Recycling Thermal Insulation Materials: A Case Study on More Circular Management of Expanded Polystyrene and Stonewool in Switzerland and Research Agenda

Abstract

The limits to linear models of production based on material extraction, manufacture, use, and disposal are becoming increasingly apparent across the global economy. The Circular Economy (CE) describes an alternative to this problematic “take-make-waste” linear model that is concerned with resource efficiency and waste minimization. The construction and demolition sector represents an important focus for a CE transition due to its significant environmental impact. The use of thermal insulation to reduce energy demand associated with heating and cooling in buildings is vital for reducing the sector’s high environmental impact; however, there are significant challenges to recycling thermal insulation materials (IM). This study examines these challenges in the context of Switzerland and evaluates the potential for more circular management of expanded polystyrene and stonewool IM. The research provides an original analysis of the Swiss IM value chain in the context of the CE agenda based on a literature review, semi-structured interviews, and a workshop. Research gaps are highlighted based on scientific literature. The roles and agency of actors involved in the Swiss IM value chain are examined. Enablers of and barriers to wider IM recycling as reported by workshop participants are outlined. Interventions for tackling the current challenges faced for the recycling of thermal IM are suggested. Finally, an agenda for future research is proposed. Throughout the discussion, the importance of the involvement, commitment, and collaboration of stakeholders across the entire IM value chain for an effective and expedient transition to a CE is highlighted.

A Review of Bio-Based Adhesives from Primary and Secondary Biomass for Wood Composite Applications

“…Polyols are transesterified fatty acids, when they are joined by ester bonds, there are few microorganisms or enzymes in nature that could break them down. Polyurethane, on the other hand, is obtained by reacting isocyanate with fatty acids, the biggest negative aspect of which is toxic cyanide [55] when it is formed during combustion, so flame retardants are always added to polyurethanes, which makes it more difficult to process at the end of its life [70]. Due to cyanide safety issues, nonisocyanide polyurethanes (NIPUs) are developed by using tannins as isocyanide replacement [55].…”

Optimizing the Thickness of Multilayer Thermal Insulation on Different Pipelines for Minimizing Overall Cost-Associated Heat Loss

“…Initial investment for one layer of insulation can be represented by Equation (11), where c j is the initial insulation cost per unit length, and x 1,1 , x 2,1 , x 3,1 , and x 4,1 are unknown outer-insulation-layer radii (b 1 , b 2 , b 3 , and b 4 ) of pipelines carrying (a) steam line, (b) furfural, (c) reduced crude, and (d) 300-distillate oil [34].…”

“…The viability of utilizing various insulation materials in pipelines has undergone thorough examination. Expanded polystyrene, rock wool, and extruded polystyrene are the materials that have been extensively researched [11]. Dasdemir et al [12] optimized insulating layer thickness for HVAC applications using rock wool, expanded polystyrene, and extruded polystyrene materials with varying sizes of steel, plastic, and copper pipes.…”

Fire Safety of External Thermal Insulation Systems (ETICS) in the Aspect of Sustainable Use of Natural Resources

“…The results, which do not show the advantage of using MW protective barriers on the facade of ETICS, and due to other basic requirements, only complicate the system, including the dimension of environmental impact. The reuse or recyclability of construction materials from the facade with EPS and MW is either impossible or very difficult [33]. In addition, considering the durability of the facade with EPS and MW, all connections between insulation materials make the system less durable [34].…”