Plant for carrying out the process according to at least of one of the foregoing claims, characterised in that this plant consists of a loop reactor (SR), in whose circulation line (L) an fixed bed catalyst device (1) that can be shut off, an expansion vessel (2), a jet pump (3) and a circulation pump (4) are integrated, whereby in the flow direction the expansion vessel (2) is positioned in front of the circulation pump (4), the fixed bed device (1) is positioned after the circulation pump (4), between the circulation pump (4) and the jet pump (3), the jet pump (3) is connected to the expansion vessel (2), whereby the intake from side arm (3a) of the jet pump (3) is connected via a line (5) to the expansion vessel (2) and the diffuser (3b) of the jet pump (3) protrudes into the expansion vessel (2) and an initial feed line (6) for cyclic olefin or solvent that can be shut off and a second feed line (7) for the reactive/inert gas that can be shut off are integrated into the circulation line (L) in front of the jet pump (3) and a line (8) that can be shut off for removing the reaction solution from the circuit is integrated into said circulation line (L) after the fixed bed device (1).