Abstract:
A process for preparing (meth)acrolein by heterogeneously catalyzed gas phase partial oxidation of a precursor compound, in which the reaction gas mixture which comprises at least 3% by volume of precursor compound is passed through a fresh fixed catalyst bed whose active material is a multielement oxide which comprises the elements Mo, Fe and Bi and at least one of the elements Ni and Co, and the fixed catalyst bed is loaded with at least 40 l (STP)/l·h of precursor compound, and the precursor compound is converted to an extent of at least 90 mol %, wherein, over the first 8000 operating hours, during X=10 to 500 operating hours, the highest temperature of the reaction gas mixture in the fixed catalyst bed is 400 to 450° C. and, during the remaining 8000−X operating hours, is 300 to
Abstract:
A process for preparing an organic target compound by heterogeneously catalyzed gas phase partial oxidation of an organic precursor compound with molecular oxygen in two oxidation reactor lines operated in parallel and removal of the target compound from the mixture of the product gas streams in a workup line, wherein the catalysts charge of one of the oxidation lines comprises a portion of catalyst over which the heterogeneously catalyzed gas phase partial oxidation has already been carried out for longer than over the portions of catalyst of the catalyst charge of the other oxidation reactor line.
Abstract:
A process for preparing (meth)acrolein by heterogeneously catalyzed gas phase partial oxidation of a precursor compound, in which the reaction gas mixture which comprises at least 3% by volume of precursor compound is passed through a fresh fixed catalyst bed whose active material is a multielement oxide which comprises the elements Mo, Fe and Bi and at least one of the elements Ni and Co, and the fixed catalyst bed is loaded with at least 40 l (STP)/l·h of precursor compound, and the precursor compound is converted to an extent of at least 90 mol %, wherein, over the first 8000 operating hours, during X=10 to 500 operating hours, the highest temperature of the reaction gas mixture in the fixed catalyst bed is 400 to 450° C. and, during the remaining 8000−X operating hours, is 300 to
Abstract:
A process for purifying removal of acrylic acid, methacrylic acid, N-vinylpyrrolidone or p-xylene crystals from their suspension in mother liquor by means of a wash column with forced transport, whose shell of the process chamber is a metal wall, the wash column additionally being enveloped by a thermal insulation material having a water vapor barrier and a specific heat flow of >0.1 W/m2 and
Abstract translation:一种通过强制运输的洗涤柱从母液中的悬浮液中除去丙烯酸,甲基丙烯酸,N-乙烯基吡咯烷酮或对二甲苯晶体的方法,其处理室的外壳是金属壁,洗涤柱 另外由具有水蒸气阻挡层和通过洗涤塔的金属壁流入处理室的> 0.1W / m 2和<10W / m 2的比热流的隔热材料包围。
Abstract:
A process for removal of a crude acrylic acid from a product gas mixture which comprises glyoxal as a by-product from a heterogeneously catalyzed partial gas phase oxidation of at least one C3 precursor compound, which comprises the absorption of the acrylic acid in a high-boiling absorbent and the rectificative workup of the resulting adsorbate, and in which absorbent present in the bottoms liquid withdrawn from the bottom space of the absorption column is distilled off in a distillation unit and recycled into the absorption, before high boilers which remain are discharged, and in which the glyoxal content of the crude acrylic acid is reduced by restricting the high boiler residence time in the distillation unit.
Abstract:
A process for operating a hydraulic wash column, in which the position of the buildup front in the wash column is positioned by means of the flow rates of control liquor conducted into the wash column and/or by means of the flow rate of the suspension conducted into the wash column, and the flow rate determination is with the aid of the pressure difference which exists in the column between points in the suspension zone disposed upstream of the buildup front and points in the zone projecting from the buildup front up to the end of the crystal bed.
Abstract:
A process for rectificatively separating at least one (meth)acrylic monomer-containing fluid by feeding the fluid into a rectification column containing at least one sieve tray without a runoff segment, wherein an elementary cell is obtained from a number of centers of passages in a sieve tray, and the cell shifts regularly and repeatedly along its edges, the lengths of two shifting vectors being the lengths of the edges of the cell along which the shifting is effected; an arrangement of the centers is such that the positions of an ideal center and a real center are separated by ≦1% of half of the sum of the lengths of the two shifting vectors; and an arrangement of the passages is such that the sum of non-overlapping surface areas of an ideal passage with a real passage and vice versa is ≦1% of the surface area of the ideal passage.
Abstract:
A process for purifying removal of acrylic acid, methacrylic acid, N-vinylpyrrolidone or p-xylene crystals from their suspension in mother liquor by means of a wash column with forced transport, whose shell of the process chamber is a metal wall, the wash column additionally being enveloped by a thermal insulation material having a water vapor barrier and a specific heat flow of >0.1 W/m2 and
Abstract translation:一种通过强制运输的洗涤柱从母液中的悬浮液中除去丙烯酸,甲基丙烯酸,N-乙烯基吡咯烷酮或对二甲苯晶体的方法,其处理室的外壳是金属壁,洗涤柱 另外由具有水蒸气阻挡层和通过洗涤塔的金属壁流入处理室的> 0.1W / m 2和<10W / m 2的比热流的隔热材料包围。
Abstract:
A process for preparing an organic target compound by heterogeneously catalyzed gas phase partial oxidation of an organic precursor compound with molecular oxygen in two oxidation reactor lines operated in parallel and removal of the target compound from the mixture of the product gas streams in a workup line, wherein the catalyst charge of one of the oxidation lines comprises a portion of catalyst over which the heterogeneously catalyzed gas phase partial oxidation has already been carried out for longer than over the portions of catalyst of the catalyst charge of the other oxidation reactor line.
Abstract:
A process for mixing a liquid stored in a vessel, in which gas is sucked in from the gas phase present above the liquid interface with a suction apparatus present in the liquid, and released into it again for the gas-induced mixing of the liquid.