- Category: Bioenergy
05 Feb 2013
- Published on Tuesday, 05 February 2013 09:17
- Hits (2666)
Blending different types of biofuel feedstocks – instead of focusing on just one source – can help make biofuels a cost-competitive transportation fuel technology.
A team of researchers from the U.S. Department of Energy’s Joint BioEnergy Institute, led by Berkeley Lab along with the Idaho National Laboratory, have found that ionic liquid pretreatment is effective with mixed biofuel feedstocks.
Ionic liquids are environmentally benign organic salts often used as green chemistry substitutes for volatile organic solvents. They have been used to pre-treat biomass allowing easier breakdown of cellulose for the release of fermentable sugar.
This is the first demonstration that ionic liquid pretreatments can effectively handle mixed and densified feedstocks or milled biomass feedstocks that are in the form of flour or pellets. These feedstocks have a higher energy density and are also easier to store and transport than unmilled biomass.
“Our results show that an ionic liquid pretreatment can efficiently handle mixed feedstocks that have been milled and densified into pellets, and can generate high yields of fermentable sugars regardless of upstream processing,” said Blake Simmons, a chemical engineer with J.B.E.I.
The team studied four biomass feedstocks – switchgrass, lodgepole pine, corn stover and eucalyptus - that were mixed and milled into either flour or pellets then pre-treated with the ionic liquid 1-ethyl-3-methylimidazolium acetate.
They found that, within 24 hours, sugar yields of up to 90 percent were obtained from the pretreated mixed feedstock. This increases the variety of feedstock that biorefinaries can use to obtain fermentable sugars for biofuels.
“Biorefineries must be able to efficiencty process available regional feedstocks at cost-competitive prices year round, but feedstocks markedly vary from region-to-region,” explained Seema Singh, director of J.B.E.I.’s Biomass Pretreatment Group.
Blending and densifying different feedstocks into a single uniform feedstock will help a biorefinary get around these regional variations and better make use of what is available when it is available and stabilize the supply.
The researchers will continue to work with mixed feedstocks, this time based on targeted regions of the United States, to further determine how their process can better convert these mixtures into fermentable sugars. – EcoSeed Staff