Biomass Fractionation and Rapid Hydrolysis
PureVision’s core technologies are 1) the countercurrent reactor technology; 2) the biomass fractionation chemistry; and 3) the rapid biomass hydrolysis chemistry.For eight years, PureVision has been conducting continuous, countercurrent processing of cellulosic biomass at elevated pressures and temperatures. The company’s fractionation and rapid hydrolysis technologies are carried out in a significantly modified extruder. In the PureVision process, cellulosic biomass is size-reduced and fed into a pressurized reaction chamber uniquely designed for countercurrent processing. The PureVision technologies can be accomplished in a single stage or in multi-stages, depending upon the desired product and co-product targets. The PureVision technologies have enormous versatility and flexibility due to the countless processing variables that can be achieved with steady state, countercurrent processing.
The company’s fractionation technology separates the primary constituents of cellulosic biomass into three streams of a xylose-rich liquor, lignin-rich liquor and a solid cellulose fraction. In a two-stage set-up, the target within the reaction chamber is to first hydrolyze most of the hemicellulose that exits the reactor in the form of a xylose-rich liquor while keeping as much of the lignin and cellulose intact in a solid form. After the solids enter the second region of the reaction chamber, the pH, temperature and pressures are adjusted to mobilize and remove as much lignin as possible exiting the reactor in the form of a lignin-rich liquor fraction. What remains is the solid and relatively pure cellulose fraction.
The xylose-rich liquor fraction can be conditioned and used as the primary raw material for making many industrial and consumer products. The lignin-rich fraction can be further processed to produce a high quality, low-molecular weight lignin that can be sold as an industrial raw material to produce hundreds of industrial and consumer products or used as a bio-fuel to provide energy for making electricity and steam to run the biorefinery. The remaining cellulose fraction can be between 90% to 97% cellulose, as most of the lignin, hemicellulose and extractives have been stripped off in the wash liquor fractions. Because of the high purity of the cellulose fraction, it can be sold as a pulp or hydrolyzed into glucose.
PureVision’s latest technology breakthrough rapidly converts diverse cellulosic biomass into fermentable sugars in less than ten minutes without the use of enzymes or concentrated acids. The company’s rapid hydrolysis technique has the flexibility of producing separated or mixed concentrated sugars. Experimental proof-of-concept of the company’s rapid hydrolysis chemistry has been completed successfully at the Ft. Lupton laboratories. Plans to scale up the rapid hydrolysis technology are currently underway. PureVision is planning to have its first commercial-scale biorefinery installation completed in 2012.