'Benchmark’ study on glass offers clear carbon footprint picture
The study provides for the first time a full cradle-to-cradle examination of the carbon footprint of glass in North America, said the US-based Glass Packaging Institute (GPI).
The body said its peer-reviewed research, conducted by independent consulting firm PE Americas, demonstrates that the increasing use of recycled glass (called cullet) in the manufacturing process is having an effect in reducing the carbon footprint of the material.
A ‘cradle-to-cradle’ LCA includes the entire cradle-to-grave life cycle of a product while factoring in the recycling of the used product back to its original purpose. This is first time any packaging sector has used this method – which it claims provides the most accurate picture - to evaluate the carbon footprint of its material, said the body.
Study methodology and findings
The research collected data from 105 furnaces, representing 75 per cent of North American glass container output for 2007. The cradle-to-cradle approach addressed all inputs and outputs for the production and end-of-life management for 1 kg of glass. Elements taken into account included the extraction and processing of raw materials, transportation, the production and combustion of fuels and energy for the formation and melting of glass and impacts of post-consumer cullet treatment. Different end life uses, such as recycling back into new packaging or non-packing applications, as well as landfill and incineration amounts, were also gauged.
The key findings looked at two main areas for 1 kg of glass; primary energy demand (PED) – the total fossil energy consumption - and global warming potential (GWP).
The study found that in North America the PED was 16.6 MJ/kg glass and the GWP was 1.25 kg CO2/kg glass.
The increasing use of cullet glass has resulted in a decrease of both PED and GWP, said the glass packing association.
"The LCA confirms the industry is on the right track with the goal to use 50 per cent recycled glass in the manufacture of new glass bottles and jars by the end of 2013," said Joseph Cattaneo, GPI president. "In creating more recycling awareness and working to improve recycled glass collection, the industry is helping boost the cullet content in manufacturing. The study shows increased cullet helps reducing energy emissions, conserve raw materials, extend the life of glass manufacturing furnaces, and save energy."
Another primary finding is that the transportation of glass has a relatively small impact of between 5 and 10 per cent of the total energy used. Transport emissions are offset by the energy savings gained from using cullet in the manufacturing process, said the study.
“The CO2 savings from glass recycling are as large, or larger, than the transportation emissions,” declared the report.
Call to other sectors
The GPI also issued a challenge to other packaging sectors to produce similar studies in a bid to advance the sustainability debate. It said the failure of other lifecycle assessments to follow a cradle to cradle approach meant “a good deal of scepticism had been injected into the sustainability debate”.
“We knew that for an LCA to be useful and to serve as an appropriate benchmark, it had to be cradle-to-cradle,” said Cattaneo. “For consumers and retailers to be able to compare the environmental impact of one packaging material to another, all industries should consider conducting complete life cycle analyses. Only then will we have clarity."
For more details on the study “Complete Life Cycle Assessment of North American Container Glass” contact the GPI at www.gpi.org
