Odor‐Free Lignin from Lignocellulose by Means of High Pressure Unit Operations: Process Design,Assessment and Validation

In this work a process for the production of odor‐free lignin from wheat straw using solely water, enzymes and CO₂ is described. Wheat straw pellets are pretreated by liquid hot water and enzymatic hydrolysis in a pilot plant with a capacity of 40 L, which enables the production of 3 – 4 kg of Aquasolv lignin per batch. Dried lignin samples are further treated using supercritical CO₂, resulting into extraction of a large number of odorous free fatty acids and volatile organic compounds. All process steps can be sequentially conducted in a fixed‐bed via different sustainable solvents in a throughput regime.