Catalytic hydrogenations 1, 4 butanediol

Butanediol. 1,4-Butanediol [110-63-4] tetramethylene glycol, 1,4-butylene glycol, was first prepared in 1890 by acid hydrolysis of N,]S3-dinitro-l,4-butanediamine (117). Other early preparations were by reduction of succinaldehyde (118) or succinic esters (119) and by saponification of the diacetate prepared from 1,4-dihalobutanes (120). Catalytic hydrogenation of butynediol, now the principal commercial route, was first described in 1910 (121). Other processes used for commercial manufacture are described in the section on Manufacture. Physical properties of butanediol are Hsted in Table 2. 

Hydrogenation. Gas-phase catalytic hydrogenation of succinic anhydride yields y-butyrolactone [96-48-0] (GBL), tetrahydrofiiran [109-99-9] (THF), 1,4-butanediol (BDO), or a mixture of these products, depending on the experimental conditions. Catalysts mentioned in the Hterature include copper chromites with various additives (72), copper—zinc oxides with promoters (73—75), and mthenium (76). The same products are obtained by hquid-phase hydrogenation catalysts used include Pd with various modifiers on various carriers (77—80), Ru on C (81) or Ru complexes (82,83), Rh on C (79), Cu—Co—Mn oxides (84), Co—Ni—Re oxides (85), Cu—Ti oxides (86), Ca—Mo—Ni on diatomaceous earth (87), and Mo—Ba—Re oxides (88). Chemical reduction of succinic anhydride to GBL or THF can be performed with 2-propanol in the presence of Zr02 catalyst (89,90). 

In the early 1990s, processes were developed for the production of 1,4-butanediol and y-butyrolactone by gas-phase catalytic hydrogenation of maleic anhydride (131—134). Succinic anhydride is obtained as a partial hydrogenation by-product in these processes. It can be recycled to complete the hydrogenation to the desired products, or be separated and purified. This process could in the future become a significant commercial route for succinic anhydride. 

Derivation (1) Catalytic hydrogenation of furan with nickel catalyst. (2) Acid-catalyzed dehydration of 1,4-butanediol. 

There are several feedstocks and production processes for manufacturing 1,4 butanediol. All commercial processes, however, involve catalytic hydrogenation as one of the synthesis steps. 

Davy-McKee has commercialized a process for 1,4 butanediol based on the conversion of maleic anhydride to diethyl maleate. The diethyl maleate is catalytically hydrogenated to 1,4 butanediol and a variety of byproducts. The first plant using this technology was commissioned in 1992 for Shinwha Petrochemical in Ulsan, Korea. 

The second step is the catalytic hydrogenation of diethyl maleate to 1,4 butanediol and by-products. The primary reaction is shown in Eq. (16) ... 

The second step is the catalytic hydrogenation of maleic acid to tetrahydrofuran. Maleic acid is quickly reduced to succinic acid, which, in turn, is reduced to 7-butyrolactone. The 7-butyrolactone is further reduced to either 1,4 butanediol or directly to tetrahydrofuran (THF). The final reaction... 

Butylene glycol n. (1,3-butanediol) CH3CHOHCH2CH2OH. A colorless liquid made by catalytic hydrogenation of aldol... 

Succinic acid is an aliphatic C-4 dicarboxylic acid (see Figure 17.12), which is currently produced at a low volume (22,000 tonnes/year) via the oxidation of 1,4-butanediol (1,4-BDO) or catalytic hydrogenation of maleic acid or fumaric acid. 

Succinic acid is one of the high-volume specialty chemicals. It is produced by the catalytic hydrogenation of petrochemical maleic acid or anhydride. However, due to cost reductions delivered via the production of succinic acid from the bacterial fermentation of carbohydrates, a large-volume commodity market could be realized. Presently, the bacterial strain used for succinic acid manufacturing is Escherichia coli. However, the requirement for lower costs is moving companies toward other microorganisms, such as Coryne-type bacteria and yeast. Succinic acid can be converted to 1,4-butanediol (EDO) and other products. It also serves as a raw material for diverse important chemicals, including polymers, polybutylene terephthalate, and polybutylene succinate. 

Maleic anhydride is also a precursor for 1,4-butanediol through an esterification route followed by hydrogenation. In this process, excess ethyl alcohol esterifies maleic anhydride to monoethyl maleate. In a second step, the monoester catalytically esterifies to the diester. Excess ethanol and water are then removed by distillation. The ethanol-water mixture is distilled to recover ethanol, which is recycled ... 

Hydrogenation Hydroformylation 100-300 edible oils hydrogasification hydrocracking desulfurization catalytic cracking naphtha hydroforming coal liquefaction fatty alcohols 1-6-hexanediol 1-4-butanediol hexamethylenedi amine C4 to Cl5 products... 

Liquid-phase hydrogenation of 1,4 butynediol to cis-1,4-butenediol and 1,4-butanediol has been carried out on nickel catalysts supported on thirteen different supports. Some commercial nickel catalysts were used as references. Furthermore, metal loading and Ni-Cu alloying have also been studied. The results obtained indicates that catalytic activity, selectivity and metal surface area of catalysts are closely correlated to some textural and/or acid-base properties of the corresponding support. Similarly, the influence of Cu as a second metal in catalyst behaviour is also related to the nature of the support. 

As catalytic semihydrogenation of alkynes to Cis-alkenes is not only a very important synthetic operation (ref. 1) but also of industrial interest, it is a challenging task for both synthetic and catalytic chemists. For instance, the importance of the problem is illustrated by numerous recent publications on different aspects of the selective hydrogenation of many compounds related to the propargyl alcohol structure (refs. 2-7). In this respect, 1,4-butenediol, obtained by the liquid-phase semihydrogenation of 1,4-butynediol, is a raw material for insecticides and Vitamin Bg (refs. 2,8,9). Furthermore, the total and selective liquid-phase hydrogenation of this compound is one of the procedure for making butanediol, the top 95 chemical produced in the United States (refs. 10,11), whose major use is in the manufacture of polyesters. 

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