Recovering liquid lignin as a renewable biofuel or biopolymer
Julian Velez, Adam S. Klett, Mark C. Thies
Mark C. Thies
Chemical Engineering (College of Engineering and Science)
Lignin is the second most abundant biopolymer on earth and has the potential to become an inexpensive and renewable platform for the production of aromatic chemicals, bio-based materials, and clean biofuels. Isolating lignin from paper mill black liquor in a dry, low-ash state would result in an excellent biofuel with essentially the same energy content as coal. In collaboration with Liquid Lignin Company, we have developed the SLRP® process for recovering from paper mill black liquors a liquid-lignin phase of reduced ash content in the form of a low-viscosity, easy-to-process fluid. The properties of this liquid lignin are such that a very low ash (< 1.0 wt %) lignin can readily be produced from it. In this work, we study the phase behavior and molecular properties of the liquid-lignin phase isolated from papermill black liquor in order to produce a more effective and efficient recovery of the lignin, as well as to produce liquid-lignin fractions with the desired properties for the convertion of lignin into bio-based materials and chemicals.