HU208662B - Process for producing dihydroxyacetone from industrial residue containing glycerine - Google Patents

Abstract

Contaminated, glycerine contg. leaves are mixed with inorganic salts, e.g. magnesium sulphate, and are oxidised with hydrogen peroxide and clarified at RT with active carbon. Final fermentation is obtd. with A. suboxidane, G. melanogenus or A. xylinum(Dwg.0/0)

Description

The present invention relates to a process for the production of dihydroxyacetone from glycerol-containing wastes in the pharmaceutical, vegetable oil and cosmetic industries.

Dihydroxyacetone is known to be a widely used drug and cosmetic agent. It is of particular use in the manufacture of sun-tanning lotions.

During the chemical oxidation of glycerol, an equilibrium mixture of glycerol aldehyde and dihydroxyacetone, the so-called. Glycerose is formed, so in modern technology dihydroxyacetone is made from glycerol exclusively by fermentation. For example, JP 7344485 uses glycerol, corn jam, calcium carbonate, ammonium fumarate for fermentation. The object of the present invention was to provide a process for the direct fermentation of glycerol-containing juices from the chemical, cosmetic and pharmaceutical and vegetable oil industries directly without fermentation, without isolation of pure glycerol to dihydroxyacetone.

The present invention is based on the discovery that glycerol-containing aqueous solutions from the above-mentioned industries can be decolorized and purified with hydrogen peroxide after mechanical filtration in the presence of an inorganic salt, preferably magnesium sulfate as a catalyst. The resulting aqueous glycerol solutions at a concentration of 0.1 to 50, preferably 10 to 30% by weight, can be fermented directly after clarification with activated carbon. Initially dark brown glycerol solutions turn yellow after oxidation with hydrogen peroxide and turn into a colorless liquid after clarification with activated carbon.

In the case of high-salt, glycerol-containing juices from fat decomposition, it is preferable to first anion then cation exchange in a dynamic system or to leave such solutions in a static system in a stirred bed column for several hours.

The magnesium sulfate content has no inhibitory effect on the enzymes and can also be removed smoothly during the ion exchange process.

Acetobacter suboxidant, Glucobacter melanogenus and Acetobacter xylinum strains were used for fermentation.

By using the process of the present invention, it is possible to convert the glycerol content of the glycerol-free juices, which have been unprocessed due to their low content of glycerol and high impurities, to a valuable product, without separate preparation, by fermentation.

By the process of the present invention, the glycerol content of glycerol waste from vegetable oil and chemical industry can be converted to 90-100% of the glycerol content in dihydroxyacetone.

Experimental part

In our experiments we used cosmetic waste containing 80-120 g / l glycerol, which was a liquid of a very brown color and with an extremely unpleasant odor. In the course of the work, a well-known type 6 liter aeration agitator was used. Water charcoal-activated charcoal was used as activated carbon, and strains of A. suboxidant, G. melanogenus and A. xylinum were used as bacterial strains.

Example 1 A liter of glycerol juice was oxidized with 1.0 g of magnesium sulfate, 7H ₂ O, 30% w / w hydrogen peroxide, with stirring until yellow. This mixture was then clarified with 5 g of Norit quality charcoal, filtered at room temperature and post-sterilized for 30 minutes at 120 DEG C. under 1 x ^{10 5} Pa.

The composition of the medium:

100 g / l glycerol g / l yeast extract g / l potassium dihydrogen phosphate buffer g / l calcium carbonate

0.5 g / L magnesium sulfate 7 H ₂ O

The sterile medium was inoculated with A. suboxidant and then fermented at 420 rpm at 30 ° C and aerated at a partial pressure of 0.05 x ^{10 5} Pa _{2 for} 4 days. Octadecanol was used as an antifoam agent. The conversion to glycerol content is 98% and the yield of dihydroxyacetone is 88%.

Example 2

All were performed as in Example 1, but the medium was inoculated with G. melanogenus strain. Yield: 87%.

Example 3

All were carried out as in Example 1, but the medium was dissolved in A. xylinum strain. Yield 84%.

Example 4

1-3. but using excess hydrogen peroxide in the fermentor which resulted in an 8-10% increase in activity. Similarly good results were obtained with increased aeration and p-benzoquinone additive.

Dihydroxyacetone was precipitated with an equimolar amount of sodium bisulfite.

Claims (1)

A process for the preparation of dihydroxyacetone from 0.1% to 50% by weight of glycerol-containing waste by fermentation with A. sylinum, G. melanogenus or A. suboxidant strains, characterized in that the glycerol-containing broths contain 1-10 ppm of inorganic salts before fermentation, preferably oxidized with 330% hydrogen peroxide in the presence of magnesium sulfate until a yellow color appears in the solution and then clarified with 0.01-0.5% by weight, preferably 0.1-0.2% by weight of activated carbon.