VTT releases its last results in bioplastic development - FDCA and muconic acid

For many experts, 2,5-Furandicarboxylic acid (FDCA) is called upon to revolutionise the biobased plastics industry in the near future. The main production material of drinking bottles is still oil-based PET using purified terephthalic acid (PTA) and ethylene glycol (EG). However, FDCA can replace PTA to obtain PEF, a new high-performance biopolymer. Recently, the Blog devoted a whole post to FDCA (see FDCA biorefineries). Such post shows a non-exhaustive list of the most important processes developed or under research by companies and research institutes. VTT Technical Research Centre of Finland Ltd is working on one of them and it has just unveiled interesting information about it.

Last week, in the webinar “Green plastics without the bio-premium: FDCA and muconic acid transforming the industry”, this Finish centre introduced its work on the aforementioned furan derivative and on the muconic acid, another versatile chemical with potential to change the polymer industry. The muconic acid is a platform to produce adipic acid, tereftalic acid, hexamethylenediamine, caprolactam and many other chemicals.

VTT began to develop the processes for the production of these molecules in late 2012. It obtained funding from Tekes (the Finnish Funding Agency for Innovation) to research on FDCA in 2014 and on muconic acid in 2015. Currently, they are looking for partners to scale-up and commercialise the technologies. Some key points of the developments can be found here below.

First step	WO/2010/072902: Conversion of hexuronic acid to hexaric acid. Publication date: 01/07/2010.
Process	Biochemical oxidation of D-galacturonic acid to meso-galactaric acid (mucic acid).
Starting point	Pectins, a side stream obtained from citrus fruit peels or from sugar beet pulp, are rich in galacturonic acid.
Catalyst	Engineered fungal biocatalyst.
Status	The conversion efficiency is high and this step has been scaled up to pilot scale (300 l) delivering kilogram amounts of galactaric acid for the second step conversion.

Figure 1. Muconic acid route developed by VTT (source: VTT webinar material)

Second step	WO 2015189481 A1: Method for producing muconic acids and furans from aldaric acids. Publication date: 17/12/2015.
Process	- Catalytic dehydroxylation of galactaric acid into furan carboxylic acid (FCA) and FDCA or muconic acid depending on the reaction conditions. The catalysis can be selectively directed towards muconic acid route or furan route by only adjusting the reaction temperature and time (temperatures between 90-150 °C give muconic acid and between 150-300 °C give FDCA and FCA). - The method is green and results low energy consumption and low waste production. - First techno-economic and life cycle analysis show promising results.
Starting point	The aldaric acid obtained in the previous step. Aldaric acids are a group of sugar acids, where the terminal hydroxyl groups of the sugars have been replaced by terminal carboxylic acids. Nomenclature of the aldaric acids is based on the sugars from which they are derived. For example, glucose is oxidized to glucaric acid and galactose to galactaric acid.
Catalyst	Transition metal catalyst. For instance, Methyltrioxorhenium together with a light alcohol as a solvent and hydrogen as a reductant.
Status furan route	- TRL 5. - Batch production. Developments underway to produce FDCA on a continuous process. - Downstream processing is the hardest part. They have the answer to get pure FDCA and FCA esters readily.
Status muconic acid route	- TRL 5. - Feasibility is dependent upon both choice of solvent and yield obtained. - It is a relatively simple process suited to scale-up. Biotech raw material can be directly used without costly purification. - Next steps: improvement of the reaction efficiency and catalyst reuse, development of isolation and decolourising route.