Processes for producing lignin-coated hydrophobic cellulose, and compositions and products produced therefrom

A process for producing a lignin-coated cellulose material, said process comprising:

• (a) providing a lignocellulosic biomass feedstock;
• (b) fractionating said feedstock in the presence of an acid, a solvent for lignin, and water, to generate cellulose-rich solids and a liquid containing hemicellulose and lignin, wherein said feedstock, said acid, said solvent for lignin, and said water are all contained together in a digestor;
• (c) depositing at least some of said lignin, from said liquid, onto a surface of said cellulose-rich solids to generate a lignin-coated cellulose material containing cellulose particles having a surface concentration of lignin that is greater than a bulk concentration of lignin;
• (d) mechanically treating said lignin-coated cellulose material with a total mechanical energy of less than about 1000 kilowatt-hours per ton of said lignin-coated cellulose material, wherein said mechanically treating releases cellulose fibrils and/or cellulose crystals;
• and
• (e) recovering said lignin-coated cellulose material,
• wherein cellulose crystallinity of said lignin-coated cellulose material is at least 60%,
• wherein said lignin-coated cellulose material is at least partially hydrophobic, and
• wherein said lignin-coated cellulose material is lignin-coated microfibrillated cellulose or lignin-coated microcrystalline cellulose.