Granting a new lease of life

26th May, 2014

The story of how the world’s largest regenerator head was built, transported and installed within a critical time-frame at Essar Oil Stanlow Refinery, UK

A significant milestone was achieved last October at Essar’s Stanlow Refinery in England with the installation of the new regenerator head for Europe’s largest fluidized catalytic cracker (FCCU). The new unit delivered a 25 year re-lifting of the FCCU regenerator cyclones, with the project alone representing a £25m investment as part of the wider turnaround undertaken last year across the facility.

Replacing the regenerator head was key to the continuing operation of the refinery as it is fundamental to the operation of the long residue catalytic cracking unit – the major upgrading unit for the whole site, converting fuel oil to high value products including ethylene, propylene, butylene, and a mixture of gasoline and diesel components. The regenerator’s role is to burn off the coke which is formed on the catalyst during the catalytic reaction, it can be immediately re-used to convert more of the residue feed to high value products.

Till date, this is the largest regenerator in the world that was built and transported; complete with cyclones and refractory. In order to ensure a close fit, the specification of the new head had to be within a fine tolerance of +/-10mm over the 14-metre diameter. However, through excellent engineering and fabrication, an amazing tolerance of 1mm was actually achieved!

It took over four years of careful planning for the new regenerator head for Europe’s largest FCCU to be lifted into place at the Essar Stanlow Refinery in England. The new unit delivered a 25-year re-lifing of the FCCU regenerator cyclones, with this project alone representing a £25m-investment at Stanlow as part of the wider block turnaround undertaken last year. The journey began in Belgium, where the manufacturer completed the head assembly in two sections to allow its movement along the country’s canals to Antwerp’s docks for final assembly. There, the head was lifted over a protective ‘can’ – which had been used to protect the cyclones during transportation for the journey by barge across the North Sea to Ellesmere Port docks in Cheshire.

Back in March 2013, the M53 motorway that links the cities of Liverpool and Chester actually had to be closed to all other traffic so the equipment could be moved safely from the docks to the Stanlow complex. The transport weight of the head and cyclones was 450 tonnes, and with 30 axle lines of self-propelled modular trailers, weighing in excess of 700 tonnes – the largest load seen on the motorway since the 1980s. The assembly completed the five-mile journey in just under six hours, entering the Stanlow complex through a newly constructed temporary entrance off the A5117 road.

Once on site, the regenerator head and cyclones were lifted onto another frame so assembly work could be completed, taking the pre-assembled unit to over 24 metres in height. Shortly after, the assembly of the platform twin rig crane began, with the huge structure being delivered to the site in over 120 containers. When finished, it towered over the refinery, standing 103 metres high with a counterweight of 1,500 tonnes.

Before the new unit could be installed, the existing head and associated overhead lines were removed and placed on specially built steel transport frames. Both the existing and new assemblies had to be moved across a 40-metre skid bridge on giant steel beams which had previously been used to raise the sunken Russian submarine, the K-141Kursk, from the Barents Sea.

The new head and cyclone assembly was lifted 70 metres into its final position in just over two hours. In the week that followed, two new overhead line sections weighing 54 and 69 tonnes respectively were successfully installed, all ahead of schedule. The installation itself was a testament to the expertise across engineering, transport and heavy lift disciplines executed by a top quality team. Mr. Allan James, Project Manager at Essar Oil UK commented: “My thanks to the integrated project team and numerous stakeholders for their help and professionalism in safely and successfully delivering this world-class project.”

Mr. Volker Schultz, Chief Executive Officer, Essar Oil UK said: “This is another major investment in the Stanlow refinery and part of our strategic plan to ensure we can be sustainably profitable moving forward. The lift was a complicated piece of engineering and I want to pay a tribute to everyone involved that it was completed safely and ahead of schedule.”