Abstract:
A process is provided for producing a biomass-derived rheology modifier, comprising: providing a pretreated feedstock comprising cellulose-rich solids; refining the cellulose-rich solids in a first high-intensity refining unit, generating refined cellulose solids; gelling the refined cellulose solids in a second high-intensity refining unit, thereby generating gelled cellulose solids; and homogenizing the gelled cellulose solids in a high-shear homogenizer, thereby generating a biomass-derived rheology modifier. The pretreated feedstock may include kraft pulp, sulfite pulp, AVAP® pulp, soda pulp, mechanical pulp, thermomechanical pulp, and/or chemimechanical pulp, derived from wood or lignocellulosic biomass. The pretreated feedstock may be GP3+® pulp, obtained from steam or hot-water extraction of lignocellulosic biomass. These rheology modifiers may be utilized in a wide variety of applications, including water-based or oil-based hydraulic fracturing fluid formulations, as gelling agents. These rheology modifiers are biodegradable, and their production does not directly involve chemicals other than biomass and water.
Abstract:
The invention provides a continuous process for enzymatic hydrolysis of pretreated biomass, the process comprising: providing a pretreated lignocellulosic biomass feed material containing cellulose; introducing the pretreated lignocellulosic biomass feed material to a mechanical-treatment unit containing one or more decompression regions configured to release pressure; introducing a liquid solution containing cellulase enzymes to one or more decompression regions in the mechanical-treatment unit, wherein the liquid solution enters void spaces between fibers of the pretreated lignocellulosic biomass feed material, to form enzymecontaining cellulose-rich solids; and retaining the enzyme-containing cellulose-rich solids under effective hydrolysis conditions to hydrolyze at least some of the cellulose to glucose. Various apparatus configurations are disclosed for the mechanicaltreatment unit.
Abstract:
A wet process for cleaning biomass is disclosed, comprising: introducing biomass feedstock to a vibrating separator, to generate an overflow stream and an underflow stream, wherein the overflow stream comprises biomass and large grit, and wherein the underflow stream comprises fines and small grit; introducing the overflow stream to a kinetic separator, to generate an intermediate biomass stream and a large-grit stream; introducing the underflow stream and elutriation water to a hydroclone separator, to generate a wet biomass-fines stream and a small-grit stream; separating water contained in the wet biomass-fines stream and recycling it as elutriation water, to generate a biomass fines stream; and combining the biomass fines stream with the intermediate biomass stream, thereby generating clean biomass. An alternative embodiment for a dry process to clean biomass is also disclosed. The clean biomass may be used in a wide variety of biorefining processes.
Abstract:
The disclosure provides a process for separating fermentation inhibitors from a biomass-derived hydrolysate, comprising: introducing a biomass-derived liquid hydrolysate stream to a stripping column; introducing a steam-rich vapor stream to the stripping column to strip fermentation inhibitors (such as acetic acid) from the liquid hydrolysate stream; recovering a stripped liquid stream and a stripper vapor output stream; compressing the stripper vapor output stream; introducing the compressed vapor stream, and a water-rich liquid stream, to an evaporator; recovering, from the evaporator, an evaporated liquid stream and an evaporator output vapor stream; and recycling the evaporator output vapor stream to the stripping column as the steam-rich vapor stream. Other variations utilize a rectification column to recover a rectified liquid stream and a rectification column vapor stream, and recycle the rectification column vapor stream to the stripping column as the steam-rich vapor stream.
Abstract:
This disclosure provides drilling fluids and additives as well as fracturing fluids and additives that contain cellulose nanofibers and/or cellulose nanocrystals. In some embodiments, hydrophobic nanocellulose is provided which can be incorporated into oil-based fluids and additives. These water-based or oil-based fluids and additives may further include lignosulfonates and other biomass-derived components. Also, these water-based or oil-based fluids and additives may further include enzymes. The drilling and fracturing fluids and additives described herein may be produced using the AVAP® process technology to produce a nanocellulose precursor, followed by low-energy refining to produce nanocellulose for incorporation into a variety of drilling and fracturing fluids and additives.
Abstract:
A low-cost process is provided to render lignocellulosic biomass accessible to cellulase enzymes, to produce fermentable sugars. Some variations provide a process to produce ethanol from lignocellulosic biomass (such as sugarcane bagasse or corn stover), comprising introducing a lignocellulosic biomass feedstock to a single-stage digestor; exposing the feedstock to a reaction solution comprising steam or liquid hot water within the digestor, to solubilize the hemicellulose in a liquid phase and to provide a cellulose-rich solid phase; refining the cellulose-rich solid phase, together with the liquid phase, in a mechanical refiner, thereby providing a mixture of refined cellulose-rich solids and the liquid phase; enzymatically hydrolyzing the mixture in a hydrolysis reactor with cellulase enzymes, to generate fermentable sugars; and fermenting the fermentable sugars to produce ethanol. Many alternative process configurations are described. The disclosed processes may be employed for other fermentation products.
Abstract:
The present invention provides a method of treating a fermentation stream to remove dissolved gases, comprising obtaining a fermentation stream including water, one or more fermentation products, and dissolved gases; continuously sonicating the fermentation stream to generate acoustically cavitated gases from the dissolved gases; and applying vacuum to release the acoustically cavitated gases from the fermentation stream. The dissolved gases may include air, oxygen, nitrogen, helium, argon, carbon dioxide, carbon monoxide, hydrogen, or other non-condensables. The release of acoustically cavitated gases may optionally be done simultaneously with sonication. At least 75 %, such as up to 95 % or more, of the dissolved gases may be released from the fermentation stream. The disclosed method positively impacts downstream operations and product quality by removing dissolved gases.