Haldor Topsoe, Braskem investigate biobased ethylene glycol

Catalyst firm Haldor Topsoe and Brazilian petrochemical giant Braskem are building a demonstration plant in Denmark to test Topsoe’s new process for making ethylene glycol from sugar.

Ethylene glycol is reacted with purified terephthalic acid to make polyethylene terephthalate (PET), and beverage companies are on the hunt for a biobased route to this common beverage bottle plastic. Coca-Cola has used biobased ethylene glycol to make its PlantBottle since 2009.

The current method for making ethylene glycol from biomass involves fermenting sugar to ethanol, which is converted to ethylene and then on to ethylene glycol using conventional petrochemical processes. Two firms to have used this route are India Glycols and Greencol Taiwan.

Topsoe touts its process as simpler. The new route uses pyrolysis to break down sugars into mixed oxygenates. A Topsoe catalyst then hydrogenates the oxygenates into ethylene glycol and co-product propylene glycol.

Braskem already operates a 200,000-metric-ton-per-year plant in Brazil that makes polyethylene from ethylene derived from domestically sourced ethanol.

The ethylene glycol demonstration plant will open in 2019. The firms hope to start up a commercial plant by 2023.

James Iademarco, president of the consulting firm Strategic Avalanche, says ethylene glycol is a good biobased chemical target because commitments to biobased PET from companies such as Coca-Cola and Danone should support demand.

Topsoe’s sleeker route may prove cheaper than the ethanol-based route in the long run. “Any time you go from five to two steps, the promise is there,” he says.

But Iademarco points out that Avantium, which promotes polyethylene furanoate as a biobased alternative to PET, also has an ethylene glycol effort. And the Iowa Corn Promotion Board has filed a patent for a catalytic route.