Industrial applications of immobilized enzymes—A review

Processes are disclosed for producing lactic acid, esters of lactic acid, acrylic acid, and esters of acrylic acid, primarily from fermentable carbohydrate materials. An overall process for producing esters of acrylic acid comprises: a) fermenting carbohydrate material with a lactic-acid-forming organism in the presence of NH 3 to produce ammonium lactate; b) combining the ammonium lactate with an alcohol; c) combining the ammonium lactate and alcohol with an effective catalyzing amount of gaseous CO 2 to catalytically esterify the ammonium lactate and alcohol into a lactic acid ester containing solution; d) recovering purified lactic acid ester; and e) vaporizing the lactic acid ester and passing it through a solid catalyst bed comprised of an effective catalyzing amount of crystalline hydrated and partially calcined calcium sulfate to catalytically convert lactic acid ester into an acrylic acid ester. Step "d" would be useful in a process for making low-cost, purified lactic acid. Similarly, step "e" would be useful in a process for making low cost, purified acrylic acid.

Production of esters of lactic acid, esters of acrylic acid, lactic acid, and acrylic acid

Preparation of derivatives of β-hydroxycarboxylic acid, including β-hydroxycarboxylic acid esters, α,β-unsaturated carboxylic acid, esters of α,β-unsaturated carboxylic acid, and alkoxy derivatives.

Methods of manufacturing derivatives of .beta.-hydroxycarboxylic acids

The invention relates to a method for producing basic (meth)acrylic acid esters IV by means of transesterification of (meth)acrylic acid alkyl esters I in the presence of a catalyst and by reprocessing the reaction mixture by distillation. An inert gas or gas mixture is guided through the reaction area and/or heat exchangers, under the reaction conditions.

Method for producing (meth)acrylic acid esters

Effects of acid concentration and solvent choice on enzymatic acrylation by Candida antarctica lipase B

Acrylic acid esters such as methyl acrylate or ethyl acrylate are continuously synthesized by esterifying one part by mole of acrylic acid with 2.0 to 3.0 parts by mole of methanol or 1.5 to 2.5 parts by mole of ethanol in the presence of 0.1 to 1.0 part by mole of a water-insoluble and unreactive organic solvent, such as a linear, cyclic or aromatic hydrocarbon compound having a boiling point of 100 DEG to 160 DEG C and sulfuric acid having a concentration of 5 to 50 % by weight in an esterification solution as a catalyst at boiling temperature, for example, 50 DEG to 100 DEG C approximately under atmospheric pressure, while azeotropically boiling water formed in the esterification together with the organic solvent and distilling acrylic acid esters simultaneously, thereby keeping the concentration of sulfuric acid constant in the esterification solution; separating the resulting effluent esterification solution into an organic solvent layer and an aqueous layer by decantation; recycling the aqueous layer containing sulfuric acid to the esterification; separating and recovering the resulting ester and organic solvent contained in the organic solvent layer by steam distillation from the resulting polymers and high boiling materials; and leading the ester and organic solvent to further purification together with the resulting distillate of the esterification.

Process for continuously synthesizing acrylic acid esters

Acrylic acid is purified from an aequeous solution containing acrylic acid and acetic acid, by distilling azeotropically with a dual solvent consisting of the first component capable of forming an azeotropic mixture with acrylic acid, acetic acid and water and the second component having a lower boiling point than that of acetic acid in a distillation column under a pressure of 300 mmHg absolute or less to distill off substantially all of acetic acid, water and the second component together with some portions of the first component at the head of the column and then distilling the resulting bottoms containing acrylic acid and the first component, almost free from acetic acid, in another distillation column under a pressure of 300 mmHg absolute or less, using water as an entrainer for the first component, where acrylic acid is obtained at a high concentration in water from the bottom.

Process for purifying acrylic acid by plural stage distillation and an extraction

Verfahren zum abtrennen von methacrolein und/oder methacrylsaeure aus methacrylsaeurehaltigen gasfoermigen reaktionsgemischen

The nitrogen oxide content of waste gases, esp. from HNO3 mfr. is reduced by burning with a combustible gas contg. heavy hydrocarbons in the presence of a catalyst at 0.5-3.0, pref. 1.5-2.0 pts. wt. steam per pt. wt. of combustible gas, and evacuating burnt gas. The waste gas pref. contains 0.2-0.4 vol.% nitrogen oxides and 2-3 vol.% O2. The hydrocarbon pref. contains >2C and/or is aromatic. The catalyst may be one contg. Pt, Pd or Rh or one based on a metal oxide. The combustion temp. is pref. >650 degrees C. The steam reduces the formation of C particles and increases the life of the catalyst.

Ohrui Tetsuya

Papers

Process for continuously synthesizing acrylic acid esters

Process for purifying acrylic acid by plural stage distillation and an extraction

Verfahren zum abtrennen von methacrolein und/oder methacrylsaeure aus methacrylsaeurehaltigen gasfoermigen reaktionsgemischen

Removal of nitrogen oxides from waste gases - by catalysed combustion in presence of steam

Verfahren zur Herstellung konzentrierter Salpetersaeure