摘要:
This invention relates to a process for preparing (meth)acrylic acid, whereby turndown control is utilized to maintain optimal distillation column performance in the dehydration of aqueous (meth)acrylic acid to provide a (meth)acrylic acid solution.
摘要:
A process for producing pure grade acrylic acid having residual aldehyde levels under 10 parts per million by means of distillation of crude acrylic acid in the presence of two selected groups of amines - chosen from the groups consisting of aromatic amino acids, alkanolamines, phenylene diamines and (di)nitrophenylhydrazines - at different points of the continuous process. The treatment provides a selective reduction, for example, of acrolein and furfural, and may be advantagenously conducted in the presence of maleic acid and maleic anhydride impurities.
摘要:
This invention relates to a process for preparing acrylic acid which utilizes an aqueous stream which includes recycled wastewater, at least part of which is stripped of undesirable components in a stripping column prior to being recycled to an acrylic acid absorber.
摘要:
Separations processes and apparati capable of purifying thermally sensitive materials at high capacity. An apparatus having a rectification section (3) and a stripping section (4) with the stripping section (4) having a stripping tray (1020) with 5 to 50 % open area (1000), a pressure drop from 0.02 psi to 0.2 psi and a tray efficiency during operation of the column which is equal to or greater than 20%.
摘要:
This invention relates to a process for preparing acrylic acid which utilizes an aqueous stream which includes recycled wastewater, at least part of which is stripped of undesirable components in a stripping column prior to being recycled to an acrylic acid absorber.
摘要:
The present invention provides a process for the preparation of an α,β-unsaturated C 3 -C 6 carboxylic acid of greater than 98% purity, which combines fractional distillation and melt crystallization procedures. One embodiment of the process of the invention is depicted schematically in Figure 1 wherein 1 represents a dehydrogenation reactor in which a C 3 -C 6 carboxylic acid is dehydrogenated to produce on α,β-unsaturated C 3 -C 6 carboxylic acid, 3 represents a distillation unit and 6 represents a melt crystallizer.
摘要:
Separations processes and apparati capable of purifying thermally sensitive materials at high capacity. An apparatus having a rectification section and a stripping section with the stripping section having a stripping tray with 5 to 50 % open area, a pressure drop from 138 Pa (0,02 psi) to 1379 Pa (0,2 psi) and a tray efficiency during operation of the column which is equal to or greater than 20%.