By Malini Hariharan
Work on commercialising a green route to paraxylene (PX) purified terphthalic acid (PTA) and other aromatics is speeding up.
US companies are at the forefront of recent developments. Virent is looking to produce a sugar-based aromatics stream containing benzene, toluene and xylenes using traditional chemical catalytic processing, writes fellow blogger Doris de Guzman in the latest issue of ICIS Chemical Business.
The company expects to have its first commercial-scale bio-PX plant on line by 2015.
Gevo plans to produce bio-based PX by converting fermentation-derived isobutanol to PX and is targeting commercial production by 2014. The company has already tied-up with Coca-Cola and Toray Industries, which claimed in November last year that it was able to develop the world's first 100% bio-PET fiber in a laboratory scale using Gevo's bio-PX.
Another US company, Avantium, is developing a new sugar-based monomer called furan dicarboxylic acid (FDCA), which can be reacted with monoethylene glycol (MEG) to make polyethylene furanoate (PEF), an alternative to PET resin.
Even SABIC is not ignoring the green wave, and has filed a patent claiming PX production via use of terpenes such as limonene found in citrus fruits.
However, the new routes come with many disadvantages and work still needs to be done on oensuring commercial viability.
Eric Bober of Nexant ChemSystems points out that capital expenditures for the initial commercial plants will be high, as these are first-of-a-kind plants as opposed to the 'nth' plant status of petrochemical facilities. A world-scale conventional PX plant is now 1m tonnes/year and likely four times as large as a bio-PX line.
Bio-derived products will likely locate near the available renewable feedstocks, which could increase logistics costs relative to the conventional supply chain.
Despite these issues, the enthusiasm for these new routes is still strong given the support from consumer product companies that are willing to pay a premium for these 'green' products. But will this continue in the changing economic climate where the focus is clearly on cutting costs?