Solids Separation for a Feedstock-Flexible Biorefinery

Hyrax Energy, Inc. is the first company to spin-out of the DOEs Great Lakes Bioenergy Research Center (GLBRC) and is the exclusive owner of intellectual property that enables biorefineries based on ionic liquids that that operate at a fraction of the cost and carbon footprint of competing technologies. Ionic liquids are true solvents for cellulose, which promises amongst other things to greatly simplify the feedstock supply chain by processing many different non-standardized and non-pre-processed feedstocks including mixtures thereof in a single facility. However, the higher cost of ionic liquids ($10/kg) requires a more stringent recovery method from solid by-products (lignin, ash and proteins) than would be needed for a common organic solvent ($1-3/kg). Here we propose to develop a method to separate solid by-products and recover ionic liquid solvent with very high recovery ratios. In Phase I, we will employ standard filtration and water- wash equipment to separate solids and recover & gt;99.9% of the ionic liquid (solids mass basis). Here, our focus will be placed on selecting equipment specs, operating conditions, and number of unit operations in series. Pressurized CO2 may be attempted as a means to enhance solids removal (by anti-dissolution) and ionic liquid recovery (by expanding fibrous particles). In Phase II, we will build and test a solids recovery module that will be integrated into our demonstration plant (1-5 ton/day). Extended operation of the demo plant will generate sufficient data to determine the economic viability of this strategy, the critical hurdle to enable a potentially game-changing cellulosic sugar biorefinery.