Process for the continuous manufacture of n-butyraldehyde by selective hydrogenation of crotonaldehyde in the liquid phase in the presence of a palladium-aluminum oxide catalyst

摘要

For the continuous manufacture of n-butyraldehyde by selective hydrogenation of crotonaldehyde, the hydrogenation is conducted in the liquid phase in the presence of a palladium-aluminum oxide supported catalyst containing the palladium in the outer layer of the supporting grain of a thickness of 0.05-0.2 mm. The palladium content of this catalyst is 0.1-0.6% by weight. The aluminum oxide support, with a specific pore volume of 0.4-0.6 cm.sup.3 /g, has 40-60% of its pores of a diameter of 0.5 nm and an internal surface area of 130-160 m.sup.2 /g. The hydrogenation is conducted under absolute pressures of 5-50 bar and at temperatures of 20-100 C. The resultant n- butyraldehyde is of a high purity without interfering by-products.