Environmental Balances of Thermal Superinsulations

This paper introduces environmental balances for three different thermal insulation concepts (evacuated multi-foils, evacuated glass fibers, and a conventional foam insulation) of a 300 L LN₂ storage tank. The calculations are based on material consumptions in the manufacturing phase and thermal losses of the tank during the use phase. Materials consumption is identified from the design of the tank taking into account stainless steel containers, thickness of container walls, mechanical supports, bellows, getter, and insulation materials. Thermal losses are calculated using finite element methods. It is demonstrated that evacuated multi-foil insulation is, from energetic and environmental considerations, by far superior to evacuated glass fibers and to conventional foam insulation. Its environmental “amortization time” (a return on investment when outbalancing environmental impacts by corresponding savings) is in the order of 80–160 weeks of operation. This also demonstrates that it is important to apply an environmental life cycle perspective, and not analyze only the energetic and materials aspects, when new technologies are assessed.