"Lignin First" Catalytic Biomass Fractionation: Cooperative Research and Development Final Report, CRADA Number CRD-18-00765 (Project 3)

In this work, a continuous zwitterionic chromatography using simulated moving beds will be conducted to separate Li and Mg from brines.The existing program that ExxonMobil is carrying out with Clariant and Genomatica is consistent with all pioneer cellulosic fuels plants inasmuch as biomass enters the facility and is processed, in its entirety, through at least the hydrolysis step of biochemical conversion. This approach creates significant operating challenges as biomass can vary widely in composition and mechanical properties across and within a given biomass type. The proposed program involves a first step fractionation using solvolysis and reductive catalysis to generate a lignin oil containing well-defined monomers, dimers, and oligomers and a delignified cellulose/ hemicellulose pulp. The amount of lignin oil vs pulp and the type of monomers produced are expected to vary with biomass type due to differences in lignin composition and chemistry. The goal of the program is to determine a) if the pulp generated across biomass types is more consistent from a processibility standpoint (vs conventional steam explosion) and b) if a higher value disposition of lignin (vs power generation) can be developed. If successful, the program will: 1. Create a new biomass pretreatment scheme that avoids operability issues seen in thermomechanical systems through the use of chemical treatment while avoiding some of the unwanted side effects associated with existing chemical treatment approaches (i.e. organosolv). 2. Demonstrate the ability to convert recovered lignin into a form that will allow it to be hydroprocessed to fuels range molecules or higher value chemicals. This would replace the conventional approach of taking lignin and burning it in a lower efficiency power generation step. 3. Define potential continuous (vs batch) process embodiments for lignin solvolysis, concentrating, and downstream upgrading and develop a new continuous lignin-first processing experimental capability using a twin-screw extruder system that can support/test continuous processing schemes.