Imperial Oil Limited

Abatement, Asset Recovery, Demolition, Recycling
Imperial Oil Limited
The project
The work is being executed in accordance with stringent protocols to protect the health and safety of the public, workers, and refinery personnel as well as the environment and nearby operating refinery infrastructures and equipment.
The out-of-service equipment and structures are being prepared for demolition by ensuring that all associated services have been disconnected and all residual products removed, and by completing the required environmental scope of work to remove and dispose of any asbestos-containing and hazardous materials, which include mercury, ozone depleting substances, and polychlorinated biphenyls.
Delsan-A.I.M. is currently undertaking a major, sixteen (16) month industrial project involving the demolition of an out-of-service facility located in an operating oil refinery. The facility, which was used for the manufacturing of various lubricants, consists of processing units that include vessels, columns, stacks, pipe racks, and piping along with twenty-nine (29) storage tanks having capacities ranging from 15,000 – 100,000 barrels.
The demolition work is being completed in accordance with engineered procedures by employing mechanical methods using primarily 45-tonne excavators equipped with specialized attachments along with a 117’ high-reach excavator.Any structures that cannot be safely demolished by conventional means due to their height or location with respect to operating services or facilities, are either being removed using a mobile crane; lowered mechanically using small demolition equipment; or control dropped. All demolition materials are being source-separated by waste type and shipped off-site to licensed recycling or disposal facilities in accordance with the applicable regulations.
A structure of note that Delsan-A.I.M. is currently demolishing is a 301-ft. high, brick-lined concrete stack which has a base diameter of 24.5-ft. that tapers to 17-ft at the top. The concrete shell is supported at grade level on a reinforced concrete foundation, while the liner, which is 118-ft high, sits on a 2’ thick suspended concrete slab inside the stack at the 62-ft level just below where the breaching is located.

The demolition consists of lowering the stack using small demolition equipment to an elevation that will allow the bottom portion to be demolished from ground level using the high-reach excavator. During the lowering phase, the demolition debris is being conveyed inside the stack to the 62-ft level where the breaching has been enlarged to allow for the periodic cleaning of the inside of the stack using the high-reach excavator.
In preparation for the demolition work, Delsan-A.I.M. arranged for the installation of high-capacity mast climber work platforms around the circumference of the stack for its entire height to provide worker access during the lowering process.

The inside brick liner was then completely removed by means of a remote-controlled mini-excavator supported from a separate custom-designed platform that was suspended inside the stack by means of a 400-tonne mobile crane. The mini excavator, which was equipped with cameras, was operated remotely by a worker safely located outside the stack on the climber platform.
In a similar manner, the outer concrete shell is currently being lowered using remote-controlled mini excavators that are located on the crane and climber platforms to systematically pulverize the concrete allowing the debris to fall within the confines of the stack. The climber platforms are providing not only protection around the circumference of the stack to contain any dust and small debris from the demolition work, but also access for workers to operate the mini-excavators and to cut the reinforcing bars using torch-cutting equipment as the work advances.
As the stack is lowered, the climber platforms are being dismantled. The final stage of the work will involve the high-reach demolition of the remaining lower portion of the stack.