摘要:
A process is described for producing a catalyst for gas-phase oxidations, in which a suspension of TiO2 and V2O5 particles is applied to a fluidized inert support, wherein at least 90% by volume of the V2O5 particles have a diameter of 20 μm or less and at least 95% by volume of the V2O5 particles have a diameter of 30 μm or less. The defined particle size distribution of the V2O5 allows a high coating efficiency.
摘要翻译:描述了一种制备用于气相氧化的催化剂的方法,其中将TiO 2和V 2 O 5颗粒的悬浮液施加到流化惰性载体上,其中至少90体积%的V 2 O 5颗粒的直径为20μm或更小 并且至少95体积%的V 2 O 5颗粒的直径为30μm或更小。 V2O5的定义的粒度分布允许高涂层效率。
摘要:
Catalyst systems for preparing phthalic anhydride by means of gas-phase oxidation of o-xylene and/or naphthalene, and a process for preparing phthalic anhydride using the catalyst systems.
摘要:
Catalyst systems for preparing phthalic anhydride by means of gas-phase oxidation of o-xylene and/or naphthalene, and a process for preparing phthalic anhydride using the catalyst systems
摘要:
A process is described for converting a precatalyst which comprises an inert support, an organic carbon source and a multimetal oxide comprising silver and vanadium to a gas phase oxidation catalyst which comprises the inert support and a catalytically active silver vanadium oxide bronze, by treating the precatalyst thermally at a temperature of at least 350° C. in a gas atmosphere which comprises less than 10% by volume of oxygen, wherein, before the thermal treatment, the amount of the carbon source in the precatalyst is adjusted to a value below a critical amount The carbon content is reduced by burning-off at a temperature of from 80 to 200° C. in an oxygenous atmosphere with decomposition of a portion of the carbon source. The catalysts obtained serve for the gas phase partial oxidation of aromatic hydrocarbons to aldehydes, carboxylic acids and/or carboxylic anhydrides.
摘要:
The invention relates to a process for preparing phthalic anhydride, in which the catalytic gas-phase oxidation of o-xylene and/or naphthalene is carried out over at least three zones of catalysts of increasing activity, with only the last zone of the catalyst system containing phosphorus and the last zone also comprising at least 10% by weight of vanadium (calculated as V2O5) based on the active composition of the catalyst and having a ratio of vanadium (calculated as V2O5) to phosphorus of greater than 35.
摘要翻译:本发明涉及一种制备邻苯二甲酸酐的方法,其中邻二甲苯和/或萘的催化气相氧化在活性增加的催化剂的至少三个区域上进行,只有催化剂体系的最后一个区域 并且最后一个区域还包含至少10重量%的钒(以V 2 O 5 N计算),基于催化剂的活性组成,并且其比例 的钒(以V 2 O 5计算)至大于35的磷。
摘要:
Catalytic titanium dioxide mixtures comprising: a first anatase titanium dioxide having a BET surface area greater than 15 m2/g and a hydrogen uptake for the reduction of Ti4+ to Ti3+ of from 5 to 20 μmol/m2; and a second anatase titanium dioxide having a BET surface area less than or equal to 15 m2/g and a hydrogen uptake for the reduction of Ti4+ to Ti3+ of from 0.6 to 7 μmol/m2, processes for preparing catalysts containing the same, catalysts containing active compositions including such titanium dioxide mixtures on support materials, and catalyst systems using the same.
摘要翻译:催化二氧化钛混合物,其包含:BET表面积大于15m 2 / g的第一锐钛型二氧化钛和用于还原Ti 4+至Ti 3+的氢吸收为5至20μmol/ m 2; 和BET表面积小于或等于15m 2 / g的第二锐钛矿型二氧化钛和用于还原Ti 4+至Ti 3+的氢吸收为0.6〜7μmol/ m 2,制备含有该催化剂的催化剂,含有 包含载体材料上的这种二氧化钛混合物的活性组合物和使用其的催化剂体系。
摘要:
Catalyst systems for preparing phthalic anhydride by means of gas-phase oxidation of o-xylene and/or naphthalene, and a process for preparing phthalic anhydride using the catalyst systems.
摘要:
A description is given of a process for preparing aldehydes, carboxylic acids and/or carboxylic anhydrides, in particular phthalic anhydride, in which a gaseous stream comprising an aromatic hydrocarbon and molecular oxygen is passed at elevated temperature over a bed of a first catalyst and a bed which is made up of a second catalyst having a higher activity than the first catalyst and is located downstream of the first catalyst in the flow direction of the gaseous stream, wherein the catalytically active composition of the first catalyst comprises at least vanadium oxide, titanium dioxide and antimony oxide and the ratio of vanadium, calculated as V2O5, to antimony, calculated as Sb2O3, in the first catalyst is from 3.5:1 to 5:1. The source of antimony oxide used for the first catalyst is preferably particulate antimony trioxide having a mean particle size of from 0.5 to 5 μm. The process allows the desired oxidation products to be obtained in high yield over longer periods of time.
摘要翻译:给出了制备醛,羧酸和/或羧酸酐,特别是邻苯二甲酸酐的方法的描述,其中包含芳族烃和分子氧的气流在升高的温度下通过第一催化剂的床和 床,其由比第一催化剂高的活性的第二催化剂组成,并且位于气流的流动方向上位于第一催化剂的下游,其中第一催化剂的催化活性组合物至少包含氧化钒,钛 二氧化锑和氧化锑,以V 2 O 5 5计算的钒与锑的比例计算为Sb 2 O 3 在第一催化剂中为3.5:1至5:1。 用于第一催化剂的氧化锑的来源优选是平均粒径为0.5-5微米的颗粒状三氧化锑。 该方法允许在较长时间内以高产率获得所需的氧化产物。
摘要:
Catalyst systems for preparing carboxylic acids and/or anhydrides, the catalyst system comprising a reaction zone and a layered catalyst, the reaction zone comprises a gas inlet region and a gas outlet region, the layered catalyst comprises an active composition and one or more middle layers, one or more first layers disposed on a side of the one or more middle layers toward the gas inlet region, and one or more second layers on a side of the one or more middle layers toward the gas outlet region, wherein the active composition content of one or more of the middle catalyst layers, based on total mass of the layered catalyst, is lower than the active composition content of the one or more first catalyst layers and is lower than one or more second catalyst layers; and processes for gas phase oxidation employing a layered catalyst of the present invention.
摘要:
The present invention relates to a catalyst system for preparing carboxylic acids and/or carboxylic anhydrides which has at least three catalyst layers arranged one on top of the other in the reaction tube, with the proviso that the most inactive catalyst layer is preceded in the upstream direction by a more active catalyst layer. The invention further relates to a process for gas phase oxidation in which a gaseous stream which comprises one hydrocarbon and molecular oxygen is passed through a plurality of catalyst layers, the least active catalyst layer being upstream of a more active catalyst layer.