Propylene, hydroformylation manufacture

Propanol has been manufactured by hydroformylation of ethylene (qv) (see Oxo process) followed by hydrogenation of propionaldehyde or propanal and as a by-product of vapor-phase oxidation of propane (see Hydrocarbon oxidation). Celanese operated the only commercial vapor-phase oxidation faciUty at Bishop, Texas. Since this faciUty was shut down ia 1973 (5,6), hydroformylation or 0x0 technology has been the principal process for commercial manufacture of 1-propanol ia the United States and Europe. Sasol ia South Africa makes 1-propanol by Fischer-Tropsch chemistry (7). Some attempts have been made to hydrate propylene ia an anti-Markovnikoff fashion to produce 1-propanol (8—10). However, these attempts have not been commercially successful. 

Acrolein is manufactured from low-cost propylene, and its hydroformyl-ation to 1,4-butanediol or a precursor of it could provide a more economical route. 

The production of 2-ethylhexanol from propylene by the rhodium catalyzed, low pressure oxo process is accomplished in three chemical steps. The first step of the process (described in section on n-butanol manufacture) converts propylene to normal butyraldehyde by hydroformylation in the presence of a rhodium catalyst. In a second step, the normal aldehyde is aldoled to form 2-ethylhexena1. 2-Ethylhexenal is then hydrogenated to 2-ethylhexanol and refined in the third and final step(see Figure 3). 

An example of a large scale application of this concept is the Ruhrchemie/ Rhone Poulenc process for the hydroformylation of propylene to n-butanal, which employs a water-soluble rhodium(I) complex of trisulfonated triphenyl-phosphine (tppts) as the catalyst [103]. The same complex also functions as the catalyst in the Rhone Poulenc process for the manufacture of the vitamin A intermediate, geranylacetone, via reaction of myrcene with methyl acetoacetate in an aqueous biphasic system (Fig. 1.35) [104]. 

Most acetone is manufactured today in the United States by thermochemical cumene oxidation. It is a co-product with phenol. Acetone is also manufactured by dehydrogenation of 2-propanol, which is made by hydration of propylene. Most 1-butanol is manufactured today by hydrogenation of n-butyraldehyde, which is obtained by the hydroformylation of propylene (0x0 reaction). It is also manufactured by hydrogenation of crotonaldehyde, which is obtained by the... 

Cobalt compounds are useful chemical catalysts for the synthesis of fuels (Fi-scher-Tropsch process), the synthesis of alcohols and aldehydes from olefins, hydrogen and carbon monoxide at elevated temperatures and pressures ( oxo process , hydroformylation ). They are also used in petroleum refining and the oxidation of organic compounds. In the oxo process, cobalt carbonyl, Co2(CO)g, is employed or generated in situ. For the selective production of n-butanol from propylene, hydrogen and CO, an organophosphine-modified cobalt carbonyl complex is used as the catalyst. Cobalt salts are proven oxidation catalysts examples include the production of terephthalic acid by the oxidation of p-xylene, and the manufacture of phenol by the oxidation of toluene. 

Figure 6.6 Manufacture of acetone (1,2 and 3) and butanol (4). The cumene hydroperoxide process (1) and the dehydrogenation of propali-2-ol are more important routes to acetone than the Shell glycerol process (3). The oxo-process for butanol manufacture (4) can be controlled so that butan-l-al is the main product of the hydroformylation of propylene...

Propylene and a-alkenes can be reacted with synthesis gas to give -butyraldehyde and alcohols, respectively. These reactions are called hydroformylation or oxo-reactions. The reaction between butadiene and hydrocyanic acid to obtain adiponitrile is called hydrocyanation. The mechanistic details and the relevance of hydroformylation and hydrocyanation reactions for the manufacture of consumer products are discussed in Chapter 5. 

---