DE696822C - Process for obtaining the proportions of polyhydric alcohols, in particular di- and polyglycerols, contained in the glycerol pitch - Google Patents

Description

Process for the extraction of the proportions contained in the glycerine pitch polyhydric alcohols, especially di- and polyglycerols. It is known that one during distillation of the crude glycerol obtained by the customary technical processes A tough, sticky, black-brown mass is obtained as residue, the glycerol pitch. This residue, which contains only a small amount of free glycerine, essentially consists from di- and polyglycerols and ash components formed during the distillation process of raw glycerine and also from metal soaps, iron oxide hydrates and taring products.

It is also known that the polyvalent ones contained in the glycerol pitch Alcohols, especially di- and polyglycerols, by treating the glycerol pitch with water, neutralization of the solutions obtained with acids or acidic salts, Precipitation of the contaminating salts and evaporation to gain. Such products however, tend to have such a high ash content that they are considered to be technical Usability are out of the question.

It has now been found that almost ashless polyhydric alcohols, especially di- and polyglycerols, can be obtained from glycerol pitch if you use the Aqueous glycerol pitch solutions neutralized in a known manner with acids or acid salts with large-surface or absorbent materials, e.g. B. sawdust, bleaching earth or liieselgur, added, the resulting masses optionally dried and with suitable organic solvents, e.g. B. acetone, ethyl acetate or low-boiling Alcohols, extracted and the Solvent evaporates. Can discoloration of the products can be achieved by treating them with known decolorizing agents or by oxidative bleaching with hydrogen peroxide, chlorinated lime or potassium permanganate connect.

The di- and polyglycerols obtained in this way are suitable as finishing agents in the textile industry for the production of synthetic resins and cosmetic preparations as well as for further processing on technically valuable esters.

It is known ztvar to thicken glycerine from distillery liquor by thickening same with cellulose; Drying the masses obtained and extracting them to be obtained with organic solvents.

However, on the basis of what we knew, it could not be foreseen that see an analogous process for the production of technically valuable di- and polyglycerols from glycerine pitch, which until recently was regarded as technically worthless would suit.

Example 500 parts by weight of glycerol pitch are used in the same amount Dissolved water, whereupon, after the solution has boiled, it is filtered; d. The filtrate is then neutralized with 40 cc of 20% sulfuric acid. The neutral solution is mixed with 212 parts by weight of sawdust and the resulting mass at 18 ° dried to constant weight. It is then exhaustively extracted with acetone; whereupon this is distilled off first under normal and finally under reduced pressure will. The residue that remains is made up of some glycerine and predominantly di- and polyglycerols existing viscous light yellow liquid containing 0.98% sulfated ash.

Claims (1)

PATLNTANSPRUCII: Process for the extraction of the contained in glycerine pitch Shares of polyhydric alcohols, especially di- and polyglycerols, through Treatment of the glycerine pitch with water, neutralization of the solutions obtained with acids or acid salts and separation of the polyhydric alcohols, thereby marked; that you can get from the neutralized solutions by adding large surface areas or absorbent substances and optionally removal of the water obtained masses extracted with suitable organic solvents and evaporated the solvents.