Continuous process for the carbonylation of ethylene

A continuous process for the carbonylation of ethylene in a liquid phase using carbon monoxide in the presence of a co-reactant having a mobile hydrogen atom and a suitable catalyst system comprising the steps of:

• (i) forming a liquid phase comprising the co-reactant having a mobile hydrogen atom and the suitable catalyst system;
• the catalyst system obtainable by combining:
• (a) a metal of Group 8, 9 or 10 or a suitable compound thereof;
• (b) a ligand of general formula (I)
• wherein
• the groups X3 and X4 independently represent univalent radicals of up to 30 atoms or X3 and X4 together form a bivalent radical of up to 40 atoms and X5 has up to 400 atoms;
• Q1 represents phosphorus, arsenic or antimony;
• and
• c) optionally, a source of anions;
• (ii) forming a gaseous phase in contact with the liquid phase by providing at least an ethylene gas input feed stream and a carbon monoxide gas input feed stream wherein the ethylene:CO molar ratio entering the liquid phase from the input feed streams is greater than 2:1;
• and
• (iii) reacting ethylene with carbon monoxide in the presence of the co-reactant, and of the suitable catalyst system in the liquid phase;
• wherein the ethylene:CO gas molar ratio in the gaseous phase is between 20:1 and 1000:1.