More than 30 billion tons of carbon dioxide are released into the atmosphere every year, creating a warming greenhouse gas resulting in climate change.
Some companies have been exploring the potential of making plastics from waste carbon dioxide instead of fossil fuels, a game changer for a material often attacked by environmentalists.
The potential for plastics to be made from carbon gases is now getting a boost from The Coca-Cola Company, which is already leading the charge to make plastics from renewable feedstocks, such as Brazilian sugar cane.
A New Jersey company called Liquid Light announced it has signed a technology development agreement with Coca-Cola to accelerate the development of a technology to make mono-ethylene glycol (MEG) from carbon dioxide (CO2).
MEG is one of two primary chemical components of polyethylene terephthalate (PET) used to make soda bottles. MEG makes up 30 percent of the PET by weight, and PTA (purified terephthalic acid), makes up the other 70 percent. In recent years, Coke has been increasing the use of PTA made from sugarcane ethanol produced in Brazil.
Coke says that its ultimate goal is a carbon neutral, 100 percent renewable bottle that is fully recyclable.
Producing MEG from renewable resources has been a tougher problem.
Liquid Light says its approach captures carbon dioxide emitted when plant material such as corn is converted into ethanol that is used as a fuel. That approach could reduce the costs to produce bio-MEG, and make it more viable as a plastic feedstock.
Liquid Light’s core technology focuses on low-energy catalytic electrochemistry to convert CO2 to multi-carbon chemicals. It extends to multiple chemicals with large existing markets, including ethylene glycol, propylene, isopropanol, and acetic acid.
Liquid Light’s investors include VantagePoint Capital Partners, BP Ventures, Chrysalix Energy Venture Capital, Osage University Partners and Sustainable Conversion Ventures.
Coca-Cola estimates that it has eliminated 319,000 metric tons of carbon dioxide emissions since it first began distributing bottles made from renewable resources in 2009. That’s the equivalent of CO2 emissions from burning 743,000 barrels of oil or 36 million gallons of gasoline.
In Germany, Bayer MaterialScience (soon to be Covestro) has been using waste carbon dioxide from a power plant to manufacture samples of polyols used to make polyurethane foam. Bayer reports that the test foams are just as good as those produced with petroleum. The carbon dioxide comes from a power plant near Cologne, Germany, operated by power producer RWE. CO2 is removed from flue gas and liquefied for transportation.
The project is funded by the German Federal Ministry of Education and Research.
“This new process was made possible by a scientific breakthrough,” says project manager Christoph Gürtler. “We finally succeeded in finding the right catalyst after the scientific community spent decades searching for it.” A catalyst is required because carbon dioxide is chemically inert and does not react readily on its own with other substances.
There are also efforts under way to produce plastics directly from waste methane.
NatureWorks, a leading global producer of bioplastic PLA is working with a company called Calysta to study the potential of converting methane gas into plastics. Methane generated from municipal and agricultural waste is as much as 30 times stronger as a heat-trapping greenhouse gas than carbon dioxide.
“Direct conversion would significantly lower NatureWorks’ cost structure and continue our mission of creating performance products that have a low environmental footprint,” says Steve Davies, global director of communications and public affairs for NatureWorks.