Available Technology

Ammonium-based Ionic Liquids for Lignocellulosic Processing 2014-167

Researchers at the Joint BioEnergy Institute (JBEI) led by Blake Simmons and Seema Singh have developed a cost effective pretreatment technology for lignocellulosic processing utilizing ammonium based ionic liquids (ILs) that perform efficiently in large amounts of water under low temperatures. This development is essential in the effort to use sustainable processes for the production of chemicals, materials, and fuels from alternative renewable sources such as biomass. The concept of inducing labile biomass deconstruction with reduced energy and minimal IL loading inputs for enzymatic saccharification is found in the Lab approach. Pretreatment of tetrabutyl-ammonium hydroxide (TBAH) containing 60% water is shown to dissolve 10 wt% of switchgrass under mild conditions at 50°C, with a 93±1.3% glucose yield after 3 hours. This indicates that the aqueous TBAH pretreatment significantly improves the accessibility of the cellulose present in the cell-wall matrix for creating fermentable glucose through enzymatic hydrolysis. The present day pretreatments of biomass include dilute acid, ammonia, and ILs, which are achieved with relatively severe conditions (~120-200°C) followed by a drastic variation of heating from 40-80°C for the enzymatic saccharification to yield around 60-90% sugar, depending on the selection of pretreatment methods. However, the ammonium based ILs pretreat biomass as efficiently as [C2C1Im][OAc], the current highest performing IL, as well as having the advantage of allowing pretreatment to be performed at low temperature (cutting 80% steam requirement) and in less than half the IL quantity (in presence of 60% water), outperforming current pretreatments methods with regards to glucose yield. In addition, these ammonium based ILs are affordable and biocompatible.
Comparable efficiency at lower temperatures and lower quantity than competitors - 93±1.3% glucose yield after 3 hours - Lower cost method compared to other ionic liquids - Potential to reduce pretreatment energy needs by 75% or more
Patent Status: 
Patent pending. Available for licensing or collaborative research.
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