Abstract:
The present disclosure relates to the production of a 2,2,4,4-tetraalkylcyclobutane-1,3-diol. In one embodiment, the present invention relates to the production of a 2,2,4,4-tetraalkylcyclobutane-1,3-diol by hydrogenation of a 2,2,4,4-tetraalkylcyclobutane-1,3-dione in the presence of a ruthenium-promoted cobalt-based catalyst.
Abstract:
The present invention relates to the production of 2,2,4,4-tetramethylcyclobutane-1,3-diol. In one embodiment, the present invention relates to the production of 2,2,4,4-tetramethylcyclobutane-1,3-diol by hydrogenation of 2,2,4,4-tetramethylcyclobutane-1,3-dione in the presence of a cobalt-based catalyst.
Abstract:
A process for recovering a desired organic acid from a solution includes the steps of: providing an aqueous solution including at least one desired organic acid or its acid anion; adjusting the proton concentration in the aqueous solution to a desired level, with the desired proton concentration being selected, at least in part, by the amount of available protons needed to associate with the acid anions of the desired organic acid(s) to be recovered and/or acid anions that are weaker than the desired organic acids; and recovering at least a portion of the at least one desired organic acid from the aqueous phase. The desired proton concentration can be based on the amount of available protons being greater than, less than or substantially equal, to the amount of protons needed to associate with the anion of the desired organic acid(s) and acid anions that are weaker than the desired organic acid(s). Specific examples of suitable organic acids include, but are not limited to, ascorbic, succinic, tartaric, glyconic, gulonic, citric, lactic, hialic, maleic, acetic, formic, gluconic pyruvic, propionic, butyric, itaconic acids and mixtures thereof. One embodiment of the present invention relates to the recovery of 2-keto-L-gulonic acid (KLG) from aqueous solutions such as fermentation baths.
Abstract:
Disclosed is a process wherein a solution of a carboxylic acid in a first solvent and an alcohol are fed to a simulated moving bed reactor (SMBR) containing a solid(s) to produce a first stream comprising a solution of an ester of the carboxylic acid and the alcohol and a second stream comprising the first solvent. The solid(s) present in the SMBR facilitates the esterification reaction and the separation of the first solvent from the carboxylic acid. The process is particularly valuable for the preparation of an alkanol solution of an alkyl 2-keto-L-gulonate ester (AKLG) from an aqueous fermentation broth containing dissolved 2-keto-L-gulonic acid (KLG) by feeding the fermentation broth and an alkanol to a simulated moving bed reactor which contains a solid acidic esterification catalyst to produce a stream comprising an alkanol solution of an ALKG. The alkanol solution of an ALKG may be used directly to convert the ALKG to ascorbic acid (Vitamin C).
Abstract:
The present invention is a process for the preparation of ascorbic acid using a simulated moving bed (SMB) reactor system to accomplish the simultaneous conversion of KLG or a derivative of KLG to ascorbic acid and the separation of reaction products. The SMB reactor contains a solid or mixture of solids effective for catalyzing the reaction of KLG or its derivative and for separating the reactions products by selective adsorption of at least one product. In a general embodiment, this process involves (1) feeding a solution of KLG or a derivative thereof in a first solvent and a desorbent which is miscible with the first solvent, to a simulated moving bed reactor; (2) reacting the KLG or the KLG derivative to form ascorbic acid; and (3) removing from the simulated moving bed reactor (i) a first liquid stream comprising a solution of ascorbic acid in the desorbent and the first solvent (ii) a second liquid stream comprising the first solvent and the desorbent.
Abstract:
Disclosed are catalysts comprising copper chromite, ruthenium and at least one promoter selected from alkali metals, alkaline earth metals, rare earth elements having hydrogenation activity. The combination of copper chromite with ruthenium and the alkali, alkaline earth, and/or rare earth elements enhances catalyst activity more than the addition of either type of promoter alone. The catalysts are useful for the preparation of methanol from carbon monoxide and hydrogen and for the hydrogenation of carbonyl compounds such as, for example, aldehydes, ketones, and esters, to their corresponding alcohols. The catalysts may be used for the preparation of cyclohexanedimethanols from dialkyl cyclohexanedicarboxylates or of ethylene glycol from alkyl glycolates.
Abstract:
The present invention provides methods and an apparatus for the manufacture of an L-ascorbic acid product in high yield by direct conversion of an aqueous solution containing 2-keto-L-gulonic acid by contact with an acid catalyst or under thermal self-catalyzed conditions at a conversion level that maximizes the formation of L-ascorbic acid and minimizes decomposition of the L-ascorbic acid thus formed. The separation process for L-ascorbic acid and KLG is operated in such a way that an efficient separation process allows the majority of the KLG to be recycled for further conversion. The product stream from the separation process is then subjected to a recovery step to obtain crystalline L-ascorbic acid product.
Abstract:
A process for recovering an organic acid or a metal salt thereof includes contacting an alcoholic phase containing one or more organic acid(s) or metal salt(s) thereof with water under conditions effective to provide an aqueous phase containing a portion of the organic acid(s) or metal salt(s) thereof. The aqueous phase does not contain substantial amounts of the alcohol(s). This process can also include recovery of the organic acid(s) or metal salt(s) thereof from the aqueous phase.
Abstract:
The present invention relates to the production of 2,2,4,4-tetramethylcyclobutane-1,3-diol. In one embodiment, the present invention relates to the production of 2,2,4,4-tetramethylcyclobutane-1,3-diol by hydrogenation of 2,2,4,4-tetramethylcyclobutane-1,3-dione in the presence of a cobalt-based catalyst.
Abstract:
The present disclosure relates to the production of a 2,2,4,4-tetraalkylcyclobutane-1,3-diol. In one embodiment, the present invention relates to the production of a 2,2,4,4-tetraalkylcyclobutane-1,3-diol by hydrogenation of a 2,2,4,4-tetraalkylcyclobutane-1,3-dione in the presence of a ruthenium-promoted cobalt-based catalyst.