ACMA completed a Life Cycle Inventory Report in 2012 that illustrates how an LCA can identify opportunities for a composites manufacturer to reduce cradle-to-gate climate impacts. For example, the report indicates the largest amount of climate impact for a typical open molded product is associated with the resin used to make the product. (The emission of significant quantities of climate warming gases associated with resin production is driven largely by the high-temperature steam cracking of hydrocarbons to produce the small reactive molecules used as building blocks in the production of polymers.) For a typical compression molded product, the process energy (electricity) needed to heat dies, operate presses and produce molding compound accounts for the largest share of the climate impact.
Composites manufacturers will have to work with suppliers to identify raw materials or processes with reduced climate impacts. Companies should also collaborate with providers of electricity, natural gas and other energy sources to evaluate the availability of energy streams associated with reduced climate impacts. For example, most electric utilities can already provide power from renewable sources, such as wind or hydropower, at a price premium.
The sustainability landscape isn’t all doom-and-gloom for the composites industry. Replacing traditional materials with composites brings important sustainability benefits – high strength, low weight, corrosion resistance, durability. And then there are the important products that would not be possible without composites, such as wind turbine blades.
But what about climate change? Does the use of composites instead of traditional materials reduce the emission of climate warming gases?
There have been some efforts to quantitatively demonstrate that this is true, and composites do provide some benefit, but overall the results are not very compelling. These comparative analyses heavily depend on assumptions about the extent of the system – the exact design, construction, use and end-of-life disposal practices, as well as the assumed lifespan of the materials and assembled end-use product. And it is not clear how to account for benefits that occur in the future, such as not needing to replace a composite-reinforced bridge deck at 75 years when a steel-reinforced deck would need to be replaced.
It may be more important to educate infrastructure users and product consumers about the hard-to-quantify social advantages of composites. For example, people living in storm- or wildfire-prone areas could be informed about the resilience of composite utility poles. Similarly, communities with highway bridges needing extensive maintenance or replacement could be informed that the resulting traffic disruption, inconvenience and economic loss can be avoided if composites are used to reconstruct or replace the bridges.