Abstract:
The present invention relates to a method for purifying adipodinitrile (ADN), wherein crude ADN is fed into a rectification device (R1). The rectification device (R1) comprises a first and preferably also a second side draw, wherein the first side draw is located below the feed point of the crude ADN and the optionally present second side draw is located above said feed point. A gaseous stream which contains ADN is drawn off via the first side draw, while undesired by-products such as 1-amino-2-cyanocyclopentene (ACCP), which often arise during ADN production and consequently may be contained in the crude ADN, are drawn off via the optionally present second side draw. The gaseous stream coming from the first side draw from (R1) is fed into a second rectification device (R2). In (R2), ADN is separated from remaining high-boilers and possibly other by-products, with pure ADN being removed at the top from (D2). In the method according to the invention, use is preferably made of crude ADN that stems from the reaction of butadiene with hydrocyanic acid (HCN).
Abstract:
The invention relates to a method for producing catalyst support particles containing zirconium dioxide and optionally silicon oxide, comprising the following steps: (i) a solution containing precursor compounds of zircon dioxide and optionally silicon dioxide is prepared; (ii) the solution(s) is/are converted into an aerosol; (iii) the aerosol is introduced into a pyrolysis zone that is directly or indirectly heated; (iv) pyrolysis is carried out; (v) the catalyst particles that have been formed are separated from the pyrolysis gas.
Abstract:
The invention relates to a method for producing compounds of general formula XPR2(OR1) (Ia), wherein X represents chlorine, bromine or iodine and R1 represents an organic radical, by reacting compounds of general formula X2PR2 (II), wherein X has the above-mentioned meaning and R2 represents an organic radical, with compounds of general formula R1OH (III), wherein R1 has the above-mentioned meaning, to form a mixture IV, wherein a) the secondary reaction is carried out at a temperature of between 50 to 240°C and at a pressure of 0,001 to 0,9 bar, b) from the mixture IV, the compounds (Ia) are separated from the compounds PR2(OR1)2 (Ib) and optionally from the compounds II and c) compounds (Ib) and optionally non-reacted compounds II are guided back to the synthesis step.
Abstract:
The invention relates to a method for producing 3-pentenenitrile, characterised by the following steps: (a) isomerisation of an educt stream containing 2-methyl-3-butenenitrile on at least one dissolved or dispersed isomerisation catalyst to form a stream (1), which contains the isomerisation catalyst(s), 2-methyl-3-butenenitrile, 3-pentenenitrile and (Z)-2-methyl-2-butenenitrile; (b) distillation of the stream (1) to obtain a stream (2) as the overhead product, which contains 2-methyl-3-butenenitrile, 3-pentenenitrile and (Z)-2-methyl-2-butenenitrile and a stream (3) as the bottom product, which contains the isomerisation catalyst(s); (c) distillation of the stream (2) to obtain a stream (4) as the overhead product, which is enriched with (Z)-2-methyl-2-butenenitrile in comparison to stream (2), (in relation to the sum of all pentenenitriles in stream (2)) and a stream (5) as the bottom product, which is enriched with 3-pentenenitrile and 2-methyl-3-butenenitrile in comparison to stream (2), (in relation to the sum of all pentenenitriles in stream (2); (d) distillation of stream (5) to obtain a stream (6) as the bottom product, which contains 3-pentenenitrile and a stream (7) as the head product, which contains 2-methyl-3-butenenitrile.
Abstract:
The invention relates to a method for the production of hydrocyanic acid, comprising the provision of gaseous formamide by evaporating liquid formamide in an evaporator (step i)) and the catalytic dehydration of the gaseous formamide (step ii)), and a device for carrying out the method according to the invention, comprising at least one micro-evaporator and a tubular reactor, and the use of a micro-evaporator for evaporating formamide in a method for the production of hydrocyanic acid from formamide.