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.

An acoustic string instrument includes a top plate, a back plate, and a body disposed between the top plate and the back plate. The body has a plurality of first positioning portions. At least one of the top plate or the back plate, or both has a plurality of second positioning portions. The first positioning portions are fixed to the second positioning portions corresponding to the first positioning portions.

An acoustic string instrument includes a top plate, a back plate, and a body disposed between the top plate and the back plate. The body has a plurality of first positioning portions. At least one of the top plate or the back plate, or both has a plurality of second positioning portions. The first positioning portions are fixed to the second positioning portions corresponding to the first positioning portions.

A process for purification of a crude product stream recovered from the production of acrylic acid by an aldolisation reaction is disclosed. The product stream comprises acrylic acid, formaldehyde, water, non-condensable vapours and optionally heavy by-products. The process comprises: providing the crude product stream in the vapour phase to a first separation column operated at a temperature and pressure to form an intermediate overhead stream comprising water, formaldehyde and methanol; and passing said intermediate overhead stream to a formaldehyde separation column operated at a temperature and pressure to enable a stream having a higher formaldehyde concentration than the formaldehyde concentration in the intermediate overhead stream to be formed and recovered from at or near the bottom of the formaldehyde separation column as a formaldehyde enriched stream.

A process for purification of a crude product stream recovered from the production of acrylic acid by an aldolisation reaction is disclosed. The product stream comprises acrylic acid, formaldehyde, water, non-condensable vapours and optionally heavy by-products. The process comprises: providing the crude product stream in the vapour phase to a first separation column operated at a temperature and pressure to form an intermediate overhead stream comprising water, formaldehyde and methanol; and passing said intermediate overhead stream to a formaldehyde separation column operated at a temperature and pressure to enable a stream having a higher formaldehyde concentration than the formaldehyde concentration in the intermediate overhead stream to be formed and recovered from at or near the bottom of the formaldehyde separation column as a formaldehyde enriched stream.

A method of obtaining ketones from a fermentation process may include collecting an off-gas and a fermented broth from a fermenter, transferring the off-gas from the fermenter to a ketone recuperation module and the fermented broth to a fluid separating module, and isolating the ketones from both the off-gas and the fermented broth. The off-gas and the fermented broth may both comprise a ketone

A method of obtaining ketones from a fermentation process may include collecting an off-gas and a fermented broth from a fermenter, transferring the off-gas from the fermenter to a ketone recuperation module and the fermented broth to a fluid separating module, and isolating the ketones from both the off-gas and the fermented broth. The off-gas and the fermented broth may both comprise a ketone

Methods may include obtaining ketones and glycols from a fermentation process, the method including: collecting an off-gas and/or a fermented broth from the fermenter, wherein the off-gas comprises a ketone, and wherein the fermented broth comprises one or more of glycol or ketone; and performing at least one of: transferring the off-gas from the fermenter to a ketone recuperation module; or transferring the fermented broth to a fluid separating module; and isolating one or more of: the ketone from the off-gas; and the glycol from the fermented broth.

Methods may include obtaining ketones and glycols from a fermentation process, the method including: collecting an off-gas and/or a fermented broth from the fermenter, wherein the off-gas comprises a ketone, and wherein the fermented broth comprises one or more of glycol or ketone; and performing at least one of: transferring the off-gas from the fermenter to a ketone recuperation module; or transferring the fermented broth to a fluid separating module; and isolating one or more of: the ketone from the off-gas; and the glycol from the fermented broth.

Method for preparing a -hydroxyketone having 4 to 8 carbon atoms by reacting formaldehyde with a branched or unbranched dialkyl ketone having 3 to 7 carbon atoms in the liquid phase in a reactor in the presence of a basic component at a temperature of 50 to 150 C. and a pressure of 0.2 to 10 MPa abs, in which (a) a trialkylamine having 1 to 4 carbon atoms per alkyl group is used as basic component and the reaction (b) is carried out in the presence of 1 to 25% by weight water, based on the liquid phase, and (c) at a molar ratio of trialkylamine to formaldehyde in the liquid phase of from 1 to 5.