Is creating plastics from biomass really a ‘green’ idea?

In the quest to add sustainability and green cred to plastics (which its detractors believe it lacks), many scientists continue their attempts to make plastic from various natural materials such as algae, switch grass, corn and sugar cane. Most of these scientists discount the fact that plastic made from petroleum is also natural—there’s nothing un-natural about petroleum or natural gas, as those materials are derived from nature, as Professor Emeritus Igor Catic of the University of Zagreb has written about in his various articles.

In a Jan. 23, 2018, article in Chem Europe, “Bio-renewable process could help ‘green’ plastic,” it was noted that plastic was developed more than 100 years ago to replace the use of ivory from elephant tusks in products, i.e. replace the natural product with a synthetic one. The fact that petroleum is a fossil fuel makes plastic no less natural than plastic made from grass or corn or sugar cane. However, the authors of this article note that plastics derived from petroleum contribute to a “reliance on fossil fuels” that drives “harmful greenhouse gas emissions.”

To change that, the article states that Great Lakes Bioenergy Research Center (BLBRC; Madison, WI) scientists are trying to take the pliable nature of plastic in another direction, developing new and renewable ways of creating plastics from biomass.

But just how efficient is biomass in producing plastics? And, given that all biomass contains CO2 (plants are massive storehouses for this critically necessary gas), just how much CO2 will be released into the atmosphere in processing biomass? Can it all be captured during processing and then used to make plastic in a new technology known as carbon upcycling technology?

According to a blog from Columbia University first published on Aug. 18, 2011, and updated on Oct. 19, 2016, by Renee Cha (“Is Biomass Really Renewable?”), biomass can be used in several ways. Those materials scientists seeking to replace plastics derived from natural petroleum and natural gas with natural biomass as a way to reduce greenhouse gases may be barking up the wrong tree.

“In 2010, a group of prominent scientists wrote to Congress explaining that the notion that all biomass results in a 100% reduction of carbon emissions is wrong,” Cha writes in her blog. “Biomass can reduce carbon dioxide if fast-growing crops are grown on otherwise unproductive land; in this case the regrowth of the plants offsets the carbon products by the combustion of the crops.”

Or, in the case of turning biomass into plastic, plant regrowth would be necessary to offset carbon emissions from the fossil fuels used to harvest, transport and turn the biomass into plastics via an industrial process. Cutting and harvesting various types of crops and grasses release the sequestered CO2 into the atmosphere. However, scientists now think they have figured out how to recycle waste CO2 back into plastic by carbon upcycling.

An article in on Jan. 21, 2018, notes that it’s been “clear for a while now that that there’s too much carbon dioxide in the Earth’s atmosphere,” so “scientists have come up with a new plan for dealing with all this excess CO2—converting it into plastic.” (But how much is too much? And since forests are growing much faster, will much of it be used to produce oxygen?)

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