Acetaldehyde and acetic acid production

The oxidation of ethylene to acetaldehyde in the gas phase, carried out at rather low temperatures (100—200°C), is very similar to the Wacker liquid phase process. One of the main steps in this process is 

Other noble metals from the palladium group, e.g. Rh and Ru, only catalyze complete oxidation [72,73], 

Cant and Hall [72] report that the reaction rate with Pd on Si02 shows a first-order dependence on oxygen. The rate is strongly suppressed by olefin. 

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In principle, the zeolite catalyst system would offer advantages over the existing homogeneous catalyst, particularly with respect to corrosion due to the absence of HC1 and chlorine-containing by-products. However, acetaldehyde and acetic-acid production via ethylene has recently become less economically attractive compared to methanol carboxylation chemistry. 

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