Process for the production of acetaldehyde and ethanol

In a process for the production of acetaldehyde and ethanol by reacting methanol with carbon monoxide and hydrogen at a temperature of between 100.degree.-250.degree. C. and under elevated pressure in the presence of a catalyst containing cobalt, an iodine and/or bromine compound and a phosphorus-containing ligand,

• the improvement which comprises reacting methanol with carbon monoxide and hydrogen under a pressure of from 200 to 450 bar in the presence of a catalyst containing cobalt, a halogen compound selected from the group consisting of hydrogen iodide and hydrogen bromide, using 0.009 to 0.0005 mole of hydrogen iodide and/or hydrogen bromide per mole of methanol used, and a biphosphine of the formula ##STR2## wherein R.sub.1 to R.sub.4 are each alkyl of 1-12 carbon atoms, alkoxy of 1-12 carbon atoms, alkylamine of 1-12 carbon atoms, aryl, aroxyl or arylamine each of 6 carbon atoms unsubstituted or substituted by alkyl of 1 to 6 carbon atoms, monocyclic rings of 5 to 12 carbon atoms or bicyclic rings of 10 to 20 carbon atoms, and
• n is the integer from 1 to 6.