HYDROFORMYLATION

The hydroformylation (oxo) reactions offer ways of converting a-olefins to aldehydes and/or alcohols containing an additional carbon atom.

In the process (Fig. 1), the olefin in a liquid state is reacted at 27 to 30 MPa and 150 to 170oC in the presence of a soluble cobalt catalyst. The aldehyde and a lesser amount of the alcohol are formed and flashed off along with steam, and the catalyst is recycled. Conversions of over 97 percent are obtained, and the reaction is strongly exothermic. The carbon monoxide and hydrogen are usually in the form of synthesis gas.

When propylene is used as the hydrocarbon, n- and iso-butyraldehyde are formed. This reaction is most frequently run with the C₃ and C₇ to C₁₂ olefins. When C₇ olefins are used, a series of dimethyl- and ethylhexanols and methyl heptanols are formed that are used as octyl alcohols to make

plasticizers and esters.