Borealis AG is a leading provider of innovative solutions in the fields of polyolefins, base chemicals and fertilisers.
The Borealis facility in Ottmarsheim was seeking an insulation material to re-insulate four storage spheres. These spheres had been insulated with a PUF-sprayed system and a CSPE-based vapour barrier. Over time, water penetrated the system and was absorbed by the PUF insulation, which led to a loss in thermal efficiency. Borealis maintenance engineers chose FOAMGLAS® insulation to replace the previous insulation.
The insulation material used on the spheres must withstand local weather conditions. The main requirement was selecting an insulation material that would be impermeable to help prevent the ingress of water or water vapour. A second requirement was an insulation material that would keep its thermal properties over a prolonged period of time, helping to provide maximum insulation efficiency.
The four spheres that were re-insulated consisted of two spheres storing CO₂ (carbon dioxide) at -31°C (-23.8 °F) and two spheres storing NH3 (ammonia) at +10°C (50°F).
The diameter of the CO₂ sphere was 12,874mm (42ft) while the NH3 sphere had a diameter of 17,210mm (56ft).
The FOAMGLAS® insulation technical services team conducted appropriate calculations to determine the correct insulation system for each individual sphere.
A double-layer system of FOAMGLAS® ONE™ insulation was specified for the CO₂ sphere. The total thickness was 120mm (4.72in) and the insulation was fully bonded with a double-component adhesive. The joints were sealed with a non-hardening sealant. Everything was finished off with an external coating that consisted of a CSPE-based mastic reinforced with fibreglass.
Because of the storage temperature of ammonia, a single-layer system would suffice for the insulation of the NH3 sphere. A single-layer FOAMGLAS® ONE™ system of 70mm (2.75in) thickness was specified. The pre-fabricated curved segments had been factory pre-assembled in two pieces to minimise the number of joints and help increase on-site efficiency.