Process Economics Program Report 265

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Bioplastics sometimes referred to as biopolymers are defined in this report as a class of compounds where at least a portion of the polymer consists of material produced from renewable sources. During the 1990s the chemical industry began exploring bio-based or renewable feedstocks for producing chemicals. Several trends are responsible for stimulating this interest in renewable feedstocks. Environmental concerns over the use of petrochemicals have grown due to global warming and the connection between petrochemicals as a source of carbon dioxide in the atmosphere. Also, the concept of sustainability and “carbon footprint” became prominent with politicians as well as in industry.

Polylactide (PLA) and polytrimethylene terephthalate (PTT) are two leading bio-derived polyesters available commercially. Lactic acid has been manufactured by fermentation for decades and serves as the feedstock for the biodegradable polymer PLA. PDO (1,3- propanediol) has been produced by fermentation since 2006, but is also produced from a petroleum–based process and is copolymerized with petroleum-based terephthalic acid to produce PTT.

Specifically, this report examines the production of the biomonomer lactic acid (LAC) by fermentation for the production of PLA and the production of the biomonomer PDO by fermentation and its reaction with terephthalic acid to produce the bioplastic PTT.

For those engaged in the production of biopolymers and their petroleum-based competitors, it is useful for its comparative economics and understanding of the importance of feedstock costs to the overall economics of biopolymers.