Sonja Salmon

This fundamental research is motivated by three major global challenges that directly involve the transformation of gas molecules: carbon dioxide (CO2) capture for greenhouse gas mitigation, CO2 conversion to fuels and chemicals, and nitrogen (N2) gas conversion to biologically available ammonia to meet growing fertilizer demand. The research focuses on creating and investigating multi-functional interfaces that durably immobilize enzymes near their gaseous substrates while simultaneously delivering essential chemical and electrical reducing equivalents and removing reaction products to achieve maximum catalytic rates. Biocatalytic systems to be explored are: conversion of CO2 to bicarbonate catalyzed by carbonic anhydrase, reduction of CO2 to formate catalyzed by formate dehydrogenase, and reduction of N2 to ammonia catalyzed by nitrogenase. We envision that minimization of reaction barriers near immobilized biocatalyst interfaces involving gas molecule conversions will lead to transformative innovations that help overcome global sustainability challenges.

Interdisciplinary Doctoral Education Program will be created to focus on Renewable Polymer production using Forest Resources to Replace Plastics. PDs from three colleges will work together to train three Ph.D. students.

We propose to enzymatically deconstruct and separate synthetic/cellulosic fiber blend materials provided by the Sponsor.

Cotton is nature���s gift to the textile industry, with excellent physical properties, biological origins, and the ability to biodegrade. Using immersive, fun, thought-provoking hands-on laboratory experiences, inspired by on-going research in the Wilson College of Textiles on cotton biodegradability, we will develop a set of learning modules to direct the educational power of student interest in textile and apparel sustainability towards curiosity about cotton fibers and knowledge-building that can help them as young professionals to shape the sustainable future that is so important to us all, and to young people especially. These modules will be an innovative new offering, designed to become incorporated in core and elective courses in the undergraduate-level Polymer and Color Chemistry and graduate-level Textile Chemistry curricula. CottonWorks��� resources and information will be closely integrated into the project-based modules. Students will work in teams to select a variety of high cotton content fabrics with various dyes, finishes and embellishments, and will subject these to accelerated degradation using an Enzymatic Fiber Separation process developed at Wilson College. They will compare results, debate potential reasons for the outcomes, and consider creative uses for degraded cotton. After completing the modules, students will have a deeper appreciation for how cotton degrades, why this is an important attribute, how colorants and finishes can interfere, and they will gain inspiration for strategies to overcome these obstacles. At least 60 students will be directly involved during the grant period, with the goal of continuing to involve at least that many annually thereafter.

This project proposes to develop a novel, biological, sustainable and low energy CO2 scrubbing technique for CO2 utilization from waste gases. More specifically, we will use one of Nature������������������s fastest enzymes carbonic anhydrase (CA) to catalyze the reactive absorption of CO2 into aqueous alkaline solvents, thereby selectively removing CO2 from mixed gas streams for applications in biogas and natural gas upgrading, CO2 production, and CO2 capture for conventional and carbon-neutral biomass power. In the proposed process, under alkaline conditions, CA catalyzes the reaction of CO2 with water to form bicarbonate in a countercurrent gas-liquid absorber column, thereby removing CO2 from the mixed gas stream. CA is also capable of catalyzing the reverse reaction from bicarbonate to CO2 in the stripping column. To overcome the high energy requirement of traditional monoethanolamine (MEA)-based CO2 scrubbing process, we aim to develop more efficient technology by: 1) improving the robustness of CA, including tolerance to high temperature, high solvent concentration and high pH; 2) improving CA longevity using biodegradable enzyme-entrapping polymeric structures (BEEPS); and 3) utilizing compatible environmentally friendly solvents to improve process sustainability. The project will demonstrate the technology at bench-scale and generate TEA and LCA assessments to support our goal of enabling 20% energy reduction compared to the MEA reference case (at 90% CO2 capture), a favorable sustainability profile, and potential for capital savings due to use of benign solvents.

Around 10 million tons of post-consumer textile waste (PCTW) are disposed of in U.S. landfills annually, 8% of all municipal solid waste. PCTW is landfilled because it contains complex blends of natural and synthetic fibers that are not easy to recycle as well as dyes and other chemicals that interfere with reuse. Microbial communities in anaerobic digesters (AD) have the potential to convert natural fibers in PCTW to a useful biofuel, biomethane, as well as degrade associated dyes and chemicals. By gently deconstructing and separating PCTW into less complex material streams, it will be possible to recover valuable non-degraded fibers, generate co-products and efficiently treat residuals to divert PCTW from landfills. The goal of this project is to use mild enzymatic methods to convert PCTW from large heavy solids to pumpable slurries with compositions that are compatible with microbial growth in AD, while recovering non-degraded fractions for recycling.