Abstract: Disclosed is a test and test apparatus used to determine whether lactic acid is suitable for polymerization. The test apparatus comprises a) means for the polycondensation of the lactic acid to form a pre-polymer, b) means for depolymerization of the prepolymer to form dilactide, and c) means for carrying out analytical methods to determine at least one of the dilactide yield and/or the racemization, wherein lactic acid which is suitable for polymerization exhibits a dilactide yield of >90% and a racemization of <5%.

Abstract: Disclosed is a method for removing and purifying carboxylic acids from fermentation broths, comprising removing biomass and any solids present from the fermentation broth, finely cleaning up the biomass-free and solids-free fermentation broth by nanofiltration, and removing the carboxylic acid from the finely cleaned, biomass-free, and solids free fermentation broth by adsorption to one or more solid phases having tertiary amino groups.

Abstract: A mixture of cyclic diesters derived from lactic acid and in cases a mixture of a racemate of dilactide may be produced in several different processes. In some instances, the process can thereby start from the corresponding alpha-hydroxycarboxylic acids, the corresponding cyclic diesters or oligomers of the corresponding alpha-hydroxycarboxylic acids.

Abstract: A process for removing, isolating and purifying dicarboxylic acid from fermentation broths, which includes the following steps: 1) removal of the biomass and any solids present from the fermentation broth in two successive stages, 2) removal of the dicarboxylic acid solution from the biomass-free fermentation broth by simulated moving bed (SMB) chromatography, 3) fine purification of the dicarboxylic acid solution, 4) multistage evaporative concentration and crystallization, and 5) separation and drying of the crystals.

Abstract: Disclosed is a method for removing and purifying carboxylic acids from fermentation broths, comprising removing biomass and any solids present from the fermentation broth, finely cleaning up the biomass-free and solids-free fermentation broth by nanofiltration, and removing the carboxylic acid from the finely cleaned, biomass-free, and solids free fermentation broth by adsorption to one or more solid phases having tertiary amino groups.

Abstract: Disclosed is a test and test apparatus used to determine whether lactic acid is suitable for polymerization.

Abstract: A method for producing optically pure propane-1,2-diol, including the method steps: a. hydrogenation of lactides, metal-catalysed heterogenous catalysis being carried out in the presence of hydrogen, a crude product containing propane-1,2-diol being produced, and b. dynamic, kinetic racemate resolution, propane-1,2-diol of an optical purity in the range of ?99% e.e. being produced.

Abstract: A process for removing, isolating and purifying dicarboxylic acid from fermentation broths, which includes the following steps: 1) removal of the biomass and any solids present from the fermentation broth in two successive stages, 2) removal of the dicarboxylic acid solution from the biomass-free fermentation broth by simulated moving bed (SMB) chromatography, 3) fine purification of the dicarboxylic acid solution, 4) multistage evaporative concentration and crystallization, and 5) separation and drying of the crystals.

Abstract: A mixture of cyclic diesters derived from lactic acid and in cases a mixture of a racemate of dilactide may be produced in several different processes. In some instances, the process can thereby start from the corresponding alpha-hydroxycarboxylic acids, the corresponding cyclic diesters or oligomers of the corresponding alpha-hydroxycarboxylic acids.

Abstract: The invention relates to a process for the production and isolation of lactic acid which is produced by way of fermentation of a carbohydrate-bearing feedstock and the addition of ammonia. The lactic acid is released from the ammonium salt of the lactate by adding a mineral acid and the lactic acid isolation takes place by extraction with the aid of an alkylated amine. The extraction is preferably operated at a pH value of 4.0 to 2.0, thereby obtaining a multi-phase mixture which is split up. The phase thus obtained with the lactate salt of amine subsequently undergoes distillation, so that lactic acid is obtained as pure product or the phase with the lactate salt of amine are thermally decomposed, thereby producing an oligolactide that is distillable and thus yields a pure dilactide. The invention also encompasses a device suitable for the performance of the inventive process.

Abstract: A method is provided for determining the end face position of an optical waveguide in a coordinate direction extending in the axial direction of the optical waveguide (1, 2) by means of a video camera via a processor. The method is simplified by means of the following steps: successive intensity values of the video signal are detected and stored by the holding unit (10) which intensity values are taken along a slit in a direction (y) which is perpendicular to the line direction (x) at the area of a coordinate position (x.sub.s); the processor converts the stored intensity values (I.sub.s) into a slit mean (averaged) intensity signal I.sub.m (x) and stores this signal; subsequently further slit signals (I.sub.s) are similarly formed and stored thereby covering an area overlying the end face of the optical waveguide (1, 2); and the position coordinates (x.sub.E1, x.sub.E2) of the end face of the optical waveguides (1, 2) is determined from the variation I.sub.m (x).