Dierlijk vet

Ecoson (te Son), onderdeel van VION, verwerkt jaarlijks 100.000 ton vetten en andere dierlijke reststromen. Er gaan dierlijke bijproducten in en er komt biodiesel, electriciteit en warmte uit.

Drie processen: vergisting, raffinage, productie biodiesel

In het raffinageproces doorloopt het dierlijk vet eerst een reinigings- en zuiveringsproces om vrije vetzuren af te scheiden. Dit pure vet gaat naar de biodiesel-productie, waarbij biodiesel ontstaat met als bijproduct glycerine.

Door methanol toe te voegen aan het gezuiverde vet zet een eerste unit het vet voor 90% om in biodiesel. Na toevoeging van nieuwe methanol maakt een tweede unit van het resterende vet biodiesel. In een derde unit wordt het surplus aan methanol afgescheiden, dat opnieuw het proces in gaat.

24-4-2009 Codexis --a privately held Silicon Valley enzymes company--is on firm ground, in large part because of the Shell deal. It already has revenues--$50 million in 2008--from its biocatalyst and enzyme business with pharmaceutical companies like Pfize

In 2006 and 2007, Shell invested $33.5 million for a 13% stake in Codexis; it made an additional equity investment (the amount was undisclosed) in March this year. Shell pays Codexis' biofuels research costs and will pay a royalty upon commercialization.

Codexis Redwood City, Calif., which was spun out of biotech company Mayxgen in 2002, is working with Shell to produce enzymes that will break down a variety of biomass (such as wheat grass) to turn it into fermentable sugars, which can then be made into cellulosic ethanol. A variety of companies, including Genencor (a unit of Denmark's Danisco) and Novozymes, have spent decades in the enzyme business and are working on similar projects.

But Shaw says Codexis has a unique approach in enzyme production. Instead of finding existing enzymes in places like termite bellies and improving them, Codexis scientists follow what Shaw calls an evolutionary approach. They start with DNA information of an enzyme and do sexual reproductions of millions of parents and millions of offspring, using computing power. "Each time [the enzymes] get incrementally better. This is a random but directed process," Shaw says.

Codexis is also working on improving the productivity of the fermentation process using designer microbes. Shaw says the whole process will be up and running and making money for Shell and Codexis by 2013.

Shell, meanwhile, has partnered with several companies in the biofuels sector, including Iogen in Canada, which is making cellulosic ethanol out of wheat straw. Last month, Shell announced that all its future investments in alternative energy would focus on biofuels and carbon capture and storage. Scoffone explains that "sustainably sourced biofuels could make a substantial contribution to reducing CO2 emissions. Second, they are a natural fit with our downstream capabilities in transport fuels."