Regeneration of a heterogeneous catalyst in ethene oligomerization

A process for oligomerizing ethene over a heterogeneous catalyst and for regenerating said catalyst, having the following features:

• a) the oligomerization is effected in an oligomerization operation in which ethene at least partly dissolved in a liquid solvent is contacted with the heterogeneous catalyst;
• b) the regeneration is effected in a regeneration operation in which the catalyst in the absence of ethene, hydrogen and oxygen is purged with a liquid purge medium;
• c) oligomerization operation and regeneration operation alternate over time, such that a time-limited oligomerization operation is followed by a time-limited regeneration operation, and the latter in turn by a time-limited oligomerization operation;
• d) the heterogeneous catalyst is always at the same location, which is the reason why both oligomerization operation and regeneration operation take place at this location;
• e) the location of the catalyst is supplied with thermal energy in order to impose a set temperature thereon, it being entirely possible for the actual temperature at the catalyst to deviate from the set temperature in a time- and space-limited manner;
• f) the set temperature in regeneration operation is higher than the set temperature in oligomerization operation.