BIOBASED CHEMICALS
developed a portfolio of molecules out of two lignin-derived monomers .
Figure 2 - Para-aminobenzoic acid chemical structure ( right ) & Pili biobased version ( above )
Bio-BTX announced € 80 million funding for a commercial-scale facility to produce BTX from mixed plastics .
This consortium has recently gained additional industry interest , with Covestro joining . Additionally , some petrochemical plants have begun incorporating a fraction of waste-derived oils into their cracking unit supply , enabling them to claim circular content in their products .
Lignin-derived aromatics
A second approach to producing biobased aromatics involves extracting these compounds from wood . The cell-wall structures of trees contain lignin , a complex , partially aromatic polymer . As the second most abundant biopolymer on Earth , lignin is composed of propylphenol units and represents a potentially attractive and sustainable source of aromatics .
In terrestrial biomass , lignin acts as a glue and its extraction remains challenging . In order to extract clean cellulose for paper manufacturing , traditional pulping processes typically dissolve lignin under harsh conditions , leading to irreversible condensation .
Whilst aromatic units are connected by both ether and C-C linkages in native lignins , so-called technical lignins are mainly connected by
H 2 N
O OH strong C-C linkages , which are newly created during the extraction process . This is what makes the selective depolymerisation of technical lignins to mono-aromatics almost impossible .
Two strategies are currently under investigation to depolymerise lignin : The first involves treating woody biomass under hydrogen in alcohol as a solvent . The second employs stabilisation techniques , where reactive lignin sites are protected with chemical groups to prevent the undesirable and irreversible formation of C-C bonds , as demonstrated by Swiss start-up Bloom Renewables . This integral and controlled valorisation of the feedstock represents a promising path to reconcile price , performance and sustainability in the chemical industry .
Nonetheless , lignin-derived aromatic monomers mostly have a guaiacol or syringol core structure and must be functionalised with an additional chain of one to three carbon atoms . These functionalised compounds are highly valuable for speciality applications , such as nontoxic antioxidants , and intermediates for fragrances , pharmaceuticals and adhesives . Although achieving high selectivity towards monomers remains a key bottleneck , companies like Linium Biochemicals have
Fermentationderived anilines
French biotech Pili has recently announced the availability of tonnescale batches of biobased anilines produced via fermentation . This technology uses microbial cells and their enzymes to convert biomass into chemicals .
While fermentation has a milleniaold history in the production of wine or beer , for example , industrial fermentation has gained interest since the 1980s thanks to the rapid acceleration of genome manipulation , enabling the enzymatic production of chemicals not synthesised natively by the microbial host .
A landmark in this field was the commercial launch of insulin by Genentech , which paved the way for many other biotherapeutics . More recently , the key ingredients in BioNTech ’ s COVID-19 mRNA vaccines were produced via the fermentation of mammalian cells .
Antibiotics are also often produced by industrial fermentation . However , beyond pharmaceuticals , the white biotechnology sector has long awaited industrialscale breakthrough .
Focusing initially on the colour industry , Pili has been working since 2015 on the development and commercialisation of biobased aromatic building blocks and their conversion into dyes and pigments . This industry is a major consumer of aromatics , such as anilines , naphthalenes and anthraquinones , among others . Pili ’ s flagship product , a biobased indigo , was recently launched commercially in collaboration with the premium denim brand Citizen of Humanity .
After years of R & D , the company successfully produced its first industrial samples of anthranilic acid ( AA2-amino benzoic acid , CAS : 118- 92-3 , Figure 1 ) at 96 % purity , thanks to a network of subcontractors .
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