The invention relates to a process for the continuous production of acrylic acid, in the absence of organic solvent and in the absence of chemical treatment of the aldehydes, and without employing a dividing-wall column, from a gaseous reaction mixture comprising acrylic acid obtained by gas-phase oxidation of a precursor of acrylic acid.

The invention relates to a process for the continuous production of acrylic acid, in the absence of organic solvent and in the absence of chemical treatment of the aldehydes, and without employing a dividing-wall column, from a gaseous reaction mixture comprising acrylic acid obtained by gas-phase oxidation of a precursor of acrylic acid.

The present invention relates to methods of extracting cannabinoid acids from cannabis plant material by combining the plant material with an aqueous solution having a high pH to solubilize cannabinoid acid anions, followed by precipitation of the cannabinoid acids at low pH and filtration. The method provides yields of up to 97%, while high pH purification of ethanol extracted oils yielded purities up to 86%.

The present invention relates to a process for recovering acrylic acid which is obtained by catalytic gas phase oxidation of propene, wherein, in an absorption stage (K2), the acrylic acid is absorbed from the reaction mixture (1) from the gas phase oxidation with a first solvent (3) and is drawn off for distillative purification, and a gas mixture from the absorption stage (K2) is passed onward to a condensation stage, wherein, in the condensation stage, the gas mixture is condensed, and a condensed phase of the gas mixture is drawn off as acid water (4) and is subjected to a phase separation operation in a phase separation vessel (B1), comprising the steps of a) feeding the aqueous phase (4*) of the acid water (4) drawn off from the condensation stage that has been obtained in the phase separation vessel (B1) to an extraction stage (K7) in which acrylic acid present in the acid water (4) is extracted with a second solvent (5), b) feeding the acrylic acid-comprising extract (6) to a stripping column (K8) in which the acrylic acid is removed from the second solvent (5) with cycle gas (8), wherein the second solvent (5) removed is fed back again after the acrylic acid has been stripped out in the extraction stage (K7), c) feeding the acrylic acid-laden cycle gas (9) to a stripping cycle gas scrubber (K5) in which the acrylic acid is removed from the cycle gas with the first solvent stream (10) fed to the stripping gas scrubber (K5) and transferred into the first solvent (3), and d) feeding a first portion of the acrylic acid-laden first solvent (3) back to the absorption stage (K2).

The present invention further relates to a corresponding plant for recovery of acrylic acid.

The present invention relates to a process for recovering acrylic acid which is obtained by catalytic gas phase oxidation of propene, wherein, in an absorption stage (K2), the acrylic acid is absorbed from the reaction mixture (1) from the gas phase oxidation with a first solvent (3) and is drawn off for distillative purification, and a gas mixture from the absorption stage (K2) is passed onward to a condensation stage, wherein, in the condensation stage, the gas mixture is condensed, and a condensed phase of the gas mixture is drawn off as acid water (4) and is subjected to a phase separation operation in a phase separation vessel (B1), comprising the steps of a) feeding the aqueous phase (4*) of the acid water (4) drawn off from the condensation stage that has been obtained in the phase separation vessel (B1) to an extraction stage (K7) in which acrylic acid present in the acid water (4) is extracted with a second solvent (5), b) feeding the acrylic acid-comprising extract (6) to a stripping column (K8) in which the acrylic acid is removed from the second solvent (5) with cycle gas (8), wherein the second solvent (5) removed is fed back again after the acrylic acid has been stripped out in the extraction stage (K7), c) feeding the acrylic acid-laden cycle gas (9) to a stripping cycle gas scrubber (K5) in which the acrylic acid is removed from the cycle gas with the first solvent stream (10) fed to the stripping gas scrubber (K5) and transferred into the first solvent (3), and d) feeding a first portion of the acrylic acid-laden first solvent (3) back to the absorption stage (K2).

The present invention further relates to a corresponding plant for recovery of acrylic acid.

Provided is a method for producing purified acetic acid from a mixed solution containing acetic acid, an organic solvent, and water in an energy-efficient manner. The method, which is for producing purified acetic acid from a mixed solution containing acetic acid, an organic solvent, and water, includes: a distillation step in which the mixed solution is distilled and separated into a purified liquid rich in acetic acid and a separated liquid rich in an organic solvent; and a membrane separation step in which the water is separated from the purified liquid by a separation membrane. The purified liquid has a water concentration of 4 wt.% or less.

Provided is a method for producing purified acetic acid from a mixed solution containing acetic acid, an organic solvent, and water in an energy-efficient manner. The method, which is for producing purified acetic acid from a mixed solution containing acetic acid, an organic solvent, and water, includes: a distillation step in which the mixed solution is distilled and separated into a purified liquid rich in acetic acid and a separated liquid rich in an organic solvent; and a membrane separation step in which the water is separated from the purified liquid by a separation membrane. The purified liquid has a water concentration of 4 wt.% or less.

Provided is a method for producing purified acetic acid from a mixed solution containing acetic acid, an organic solvent, and water in an energy-efficient manner. The method, which is for producing purified acetic acid from a mixed solution containing acetic acid, an organic solvent, and water, includes: a distillation step in which the mixed solution is distilled and separated into a purified liquid rich in acetic acid and a separated liquid rich in an organic solvent; and a membrane separation step in which the water is separated from the purified liquid by a separation membrane. The purified liquid has a water concentration of 4 wt.% or less.

This process relates to controlling acetal formation when removing acetaldehyde from a methanol carbonylation process using an extractive distillation column. Acetals may be formed by a secondary reaction of acetaldehyde and an alcohol (such as methanol). The process controls the formations to prevent excess acetal accumulation in the lower stream from the extractive distillation column.

Provided herein is a process for the production and purification of acetic acid. In particular, this disclosure relates to improved processes for producing and purifying acetic acid by the carbonylation of methanol in the presence of a Group VIII metal carbonylation catalyst. The acetic acid production and purification process described herein controls the formation and mass composition of acetal impurities, such as 1,1-dimethoxyethane.