Virent's biopetroleum catalysis system wins US green chemistry award
US biofuel producer Virent Energy Systems has been awarded the US Environmental Protection Agency (EPA)’s Presidential Green Chemistry Challenge Small Business Award for its development of a cost-effective and energy-efficient method of turning plant sugars into hydrocarbon fuels.
’Winning the award is a great honour - we were in competition with a lot of good companies,’ Randy Cortright, co-founder and chief technical officer of Virent, told Chemistry World. ’With the US looking to lower its CO2 footprint, this award gives us the recognition that we are at the forefront of providing technical answers that will allow us to reduce the CO2 footprint for the production of biofuels,’ he adds.
According to Cortright, Virent’s ’Bio-forming’ process produces between 30 and 50 per cent more energy per acre of biomass than ethanol for any given crop. And because the hydrocarbons produced are the same as those found in fossil fuels, vehicles do not need to be modified to use the biofuel as they would if they were to run on ethanol.
Hydrocarbon fuels also contain more energy per unit volume than the already partially oxidised ethanol, making them more efficient fuels for transportation purposes. This energy density is particularly important for aircraft, which need high energy fuels that don’t freeze at high altitude.
At the heart of the company’s technology is its aqueous phase reforming (APR) process, invented at the University of Wisconsin-Madison by Cortright and James Dumesic. The process catalytically converts sugars into hydrogen and chemical intermediates that can be processed into petrochemical fuels and products.
When the company was founded it started looking into producing hydrogen for fuel cell-powered vehicles, but with the price of oil increasing sharply the process was adapted to produce hydrocarbons - originally seen as a pesky by-product that ate up valuable hydrogen.
The process uses a catalyst similar to those used in the petrochemical industry and contains precious metals like platinum. According to Cortright, the catalyst works at low temperature and is formulated in such a way as to survive working in aqueous conditions.
’Our catalytic process only takes one to two hours, whereas the fermentation techniques normally used to generate biofuels can take days,’ says Cortright. ’Another advantage is that we are feedstock agnostic - we are not tied to a single sugar stream, which is a major issue for fermentation-based processes.’
An added problem with fermentation is that the ethanol needs to be separated from water - an energy-intensive process. ’Ethanol is a great molecule if you want to mix it to make drinks because it is completely miscible in water, but that’s bad when you want to make fuels as you have to remove the water - and that takes a lot of energy,’ says Cortright. ’In our system, because we make hydrocarbons that float on top of water, the separation step uses much less energy.’
With the help of investment from the venture capital arms of Honda and Cargill and a collaboration agreement with Shell, Virent is moving towards commercialising the process and should have finished constructing a large scale pilot plant capable of producing 10,000 gallons of biogasoline a year by the end of 2009.
By that time, the company also hopes to have completed a third round of financing, in which it aims to raise a further $40 million (?24 million) to add to the $70 million it has raised to date - and winning the prestigious Presidential award should help raise its appeal to investors. Looking further into the future, the company aims to build a 100 million gallon per year full-scale plant by 2015.
Matt Wilkinson
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