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liquid-liquid extraction step a washing (W) column, a back-washing (BW) column and at least one injection (F2) of a cut withdrawn in step b), located in the top half of the back-washing column, (b) a distillation of an aldehyde and ethanol separation producing at least one aldehyde-rich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.

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liquid-liquid extraction step a washing (W) column, a back-washing (BW) column and at least one injection (F2) of a cut withdrawn in step b), located in the top half of the back-washing column, (b) a distillation of an aldehyde and ethanol separation producing at least one aldehyde-rich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 method for producing dimethylolbutanal, the method including: (A) distilling a raw material comprising dimethylolbutanal (DMB) in a distillation column; (B) separating the distilled raw material in the distillation column into a low boiling point component, dimethylolbutanal, and a high boiling point component; and (C) refluxing a portion or all of the high boiling point component to the distillation column by heating the portion or all of the high boiling point component, in which the dimethylolbutanal is separated from a side cut of the distillation column.

A method for producing dimethylolbutanal, the method including: (A) distilling a raw material comprising dimethylolbutanal (DMB) in a distillation column; (B) separating the distilled raw material in the distillation column into a low boiling point component, dimethylolbutanal, and a high boiling point component; and (C) refluxing a portion or all of the high boiling point component to the distillation column by heating the portion or all of the high boiling point component, in which the dimethylolbutanal is separated from a side cut of the distillation column.

Methods and systems for recovering materials from streams from processes for the co-production of propylene oxide and styrene monomer. The processes may permit the recovery of products, such a mono-propylene glycol, or the recycling of products, such as -methyl benzyl alcohol.

Methods and systems for recovering materials from streams from processes for the co-production of propylene oxide and styrene monomer. The processes may permit the recovery of products, such a mono-propylene glycol, or the recycling of products, such as -methyl benzyl alcohol.

A process for producing methacrylic acid or a methacrylic acid ester including, producing acrolein, reacting the produced acrolein with hydrogen to produce propanal, reacting the propanal with formaldehyde to produce methacrolein, and oxidizing the methacrolein in the presence of an oxygen containing gas and optionally an alcohol, to methacrylic acid or a methacrylic acid ester.

A process for producing methacrylic acid or a methacrylic acid ester including, producing acrolein, reacting the produced acrolein with hydrogen to produce propanal, reacting the propanal with formaldehyde to produce methacrolein, and oxidizing the methacrolein in the presence of an oxygen containing gas and optionally an alcohol, to methacrylic acid or a methacrylic acid ester.

A method for separating a mixture of materials A and B by extractive distillation, using an extraction medium having a higher affinity to B than to A, collecting a liquid fraction on a collecting tray and heated and partially evaporated in a first indirect heat exchanger, collecting the resultant vapor is released into the column and a non-evaporated proportion of the liquid fraction in the sump of the column, and a series of heating, separation and cooling where partially cooled extraction medium fraction is used as heating medium for a heat exchanger.

A method for separating a mixture of materials A and B by extractive distillation, using an extraction medium having a higher affinity to B than to A, collecting a liquid fraction on a collecting tray and heated and partially evaporated in a first indirect heat exchanger, collecting the resultant vapor is released into the column and a non-evaporated proportion of the liquid fraction in the sump of the column, and a series of heating, separation and cooling where partially cooled extraction medium fraction is used as heating medium for a heat exchanger.