprising a molecular sieve with the type of structure of ERI, having a molar ratio of silica to alumina of about 8 to about 100 and a crystalline morphology defined by the ratio between the rc dimensions throughout and ra orthogonal to the single c axis between 0.5 and 2.0. 2. The catalyst of claim 1, wherein the calcined form of the ERI molecular sieve has a powder X-ray diffraction pattern, collected in a Bragg-Brentano geometry with a variable divergence groove using Cu K radiation. -alpha, essentially as shown in the following Table:

* The intensities of the peaks and the assignment of the letter is uncertain due to the significant overlap of the peaks. in which the relative areas of the peaks observed in the 2-Theta interval of 7-19 degrees are shown according to: W = weak: 0-20%; M = medium: 20-40%; S = strong: 40-60% and VS = very strong: 60-100%. The values of 2-Theta are ± 0.20 °. The catalyst of claim 1 or 2, wherein the molecular sieve of ERI has a molar ratio of silica to alumina between 8 and 100. 4. The catalyst of claim 1 or 2, wherein the molecular sieve of ERI has a molar ratio of silica to alumina between 10 and 60. The catalyst of any one of claims 1 to 4, wherein at least a portion of the aluminum and / or silicon of the molecular sieve of ERI is replaced by one or more metals selected from tin, zirconium, titanium, hafnium, germanium , boron, iron, indium and gallium. 6. The catalyst of any one of claims 1 to 5, wherein the molecular sieve of ERI contains copper and / or iron. 7. A method for the conversion of nitrogen oxides into nitrogen in the presence of a reducing agent, comprising the step of contacting the nitrogen oxides and the reducing agent with the catalyst according to any one of claims 1 to 6. The method of claim 7, wherein the reducing agent comprises hydrocarbons and / or ammonia or a precursor thereof. The method of claim 7 or 8, wherein the nitrogen oxides are contained in the engine exhaust. The method of claim 7 or 8, wherein the nitrogen oxides are contained in the exhaust of a gas turbine. The method of any one of claims 7 to 10, wherein the nitrogen oxides comprise nitrous oxide. 12. A method for the selective oxidation of ammonia to nitrogen, which comprises step of contacting the ammonia or a gas comprising the ammonia with the catalyst according to any one of claims 1 to 6. The method of claim 12, wherein the catalyst is disposed downstream and / or upstream of a diesel oxidation catalyst. The method of claim 12 or 13, wherein the catalyst is disposed upstream of an ammonia leakage catalyst. 15. The method of any one of claims 12 to 14, wherein the catalyst is disposed upstream and / or downstream of a diesel particulate filter. 16. The method of claim 12, wherein the catalyst further comprises an oxidation functionality or an oxidation catalyst. The method of claim 16, wherein the catalyst is disposed downstream of a selective catalytic reduction catalyst, and wherein an excess of ammonia is used to reduce the nitrogen oxides. 18. A method for the simultaneous oxidation of hydrocarbons and carbon monoxide and the reduction of nitrogen oxides, comprising the step of contacting the hydrocarbons, carbon monoxide and oxides of nitrogen with the catalyst according to any one of the claims 1 to 6. The method of any one of claims 15 to 18, wherein the catalyst further comprises one or more metals of the platinum group. The method of any one of claims 12 to 19, wherein the catalyst is coated on a monolith or on a corrugated surface, or in the form of an extrudate. 21. A method for the conversion of oxygenated substances into hydrocarbons, comprising the step of contacting the oxygenated substances with a catalyst according to any one of claims 1 to 6. 22. The method according to claim 21, wherein the hydrocarbons produced comprise olefins. 23. A method for the partial oxidation of methane to methanol and / or dimethyl ether, which comprises the step of contacting the methane with a catalyst according to any one of claims 1 to 6. 24. A method for the preparation of lower amines by reaction of ammonia with methanol in the presence of a catalyst according to any one of claims 1 to 6.