Abstract:
A process for preparing a cyclic diester or a cyclic diamide by reacting a hydroxycarboxylic acid or amide with an acidic BEA (H-beta polymorph A) type zeolite. The process is characterised in that the total amount of acid sites is in the range of from 0.25 to 1.0 mmol/g and the amount of medium acid sites is at least 40% of the total amount of acid sites. The total amount of acid sites and the amount of medium acid sites are determined by NH3-TPD (temperature-programmed desorption of ammonia). Preferably, the process refers to the preparation of lactide from lactic acid. The framework structure of the zeolitic material comprises Si, Al, O, and H.
Abstract:
A process comprising hydrothermally synthesizing a titanium-containing zeolitic material having framework type MWW in the presence of an MWW template compound, obtaining a mother liquor comprising water, a first portion of the MWW template compound and a titanium-containing zeolitic material having framework type MWW comprising a second portion of the MWW template compound, separating the first portion of the MWW template compound from the mother liquor and recycling the first portion of the MWW template compound into a hydrothermal synthesis of a titanium-containing zeolitic material having framework type MWW.
Abstract:
A continuous process for the preparation of propylene oxide, comprising a start-up stage and normal run stage, wherein the normal run stage comprises (i) continuously providing a liquid feed stream comprising propene, hydrogen peroxide, acetonitrile, a formate salt, water and optionally propane, wherein in the liquid feed stream, the molar amount of the formate salt relative to the molar amount of hydrogen peroxide at a given point of time during the normal run stage is a N (Fo/H 2 O 2 ); (ii) continuously passing the liquid feed stream provided in (i) into an epoxidation zone comprising a catalyst comprising a titanium zeolite having framework type MWW, and subjecting the liquid feed stream to epoxidation reaction conditions in the epoxidation zone, obtaining a reaction mixture comprising propylene oxide, acetonitrile, water, the formate salt, optionally propene, and optionally propane; (iii) continuously removing an effluent stream from the epoxidation zone, the effluent stream comprising propylene oxide, acetonitrile, water, at least a portion of the formate salt, optionally propene, and optionally propane; wherein the normal run stage is characterized in an average rate of change of a N (Fo/H 2 O 2 ) of less than 0 h -1 .
Abstract:
A process for preparing a tin-containing zeolitic material having framework type BEA, comprising providing an aqueous synthesis mixture comprising a boron source, a silicon source, and a BEA structure directing agent; subjecting the synthesis mixture provided in to hydrothermal pre-crystallization conditions; adding the tin source to the obtained mixture; subjecting the obtained aqueous synthesis mixture to hydrothermal crystallization conditions, obtaining a tin-containing zeolitic material having framework type BEA comprised in its mother liquor.
Abstract:
The invention is related to a storage vessel (1) comprising a shaped body (3) of a porous solid, wherein the storage vessel (1) comprises a wall (5) with a section (7) comprising at least one inlet (9), wherein the storage vessel (1) has a central axis (11) and the central axis (11) is a longitudinal axis of the storage vessel (1) and/or perpendicular to a cross-sectional area of the at least one inlet (9), wherein the shaped body (3) covers at least 85 % of an inner volume (13) of the storage vessel (1) and the shaped body (3) comprises an opening (19) in an axial direction (17), axial referring to the central axis (11) of the storage vessel (1), wherein the opening (19) extends from a first end (21) of the shaped body (3) to an opposing second end (23) of the shaped body (3) and wherein the storage vessel (1) comprises exactly one shaped body (3), which is formed in one piece. The invention is further related to a shaped body and use of the shaped body.
Abstract:
The present invention relates to a process for the preparation of a zeolitic material having a CHA-type framework structure comprising YO 2 and X 2 O 3 , wherein said process comprises the steps of: (1) providing a mixture comprising one or more sources for YO 2 , one or more sources for X 2 O 3 , one or more tetraalkylammonium cation R 1 R 2 R 3 R 4 N + -containing compounds, and one or more tetraalkylammonium cation R 5 R 6 R 7 R 8 N + -containing compounds as structure directing agent; (2) crystallizing the mixture obtained in step (1) for obtaining a zeolitic material having a CHA-type framework structure; wherein Y is a tetravalent element and X is a trivalent element, wherein R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , and R 7 independently from one another stand for alkyl, and wherein R 8 stands for cycloalkyl, as well as to zeolitic materials which may be obtained according to the inventive process and to their use.
Abstract:
The invention relates to a method for tertiary mineral oil production, in which an aqueous suspension, comprising at least one porous metal-organic framework material,is injected through at least one injection borehole into a mineral oil deposit, and crude oil is withdrawn from the deposit through at least one production borehole. The invention further relates to the use of an aqueous suspension, comprising at least one porous metal-organic framework material. The invention further relates to the use of at least one porous metal-organic framework material or an aqueous suspension for tertiary mineral production.
Abstract:
The present invention relates to a method for at least partly uptaking a spilled liquid comprising at least one liquid hydrocarbon, the method comprising the step of contacting the at least one liquid hydrocarbon with a binder agent comprising at least one porous metal-organic framework material, wherein the at least one metal-organic framework material comprises at least one organic compound coordinated to at least one metal ion, wherein the at least one organic com- pound is based on imidazole, which is unsubstituted or substituted with one or more substituents independently selected from the group consisting of C 1-6 alkyl, phenyl and benzyl. The invention further relates to the use of such a binder agent for at least partly uptaking the liquid.
Abstract:
The present invention relates to a process for the oxygen free conversion of methane to ethylene on zeolite catalysts and catalysts comprising a zeolite, a metal and a further component.
Abstract:
Verfahren zur Herstellung eines passivierten Katalysators, der einen Zeolith und mindestens ein aktives Metall enthält, dadurch gekennzeichnet, dass - der Katalysator in einer Wirbelschicht gehalten wird und - in der Wirbelschicht mit einer Siliciumverbindung passiviert wird.