LCA study expresses caution over assuming bio-based is green

James Sherwood is a guest web-writer for Green Chemistry. James is a research associate in the Green Chemistry Centre of Excellence at the University of York. His interests range from the certification and application of bio-based products, to the understanding of solvent effects in organic synthesis.

A new study comparing life cycle assessments has shown that changing from a fossil derived feedstock to biomass is not necessarily beneficial to the environment. A reliance on food crops and inefficient conversion into chemical products will cause impact the environmental and result in an expensive product, also limiting its commercial opportunities.

Taking the example of hexamethylenediamine, the precursor to nylon-66, scientists based at Solvay in China have shown that the benefit of adopting a renewable feedstock (starch, in this instance) is counteracted by eutrophication concerns and greenhouse gas emissions. The issue largely stems from the cultivation of the biomass and the energy required to process the starch into chemical intermediates. The renewable route requires several high energy transformations to remove the original functionality of the biomass and obtain the conventional nylon monomer.

One lesson to be taken from this study is to give greater consideration to novel bio-based polymers that can be produced advantageously from bio-based feedstocks. Ideally, these would include wastes and agricultural by-products, thus making use of the reactive chemical groups inherent to the biomass rather than removing them.

Hexamethylenediamine (HMDA) from Fossil vs. Bio-based Routes: An Economic and Life Cycle Assessment Comparative Study

A. B. Dros et al., Green Chem., 2015, advanced article. DOI: 10.1039/C5GC01549A

Digg This
Reddit This
Stumble Now!
Share on Facebook
Bookmark this on Delicious
Share on LinkedIn
Bookmark this on Technorati
Post on Twitter
Google Buzz (aka. Google Reader)

Leave a Reply