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bioplasticsMAGAZINE_1101

Foam A Comparative LCA

Foam A Comparative LCA of Building Insulation Products Synbra has together with the Sustainable Development Group of AkzoNobel conducted an ex-ante Life Cycle Assessment (LCA) of BioFoam production from lactide produced from cane sugar in Thailand by Purac (Borén and Synbra 2010). An LCA allows holistic and quantitative environmental impact evaluations of economic systems, and facilitates relating environmental impacts to a functional unit. With the goal to probe which of the materials BioFoam ® , expanded polystyrene foam (EPS foam), polyurethane foam (PUR foam) and mineral wool (as produced today under average European conditions) that are most often used as thermal insulation products for buildings from an environmental point of view, a comparative life cycle assessment (LCA) of these materials has been performed by AkzoNobel. This model has been made to supply prospective customers a full LCA on their particular application and to compare it with insulants when used in insulation and with EPS cardboard when used as packaging. This is subject of another comparison. BioFoam; is a polylactic acid based foam material that can be used as an alternative to traditional insulation materials. It has passed stringent stability tests on fire resistance moisture resistance, fungus resistance and attack by pests such as termites see cadre 2 and at use temperatures below 60°C does not degrade to any significant extend even after many years of exposure. The functional unit of this LCA is the thermal resistance of 5 m 2 •K/W and the following environmental aspects are assessed: renewable and non-renewable energy use, abiotic resource depletion, global warming, acidification, photochemical oxidant formation, eutrophication and farm land use. The study focuses on the insulating and environmental properties of the insulation products per se, and the studied system includes the production, delivery and disposal (incineration with or without energy recovery, landfill with or without energy recovery, industrial composting or recycling) of the insulation products. The delivery and disposal is modelled for average European conditions. An external critical review has been carried out to validate that the methodology, data, interpretation and report of this LCA complies with the ISO 14040 standard series. PUR foam and mineral wool as produced under average European conditions. It has been performed according to the ISO standards on LCA (ISO 14040 and 14044). The focus is on the production and disposal (recycling, incineration with or without energy recovery and composting) of the materials. Figure 1 presents a simplified flowchart of the studied system of this LCA. As the study focuses on the environmental properties of the insulation products per se, the application and use stages are excluded, and no regard is taken to situations which impose different demands concerning ancillary material and energy inputs in the application and future demolition and disassembly of insulated buildings, and it is noted that the conclusions may not be valid for such situations. The system boundaries are defined by a system expansion approach as recommended by the ISO standards, meaning that only the activities affected by an additional demand of insulation product are included. This approach is best combined with marginal production data, however the difference between marginal and average production data for the activities in scope of this assessment is considered to be minor and therefore average production data has been applied for all activities for reasons of practicality. With regard to technical and temporal boundaries all industrial activities are modeled as if they would take place today within the current infrastructure. The application, use and final disposal of the insulation products is accounted for to take place in Europe. Where applicable average European LCA data has been applied for these activities. The functional unit is defined in the ISO 14040 standard as ‘the quantified performance of a product system for use as a reference unit in a life cycle assessment study’. The key performance aspect of thermal insulation products is that they are used for limiting the transfer, or conduction, of thermal energy, or heat. Thermal resistance, R, is the resistance of a material to the conduction of thermal energy, and is a measure of a material’s insulating capacity. According to Schmidt et al. (2004) the thermal resistance measured in m 2 •K/W has been generally accepted as an adequate functional unit for LCAs of thermal insulation products. In this LCA the materials are compared on the basis of 1 m 2 of insulating material with an insulating capacity/thermal resistance of 5 m 2 •K/W. 30 bioplastics MAGAZINE [01/11] Vol. 6

Foam Article contributed by Jan Noordegraaf Peter Matthijssen Jürgen de Jong Peter de Loose Synbra Technology bv Etten Leur, The Netherlands. The mass of an insulation product, m, required to achieve a certain thermal resistance can be defined according to: m = R • λ • ρ • A (1) Where R is the material’s thermal resistance 5 m 2 •K/W; λ is the material’s thermal conductivity (the property of a material that indicates its ability to conduct heat) measured as W/(m • K); ρ is the material’s density measured as kg/m 3 ; A is the area in m 2 , here 1 m 2 ; K is degree Kelvin; W is Watt. Based on this formula the mass of the studied materials that must be installed in order to achieve the functional unit, i.e. a thermal resistance of 5 m 2 •K/W, can be calculated (table 1). Knowing the mass and the area, the associated thickness, t, in cm, of the insulating product can also be calculated. Table 1. Properties of the studied materials Material λ (mW/m • K) ρ (kg/m 3 ) m (kg/F.U.) t (cm) BioFoam 36 20 3,6 18 EPS Foam 36 20 3,6 18 PUR Foam 26 40 5,2 13 Rock Wool 42 120 25,2 21 Table 2 and 3 presents the cradle-to-gate results for the production of the insulation products from 100% primary raw materials. Note that the CO 2 sequestration associated with the cultivation of sugar cane for PLA production is accounted for, see cadre1. Table 2. Results for the production of 1 kg of the insulation products BioFoam EPS Foam PUR Foam MWool Non-Renewable Energy Use (gross calorific value) (MJ) 62 116 102 27 Renewable Energy Use (gross calorific value) (MJ) 56 1.0 1.5 2.7 Abiotic Resource Depletion (kg Crude Oil-Equiv.) 1.3 2.4 2.1 0.6 Global Warming Potential (GWP 100 yrs)(kg CO 2 -Equiv.) 2.2 4.6 4.2 1.6 Acidification Potential (kg SO 2 -Equiv.) 0.028 0.012 0.017 0.009 Photochem. Oxidant Formation (kg Ethene-Equiv.) 0.0028 0.011 0.0019 0.0008 Eutrophication Potential (kg Phosphate-Equiv.) 0.013 0.0013 0.0031 0.0011 Farm Land Use (m 2 /yr) 2.1 - - 0.4 Table 3. Results for the production of the amounts of the insulation products needed to fulfil the functional unit (see table 1) Land use due to farm land resp. wood use in transport pallets BioFoam EPS Foam PUR Foam MWool Non-Renewable Energy Use (gross calorific value) (MJ) 222 418 529 687 Renewable Energy Use (gross calorific value) (MJ) 202 3 8 69 Abiotic Resource Depletion (kg Crude Oil-Equiv.) 4.6 8.7 10.6 13.9 Global Warming Potential (GWP 100 yrs)(kg CO 2 -Equiv.) 8.1 16.6 21.8 41.3 Acidification Potential (kg SO 2 -Equiv.) 0.10 0.04 0.09 0.22 Photochem. Oxidant Formation (kg Ethene-Equiv.) 0.010 0.039 0.010 0.020 Eutrophication Potential (kg Phosphate-Equiv.) 0.045 0.005 0.016 0.029 Farm Land Use (m 2 /yr) 7.6 0.013 - 9.8 bioplastics MAGAZINE [01/11] Vol. 6 31

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