Client: Argent Energy
Works commenced in March 2015 on the construction of the Biodiesel Preprocessing Plant, the first phase of the Argent Energy expansion plan within the Essar Stanlow Refinery in Ellesmere Port, Cheshire.
Initially targeted for a year-long programme, the works comprised the construction of a 4,500 m2 structure, comprising materials reception and offloading area, main process hall, specialist process hall, plant and boiler rooms, odour control plant, external covered storage areas and associated offices and welfare facilities.
Along with the structure, an extensive civils and groundworks package was included for the footprint of the entire site, including 7,000 m2 of the external yard and roadways, with all associated services, utilities, drainage, gas and water management systems.
Before construction commenced, a site clearance and preparation exercise generated approximately 3,000 m3 of existing, below-ground foundations and obstructions which were stockpiled, crushed, graded and re-incorporated within the works as a piling mat and final formation for the ground-floor concrete raft construction.
1200 concrete piles were driven to an average depth of 18 m to support the waterproof, in-situ concrete, multi-level, raft slab construction. Slab depths were between 300 mm and 550 mm with all associated bund upstand walls and plant plinths and platforms.
A ground gas-venting system was installed below to accommodate the environmental requirements associated with the previous land use of the site.
The early works also included the excavation of a 6 m deep, 150 m2 pit to accommodate the installation of the in-situ, product reception bins. Working at sea level in the estuary of the River Mersey, these works included a large cofferdam installation and full water management exercise.
Steelwork commenced early September 2015 and was sequenced to allow the early entry of specialist process works and plant installations. The erection of the structure was sequenced around the client’s main process, product tanks and plant installation, and included a large, three-storey internal mezzanine structure plus associated access walkways, platforms, internal cranage and hoisting rails. Approximately 500 tonnes of structural and secondary steelwork was erected, combining several finishes, including intumescent, galvanised and powder-coated material, all required to accommodate the fire and environmental performance requirements of the structure and the processes within.
With the installation of main plant items and completion of the steel structure, the internal fire and explosive division walls could be installed with the main roof and wall cladding commencing after that.
Working at heights of up to 22 m, the envelope completion allowed the client’s process fit-out works to commence in earnest. Running alongside these works, the office and welfare fit-out and the external works were completed as availability and access allowed.
Process commissioning works commenced in May 2016 and the first raw sample product was produced from the plant in September 2016.