Eco-profile of and Environmental Declaration for polyurethan
Aims
The aim of the work was to assess the eco-profile of SPU Systems Oy’s polyurethane product and to prepare an Environmental Declaration for the product. The input data used was literature concerning the environmental impacts of the raw material, as well as information provided by the manufacturer on the energy and material requirements for manufacturing the product, the emissions generated during manufacture, and the transportation of the product.Eco-profile of raw materials
The eco-profile of the raw materials of polyurethane presented in Table 1 is based on Reference 1. In the manufacturing process of polyurethane, two or more liquid precursors (raw materials) of polyurethane are mixed together. The final polymer (and product) is usually produced in an individual production plant, and not in the plants producing the precursors of polyurethane. The grades and mixture ratios of the polyurethane precursors are tailored to suit both the specific product and the production process.The precursors of polyurethane are polyols and di-isocyanates. Of the di-isocyanates,diphenylmethane-di-isocyanate (MDI) is used in the products of the construction materials industry. Other substances, such as catalysts, surface-active agents and pigments, are needed in the production of polyurethane products in addition to polyols and MDI. Usually, lifecycle data for these compounds is not available, but the proportion of the substances in question is usually only 1-2%. From the viewpoint of lifecycle inventories, fire retardants and propellants are more problematic because, depending on the product, their weight ratio can be 2-20%. There is also a scarcity of lifecycle information about these.
The eco-profile of Table 1 is based on a typical polyurethane used in construction materials or products, in which the propellant is pentane. The eco-profile includes the production of polyol, MDI and pentane as well as the average transport. The profile also includes the energy consumed and emissions produced in acquiring the material and energy raw materials for all the components mentioned. The environmental loads caused by the production of the fuels used for transportation is also included.
1Boustead, I. 1997. Ecoprofiles of the European plastic industry. Report 9: Polyurethane precursors (TDI, MDI, polyols) (Second edition). 64 p.
Table 1. Eco-profile of the raw materials and propellant of PUR per one kilogramme of PUR.
| Energy resources |
||
| - renewable | MJ | 1,1 |
| - non-renewable | MJ | 99 |
| - total |
MJ | 100 |
| Raw materials resources |
||
| - renewable | kg | 0,047 |
| - non-renewable | kg | 3,2 |
| - water |
kg | 358 |
| Emissions into the air |
||
| - CO2 | kg | 3,4 |
| - CO | g | 2,8 |
| - NOx | g | 16 |
| - SO2 | g | 15 |
| - HCl | g | 0,18 |
| - NH3 | g | 0,12 |
| - CxHy / VOC (other) | g | 3,7 |
| - CH4 | g | 19 |
| - particles | g | 5,9 |
| - heavy metals |
mg | - |
| Emissions into water |
||
| - COD | g | 4,6 |
| - BOD | g | 0,75 |
| - Na+ | g | 290 |
| - Cl- | g | 511 |
| - SO42- | g | 4,7 |
| - Ca 2+ | g | 50 |
| - CO3 2- | g | 0,87 |
| - solids into water |
g | 24 |
| Solid waste |
||
| - waste |
g | 410 |
In eco-profiles, renewable energy refers to the energy produced using water power and biofuels. Biofuels are, for instance, wood-based fuels and biogas. In this study, non-renewable energy refers to fossil fuels such as coal, natural gas, fuels based on crude oil, and peat.
The use of non-renewable raw materials refers to the total aggregate use of natural non-renewable raw materials and the raw materials of energy.
The carbon hydride emissions (CxHy/VOC) in the eco-profiles do not include methane emissions.
For heavy metal emissions, the following are included:
- arsenic
- mercury
- cadmium
- chromium
- lead
Eco-profile of a product
The eco-profile of a product is calculated by multiplying the eco-profile of a raw material by the consumption of the raw material, and then adding to the result the emissions caused by the use of energy during production, the resources consumed plus process emissions. The energy consumption and process emissions of production are shown in Table 2. The eco-profile of the product is shown in Table 3. Some parameters have been omitted from the table (see Table 2).The result of Table 3 has been calculated using the national electrical power profile 2 as the eco-profile for the electrical power consumption during manufacture of the product. According to the manufacturer, however, wind power is used in manufacturing the product (settlement procedure with the power provider). No separate eco-profile exists for wind power. In Table 4, the eco-profile of the product has been calculated by using the consumption value for wind power instead of the primary value and by assuming that the power is emission-free 3.
The difference between the results of Tables 3 and 4 is minor because the manufacturing power accounts for a small proportion of the total load and total resources.
Table 2. Energy consumption and process emissions for manufacturing the product, as well as the average transport distance for the product.
| Energy consumption during the production process |
| Electrical power 0.33 kWh/kg (wind power) |
| Process emissions |
| Pentane approx. 5 g/kg |
| Polyuretaanilevyjen työstöhukka noin 2 g/kg |
| Transport distance and vehicle |
| 220 km by truck |
2Eco-profiles for electrical power and district heating in 1998 using the distribution of benefits method. Kai Tattari. VTT Construction Technology. The environmental effects and LCA estimates of equipment and systems for building services.
1The national average is always used as the eco-profile for electrical power when compiling RT Environmental Declarations (see The Building Information Foundation RTS www.rts.fi) in the calculation of other construction products.
Table 3. Eco-profile of polyurethane boards (result calculated using the average profile as the eco-profile for electrical power)
| Energy resources |
||
| - renewable | MJ | 1,7 |
| - non-renewable | MJ | 100 |
| Material resoiurces |
||
| - renewable | kg | 0,047 |
| - non-renewable | kg | 3,2 |
| - water | kg | 360 |
| Emissions into the air |
||
| - CO2 | kg | 3,4 |
| - CO | g | 2,9 |
| - NOx | g | 16 |
| - SO2 | g | 15 |
| - CxHy / VOC | g | 8.7 |
| - CH4 | g | 20 |
| - particles | g | 6,0 |
| - heavy metals |
mg | - |
| Emissions into water |
||
| - COD | g | 4,6 |
| - BOD | g | 0,75 |
| Solid waste |
||
| - waste | g | 410 |
Table 4. Eco-profile of polyurethane boards (result calculated assuming that the electrical power used in manufacturing is renewable energy).
| Energy resoiurces |
||
| - renewable | MJ | 2,3 |
| - non-renewable | MJ | 99 |
| Material resoiurces |
||
| - renewable | kg | 0,047 |
| - non-renewable | kg | 3,2 |
| - water | kg | 360 |
| Emissions into the air |
||
| - CO2 | kg | 3,4 |
| - CO | g | 2,8 |
| - NOx | g | 16 |
| - SO2 | g | 15 |
| - CxHy / VOC | g | 8.7 |
| - CH4 | g | 19 |
| - particles | g | 5,9 |
| - heavy metals |
mg | - |
| Emissions into water |
||
| - COD | g | 4,6 |
| - BOD | g | 0,75 |
| Solid waste |
||
| - waste |
g | 410 |