Provided is a method for producing purified acetic acid with a good hue. A method for producing purified acetic acid, including treating acetic acid having a poor hue with a synthetic adsorbent to obtain acetic acid with an improved hue. The acetic acid to be treated is, for example, acetic acid having an absorbance of 0.01 or greater at a wavelength of 430 nm. The acetic acid to be treated may be acetic acid recovered from an acetic acid-containing solution that is discharged in a cellulose acetate production process. The synthetic adsorbent may have a cation exchange group on a resin surface. The synthetic adsorbent may have a pore structure.

Some variations provide a system for extracting a product from biomass, comprising: a process chamber having an internal volume; one or more mechanical elements configured to controllably and reversibly mechanically seal the process chamber and reduce the internal volume to mechanically compress the biomass; a fluid port in flow communication with the process chamber; and a collection sub-system in flow communication with the fluid port. Other variations provide a method of extracting a product from biomass, the method comprising: introducing biomass into a process chamber; mechanically sealing the process chamber; mechanically compressing the biomass to release a first fluid material; mechanically decompressing the biomass; introducing an extraction solvent into the process chamber; maintaining process-chamber pressure from about 1 bar to about 1000 bar, wherein the extraction solvent extracts a second fluid material; and recovering the second fluid material from the process chamber. High processing throughput is enabled with this invention.

Some variations provide a system for extracting a product from biomass, comprising: a process chamber having an internal volume; one or more mechanical elements configured to controllably and reversibly mechanically seal the process chamber and reduce the internal volume to mechanically compress the biomass; a fluid port in flow communication with the process chamber; and a collection sub-system in flow communication with the fluid port. Other variations provide a method of extracting a product from biomass, the method comprising: introducing biomass into a process chamber; mechanically sealing the process chamber; mechanically compressing the biomass to release a first fluid material; mechanically decompressing the biomass; introducing an extraction solvent into the process chamber; maintaining process-chamber pressure from about 1 bar to about 1000 bar, wherein the extraction solvent extracts a second fluid material; and recovering the second fluid material from the process chamber. High processing throughput is enabled with this invention.

Method for visible-light driven oxidation of aldehydes to carboxylic acid using carbon dioxide (CO.sub.2) as the oxidant in the absence of any catalyst are provided. In the disclosed process, aldehydes, when reacted with CO.sub.2 in an organic solvent, either in a batch reactor or in a continuous flow reactor, under conditions of ambient temperature and pressure, using a readily available household LED lamp, yield corresponding carboxylic acids along with the formation of carbon monoxide (CO) in the effluent gas.

Method for visible-light driven oxidation of aldehydes to carboxylic acid using carbon dioxide (CO.sub.2) as the oxidant in the absence of any catalyst are provided. In the disclosed process, aldehydes, when reacted with CO.sub.2 in an organic solvent, either in a batch reactor or in a continuous flow reactor, under conditions of ambient temperature and pressure, using a readily available household LED lamp, yield corresponding carboxylic acids along with the formation of carbon monoxide (CO) in the effluent gas.

A method for purification of a biphenol tetraacid composition includes contacting the biphenol tetraacid composition with a solvent including a C1-6 alcohol to form a slurry and isolating the purified biphenol tetraacid from the slurry. The biphenol tetraacid composition includes a biphenol tetraacid and a biphenol. A purified biphenol tetraacid composition is also described.

A method for purification of a biphenol tetraacid composition includes contacting the biphenol tetraacid composition with a solvent including a C1-6 alcohol to form a slurry and isolating the purified biphenol tetraacid from the slurry. The biphenol tetraacid composition includes a biphenol tetraacid and a biphenol. A purified biphenol tetraacid composition is also described.

A method for purification of a biphenol tetraacid composition includes contacting the biphenol tetraacid composition with a solvent including a C1-6 alcohol to form a slurry and isolating the purified biphenol tetraacid from the slurry. The biphenol tetraacid composition includes a biphenol tetraacid and a biphenol. A purified biphenol tetraacid composition is also described.

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 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%.