Provided is a method capable of industrially efficiently producing acetic acid yielding a good potassium permanganate test result, without costing much. In the acetic acid production method, (1) by-produced acetaldehyde is industrially advantageously removed from a process stream, and (2) a crotonaldehyde concentration in an acetic acid stream from a light ends column is controlled to a specific level or lower, and/or a reflux ratio at a second distillation column is controlled to 0.1 or more. In addition, (3) the method includes the step of subjecting at least one of an aqueous phase and an organic phase of a light ends column overhead condensate to distillation in a crotonaldehyde-removing column; the light ends column is operated at a reflux ratio of 2 or more (when the aqueous phase is refluxed); and the crotonaldehyde-removing column is operated so as to meet a specific condition(s).

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%.

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.

A carbonylation process for producing acetic acid including: (a) carbonylating methanol or its reactive derivatives in the presence of a Group VIII metal catalyst and methyl iodide promoter to produce a liquid reaction mixture including acetic acid, water, methyl acetate and methyl iodide; (b) feeding the liquid reaction mixture to a flash vessel; (c) flashing the reaction mixture to produce a crude product vapor stream.

An object of the present invention is to provide a method in which, when a steam ejector is used as a decompression apparatus for a vacuum distillation process for an easily polymerizable compound, the steam ejector is prevented from being occluded due to polymerization of the easily polymerizable compound. Another object of the present invention is to provide a method for manufacturing an acrylic acid that is an easily polymerizable compound, using the above-described method. The above object is accomplished by a method for manufacturing an acrylic acid, which comprises a step of executing vacuum distillation, using a steam ejector, on an acrylic acid resulting from gas-phase catalytic oxidation using propane, propylene, or acrolein as a material, wherein the vacuum distillation step includes a step of heating an outer surface of the steam ejector.

An object of the present invention is to provide a method in which, when a steam ejector is used as a decompression apparatus for a vacuum distillation process for an easily polymerizable compound, the steam ejector is prevented from being occluded due to polymerization of the easily polymerizable compound. Another object of the present invention is to provide a method for manufacturing an acrylic acid that is an easily polymerizable compound, using the above-described method. The above object is accomplished by a method for manufacturing an acrylic acid, which comprises a step of executing vacuum distillation, using a steam ejector, on an acrylic acid resulting from gas-phase catalytic oxidation using propane, propylene, or acrolein as a material, wherein the vacuum distillation step includes a step of heating an outer surface of the steam ejector.

Processes for manufacturing purified aromatic carboxylic acids include: generating high-pressure steam from boiler feed water supplied to a boiler, the boiler producing a flue gas; removing a portion of the flue gas from the boiler and pre-heating the boiler feed water with removed flue gas and/or pre heating at least a portion of the boiler feed water prior to its introduction into the boiler with a first portion of the high-pressure steam; heating a crude aromatic carboxylic acid in a heating zone using the high-pressure steam, whereby the high pressure steam is condensed in the heating zone to form a high-pressure condensate; and purifying the crude aromatic carboxylic acid to form a purified aromatic carboxylic acid; wherein the boiler feed water comprises at least a portion of the high-pressure condensate.

Provided is a method capable of industrially efficiently producing acetic acid yielding a good potassium permanganate test result, without costing much. In the acetic acid production method, (1) by-produced acetaldehyde is industrially advantageously removed from a process stream, and (2) a crotonaldehyde concentration in an acetic acid stream from a light ends column is controlled to a specific level or lower, and/or a reflux ratio at a second distillation column is controlled to 0.1 or more. In addition, (3) the method includes the step of subjecting at least one of an aqueous phase and an organic phase of a light ends column overhead condensate to distillation in a crotonaldehyde-removing column; the light ends column is operated at a reflux ratio of 2 or more (when the aqueous phase is refluxed); and the crotonaldehyde-removing column is operated so as to meet a specific condition(s).

A plant for concentrating a tartaric acid solution includes a first and a second evaporation unit arranged in series, a pump for feeding a diluted tartaric acid solution into the first evaporation unit, a barometric condenser placed downstream of the second evaporation unit, and a system for feeding a first low-temperature vapor into the first evaporation unit. A process for concentrating tartaric acid includes providing a plant according to the above description, performing a first concentration, by evaporation, of the diluted tartaric acid solution, inside the first evaporation unit, and performing a second concentration, by evaporation, of the partially concentrated tartaric acid solution from the first evaporation unit, inside the second evaporation unit. The plant and process for concentrating tartaric acid have the advantages of ensuring low energy consumption, allowing concentration of solutions tending to crystallization, and allowing the continuous measurement of the tartaric acid concentration to be concentrated.

Methods and systems for producing acetic acid, including glacial acetic acid. A first stream of a reactor fluid that includes methyl acetate, water, and a first amount of carbon monoxide may be forwarded from a reactor to a reactor cooler to form a cooled reactor fluid. The cooled reactor fluid may have a concentration of methyl acetate that is lower than the concentration of methyl acetate in the reactor fluid.