Specialist equipment is needed for the loading and unloading of chemicals that pose a hazard for people, equipment, and marine environments.
For infrequently served chemical terminals, it is difficult to justify high CAPEX solutions.
Demand for these terminals is often in areas with limited space – or where building large infrastructure would have a disproportionate impact on the marine environment.
The Mina Justa [copper mining] project in Peru faced these difficulties.
The project will consume the equivalent of a chemical tanker full of sulphuric acid every eight to twelve days, which is transported first via tanker and offloaded at a terminal in Marcona, Peru.
Marcona’s sea conditions make it difficult to construct fixed infrastructure, as the sea depth means that any fixed pier must be unusually long.
This level of construction would have knock on impacts on marine ecosystems in the area, and make it difficult for local fishing boats to navigate the waters.
Therefore, the project owners sought to design a terminal that posed as little impact and risk as possible.
Reel on floating platform
The project owners worked with Trelleborg and its Chemiline marine transfer hose design.
The hose is used in a floating configuration and attached to a reel.
It allows for a floating platform able to service any size of tanker that fits in its multi-buoy mooring capabilities.
The floating line is fully recoverable onshore when not in use, meaning that there are no piping or other assets left at sea.
The hose is 850 metres long when fully unspooled from the reel, with 550 metres of the hose floating when deployed.
Building fixed infrastructure of this length and size would have undeniable impacts on navigation and local ecosystems – and incur significant costs in construction.
Sulphuric acid
Sulphuric acid is extremely corrosive and very dense.
Any chemical transfer requires hoses designed to cope with the unique stresses associated with the product handled and the environment.
This means that the vital hose components need protection from the corrosive nature of the product handled. While the hose structure must withstand the physical forces associated with transfer at sea.
This performance can be delivered through a fluoroelastomer (FKM) continuous inner liner, which stops the product handled from reacting with the rubber or the metal nipple flanges and prevents the potential disbonding that could occur with a nipple-based hose construction.
Pressure must also be considered. Sulphuric acid has a density of 1830kg/m3, which means there is a requirement for the proper rating of hoses for repeated high-pressure transfer and designed to ensure that this pressure does not degrade the integrity of the hose.
Trelleborg’s Chemiline hoses have a dual carcass to provide resistance against both internal pressure and external forces, ensuring long term durability during repeated transfers.
Coupled with a unique nippleless design, this protects the hose from bending forces by eliminating the stiff metal connector, alongside a marine breakaway coupling to protect the hoses from excessive tensile forces.
This reduces the risk of premature wear and ensures the routine completion of transfers safely.