摘要:
A process for preparing shaped catalyst bodies whose active composition is a multielement oxide, in which a finely divided precursor mixture with addition of graphite having a specific particle size is shaped to the desired geometry and then treated thermally.
摘要:
A catalyst is described which has a catalytically active composition which contains a phase A and a phase B in the form of three-dimensional delimited regions, wherein phase A is a silver-vanadium oxide bronze and phase B a mixed oxide phase based on titanium dioxide and vanadium pentoxide. The catalyst serves to prepare aldehydes, carboxylic acids and/or carboxylic anhydrides from aromatic or heteroaromatic hydrocarbons by gas phase oxidation.
摘要:
Multimetal oxides corresponding to the general formula (I), processes for their preparation, precatalysts containing such oxides and catalysts made therefrom for gas phase partial oxidation of hydrocarbons: Aga-cQbMcV12Od.eH2O (I)wherein a represents a number having a value of 5 to 9; Q represents an element selected from the group consisting of P, As, Sb, Bi and mixtures thereof; b represents a number having a value of 0.2 to 3; M represents a metal selected from the group consisting of Li, Na, K, Rb, Cs, Tl, Mg, Ca, Sr, Ba, Cu, Zn, Cd, Pb, Cr, Au, Al, Fe, Co, Ni, Ce, Mn, Nb, W, Ta, Mo and mixtures thereof; c represents a number having a value of less than 1; d represents a number having a value of which is determined by the valency and frequency of Ag, Q, M and V in the formula (I); and e represents a number having a value of 0 to 20; wherein the multimetal oxide has a crystal structure wherein its powder X-ray diffractogram includes reflections at at least 5 interplanar spacings selected from the group of 7.13 Å, 5.52 Å, 5.14 Å, 3.57 Å, 3.25 Å, 2.83 Å, 2.79 Å, 2.73 Å, 2.23 Å and 1.71 Å, each interplanar spacing value±0.04 Å.
摘要翻译:对应于通式(I)的多金属氧化物,其制备方法,含有此类氧化物的预催化剂和由其制备的催化剂用于烃的气相部分氧化:<?in-line-formula description =“In-line Formulas”end =“ 导线“>> Ag sub> C sub> C b> sub> 其中a表示数值为5〜9的数字,其中a表示0〜5的整数。 Q表示选自P,As,Sb,Bi及其混合物的元素; b表示数值为0.2〜3的数; M表示选自Li,Na,K,Rb,Cs,Tl,Mg,Ca,Sr,Ba,Cu,Zn,Cd,Pb,Cr,Au,Al,Fe,Co,Ni, Ce,Mn,Nb,W,Ta,Mo及其混合物; c表示小于1的数字; d表示数值,其数值由式(I)中Ag,Q,M和V的化合价和频率决定; e表示0〜20的数, 其中所述多金属氧化物具有晶体结构,其中其粉末X射线衍射图包括选自7.13,5.52,5.14,3.57,3.25,2.83,2.79,2.73的至少5个面间距的反射 Å,2.23Å和1.71Å,每个晶面间距值±0.04Å。
摘要:
The invention relates to a process for preparing unsaturated nitrites from the corresponding alkanes which comprises the steps: a) feeding an alkane into a dehydrogenation zone and catalytically dehydrogenating the alkane to the corresponding alkene to obtain a product gas stream A which comprises the alkene, unconverted alkane and possibly one or more further gas components selected from the group consisting of steam, hydrogen, carbon oxides, hydrocarbons having a lower boiling point than the alkane or the alkene (low-boilers), nitrogen and noble gases, b) at least partially removing further gas components from the product gas stream A to give a feed gas stream B which comprises the alkane and the alkene, c) feeding the feed gas stream B, ammonia, an oxygen-containing gas and, if desired, steam into an oxidation zone and catalytically ammoxidizing the alkene to the corresponding unsaturated nitrile to give a product gas stream C which comprises the unsaturated nitrile, ammoxidation by-products, unconverted alkane and alkene and possibly one or more further gas components selected from the group consisting of steam, oxygen, carbon oxides, ammonia, nitrogen and noble gases, d) optionally removing ammonia from the product gas stream C to give an ammonia-depleted product gas stream D, e) removing the unsaturated nitrile and ammoxidation by-products from the product gas stream C or D by absorption in an aqueous absorbent to give a gas stream E which comprises unconverted alkane and alkene and possibly one or more further gas components selected from the group consisting of oxygen, carbon oxides, ammonia, nitrogen and noble gases, and an aqueous stream which comprises the nitrile and the by-products, and recovery of the unsaturated nitrile from the aqueous stream, f) recycling the gas stream E into the dehydrogenation zone.
摘要:
A process for preparing (meth)acrylic acid by heterogeneously catalyzed gas phase partial oxidation of a saturated hydrocarbon precursor compound, in which the charging gas mixture contains from 5 to 25% by volume of steam and the molar ratio of molecular oxygen present in the charging gas mixture to saturated hydrocarbon precursor compound present in the charging gas mixture is from 1.5:1 to 2.5:1.
摘要:
The invention relates to an apparatus for mixing, drying and coating pulverulent, granular or shaped loose material in a fluidized bed, in particular for use in a process for producing supported catalysts for gas-phase oxidations, which comprises a container (10) for accommodating the loose material, with a bowl-like depression (17) being provided in a lower region (13) of the container (10), a central tube (27) for introducing a gas, with the central tube entering the container in an upper region (12) of the container (10), extending essentially axially downward in the container (10) and opening into the depression (17), an essentially annular deflection shield (29) which is fixed to the central tube (27) in the upper region (12) of the container (10), a guide ring (31) which is located in the lower region (13) of the container (10) and surrounds the central tube (27) essentially concentrically at a distance (L) for part of its length so that a first opening (34) is formed between the wall of the container (10) at the upper edge (22) of the depression and the lower end (33) of the guide ring (31) and a second opening (36) is formed between the deflection shield (29) and the upper edge (35) of the guide ring (31), and means, for example valves (21), for introducing a fluid into the container (10). In the apparatus of the present invention, the outer wall of the central tube (27) is at least partly provided with an adhesion-reducing coating (38). In a preferred embodiment, the distance (L) between the wall of the central tube (27) and the wall of the guide ring (27) is greater than the open height (H3) of the first opening (34). The invention also provides a process for producing supported catalysts using such an apparatus.
摘要:
A multimetal oxide of the formula I, Aga-cQbMcV2Od*eH2O, I where a is from 0.3 to 1.9, Q is an element selected from among P, As, Sb and/or Bi, is from 0 to 0.3, M is a metal selected from among Nb, Ce, W, Mn, Ta, Pd, Pt, Ru and/or Rh, c is from 0.001 to 0.5, with the proviso that (a-c)≧0.1, d is a number which is determined by the valence and abundance of the elements other than oxygen in the formula I and e is from 0 to 20, and also precatalysts and catalysts produced therefrom for the partial oxidation of aromatic hydrocarbons are described.
摘要翻译:式I的多金属氧化物,<?in-line-formula description =“In-line Formulas”end =“lead”?> Ag sub> ?V V V V V * O O O O O,,------------------------------------- 其中a为0.3〜1.9,Q为选自P,As,Sb和/或Bi的元素,为0〜0.3,M为选自Nb, Ce,W,Mn,Ta,Pd,Pt,Ru和/或Rh,c为0.001至0.5,条件是(ac)> = 0.1,d为由化合价 描述了式I中的氧以外的元素和e为0至20,并且还描述了由其制备的用于芳族烃的部分氧化的预催化剂和催化剂。
摘要:
A process for preparing (meth)acrylic acid by conducting a saturated hydrocarbon precursor compound through a catalyst bed I whose catalysts I have, as the active composition, a multimetal oxide I which has a specific X-ray diffractogram and contains the elements Mo and V, at least one of the elements Te and Sb, and also at least one of the elements from the group consisting of Nb, Ta, W, Ce and Ti, wherein the catalyst bed I is interrupted by at least one catalyst bed II whose catalysts II have, as the active composition, a multimetal oxide II which contains the elements Mo, Bi and Fe.
摘要:
Process for preparing phthalic anhydride by gas-phase oxidation of xylene, naphthalene or mixtures thereof in a shell-and-tube reactor thermostatted by means of a heat transfer medium over three or more different fixed-bed catalysts arranged in zones, wherein the process is carried out so that the maximum temperature in the second catalyst zone in the flow direction is up to 50° C. lower than the maximum temperature in the first catalyst zone and the maximum temperature in the third zone from the gas inlet is from 30 to 100° C. lower than that in the first catalyst zone. The process of the present invention makes it possible to prepare phthalic anhydride in high yields under industrially relevant conditions.
摘要:
A process for preparing (meth)acrylic acid, in which a saturated hydrocarbon precursor compound is conducted through a catalyst charge which consists of two spatially successive catalyst beds I, II in the flow direction of the reaction mixture, each of which contains different catalysts and has different reaction-selectivity behavior.