Abstract: To obtain a Raney catalyst for fixed bed permitting a continuous use with a high initial activity and to produce a high purity sugar-alcohol at a low cost using the same. For this object, sugar-alcohol is produced by: using the powder type Raney catalyst made by using for the hydrogenation under the hydrogen pressure a lump form Raney catalyst made by (i) the first step for melting nickel and aluminum, (ii) the second step for obtaining quenched lump alloy by quenching droplets of said melted mixture and (iii) the third step for classifying and activating said quenched lump alloy as it is or once it is broken, collecting said lump form Raney catalyst, crushing into powder and reactivating, and hydrogenating sugars under the hydrogen pressure.

Abstract: To obtain a Raney catalyst for fixed bed permitting a continuous use with a high initial activity and to produce a high purity sugar-alcohol at a low cost using the same. For this object, sugar-alcohol is produced by: using the powder type Raney catalyst made by using for the hydrogenation under the hydrogen pressure a lump form Raney catalyst made by (i) the first step for melting nickel and aluminum, (ii) the second step for obtaining quenched lump alloy by quenching droplets of said melted mixture and (iii) the third step for classifying and activating said quenched lump alloy as it is or once it is broken, collecting said lump form Raney catalyst, crushing into powder and reactivating, and hydrogenating sugars under the hydrogen pressure.

Abstract: To obtain a Raney catalyst for fixed bed permitting a continuous use with a high initial activity and to produce a high purity sugar-alcohol at a low cost using the same. For this object, sugar-alcohol is produced by: using the powder type Raney catalyst made by using for the hydrogenation under the hydrogen pressure a lump form Raney catalyst made by (i) the first step for melting nickel and aluminum, (ii) the second step for obtaining quenched lump alloy by quenching droplets of said melted mixture and (iii) the third step for classifying and activating said quenched lump alloy as it is or once it is broken, collecting said lump form Raney catalyst, crushing into powder and reactivating, and hydrogenating sugars under the hydrogen pressure.

Abstract: Provides an economical method for manufacturing high-value added crystalline maltitol and crystalline mixture solid containing this by means of a process wherein a syrup with a maltose content of 40 to 75% by weight in the solid component is subjected to catalytic hydrogenation, the sugar alcohol syrup is then subjected to chromatographic separation to produce a maltitol-containing syrup fraction with a high maltitol content in the solid component, and the maltitol-containing syrup fraction is then subjected to chromatographic separation.

Abstract: To provide an economically advantageous process for manufacturing crystalline maltitol and crystalline mixture solid containing crystalline maltitol. The process of this invention uses the syrup having a maltose purity of 81 to 90% as the starting material. The syrup is hydrogenated under the existence of catalyst, and then subjected to a chromatographic separation by using cation-exchange resin, resulting in an aqueous solution of maltitol having a maltitol purity of 94 to 99.9%. The aqueous solution, is further crystallized in the presence of a seed crystal, subjected to a separation, cooled and kneaded so as to manufacture both crystalline maltitol and crystalline mixture solid containing crystalline maltitol at the same time.

Abstract: An economic hydrogenation process is provided which significantly suppresses palladium catalyzer activity loss, for obtaining very high purity 1,4-CHDA through a simple operation. The process includes bringing the solution containing the hydrogenation reaction product of interest into contact with steam. The resultant products may include resins having excellent weather resistance or physical properties or high purity medical drugs. The process for preparing 1,4-cyclohexandicarboxylic acid is characterized by two consecutive steps. The first step includes the hydrogenation of a solution containing terephthalic acid in the presence of a palladium catalyzer in an acid resistant vessel or in a vessel layered with acid resistant material for preparing 1,4-cyclohexandicarboxylic acid. The second step includes contacting the solution containing 1,4-cyclohexandicarboxylic acid obtained in the first step with the steam, and extracting impurities moved to the steam.

Abstract: A process of preparing industrially trans-1,4-cyclohexanedimethanol of high purity by distilling a mixture of cis- and trans-1,4-cyclohexanedimethanol in the presence of alkali, or by heating a mixture of cis- and trans-1,4-cyclohexanedimethanol in the presence of alkali and then distilling the heated mixture, and a process of preparing powdered trans-1,4-cyclohexanedimethanol by pulverizing the distillate obtained above.

Abstract: This invention relates to a process for readily and efficiently preparing L-rhamnose with the use of a marine alga belonging to the family Monostromaceae, Ulvales.According to the process of the present invention, rhamnan sulfate is extracted from a marine alga belonging to the family Monostromaceae such as Monostroma nitidium Wittrock and the obtained extract is hydrolyzed by adding acid(s) thereto followed by heating or treating thereof with a cation exchange resin followed by heating to thereby give a solution containing free L-rhamnose.Since the solution thus obtained contains a large amount of salts, the removal of these salts is significantly important in the preparation of L-rhamnose. In the present invention, an effective process therefor is combined with a conventional method by using an ion exchange resin to thereby establish an efficient desalting process.

Abstract: A D-glucose solution is added molybdic acid compound thereto and heated at a temperature of 110.degree.-160.degree. C with pH 2.0-4.5 to perform epimerizing reaction of D-glucose, and thereby 30-36%, based on the D-glucose, of D-mannose is formed. To the epimerized mixture thus obtained is further added glucose-isomerase to perform enzymatic isomerizing reaction of D-glucose remaining in the epimerized mixture, thereby 46% based on the remaining D-glucose is converted into D-fructose. The epimerized mixture or enzymatically isomerized mixture is subjected to catalytic hydrogenation under high pressure, and thereby is produced D-mannitol at high yield based on the initial D-glucose.