1437965 (Zimmerman), 1437595 (Beckman), and 1437688 (Soh). Biomass has potential to meet many of society's energy and chemical needs, replacing the need for fossil fuels, while minimizing environmental impact. In this project, a biorefinery approach will be explored to achieve viable and sustainable utilization of biomass for fuels and valuable co-products. Analogous to petroleum refining for a wide spectrum of products, biorefining maximizes utilization of all fractions, reducing economic and environmental barriers. In addition to fuel, some of the components also represent a palette of higher-value, non-fuel products such as nutritional supplements and feedstocks for bioplastics. There are orders of magnitude differences in the value of products that can be produced depending chemical structure and intended end-use (i.e., fuel, fine chemicals, nutraceuticals). Advances in selective, efficient, and sustainable technologies for the extraction and conversion of lipids from crude biomass are essential to enhance a transition to a biobased economy. This project will develop separation and processing techniques that are robust, selective, and tolerant of varying biomass compositions, to gain economic and environmental benefits through a biorefinery approach.
The overall aim of this work is to fundamentally understand the system variables for extraction, fractionation and transformation of minimally processed biomass to produce fuel and other value-added co-products using a carbon dioxide and methanol mixture for efficient processing and separation. The work will model the fundamental system properties based on experiments with representative compounds and in turn the model will be used to control processing of real world wet biomass samples. The specific aims of the project are: 1) Ascertain and model the phase behavior of systems consisting of methanol, CO2, trans-esterification reaction substrates (reagents, intermediates, and products/byproducts), with or without water, to better understand the necessary operating conditions for conversion and fractionation of fatty acid methyl esters; 2) Evaluate and optimize heterogeneously catalyzed trans-esterification in CO2-methanol for selective conversion of model lipids and recovery of specific methyl ester fractions; 3) Apply experimentally determined parameters and model outcomes to optimize conversion and fractionation of real world biomass feedstocks including pre-extracted oils, waste feedstocks, and wet algal biomass; 4) Perform process design, life cycle assessment, and techno-economic analyses for informing system design to integrate this technology into a biorefinery setting. As such the efforts of this collaborative research will provide information on system fundamentals as well as the broader economic and environmental impacts of the system if implemented effectively. The project intrinsically provides student-learning opportunities in terms of high level research as well as educational resources regarding sustainability. The design approach modeled in this project provides an example of life cycle thinking mitigating the potential for unintended consequences. Graduate student researchers will have the opportunity to translate experimental results into educational materials, to be delivered on campus, in the community, and also globally via online curricula. Undergraduate researchers will be recruited through campus programs that support students from groups that are historically underrepresented in science, technology, engineering, and mathematics (STEM). The project will be used in undergraduate process design courses, integrating sustainability and green design into the core chemical engineering curriculum. Further, a short-course will be developed between the collaborators in the topic of green engineering and sustainable design, using this project as an example platform with developed materials made publically accessible. In terms of K-12, the project will be used to expand on established relationships serving underrepresented populations. Efforts will range from "greener" school competitions for Grades 6-8, to a focused experience for early high school students associated with a 3-week program in residence on campus. A new course, "Energy and Sustainability" will be designed and implemented to reinforce scientific principles that students will have learned in their 9th grade physical science class and to prepare these students for their 10th grade biology and 11th grade chemistry classes while introducing concepts of green design.
