Is a Negative CO2 Footprint Possible?
by Jenna Watson, Barcelona on 11. 2.07
We’ve told you about Metabolix and their bioplastic resins. Recently the producers of the corn-based plastic resin, Mirel™, released the results of a life cycle assessment conducted by chemical engineers at Michigan State University. They determined that, “production of Mirel reduces the use of nonrenewable energy by more than 95% and provides a 200% reduction in greenhouse gases (GHG) compared to production of conventional petroleum-based plastics.”
The article notes that Mirel is made from corn and uses renewable energy for production. The LCA study measures the impacts of the resin from “cradle to factory gate” and says that Mirel actually has a negative net CO2 footprint. They also compare Mirel to other olefins such as polypropylene and polyethylene, saying that the biobased plastic requires only 2.5 MJ/kg of nonrenewable energy per kilogram verses 70 MJ/kg. The full LCA is not available yet online, but we look forward to seeing the published results. Read the full story here. Image via the Metabolix website.
More on green plastics here and here.
Visit the Metabolix website here. Via: Stockhouse.
It is actually possible to have a negative carbon footprint (the nomenclature is not yet settled; I've seen the term "carbon positive" to describe something that takes up carbon rather than releasing carbon dioxide emissions–here on Treehugger, in fact).
If you think about it proper sustainable harvest of timber and the use of wood for buildings and things such as archival paper have a net negative carbon footprint for the wood, though not for the machinery if it burns fossil fuels; the machinery's operation can be made carbon neutral if it uses biodiesel. The carbon in the wood comes from carbon dioxide drawn out of the air; if that wood is then used to build a permanent structure or made into paper that is then used to print documents that are archived, that carbon is locked away unless the building or the paper burns. In that sense, anything that uses a plant product to make something permanent has a negative carbon footprint until / unless the thing burns.
They have a ways to come with the corn plastic. I can buy a corn plastic travel cup from the fair trade coffee supplier, but it may melt when I pour my coffee into it!