As the world?s population and energy demands increase, our global reliance on fossil fuel resources to provide this energy puts an incredible strain on the environment. The modern biorefinery could produce sustainable energy by converting lignocellulosic biomass to fuels through thermal and chemical routes. However, one of the primary issues with using pyrolysis (heating in the absence of oxygen) as a thermochemical conversion technique is the need for significant fuel upgrading to improve stability and increase the heating value of the oil. Though bio-oils can be upgraded post-production, current methods suffer from catalyst poisoning and high materials and operation costs. This research project aims to address these issues by incorporating inorganic compounds, such as metal nitrates and acetates into cellulosic feedstocks, to simultaneously engineer high-value nanomaterials via bio-templating and catalytically upgrade pyrolysis bio-oils, thus reducing the need for costly downstream upgrading. Using machine learning based techniques, such as materials informatics for potential catalyst selection and statistical design of experiments, to inform process variable decisions, the proposed work will add to a fundamental body of knowledge on in situ upgrading of thermochemically derived biofuels while offering a new paradigm in computationally informed, experimentally verified renewable fuel design.
The proposed research will focus on upgrading of biofuels during pyrolysis by simultaneously making bio-templated nanoparticles. Materials Informatics approaches will be used to select in situ pyrolysis catalysts and surrogate reactions will be used to predict (and then validate via integrated feedback loop) potential reaction pathways and formed nanomaterial structure. By developing a new Pyrolysis Product Index that looks at where, for example, oxygen goes during pyrolysis, and how yields of marker compounds change upon catalyst incorporation, the principal investigators aim to synthesize a new way to discuss biofuel upgrading pathways, helping to standardize what is a rather diverse literature in terms of what is deemed to be a good pathway. The project also aims to elucidate the physical changes occurring during pyrolysis of metal-impregnated biomass using in operando Raman spectroscopy through an international collaboration with a group from Queens Mary University (United Kingdom). The objective is to improve our knowledge of which reaction pathways are most critical to devolatilization, and how to better design catalysts to improve both primary pyrolysis and to limit secondary reactions, such as re-condensation, and to promote cracking, thereby reducing tar formation. The proposed work also involves nanomaterials characterization to understand the process variables impacting size, morphology and crystallinity of bio-templated nanomaterials. Advances in fundamental science stemming from the proposed work may lead to the design of an optimized integrated biorefinery to convert renewable sources to energy and materials. In addition to training graduate and undergraduate students in research, there ae plans to engage and mentor underrepresented students and develop and international graduate student exchange between Cornell, Boston and Queen Mary Universities. An active learning module for renewable energy applications will be developed, implemented and assessed in the three participating universities.
This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
