Assessing the Recycling “Advantage”

While FRP can be recycled1, it is not usually economically feasible currently. However, in most of the applications studied to date, production of virgin FRP parts actually consumes less energy and produces less greenhouse effect than recycling of steel and aluminum. For instance:

A study2 comparing the energetic values (exergy) of various material options for construction of a pedestrian bridge yielded these results:

Material % Recycled Material Consumed energy and energetic material value (MJ/kg)
Structural Steel 0% 46
Structural Steel 100% 36
Stainless Steel 0% 69
Stainless Steel 100% 54
Composites 0% 33
Aluminum 0% 137
Aluminum 100% 45

A Life Cycle Inventory (LCI) study3 of steel, aluminum and FRP composites in a number of applications also indicated a clear advantage in energy usage for composites over recycled steel, and from near parity to clear advantage over recycled aluminum4:

Materials (% recycle)
Relative energy requirements per application
Grating Handrail Channel Plate
Aluminum(0) 100 100 100
Aluminum(100)5 ~17 ~17 ~12
Steel(0) 46 76 100 17.5
Steel(100)6 ~33 ~57 ~75 ~13
Composites(0) 20 17 60 6

1 Plasti-Fab Recycles and Reuses Fiberglass in Composites Manufacturing. Composites Week, No. 14, Vol. 12, April 5, 2010.

2 Daniel, Ryszard A., Environmental Considerations to Structural Material Selection for a Bridge. European Bridge Engineering Conference, Rotterdam, March 2003.

3 Jakubcin, Gary – LCACP. A Life Cycle Assessment Approach in Examining Composite Raw Materials, Steel and Aluminum Materials Used in the Manufacturing of Structural Components. Report prepared for Strongwell, Inc., June 19,2009.

4 The LCI did not include energy required for the pultrusion of composite material (small), the re-melting, rolling and fabrication of recycled aluminum ingots (large) nor the shaping and cutting of recycled steel plate for required parts (moderate). In general, including all energy required for each material is believed to further favor composites.

5 Data for 100% recycle aluminum extrapolated from that for 0%, 50% and 80% cited in the report(3).

6 Calculated as 75% of energy required for steel production cited in the report(3).