SELECTIVE CO2 SEQUESTRATION IN LIGNIN-BASED CARBON COMPOSITE MEMBRANES VIA NANOSCALE ENGINEERED QUADRUPOLE MOMENTS OF ADSORPTION SITES

The global objective of this project is to reduce the impact that energy production has on the environment. We will do this by engineering lignin based carbon fibers to selectively capture carbon dioxide from exhaust air and combustion gases. We address USDA's program priority by adding significant value to lignin, a nonfood coproduct of paper and biofuel production, while reducing carbon emissions. Lignin is primarily produced in rural areas, and the addition of a high value product would add to a local rural economy. We will accomplish this objective by 1) synthesizing lignin activated carbon fibers (LACFs) decorated with carbon quantum dots (CQDs) to 2) selectively capture carbon dioxide gas from combustion processes by tailoring adsorption sites of LACFs to exploit the much larger quadrupole moment of carbon dioxide relative to other flue gases, such as nitrogen and oxygen; by 3) ahigh-throughput modeling effort will identify optimal CQD architecture (size, functionality and extent of heteroatom doping) for target LACF/CQD membranes based on a binding strength indicator; 4) the top candidates will be synthesized and tested for adsorption selectivity. The modeling process will be informed and refined iterativel by analytical analysis. We will test the hypothesis that we can synthesize LACF/CQD membranes tailored to achieve carbon dioxide selectivity, performance, and cost-point for large-scale deployment. By testing this hypothesis, we gain a fundamental understanding into the processing-structure-property-performance relationship of LACF/CQD resulting in the development of a practical membrane. We will achieve this through four targeted project aims: 1) make LACFs and CQDs,2) determine physicochemical composition of LACF/CQD membranes,3) compute and evaluate selective binding of carbon dioxide based on models and then characterization of the membranes as input, and4) assess membrane performance and inform the model.We will leverage this research to train graduate and undergraduate students to use the methods described to rapidly develop biomaterials by combining modeling and experimental methods to determine processing-structure-property-performance relationships.In turn, we will strive to have stakeholder involvement to guid materials development and student training.