Liquid-liquid extraction and distillation of a liquid feedstock of at least ethanol, water, acetaldehyde and at least one hydrocarbon-based impurity with a boiling point of between 20° C. and 100° C. at atmospheric pressure, or which generates, with at least one of the compounds of the liquid feedstock and/or with the organic extraction solvent and/or with the aqueous back-washing solvent, an azeotrope and a partition coefficient of between 0.1 and 5 at any point in a back-washing (BW) column of the extraction section, by (a) a liquid-liquid extraction step a washing (W) column, a back-washing (BW) column and at least one injection (F2) of a cut withdrawn in step b), located in the top half of the back-washing column, (b) distillation of an aldehyde and ethanol separation producing at least one aldehyde-rich effluent, one ethanol-rich effluent and one water-rich effluent.

Process for isolating pure 1,3-butadiene from a crude C.sub.4 fraction by extractive distillation using a selective solvent, wherein (a) the crude C.sub.4 fraction is introduced into a predistillation column, a first low boiler fraction comprising C.sub.3-hydrocarbons is taken off as overhead stream, a gaseous C.sub.4 fraction is taken off as side stream and a first high boiler fraction is taken off as bottom stream, (b) the gaseous C.sub.4 fraction is brought into contact with a selective solvent in at least one extraction column, giving an overhead fraction comprising butanes and butenes and a bottom fraction comprising 1,3-butadiene and selective solvent, (c) crude 1,3-butadiene is desorbed from the bottom fraction in at least one stripping column, with a stripped selective solvent being obtained and the stripped selective solvent being recirculated to the extraction column, and (d) at least part of the crude 1-3-butadiene is fed to a pure distillation column and a second high boiler fraction is separated off and a gaseous purge stream is taken off. Gaseous purge streams from the columns which are necessary in order to keep the concentration of molecular oxygen below a predetermined concentration limit are consolidated with output streams which are in any case provided for discharging other components in the process. The recirculation of the second high boiler fraction to a lower section of the predistillation column creates a further degree of freedom in operation of the pure distillation column.

The present disclosure relates to a composition that includes a lignin-derived mixture that includes at least one of a dimer, a trimer, and/or a tetramer, where the composition is characterized by a thermal stability up to a maximum temperature between about 260° C. and about 300° C.

The present disclosure is related to the continuous liquid-liquid chromatographic separation of chemical species using multiple liquid phases and related systems and articles.

Disclosed are a pretreatment method and system for a fraction oil for the production of alkylbenzene, the method comprising: adding a fraction oil, a weak base solution and an inorganic salt solution into a reactor, and leaving same to stand and layering same after the reaction is complete; adding water and an inorganic salt solution into an oil phase for washing with water; extracting same with a polar solvent having a high boiling point, and then adsorbing same with an adsorbent to separate oxygen-containing compounds in the neutral fraction oil; sending the extraction agent containing the oxygen-containing compounds to an extraction agent recovery unit; and then sending the neutral fraction oil to an alkylation reactor for a reaction.

Liquid-liquid extraction and distillation of a liquid feedstock of at least ethanol, water, acetaldehyde and at least one hydrocarbon-based impurity with a boiling point of between 20 C. and 100 C. at atmospheric pressure, or which generates, with at least one of the compounds of the liquid feedstock and/or with the organic extraction solvent and/or with the aqueous back-washing solvent, an azeotrope and a partition coefficient of between 0.1 and 5 at any point in a back-washing (BW) column of the extraction section, by (a) a liquid-liquid extraction step a washing (W) column, a back-washing (BW) column and at least one injection (F2) of a cut withdrawn in step b), located in the top half of the back-washing column, (b) a distillation of an aldehyde and ethanol separation producing at least one aldehyde-rich effluent, one ethanol-rich effluent and one water-rich effluent.

A new system in which a forward extraction part, a scrubbing part, and a backward extraction part operate together and synchronously to produce specific substances by extraction and separation in a liquid-liquid system. The aqueous phase is circulated independently only in the forward extraction part one or more times, and the organic phase is circulated from the forward extraction part through the scrubbing part and the backward extraction part to the forward extraction part again in synchronization with the liquid circulation of the aqueous phase.

A method for purification of a styrene-containing feedstock includes steps of introducing the styrene-containing feedstock into the middle of an extractive distillation column, and a solvent for the extractive distillation into the upper part of the column; discharging a raffinate oil from the top of the column, and a rich solvent rich in styrene from the bottom of the column. The rich solvent is then introduced into the middle of the solvent recovery column for vacuum distillation to obtain a crude styrene from the top of the solvent recovery column, and a lean solvent is discharged from the bottom of the solvent recovery column and recycled to the upper part of the extractive distillation column. A portion of the rich solvent is sent to a solvent purification zone for a liquid-liquid extraction using water to obtain a mixture of a styrene polymer and styrene.

Process for isolating pure 1,3-butadiene from a crude C.sub.4 fraction by extractive distillation using a selective solvent, wherein (a) the crude C.sub.4 fraction is introduced into a predistillation column, a first low boiler fraction comprising C.sub.3-hydrocarbons is taken off as overhead stream, a gaseous C.sub.4 fraction is taken off as side stream and a first high boiler fraction is taken off as bottom stream, (b) the gaseous C.sub.4 fraction is brought into contact with a selective solvent in at least one extraction column, giving an overhead fraction comprising butanes and butenes and a bottom fraction comprising 1,3-butadiene and selective solvent, (c) crude 1,3-butadiene is desorbed from the bottom fraction in at least one stripping column, with a stripped selective solvent being obtained and the stripped selective solvent being recirculated to the extraction column, and (d) at least part of the crude 1-3-butadiene is fed to a pure distillation column and a second high boiler fraction is separated off and a gaseous purge stream is taken off. Gaseous purge streams from the columns which are necessary in order to keep the concentration of molecular oxygen below a predetermined concentration limit are consolidated with output streams which are in any case provided for discharging other components in the process. The recirculation of the second high boiler fraction to a lower section of the predistillation column creates a further degree of freedom in operation of the pure distillation column.

A process for producing products from biomass comprising fermenting biomass to produce a first product stream comprising carboxylic acid salts; acidifying at least one of the first product stream and a second product stream to produce a third product stream comprising acids; extracting such acids from the third product stream with a solvent; separating the extracting solvent from the acids to produce the separated extracting solvent and a fourth product stream comprising acids; and processing the fourth product stream to produce a fifth product stream.