Catalyst based on a zeolite and an alpo structure, exhibiting a high macroporous volume

Abstract

The present invention relates to a catalyst comprising a zeolite having at least one series of channels with an aperture of at least 10 oxygen atoms (10MR) and a binder, wherein: - the catalyst comprises phosphorus and an AlPO₄ structure, as determined by a signal between 35 and 45 ppm on a spectrum obtained by 27Al NMR analysis of the catalyst; - the pore volume (V(4-900)) of the catalyst pores with a size between 3.6 and 900 nm is greater than or equal to 0.25 ml / g; - the pore volume (V(30-310)) of the catalyst pores with a size between 30 and 310 nm is less than or equal to 0.080 ml / g. The present invention also relates to the use of said catalyst in a process for the dehydration of an alcohol and a process for the production of ethylene from a feedstock comprising ethanol using said catalyst.

Description

Description Title of the invention: CATALYST BASED ON A ZEOLITE AND AN ALPO STRUCTURE AND HAVING A VOLUME HIGH MACROPOROUS Technical field

[0001] = The present invention relates to a catalyst comprising a zeolite having, at less in part, an ALPO structure, a binder and advantageously phosphorus, and having a high macroporous volume. The present invention also relates to a process for preparing such a catalyst. Such a catalyst is of great interest for industrial processes involving the presence of steam at high temperatures, such as the dehydration of alcohol to the corresponding olefin, such as dehy- ethanol conversion to selectively produce ethylene. The invention relates to also the use of a catalyst according to the invention in a dehy- dehydration of an alcohol, such as the dehydration of ethanol into ethylene. Prior art

[0002] = The use of efficient catalysts is one of the keys to obtaining in- viable industrials. More specifically, the dehydration of alcohols in the presence of catalysts for producing olefins is already well described in the literature. The ca- The reference catalyst often used is a monofunctional acid catalyst. Gamma alumina is one of the most cited catalysts in the literature for converting (cf. H. Knôzinger, R. Kôhne, “The Dehydration of Alcohols over Alumina. I: The reaction scheme”, Journal of Catalysis (1966), 5, 264-270). Zeolites are also used for this application, and in particular the ZSM-5 since the 1980s (cf. SN Chaudhuri et al. "Reactions of ethanol over ZSM-5", Journal of Molecular Catalysis 62: 289-295 (1990)). For example, patent FR2978145 describes, in par- particular, a process for producing ethylene from an ethanol feedstock, in the presence of a dehydration catalyst comprising a ZSM-5 zeolite treated with H3PO4, so that the P2O5 content is 3.5% by weight.

[0003] Application WO 2013 / 017499 discloses a method for manufacturing a zeolite phosphorus-modified, which includes a high-temperature steam treatment step- temperatures (or steaming according to the Anglo-Saxon term) of a zeolite comprising at least one ring of ten members in the structure, followed by the introduction of phosphorus and then the shaping of the modified zeolite with a binder and deposition of a metal, and finally a new steam treatment (or steaming). Application WO 2013 / 017497 also discloses a method for manufacturing a phosphorus-modified zeolite. The method described in application WO 2013 / 017497 includes the shaping with a binder of a zeolite comprising at least one ring of ten members in the structure, a step of high temperature steam treatment (or steaming according to the Anglo-Saxon term) of the Zeolite, before or after shaping, then the introduction of phosphorus and a metallic element, and finally a new steam treatment (or steaming).In parallel, document WO 2013 / 017496 describes the use of a catalyst comprising a phosphorus-modified zeolite for converting at least one alcohol into olefins in a dehydration process in order to manufacture an olefin having the same number of carbon atoms as the alcohol in which said catalyst is manufactured by a process comprising shaping with a binder a zeolite comprising at least one ten-membered ring in the structure, a step of high-temperature steam treatment of the zeolite, then introducing phosphorus and a metallic element, and finally a new steam treatment. Application WO 2013 / 017498 discloses a catalyst comprising a phosphorus-modified zeolite having a partial ALPO structure and comprising at least one ten-membered ring in the structure, and a binder, said ALPO structure being determined by a signal at 35-45 ppm on the Aluminum 27 NMR spectrum. EP511013 provides a process for producing C2-CS5 olefins from heavier olefinic and / or paraffinic compounds by contacting with a particular ZSM-5 catalyst at high temperatures, high space velocity and low hydrocarbon partial pressure. The catalysts are steamed prior to use in hydrocarbon conversion and comprise 1-50 wt% of a phosphorus-containing ZSM-5 zeolite (0.1-10 wt% phosphorus based on catalyst weight) and having a surface Si / Al ratio of 20-60. No metal such as Ca is introduced into the catalyst. US 2006 / 106270 relates to the use of a catalytic system in the synthesis of hydrocarbons by conversion of an oxygenate to propylene, at elevated temperatures. The catalytic system comprises a molecular sieve dispersed in a phosphorus-modified alumina matrix containing labile phosphorus and / or aluminum anions, the latter allowing hydrothermal stabilization of the catalytic system. WO 2009-098262 also discloses a catalyst for the dehydration of ethanol to ethylene. Said catalyst comprises a steam-treated and phosphorus-modified ZSM-5 zeolite and a binder. AIPO aluminophosphate materials are well known in the state of the art. They exist in different AI / P atomic ratios and exhibit acidic properties at Al / P atomic ratios > 1, and even more pronouncedly in the form of hydrogen phosphates with Al / P < 1. These are known to be used as acid catalysts in the dehydration of alcohols, in particular methanol (cf. US5753716). In the state of the art, the aluminum source used for the manufacture of AIPO aluminophosphates is generally produced by treating an external source of aluminum (alumina or aluminum salts) with a source of phosphorus, followed by mixing with a zeolite, to prepare a catalyst. It may also happen that different types of aluminas or aluminum salts are mixed simultaneously with phosphorus and a zeolite. An objective of the present invention is to provide a novel zeolite-based catalyst for the dehydration of ethanol to ethylene, making it possible to achieve high ethanol conversion rates and ethylene selectivity by limiting the formation of undesirable products (oligomers and oxygenates), while exhibiting satisfactory hydrothermal resistance. Summary of the invention The invention relates to a catalyst comprising a zeolite having at least one series of channels whose opening is at least equal to 10 oxygen atoms (10MR) and a binder, in which: - the catalyst comprises phosphorus and comprises an AIPO structure, determined by a signal between 35 and 45 ppm on a spectrum obtained by ?AI NMR analysis of the catalyst; - the pore volume (V(4-500;) of the pores of the catalyst, the size of which is between 3.6 and 900 nm, is greater than or equal to 0.254 ml / g; - the pore volume (V(40.310)) of the pores of size between 30 and 310 nm of the catalyst is less than or equal to 0.080 ml / g. Surprisingly, the inventors have found that such a catalyst having the particular composition and textural characteristics (porosity) according to the invention makes it possible to obtain improved performance in the reaction of dehydration of an alcohol into the corresponding olefin having the same number of carbon atoms, in particular in the dehydration of ethanol into ethylene, while having satisfactory mechanical strength. In particular, such a catalyst makes it possible to achieve a high selectivity in targeted olefin, more particularly in ethylene, while ensuring a high conversion of the alcohol, in particular ethanol, and an optimal yield in targeted olefin, in a process of dehydration of said alcohol. In addition, such a catalyst has entirely suitable mechanical properties, in other words sufficient mechanical properties to allow handling and use on industrial type units.In particular, the catalyst according to the invention has an EGG value, grain-to-grain crushing, greater than or equal to 0.7 daN / mm, of . preferably greater than or equal to 0.8 daN / mm. The invention also relates, according to a second aspect, to the use of a catalyst according to the invention in a process for dehydrating an alcohol into an olefin having the same number of carbon atoms, in particular a process for dehydrating ethanol into ethylene. The invention also relates, according to a third aspect, to a process for producing ethylene from a feedstock comprising ethanol, said process comprising a step of dehydration of the ethanol carried out in the presence of the catalyst as described above, at an inlet temperature of between 250 and 550°C, at an inlet pressure of between 0.1 and 1.7 MPa and at an hourly weight rate of between 0.1 and 30 h", Description of the embodiments Advantageously, the mechanical properties can be determined by the grain-to-grain crushing (EGG) test described by the ASTM D 6175-3 method. This consists of measuring the breaking force of each particle of a representative sample comprising at least 50 particles. The result is weighted by the length of the extrudate. The EGG value is the average of the breaking forces measured and reduced to the unit length of the extrudate (expressed in daN.mm-1) for all the particles in the sample. According to the present invention, the expression "between ... and ..." means that the limit values ​​of the interval are included in the range of values ​​described. If this were not the case and the limit values ​​were not included in the range described, such precision will be provided by the present invention. In this description, the expression "greater than..." is understood as strictly greater than, and symbolized by the sign ">", and the expression "less than" as strictly less than, and symbolized by the sign "<". When the limit is understood, the precision will be provided by the respective expressions "greater than or equal to..." (and corresponding to the sign ">") and "less than or equal to" (corresponding to the sign "<"), For the purposes of the present invention, the different parameter ranges may be used alone or in combination. For example, for the purposes of the present invention, a range of preferred values ​​of zeolite structure may be combined with a range of more preferred values ​​of pore volume. In the following, particular embodiments of the invention are described. They can be implemented separately or combined with each other, without limitation of combinations when technically feasible. The invention relates to a catalyst comprising a zeolite having at least one series of channels whose opening is at least equal to 10 oxygen atoms (10MR), preferably a zeolite of structure MFI, MTT, FER, MEL, TON, MWW, EUO and MEFS, preferentially of structure MFI and preferably a ZSM-5, and a binder, preferably a silicic binder or a clay, in which: - the catalyst comprises phosphorus and comprises an AIPO structure, the content of the catalyst in AIPO structure preferably representing between 15 and 40%, preferably between 20 and 35% and more preferably between 25 and 34%, of the aluminum-containing species of the catalyst, the presence and quantification of the AIPO structure in the catalyst being determined by a signal measured between 35 and 45 ppm on a spectrum obtained by 27AI NMR analysis of the catalyst, and in particular the content of AIPO structure corresponding to the ratio between the surface area of ​​the signal at 35-45 ppm relative to the total surface area of ​​the signal between -50 and 100 ppm on the spectrum obtained by 27A NMR analysis of the catalyst; - the pore volume (Vea-500) of the pores of the catalyst, the size of which is between 3.6 and 900 nm, is greater than or equal to 0.25 ml / g, preferably greater than or equal to 0.250 ml / g, preferentially greater than or equal to 0.26 ml / g, or even greater than or equal to 0.260 ml / g, and preferably less than or equal to 1.00 ml / g, preferably less than or equal to 0.80 ml / g, or even less than or equal to 0.60 ml / g; -the pore volume (V(30.310)) of the pores of size between 30 and 310 nm of the catalyst is less than or equal to 0.080 ml / g, preferably less than or equal to 0.070 ml / g; - advantageously, the zeolite content of the catalyst is between 5.0 and 95.0% by weight, preferably between 15.0 and 95.0% by weight, preferentially between 50.0 and 90.0% by weight, preferably between 65.0 and 85.0% by weight, relative to the total weight of the catalyst; - advantageously, the phosphorus element content of the catalyst is between 0.5 and 20.0% by weight, preferably between 0.5 and 10.0% by weight, preferentially between 1.0 and 5.0% by weight, preferably between 2.0 and 4.0% by weight, relative to the total weight of the catalyst; - advantageously the catalyst comprises a metal, preferably in the form of a metal oxide, said metal preferably being an alkaline earth metal or a rare earth, preferably chosen from magnesium, calcium, strontium, barium, lanthanum and cerium. According to the invention, the catalyst comprises a zeolite having at least one series of channels whose opening is at least equal to, preferably equal to, 10 oxygen atoms (10MR) and a binder. Very advantageously, the zeolite content of the catalyst is between 5.0 and 95.0% by weight, preferably between 15.0 and 95.0% by weight, preferentially between 50.0 and 90.0% by weight, preferably between 65.0 and 85.0% by weight, relative to the total weight of the catalyst. The binder content of the catalyst is, for its part, advantageously between 5.0 and 95.0% by weight, preferably between 5.0 and 85.0% by weight, preferentially between 10.0 and 50.0% by weight, preferably between 15.0 and 35.0% by weight, relative to the total weight of the catalyst. Advantageously, the zeolite of the catalyst according to the invention which has at least one series of channels whose opening is at least equal, preferably equal, to 10 oxygen atoms (10MR) is a crystalline silicate having at least one series of channels whose opening is at least equal, preferably equal, to 10 oxygen atoms (10MR), and preferentially chosen from zeolites of structure MFI, MTT, FER, MEL, TON, MWW, EUO and MFS. The zeolite is very preferentially a zeolite of type MFI and preferably a zeolite ZSM-5. Preferably, the zeolite of the catalyst has a molar ratio Si / Al, of the element silicon relative to the element aluminum, of between 11 and 300, preferably between 11 and 40. Advantageously, the catalyst binder is an inorganic compound, typically inert in particular with respect to alcohols and in particular ethanol. Preferably, the binder is a silicic binder, such as silicas and in particular amorphous silicas; a clay such as kaolin, kaolinite, montmorillonite, attapulgite, saponite and bentonite; or mixtures thereof. Preferably, the binder comprises, preferably consists of, a silicic binder and preferably an amorphous silica or a mixture of amorphous silicas. According to the invention, the catalyst comprises phosphorus. Preferably, the phosphorus element content of the catalyst is between 0.5 and 20.0% by weight, preferably between 0.5 and 10.0% by weight, preferably between 1.0 and 5.0% by weight, preferably between 2.0 and 4.0% by weight, relative to the total weight of the catalyst. According to a particular embodiment of the invention, the zeolite of the catalyst is modified with phosphorus. Advantageously, the catalyst comprises an AIPO structure. The structure of aluminum-containing species can be shown and quantified by a solid-state, magic angle spinning (MAS) nuclear magnetic resonance spectroscopy (NMR) method of analysis of aluminum atoms 27 (or AI NMR). AI NMR-MAS characterizations are performed using a Bruker Avance 500 spectrometer with a 4 mm zirconia MAS probe at a rotation speed of 15 kHz. In order to obtain quantitative spectra, a single excitation pulse is applied using a short excitation length of 0.6 psec. Each spectrum obtained is the result of 5000 scans separated by a 0.5 sec delay. Chemical shifts on the AI ​​NMR spectrum are determined relative to a 0.1 M AI1 reference solution (chemical shift of 0 ppm). Preferably the Solid samples are dehydrated before NMR-MAS”AI analysis: for example, the samples are left for 24 hours in a desiccator in the presence of a saturated solution of NH,NO; then transferred to the NMR spectrometer without contact with air or humidity. The presence of an AIPO structure in the catalyst according to the invention is determined by the AI ​​NMR method, with the presence of a signal between 35 and 45 ppm on a spectrum obtained by AI NMR analysis of the catalyst. The proportion of the AIPO structure in the catalyst according to the invention is determined by carrying out a ratio of the surface area of ​​the signal (or peak) between 35 and 45 ppm on the spectrum obtained by AI NMR analysis of the catalyst relative to the total surface area measured between -50 and 100 ppm of the AI ​​NMR spectrum of the catalyst. Preferably, the AIPO structure content of the catalyst represents between 15 and 40%, preferably between 20 and 35% and more preferably between 25 and 34%, of the aluminum-containing species of the catalyst. Preferably, the zeolite of the catalyst is phosphorus-modified and has, for a part of its structure, an AIPO structure. According to a preferred embodiment, the catalyst binder does not comprise any species containing aluminum, preferably the binder is a silicic binder, and the AIPO structure content of the catalyst corresponds to the AIPO structure content of the zeolite (the zeolite being in fact the only source of element Al in the entire catalyst). Thus in this preferred embodiment, in which the catalyst binder does not comprise any species containing aluminum, preferably is a silicic binder, the zeolite has for a part of its structure an AIPO structure, and the AIPO structure content of the zeolite represents between 15 and 40%, preferably between 20 and 35% and preferably between 25 and 34%, of the aluminum-containing species of the zeolite. The pore volumes of the catalyst according to the invention, detailed below, are measured by mercury volumetric analysis, detailed below. More precisely, the pore volumes of the catalyst are measured by intrusion with a mercury porosimeter according to ASTM D4284-83 at a maximum pressure of 4000 bars, using a surface tension of 484 dyne / cm and a contact angle of 141°. The wetting angle was taken as 110° following the recommendations of the book “Techniques de l'ingénieur, traité analyse et caractérisation”, 1050, by J. Charpin and B. Rasneur. In order to obtain better precision, the value of the mercury volume in ml / g given in the following text corresponds to the value of the total mercury volume in ml / g measured on the sample minus the value of the mercury volume in ml / g measured on the same sample for a pressure corresponding to 30 psi (approximately 2 bars). According to the invention, the pore volume (V(4.500)) of the pores of the catalyst, the size of which is between 4 and 900 nm (more precisely between 3.6 nm and 900 nm), is greater than or equal to 0.25 ml / g, preferably greater than or equal to 0.250 ml / g, preferably greater than or equal to 0.26 ml / g, or even greater than or equal to 0.260 ml / g. Preferably, the pore volume (V(4.900,0)) of the pores of the catalyst, the size of which is between 4 and 900 nm (more precisely between 3.6 nm and 900 nm), is less than or equal to 1.00 ml / g, preferably less than or equal to 0.80 ml / g, or even less than or equal to 0.60 ml / g, so as to contribute to satisfactory mechanical strength of the catalyst, which can then be handled easily and not form fines in the reactor. According to the invention, the pore volume {V(30.310)) of the pores of the catalyst, the size of which is between 30 and 310 nm, is less than or equal to 0.080 ml / g, preferably less than or equal to 0.070 ml / g, and generally greater than or equal to 0.01 ml / g, preferably greater than or equal to 0.02 ml / g. Preferably, the pore volume of pores of size between 3 and 100 nm is less than 0.25 ml / g. Preferably, the catalyst comprises mesopores, i.e. pores with a size of between approximately 4 and 50 nm, advantageously having an average mesoporous diameter of less than or equal to 14 nm, preferably less than or equal to 12 nm, and preferentially greater than or equal to 4 nm. Preferably, the mesoporous volume of the catalyst, i.e. the volume of pores with a size of between 4 and 50 nm (and more precisely measured between 3.6 and 50 nm by mercury intrusion, i.e. by mercury volume analysis), is preferably less than or equal to 0.080, preferably less than or equal to 0.07, and generally greater than or equal to 0.01 ml / g, typically greater than or equal to 0.030 ml / g. Very advantageously, the catalyst has microporosity, i.e. pores with a size of less than 2 nm. Preferably, the catalyst has a microporous volume of between 0.04 and 1.5 ml / g, preferably between 0.06 and 1.3 ml / g, in particular between 0.06 and 1.0 ml / g. The micropore volume of the catalyst is measured by nitrogen adsorption isotherm analysis. The micropore volume of the catalyst corresponds to the volume occupied by pores with a diameter of less than 2 nm. The analysis of the nitrogen adsorption isotherm corresponds to the physical adsorption of nitrogen molecules in the porosity of the catalyst via a progressive increase in pressure at constant temperature and provides information on the textural characteristics (pore diameter, porosity type, specific surface area) of the catalyst. To determine the micropore volume, the t method (of Lippens and De Boer) described in the periodical Journal of catalysis, (Studies on pore systems in catalysts V. The t method, J. Catal., 1965, 4(3), p. 319) is used. It is based on the comparison between the experimental isotherm of the microporous solid and the reference isotherm (non-porous solid) of the same chemical nature.From the Lippens-De Boer equation, the thickness t of the multilayer can be . calculated with the following equation (called t-plot): | 0.034—log(P / P,}} where P / PO is the relative nitrogen pressure. The micropore volume is calculated with the following equation: Vy(onU / g)=D+Y where Y is the y-intercept of the t-plot curve and D is the density conversion factor (D = 15.468 x 10-4, coefficient to ensure the conversion of gas volume to liquid volume). The chosen range of t corresponds to a plateau on the curve of adsorbed nitrogen volume as a function of thickness t and is between 0.4 and 0.8 nm. Advantageously, the catalyst comprises a metal M, preferably in the form of a metal oxide. Preferably, said metal M is chosen from alkali metals and rare earths, preferably from magnesium, calcium, strontium, barium, lanthanum and cerium. Preferably, said metal M is an alkaline earth metal, preferably calcium. Very advantageously, when the catalyst comprises a metal, preferably an alkaline earth metal or a rare earth, the content of the catalyst in said metal, expressed as the weight of the element metal M relative to the total weight of the catalyst, is between 0.1 and 10.0% by weight, preferably between 0.5 and 3.0% by weight. Preferably, the catalyst comprises a low alkali metal (in particular sodium) content, in particular less than or equal to 1000 ppm by weight, preferably less than or equal to 600 ppm. A catalyst having such a composition and such textural characteristics makes it possible to achieve excellent performance in the dehydration reaction of an alcohol into corresponding olefins having the same number of carbon atoms, in particular in the dehydration of ethanol into ethylene, while having satisfactory mechanical strength thus allowing its handling and therefore its use in industrial type units. The present invention also relates to the use of the catalyst according to the invention in a process for dehydrating an alcohol into an olefin having the same number of carbon atoms, in particular ethanol into ethylene, advantageously operated at a temperature of between 250 and 550°C, preferably between 300 and 500°C, and at a pressure of between 0.1 and 1.7 MPa absolute, preferably between 0.2 and 1.3 MPa, and at an hourly weight rate of between 0.1 and 30 h" and preferably between 0.5 and 25 h", The hourly weight rate is defined as being the ratio of the mass flow rate of pure alcohol, in particular ethanol, to the mass of catalyst. The present invention also relates to a process for producing olefin from a feedstock comprising an alcohol, preferably for producing ethylene from a feedstock comprising ethanol, said process comprising a step of dehydration of the alcohol, preferably ethanol, carried out in the presence of the catalyst according to the invention and at an inlet temperature (i.e. temperature of the feedstock at the inlet to said dehydration step) of between 250 and 550°C, preferably between 300°C and 500°C, at an inlet pressure (i.e. pressure of the feedstock at the inlet to said dehydration step) of between 0.1 and 1.7 MPa, preferably between 0.1 and 1.3 MPa, and at an hourly weight rate of between 0.1 and 30 hr! and preferably between 0.5 and 25 h -!. The hourly weight rate is defined as the ratio of the mass flow rate of alcohol, in particular ethanol, included in the charge to the mass of catalyst.A reaction effluent is advantageously recovered at the outlet of the dehydration step. Said reaction effluent comprises water and the targeted olefin advantageously generated by the conversion of the alcohol, preferably ethanol, included in the feedstock. Said reaction effluent may also comprise other compounds, co-products or possibly already present in the feedstock. Advantageously, the feedstock at the input of the process comprises at least 20% by weight, preferably at least 50% by weight, preferentially at least 60% by weight and preferably at least 85% by weight of alcohol, preferably ethanol. Preferably, the process for producing olefin from a feedstock comprising an alcohol, preferably for producing ethylene from a feedstock comprising ethanol, comprises a step of vaporizing the feedstock, in part or in full, upstream of the dehydration step. Said vaporization step can be carried out by heat exchange, in particular with the reaction effluent from the dehydration step. Very advantageously, the production process comprises at least one step of purifying the reaction effluent, downstream of the dehydration step. In particular, the production process comprises a step of fractionating the reaction effluent, into at least one effluent comprising the targeted olefin, for example ethylene, and an effluent comprising water. The following examples are presented for the purpose of illustrating and not limiting the invention. EXAMPLES Example | The pore volumes of the catalysts were measured using the intrusion method with the mercury porosimeter, described earlier in this text. The presence and quantification of AIPO structure in the catalysts were determined by "AI" NMR analysis, as explained above. The AIPO structure contents are expressed as a percentage of the aluminum-containing species and calculated by the ratio of the signal areas between 35 and 45 ppm compared to the signal between -50 and 100 ppm of the obtained spectrum. Two catalysts were analyzed. Both catalysts include a ZSM-5 zeolite (CBV2320 from Zeolyst) and amorphous silica (a mixture of colloidal silica and silica sol) as a binder. They both also include phosphorus and calcium. The compositional and textural characteristics of these catalysts, as well as the EGG value significant for their mechanical strength, are presented in Table 1 below. [Tables 1] 1 0.9 Catalyst A (non-compliant) AIPO content (%) 36 V4-000, (MI / g) 0.236 Veao-s10) (ML / g) 0.0852 Vmesoporous (ml / g) 0.060 ZSM-5 content (% wt) 772 Silica content (% wt) 19.3 Phosphorus content (% wt) 2.5 Calcium content (% wt) |1 EGG (daN / mm) 0.9 Catalyst A has a pore volume V (4.000) of pores with a size between 3.6 and 900 nm, equal to 0.236 ml / g, i.e. less than 0.25 ml / g, and a pore volume V(a0-310) of pores with a size between 30 and 310 nm, equal to 0.0852 ml / g, i.e. less than or equal to 0.080 ml / g. Catalyst A is therefore non-compliant. Catalysts A and B were tested in catalytic tests for the dehydration of ethanol to produce ethylene. Example 2: Catalytic test of a 95% weight ethanol charge A feedstock comprising 95% by weight of ethanol and 5% by weight of water was tested on a catalytic test unit comprising a fixed bed operating in "down flow" mode, i.e. in descending flow. The catalyst is loaded into a stainless steel reactor 316L with an internal diameter of 13 mm. The catalyst is then activated at 450°C under 6 Vh of air for a one-hour hold after a temperature rise of 10°C / min. The temperature is then lowered to the test temperature under 61 / h of nitrogen in order to eliminate the air present in the system before injection of the alcohol charge. The feedstock is vaporized in lines heated to 150-180°C upstream of the reactor and then injected into the catalytic reactor. The operating conditions during dehydration are as follows: - inlet temperature 390°C, - inlet pressure 0.2 MPa absolute - PPH (weight of pure ethanol charge per weight of catalyst per hour) 21 h*. Each of the catalysts A and B is tested separately. The analysis of the reaction effluent is carried out at the reactor outlet on an online gas chromatograph equipped with two columns, which makes it possible to determine the conversion of ethanol, the yields of different products and the selectivity to ethylene. Conversion to ethanol corresponds to the quantity of ethanol converted in relation to the quantity of ethanol introduced (expressed in % weight). The yields correspond to the quantity of the product considered in the reaction effluent in relation to the quantity of carbon-based ethanol introduced (expressed in % weight). Ethylene selectivity corresponds to the quantity of ethylene recovered in the reaction effluent compared to the total quantity of carbon products in the reaction effluent (i.e. excluding water). The results obtained are presented in the table below. [Tables 2] Catalyst A (non-compliant) EtOH Conversion (wt%) 99.94 Yield (on C basis) (wt%): 10.00 Diethyl Ether 0.06 Ethanol 0.58 Acetaldehyde 0.00 Methane 0.16 Ethane 95.65 Ethylene 0.01 Propylene 1.63 C4 (olefins) 1.91 C5+ and other oxygenated impurities Ethylene Selectivity (wt%) 95.7 97.1 It appears that, even if the ethanol conversions are identical (99.94%), catalyst B, in accordance with the invention, (selectivity 97.1%) makes it possible to achieve an ethylene selectivity of 1.4 points higher than the ethylene selectivity obtained with catalyst A, not in accordance with the invention (selectivity 95.7%). Conforming catalyst B makes it possible to limit the formation of undesirable compounds (C4, C5+ and other oxygenated impurities, diethyl ether and acetaldehyde) to 2.75% (1.17+1.18+0.00+0.40) compared to 4.12% (1.91+1.63+0.00+0.58) of undesirable compounds produced with catalyst A, not in accordance with the invention. Example 3: Tick of a ci 25% weight of ethanol A feed comprising 25% by weight of ethanol and 75% by weight of water was tested on the same catalytic test unit as described in Example 2. The catalyst is loaded and activated as described in Example 2. The feedstock is vaporized in lines heated to 150-180°C upstream of the reactor and then injected into the catalytic reactor. The operating conditions during dehydration are as follows: - inlet temperature 380°C, - inlet pressure 0.2 MPa absolute - PPH (weight of charge per weight of catalyst per hour) 7h". Each of the catalysts A and B is tested separately. The analysis of the reaction effluent is carried out at the reactor outlet on an online gas chromatograph, as described in Example 2. The conversion of ethanol, yields of different products and selectivity to ethylene are determined as described in Example 2. The results obtained are presented in the table below. [Tables 3] Catalyst A (non-compliant) EtOH Conversion (wt%) 99.99 Yield (on C basis) (wt%): |0.00 diethyl ether 0.00 ethanol 0.20 acetaldehyde 0.0 methane 0.07 ethane 97.73 ethylene 0.1 propylene 0.5 C4 (olefins) 14 C5+ and other oxygenated impurities Ethylene Selectivity (wt%) 97.73 98.75 The ethanol conversions are identical (99.99%) for both catalysts. However, starting from a 25% ethanol feed and under the test conditions of Example 3, catalyst B, in accordance with the invention, (selectivity 98.75%) makes it possible to achieve an ethylene selectivity approximately 1 point higher than the ethylene selectivity obtained with catalyst A, not in accordance with the invention (selectivity 97.73%).

Claims

Claims

1. Catalyst comprising a zeolite having at least one seric of channels whose opening is at least equal to 10 oxygen atoms (10MR) and a binder, in which: - the catalyst comprises phosphorus and comprises an AIPO structure, determined by a signal between 35 and 45 ppm on a spectrum obtained by AI NMR analysis of the catalyst; - the pore volume (V{4-500;) of the pores of the catalyst, the size of which is between 3.6 and 900 nm, is greater than or equal to 0.25 ml / g; -the pore volume (V(30.310)) of pores of size between 30 and 310 nm of the catalyst is less than or equal to 0.080 ml / g.

2. A catalyst according to claim 1 wherein the catalyst content in AIPO structure represents between 15 and 40%, preferably between 20 and 35% and preferably between 25 and 34%, of species containing of the aluminum of the catalyst, the content of AIPO structure corresponding to the ratio of the signal area between 35 and 45 ppm compared to the total signal area between -50 and 100 ppm on the spectrum obtained by NMR analysis “AI” of the catalyst.

3. A catalyst according to claim 1 or 2 wherein the pore volume (V;4-000)) of the pores of the catalyst, the size of which is between 3.6 and 900 nm, is greater than or equal to 0.26 ml / g, and preferably less than or equal to 1.00 ml / g, preferably less than or equal to 0.60 ml / g.

4. Catalyst according to one of the preceding claims in which the pore volume Y(30-310; pores with a size between 30 and 310 nm of the catalyst is less than or equal to 0.070 ml / g.

5. Catalyst according to one of the preceding claims in which the binder is a silicic binder or a clay silicic binder, preferably primarily an amorphous silica or a mixture of amorphous silicas.

6. Catalyst according to one of the preceding claims in which the Zeolite has at least one series of channels whose opening is at less than 10 oxygen atoms (10MR) is a zeolite whose structure is chosen from the structures MFI, MTT, FER, MEL, TON, MWW, EUO and MFS, preferably the zeolite is of structure MFI, preferably the zeolite is a ZSM-5 zeolite.

7. Catalyst according to one of the preceding claims in which the Zeolite has a Si / Al molar ratio between 11 and 300, preferably between 11 and 40.

8. Catalyst according to one of the preceding claims in which the zeolite content of the catalyst is between 5.0 and 95.0% by weight, preferably between 15.0 and 95.0% by weight, preferably between 50.0 and 90.0% by weight, preferably between 65.0 and 85.0% by weight, relative to the total weight of the catalyst.

9. Catalyst according to one of the preceding claims in which the phosphorus element content of the catalyst is between 0.5 and 20.0% by weight, preferably between 0.5 and 10.0% by weight, preferably between 1.0 and 5.0% by weight, preferably between 2.0 and 4.0% by weight, by relative to the total weight of the catalyst.

10. Catalyst according to one of the preceding claims comprising a metal, preferably a metal chosen from magnesium, calcium, strontium, barium, lanthanum and cerium, very preferentially the calcium, the content of the catalyst in said metal being between 0.1 and 10.0% by weight, preferably between 0.5 and 3.0% by weight, relative to the total weight of the catalyst.

11. | Use of the catalyst according to one of the preceding claims, in a process for dehydrating an alcohol into an olefin having the same number of carbon atoms, in particular a dehy- conversion of ethanol into ethylene.

12. A process for producing ethylene from a feedstock comprising ethanol, said method comprising a step of dehydration of ethanol operated in the presence of the catalyst according to one of the res- indications 1 to 10, at an inlet temperature between 250 and 550°C, at an inlet pressure between 0.1 and 1.7 MPa and at a hourly weight rate between 0.1 and 30 h",