SA99200361B1 - CATALYST CATALYST BASED ON MOLYBDENUM - VANADIUM FOR SELECTIVE OXIDATION OF PROPYLENE AT LOW TEMPERATURE, METHODOLOGY FOR ITS MANUFACTURING AND USAGE - Google Patents

Abstract

Abstract: This invention relates to a mixed metals oxide catalyst system for the selective oxidation of ethylene to acrylic acid and acrolein. The new catalytic system contains molybdenum, vanadium, palladium, lanthanum, niobium and X, where X is copper or chromium or mixtures thereof. The new catalytic system prepares higher yields of acrylic acid and acrolein in the oxidation that takes place at a low temperature of propylene by gases containing molecular oxygen without producing side products such as CO. The invention also relates to methods for the manufacture and use of catalytic systems.

Description

Y

For oxidation vanadium vanadium - molybdenum p gait gall depends on a catalyst catalyst ¢ low 5) ja at propylene degree 485M) oxidation Methods for its manufacture and use Full description Background The invention is a metal oxide catalyst. This invention relates to a catalyst system to propylene selective oxidation mixed with acrylic acid for the new oxidation on catalytic. The catalytic system contains . acrolein, acrolein, acrylic acid, lanthanum, palladium, vanadium, molybdenum, molybdenum, or chromium copper are copper X where X, niobium, and lanthanum, or mixtures thereof. The new catalytic system prepares chromium yields in the oxidation of acrolein and acrolein, an acrylic acid greater than an acrylic acid containing gas by a gaseous propylene at a low temperature to propylene. CO without producing byproducts enriched molecular oxygen 0 The invention also provides methods for the manufacture and use of catalytic systems. Several publications are referenced in this application. These references indicate the state of the field to which this invention relates. Which have been included here by reference. For the production of propylene The catalytic vapor phase oxidation of propylene with acrylic acid in two phases is known in the field. The reaction takes place in stage 10 mainly. The second stage converts the first acrolein by converting propylene into acrolein v

Acrolein is basically an acrylic acid. Attempts to improve the process conditions in the first stage focused on the following defects: 1- The increase in the percentage of propylene in the charged gas is limited due to the reaction heat. In particular; when

©=i The reaction system must be protected against the risk of explosion at higher reaction temperatures. ii - The selectivity is not improved for the beneficial oxidation products when the reaction is carried out at higher temperatures because part of the propylene charge is converted during the total oxidation into products such as carbon dioxide and water.

And under those circumstances; Various studies have been directed at optimizing the reaction conditions

0 For those processes, US Patent No. 0718149 relates to a process for the production of acrylic acid by two-stage catalytic oxidation in the vapor phase of propylene by molecular oxygen. The first stage includes the oxidation of propylene to acrolein mostly; The supply to the first stage of the reaction includes a mixture containing propylene; oxygen

Ve molecular molecular oxygen; Propane aul SLA » propane carbon dioxide ¢ carbon monoxide and water vapor using a catalyst of metal oxide mixed MoFeB. The reaction temperature ranges from You to 1560 C; The preferred range is FTO TY. AT 46-10m was observed in the reactor. 0 .

Therefore, the highest temperature observed in the reactor may reach 5060 C. This temperature is high enough for any oxidation reaction required for fine tuning

for operating parameters and variables; In particular, to precisely adjust the concentration of oxygen and propylene

EP 17,681,749 a1 relates to a process for the production of an unsaturated aldehyde and an unsaturated acid that involves exposing propylene to catalytic oxidation 0 in a gas phase by means of molecular oxygen in the presence of a catalyst It includes a compound oxide of formula 0, 3,000 and 10,31,7 at 1 um; where: A represents nickel and/or cobalt; 3 represents at least one selected element of phosphorus, boron, arsenic, tellurium text: N1611, tungsten, antimony, and silicon) and © represents at least one selected element of potassium And niobium, and rubidium, and cesium, and thallium | ; and where e and Cc sb sds are m + and aw J idx, respectively, dare m114 lies q2 has qqm 6 and 0, and where m is in 11; Str jiale=b> (Ve=d=) zero = 01 o = zero 01 f= and zero > p = ? And x has a value that depends on the oxidation state yo of the given elements. and at a turn of 780,5; Its selectivity was mentioned

7 for acrolein and acrylic acid. European Patent 1,797,774 relates to a process for producing propylene acrolein using the catalyst 0:0, 31.764.3,0N110.77 » A Gua is a selected element from the group consisting of nickel and cobalt; 3 is at least one element 0 selected from the group consisting of the base metals, alkali-earths, and thallium ; © is at least one element

°

Selected from the group consisting of phosphorus, arsenic, boron, and niobium; Where 0 is at least one element selected from the group consisting of silicon, aluminum, and titanium ¢ and the subscripts hgfedeba and x, respectively, are the number of atoms of the elements A, Fe, Bi , W, Mo , 3 © , 1 and © »; Provided that p-? to 01; 5 - zero to 01 ; And on the condition that .8 + - 17 © = 1 to 201 1 - that to 10 nM - ? To =f Ye rounded to 2.0 p - zero to 4 0 - to 15 and " is a number needed to satisfy the valence requirements for those elements.

The temperature of the reaction was AY catalytic by catalytic oxidation Fi 114584797 Another European patent relates aldehydes and carboxylic acids to carboxylic acids olefins of olefins at a temperature in the range 15-80; 3 ca unsaturated at position 5. psi VTA to 1 but conducted at high pressure in the range in liquid phase mode and furthermore; The method was run in a liquid phase

1 Payments. and at the end; hours ; A catalyst productivity of 0 liter fan of acrylic acid was obtained. This system had many drawbacks, for example, it required batch mode operation, liquid phase reaction, and Ale pressure.

z and catalytic recovery and activation; etc. None of the foregoing field demonstrated or suggested the advantages of the catalysts described in

Y. This invention gives high performance for the selective production of acrylic acid and acrolein

acrolein through a partial oxidation process of propylene in gas phase YEYY

gas phase with (ZU) zero or small for carbon monoxide at low temperatures. Las for that; It may be desirable to produce an improved catalyst for use in the selective production of acrylic acid and acrolein without the production of carbon monoxide © sal. The objectives of the invention are to overcome the defects previously identified. Another object of the invention is to prepare an improved catalytic system for the selective oxidation of propylene at a low temperature. JAL's objective of the invention is to prepare an improved catalyst for the oxidation of 0 propylene to acrylic acid and acrolein in one stage at a low temperature. Another object Lad of the invention is to prepare methods for the fabrication and use of the improved catalytic system. It will show the aforementioned objectives and advantages and others related to the invention or Ne will be clear from the following description. A general description of the invention as set out in this invention; The ability to lower the reaction temperatures in proportion to the oxidation of propylene in a vapor phase in a continuous setting and also to prepare very high yields of acrolein and acrylic acid together is achieved in an amazing way using the gaskets subject of the invention. The catalysts shown in this invention are prepared in such a way that a single catalyst gives dual functions of activation

propylene to acrolein and also the oxidation of acrolein to acrylic acid, and more specifically; The invention relates to a catalytic system for use in a method in which propylene is oxidized by molecular oxygen© to acrylic acid and acrolein in a gas phase reaction with Ale selectivity at temperatures ranging from #6 um to ster at pressures ranging from 1-90 bar. This is achieved using a catalyst having a sintered composition of Mo,VpLaPdgNbeXs where: Cu = X or Cr or both; a 0 is 1; b is +1 to ca, © is > zero to 0.7 preferably 0001 to CLF 4 0 is kent to CX 6 is zero to 1.1; preferably 0.0006661 to SEY f 0 zero to 0.7 ge preferably 1 to CX The several values of 0 and © represent the relative gram-atomic ratios for elements 1340, V, 18, 20, 110, and X, respectively, in the catalyst. The elements exist in union with oxygen; Preferably in the form of different oxides. The composition can also be shown in the form “Mo, ViLaPdiNbeX0y, where T is XY. A number needed to satisfy the valence requirements of other elements.

A

The invention also relates to a low-temperature selective catalytic process for the production of gl acrolein (acrylic acid) or both by vapor phase oxidation of propylene. The catalytic process, subject of the invention, does not produce carbon monoxide, which is not considered environmentally friendly and has a significant impact on the separation costs carried out in this direction. Other targets will become dials in addition; The z characteristics and advantages of this invention are evident from the examination of this full description; Including claims and specific examples. 1 One aspect of the invention relates to an improved catalytic system for the selective oxidation of propylene. The catalysts of the invention may be used with or without a support. Suitable supports for catalysts include alumina, silica, titania, zirconia, zeolites, mo silicon carbide, carbide, partial sieves (a type of vo zeolite) and other fine materials. Pores/non-toxic and mixtures thereof. and when used on a support; The catalyst booster usually includes from about 0.01 to 0.0 by weight of the catalyst composition; The remainder is the backing material. Another aspect of the invention relates to methods for manufacturing improved catalysts. 0 can test the compounds used in addition to the remaining special steps in preparation

A catalyst that has a significant impact on catalytic performance. It is preferable that the elements of the catalyst composition be bonded with oxygen in the form of oxides 0 < 1068. According to one embodiment; The catalyst is prepared from a solution of soluble compounds (salts, complex compounds or other compounds) of all metals. It is preferred that the solution be in an aqueous system having a pH of 1 to 01, and most preferably a pH of 1 to 1; And a temperature from about +0” C to about 100 C . And in general; Lda is prepared from compounds containing elements by dissolving large amounts of soluble compounds and diffusion of insoluble compounds in order to prepare the desired gram-atomic ratios of the elements in the composition of the catalyst. Composition 0 catalyst is then prepared by removing water and/or another solvent from the mixture of compounds in the solution system. The dried catalyst is calcined by heating to a temperature ranging from about Ja You about 0045 C in air or oxygen for a period of time from about one hour to about 11 hours to produce the desired catalyst composition. It is preferable to introduce molybdenum into the solution in the form of 0 ammonium salts, Mia paramolybdate, or organic acid salts of molybdenum, such as acetates, oxalates, and mandelates. mandelates and glycols 98 . Other molybdenum compounds that are partially soluble in water that may be used on molybdenum oxides include molybdic acid and molybdenum chlorides. molybddenum VEY

. It is preferable to introduce vanadium into the solution in the form of ammonium salts; Such as ammonium metavanadate 2061878080816 ammonium and ammonium decavanadate “or organic salts of vanadium Jie vanadium acetates, oxalates and tartrates ©. Load can use partially soluble vanadium compounds such as vanadium oxides and vanadium sulfate. and to achieve complete solubility; ald You can add an amount of oxalates or tartaric acid. It is preferred that lanthanum be introduced into the catalyst paste in the form of La salts such as oxides, acetates, chlorides, nitrates, etc. It is preferred that palladium be introduced into the catalyst paste in the form of Pd on activated charcoal, alumina, or a solution of palladium salts Jie acetates, chlorides, nitrates, etc. It is preferable to add copper to the catalyst paste in the form of copper salts, acetates, chlorides, nitrates, etc. It is preferable to add chromium to the catalyst paste in the form of chromium salts (Jie chromium oxides, acetates, chlorides, nitrates, etc.). preferably; To use niobium in the form of oxalates or © hydrated oxides. Other sources of this metal are in soluble form, including compounds in which the metal is coordinately or bonded, or to form a complex compound with

11 amine carboxylic acid and carboxylic acid beta-diketonate beta-diketones alkanolamine alcohol and alcohol amine by the method catalyst embodiments; The catalyst is prepared aay and according to . molybdenum next year. Aqueous solutions of vanadium and molybdenum are prepared

0 is preferred. The vanadium solution is mixed with a molybdenum solution at a specific temperature and a specific PH to form a gel solution, and the rest of the necessary components are slowly added to the combined gel solution. And after mixing and heating for about 1/7 to ¥ an hour; The resulting gel is dried to initial wetness with continuous stirring at about 100 m

1 And after drying the resulting gel mixture at 1710°C for 165 hours; The catalyst is heated to 7568°C at a rate of LY per minute and calcined at this temperature for ; Hours to produce the desired oxide composition and it seems that this system is close to the optimum that gives a catalyst with the desired composition and properties.

There is another aspect of the invention related to the methods of using the catalyst system

0 Subject matter of the invention. and more specific; The invention relates to an improved method for the oxidation of propylene. The raw material used as a source of propylene can be a stream containing at least three volume percent of propylene or mixtures of propylene and propane. The gas stream also contains small amounts of alkanes or alkenes Cp alkenes or b© « with less than

OEY. Volume in percent of each. The load gas stream may contain quantities

VY

argon/nitrogen major » more than five volume percent; Of nitrogen and water in the form of water vapor, carbon dioxide and carbon dioxide 2, and the reaction mixture when conducting the process is one mole of • molecular oxygen 00 to 0.000 mol of molecular oxygen. 00 + propylene as pure oxygen or in the form of air; Zero to 4.0 moles of water in the form of water vapor. Molecular oxygen sources of charge include; Pure oxygen, air, and oxygen-rich air, depending on the economic aspects of separation and transformation of the investigator. The ratio of propylene to oxygen varies with hydrocarbon | desirable conversion and catalyst selectivity; However, they generally vary in the extent that the reaction is particularly effective in the presence of Lad diluents. Ve — E/1 0 or water vapour. It can range from nitrogen such as argon 8 or nitrogen, and water vapor or nitrogen may be used. 1/1 - 1/5 of the ratio of propylene to diluents in the vapor range as a diluent for the reaction and as a heat modifier for the reaction. Other helium and nitrogen gases may be used as reaction diluents or heat modifiers such as helium 0, carbon dioxide and carbon dioxide, nitrogen propylene and accordingly; The components of the reaction mixture include propylene, oxygen and diluents; These components are mixed homogeneously before or until they are introduced into the reaction area. The ingredients may be pre-heated individually or after they have been mixed; Before it is introduced into the reaction zone, it must have a temperature of 0

Caton to about aver range from about

VY

The reaction zone generally has a pressure ranging from 1 to .5 bar, preferably from 11 to Fe bar; temperature from about 1001°C to 0056°C ¢ and preferably from 1100°C to 000°C; contact time between reaction mixture and catalyst ranging from about 0.00 sec to 100 sec; preferably 0.1 seconds to 10 seconds; and a speed of 0 vacuum per hour ranging from about 50, or about 50,000 hours; Preferably from 001 to Ye, eee TT hours, and most preferably from 000 to 008068 hours. The contact time is defined as the ratio between the apparent volume of the catalytic bed layer and the charge volume of the gaseous reaction mixture to the catalytic bed layer under the specified reaction conditions per unit time. 1 The vacuum velocity is calculated by defining the total gas equivalent of gas leaving the reactor in liters of the total stream rising for a time period of one hour divided by the number of liters of catalyst in the reactor. This volume at room temperature is converted to the volume at zero and 1 bar. The reaction pressure is initially set up by the charge of the gaseous reactants 1 and the diluents and after the reaction fay may be maintained by the use of a suitable back pressure adjusting unit placed on the reactor outlet stream. The reaction temperature is set up by placing the catalyst through a tubular-walled transformer that is placed in an oven preheated to the desired reaction temperature.

1 The concentration of oxygen in the charge gas mixture can vary over a wide range; or higher in the charge mixture, using appropriate measures, Tov up to 0.1 to avoid explosion problems. And air is the preferred source of oxygen in the charge. The process is generally carried out in one stage and all oxygen and reactants are supplied as one charge with the unreacted primary reactants to be returned oo A multi-stage addition of oxygen or Ala can be used to rotate it. However, to the reactor with the possibility of using the technology situation to improve the hydrocarbon yield or the total yield of the desired products. Hydrocarbons The liquid products can be separated from the unreacted charge hydrocarbons by condensation or washing; Usually with water or dilute acid. 0 The subject of the invention is limited to catalyst and the methods of using the catalyst and acrolein acrylic acid to propylene oxidation of propylene are not. The catalyst may also be used for the oxidation of aliphatic aldehydes. acrolein in the unsaturated alpha-beta phase in the alpha-beta position aliphatic aldehydes to produce carboxylic acids molecular oxygen vapor by means of corresponding molecular oxygen ve such as unsaturated alpha-beta in the alpha-beta position carboxylic acids from meth-acrolein and meth-acrylic acid.isobutane

0 Examples The following examples are for illustration of some of the products and their manufacturing methods

within the scope of this invention. And it is of course; They are not considered to be any dla specification of the invention. Numerous changes and modifications can be made to the invention.

The catalyst samples prepared in the examples were evaluated using the following method: Catalyst test

Catalyst evaluations were carried out in a bed-bed tubular reactor

Fixed stainless steel under standard conditions of the process. The gas charge formulations used to evaluate the catalysts contained propylene

0, propane, oxygen, water, 0©, and argon. Molecular and gram ratio (molar) 0:00:01 : 01 : 01 : 01 ; Respectively . The reactions were carried out at a temperature of 70 °C, an absolute pressure of 11 psi, and a vacuum velocity of about 0.060 h-1 using 11 cc of a calcined catalyst.

\o The reaction products were analyzed during operation by gas chromatography. Oxygen, argon and carbon monoxide were analyzed using a column of 7.5 m x mm from a 13Xx molecular sieve. Carbon dioxide and propane were analyzed using a column whose dimensions were “m*©mm” and filled with a substance sold under the trade name ©HAYESEP.

0 Liquid products (acrylic acid, acrolein, acetic acid P8060 and water) for a certain period in a cold collection buffer and were analyzed using

Column 7m X © mm Lima with material sold under the brand name PORAPAK QS . and in all cases; The calculations of cyclicity and selectivity were based on a federated elemental measure. Example 1 ° [7-03 Ptwer. Wat Albmoyo [Mo1V.398La1£.05Pd;] ammonium metaphadate (Aldrich Chemicals, Assay = +,44%) was added in an amount of VL gm to 80 ml of distilled water and heated to 5 m with stirring, a yellow solution of 211 between 50 + (Solution A) was obtained, and 7.4 g of hydrated niobium oxide (7860 Niobium “NbyOs”) was added Company, USA 0 and 10 gm of Av oxalic acid ml of water was heated to 15°C with continuous stirring to give a clear white solution having a pH of 075 (Solution B).The two solutions A and B were mixed together at 18 m with continuous stirring of the mixture content, changes in color were observed from call yellow - brown - green - dark green, and the PH of the solution was 0.01 0 at 85 m. Oxalic acid was added very slowly to the previous solution with continuous stirring of the contents of the mixture at 10 C. A dark blue-green solution with a pH of 1875 was obtained at AT C (solution C). ) sill 2--12054 - 2.0.8) in an amount of YALA g to 1 ml of water and heated from 0 to 12 C to give a colorless solution with a PH ranging between 0.5 and Tv (solution d). Then, solution D was combined with solution C slowly to give a dark blue precipitate

VY

To taupe (mixture E). The required amount of palladium was slowly added to lanthanum and lanthanum copper nitrate, followed by palladium copper oxide gel mixture. This dark-coloured mixture was stirred vigorously to obtain a homogeneous gelatinous mixture, which was then slowly dried to the state of initial wetness with continuous stirring. The resulting solid was placed in a porcelain dish and dried again. In an oven at 1071 m for sixteen hours. The resulting material was cooled to room temperature and placed in an oven. The temperature was raised from a temperature at a rate of lm/min and then maintained at 7050°C for a room oF period of up to four hours. In the form of particles with a temperature of Z. propylene evaluated for the oxidation reaction of propylene, Ps, the reaction of 70 m; The product of the reaction showed a recycled yield of 719.81 (acrylic acid) acrolein for acrylic acid and acrolein 15.51 and the remaining acetic acid and 00. At 0158 m + the clearest product was (TAY) and acrolein ve (acid acrolein The reaction is selectivity of 7977 to acrylic acid and acrolein, and the residue is acetic acid and (ZY) and acrolein 7979 acrylic acid acrylic CO, example? 35.03]ve

YEYY

Ya

Except that 1 05 gm was used, the method was the same as in the example of copper oxide. and at a reaction temperature of 0107 m; The yield of acrylic acid and acrolein (acid 745.01, the reaction showed a recycled yield of .002 acrylic 717 and acrolein 7/4) and the remaining part is acetic acid and

Y dda oo [MoV Y dda oo 888-04NDo.126C 04.38.03 Cr4.1504] g of +, VEY The method was the same as in Example 7 followed by addition and at a reaction temperature. ammonium dichlormate of 7096m ¢ and the reaction product showed a recycled yield of 747.15 of acid and acrolein 717) and the remaining fraction IVE acrylic and acrolein (acrylic acid 0 is acetic acid and . Ex. Ardo Mentao 12. Albo 0:181-0:1101170.3] CTo.0135] g of 0.4 except that 1 was added. The method was the same as in Ex. Cupric oxide p20, YO and ammonium dichlormate ammonium dichromate Vo reaction temperature of 7059 °C; the product of the reaction indicated a reaction yield aie

IXY for acrylic acid and acrolein (acrylic acid 795,11 turnover

COz and acrolein 7978) and the remaining part is acetic acid, acid 02, and a retarder and ligand [Nbg 126] ve except that no oxide 1 was added. The method was the same as that of the copper example. And at a reaction temperature of 7101 m; The reaction products gave a yield

Recycled to acrylic acid and acrolein (acrylic acid 2009 and acrolein 785) with the remainder being acetic acid and CO; the BET surface area (according to the Bruneier-Emmett-Taylor equation for measuring surface area) of the catalysts was varied shown in BY 01 to Yo m'/g. M. The catalysts subject of this invention showed the behavior of optimizations of oxidation (reduction and oxidation reactions) leading to high efficiency and great selectivity towards molecular oxidation products 0. Depending on the catalytic data, the following general characteristics of the catalysts subject of the invention can be deduced. 1- The catalyst system shows high selectivity for acrylic acid and acrolein 0 at low temperatures in a one-stage reaction. 1 The oxidation of AT propylene shows less than 0-11 © 0 M. The lower AT can have a positive effect on reactor design. »- - The low temperature oxidation of propylene over the catalysts shown in this invention does not produce carbon monoxide as a by-product. yo ;-_ The relative selectivity of acrylic acid and acrolein depends on the catalyst composition, reaction temperature, vacuum velocity, pressure, and charge composition. The previous detailed description of the invention is meant to be for clarification and not for defining. p1

Claims (1)

Ya protection elements acrylic acid to propylene acrylic acid for the selective oxidation of propylene catalyst -1 1 110, 70, La, V, contains the elements catalyst contains a catalyst composition acrolein and acrolein For the following: X and 100 Mo,ViLa PdgNb Xs ¢ © where Cu = X, Cr, or mixtures thereof; Z 1 8 is 3 tot to 0.10 is 1 tot ¢ 0.7 is > zero to Cc A EY to 0000010 is d 4 eV is zero to e 0 CY Gafy V and © are the relative atomic-gram ratios of the elements 140 and ed,eba where are the multiple values of 0 and the elements exist in union with . catalyst respectively; In the catalyst X 20, 115, sla and yy oxygen 04 1 "- catalyst According to item 1 - Gua said catalyst is a supported catalyst including a support. D 1 “- catalyst according to item 7; Where the selection of the aforementioned support is from the group ¥ consisting of alumina, silica, titania, zirconia, silicon carbide Y, Mo — carbide, zeolites 1 ¢ — catalyst according to item 7; The aforementioned support includes the products of ¥ molecular sieves and/or microporous/microporous/medium porous materials. 0 #- catalyst according to element? ; The aforementioned supported catalyst from 0 » to 720 wt. catalyst includes *0 catalyst to 796 wt support. 1 +>- a one-stage catalytic process for the direct conversion of propylene into ¥ acrylic acid and acrolein by oxidation of propylene “| The propylene oxidation step involves a reaction mixture that includes propylene ; oxygen and a compound that can supply oxygen in a reaction zone in the presence of a catalyst: 6 the subject of element 1.1 7- the process according to element 6; Where the aforementioned catalyst is in the form of a stable bed layer and the aforementioned “oxidation” is carried out by introducing a charge mixture that includes propylene to the reaction zone. Ania »The aforementioned oxidation is carried out by introducing a feed charge mixture that includes propylene v into the reaction zone. Ga for element 7 » where the charge mixture includes molecular oxygen Y with a charge ranging from 0.1 to 7560 by volume of feed charge. YY Operation according to item 7; Where the mixture of said charge is diluted with vapor by an amount from zero to 1 -11 by volume. 710 gas phase Process according to item 6; Where the oxidation takes place during operation in the gas phase, 11-1; with a contact time between JO to 1; under pressure from afer to 001 at a temperature of 0 sec. 01 and 1.1 the reaction mixture and the catalyst varies between process according to element +; Where the aforementioned oxidation includes at least 7850 of 1-1” 01 at the degree of acrolein and acrolein acrylic acid from a recycled product of acrylic acid » low temperature in the reaction zone. © The aforementioned oxidation of the products does not result Propylene Cum process according to item 6; - » The process according to item 6 also includes the introduction of oxygen into the trophic charge mixture in 0©-1 in various steps to increase the yield and selectivity of the desired products. 11-1 with acrolein from the proceeds of the product recycled into acrylic acid and acrolein JV on and at least 775 of acrolein. 6; Where the oxidation step of propylene -17-1 with acrolein and acrolein acrylic acid selectivity of at least 7978 for acrylic acid 1 at least. 711 with a ratio of acrolein an acrylic acid of at least 7976 and acrolein +” Provide propylene process according to item 6; Where the oxidation step of propylene - 08 1 and acrolein acrylic acid acrylic (meal yield of recycled product by at least 797 ¥ ed LOVE ¥ 01:60 with acrylic acid with 777 caprylic acid on JAY 3; acrolein by at least 79748. Z -14 1 Process according to item 6 ¢ where the mentioned propylene oxidation step provides “| Respective of at least AVY of acrylic acid and acrolein with ¥ of acrylic acid of at least VA and acrolein of 11 over; the least. -*1 1 The process according to item 6 where at least one reaction is in the fluid phase and is converted to at least one fluid phase product. -71 1 process to form the catalyst according to item 7; The following steps include: (Iv) forming a mixture containing 718701170 140 and (AX) “©” solution b) drying said mixture to form a solid; and a (x 4) calcination of said dried solid to form said catalyst. ——YY 0 Process according to element 71; Cum the said mixture is an aqueous system having a “| pH 1 to .01 0 *”- process according to element YY; where the said mixture is an aqueous system It has S "| pH 1 to 7. YE 0 Process according to element 71; Cum The aforementioned mixture is formed by mixing a first aqueous solution with a second aqueous solution, where both the aforementioned first and second solutions contain M-element At least one of the group consisting of Mo, V, Nb, La, Cr, Cu and Pd. Y¢; Wherein the aforementioned calcination step includes heating the solid material, 71 process according to the element, Yo 1, in air or oxygen for the aforementioned desiccant at On to You to a calcining temperature from 1 hour to 11 hours. ©