Mammoet replaces reactor

TotalEnergies Raffinerie Mitteldeutschland contracted Mammoet to replace two reactors at a POX methanol plant on a chemical site in Leuna, Germany.

Lifting the sub-reactor to the installation position. (Photo: Mammoet)

A complete shutdown of the plant was not possible, as the required production volume had to be always guaranteed. Therefore, only one reactor at a time could be removed and replaced.

Engineering plan

Mammoet had to devise a solution to minimise disruption of operations.

A preliminary engineering study carried out by Mammoet concluded that the most efficient solution to replace the reactor unit would be to use a Liebherr LR 1750 crawler crane.

Pivoting the sub-reactor in the direction of the plant. (Photo: Mammoet)

It can lift and move a load of 140 tonnes at the same time, as well as perform all other lifting operations. This was necessary because, due to space limitations, the pre-assembly and storage area for the components was located approximately 200 metres from the installation position.

Winch system

In order to safely lift the steel construction module, completely fitted with equipment, Mammoet used its specially developed COGAS winch with four-point rigging.

The winch acts as a centre of gravity balancing system. The operator controls the winch via a remote control and can change the length of the individual rope strands so that the crane hook exactly matches the component’s centre of gravity.

Plan in action

Installation of heavy-duty rigging on the sub-reactor. (Photo: Mammoet)

First, the old reactor and the old sub-reactor were removed one by one, transported by the crawler crane to the laydown area about 200 metres away to be stored.

Special demolition chains were used for rigging. The heavy-duty rigging was then modified, and the new components were lifted into place with the LR 1750.

The new sub-reactor, weighing 120 tonnes, was already stored upright at the pre-assembly area. It was attached, lifted, moved 200 metres to the plant on the hook of the crawler crane and pivoted into place. The new reactor, weighing 140 tonnes, followed in the same way.

Finally, the steel construction module, weighing 100 tonnes, was lifted and moved safely into position using the Mammoet COGAS winch.

Lifting the sub-reactor on the pre-assembly area. (Photo: Mammoet)