(6dz) Systems Approaches to Design Sustainable Food-Water-Energy-Waste Nexus Processes and Systems

Research Interests: sustainability, food-water-energy-waste nexus, process systems engineering, mathematical modeling, optimization, ecology, life cycle assessment, smart and sustainable manufacturing

Sustainable Design of Food-Water-Energy-Waste Nexus Systems

Water, energy, and food are all fundamentally connected in a concept termed the Food-Water-Energy-Waste Nexus (FWEWN), and it is difficult to think of any human activity that does not depend on these resources. However, these systems are currently unsustainable. Over 650 million people do not have safe access to water, and expected increases in severe weather wrought by climate change will increase stresses on freshwater sources. Nearly 800 million people are undernourished, and mounting evidence suggests there is not enough land to support a projected 10 billion people by 2050 with a typical Western/American diet, especially if we also choose to produce biofuels from edible crops like corn or soy. The production, distribution, and consumption systems of water, energy, or food cannot be studied independently of the corresponding systems of the other resources. Thus, chemical engineers, and process systems engineers especially, are well-positioned to handle the challenge of designing sustainable processes and systems in the FWEWN.

Interconnected systems of food, water, and energy are often multi-scale both in space and time and involve multiple stakeholders with multiple objectives. Each of these properties defines significant research challenges for design of sustainable FWEWN systems. I have developed frameworks that systematically address these challenges for large biofuel and biochemical product and process networks, global biofuel production, and sustainable production networks. I presented the first ever framework integrating global, computable general equilibrium (CGE) models from economics to model global environmental impacts of production, like land use change. With our collaborators in mechanical engineering, I designed a framework to leverage emerging smart manufacturing technologies to not only increase economic efficiency, but also to limit energy consumption and emissions of a multi-stakeholder manufacturing network. In the future, I plan to integrate the developed multi-objective, multi-stakeholder approach into design of sustainable FWEWN systems and processes.

Ecosystem Services Valuation in Sustainable Design

Many systems including those in the FWEWN are intimately connected with ecological systems and processes (especially food production). However, design of chemical processes and supply chains based on interactions with natural ecosystems and their services is poorly understood and rarely considered. To address this challenge, I presented the first work that integrates different types of ecosystem service valuation methodologies into sustainable supply chain design, maximizing Green GDP (nominal GDP plus natural capital) as an objective. Three different valuation methods from ecological economics - the aggregated benefit transfer method, the hedonic method, and the avoided cost method - were integrated into a spatially-explicit supply chain decision-making model. Ecosystem services from forests, grasslands, rivers, wetlands, etc. were all considered. More tangible results surface when the values of ecosystem services lost or gained are calculated and presented for various supply chain decisions. Economically-driven decisions are familiar to both public and private actors, so such approaches can leverage existing ecological valuation methods to guide policy and supply chain design decisions that resonate directly with all stakeholders. I will use this foundational work to galvanize my future research to consider ecosystem services in multi-scale, multi-stakeholder decision-making models. The method also integrates GIS data analysis with mathematical programming, a research approach which I will also focus on moving forward.

Quantitatively Considering Social Sustainability

Sustainability is made of three pillars: economic, environmental, and social. We process systems engineers have devised sophisticated and effective means to design systems based on economic and environmental objectives. However, rigorous, creative approaches to model social sustainability in process and supply chain design are less developed. I pose that social sustainability can be modeled systematically with emerging methodology in social network analysis (SNA). New frameworks using SNA could help determine where facilities, plants, or processes should be located to maximize social good (perhaps through focusing on job creation in highly socially-connected areas), identify key stakeholders along the value chain, and evaluate how current facilities and supply chains are operating in terms of social sustainability. This new area of research will leverage my background on network optimization and large-scale data analysis.

Teaching Interests:

I am qualified to teach all core chemical engineering courses, but I am especially interested in teaching the introductory chemical engineering course, thermodynamics, mathematical optimization (especially geared towards chemical process or supply chain design), and courses on environmental/sustainability topics. At the graduate level, I will develop courses based on sustainable design of chemical processes and supply chains, as well as a course that defines, quantifies, and integrates problem solving in the Food-Water-Energy-Waste Nexus from a chemical engineering perspective.

Presentations at the 2018 AIChE Annual Meeting

Sustainable Engineering Forum (SEF) Plenary, David L. Lawrence Convention Center - 315, Wednesday, October 31, 9:30 AM: Addressing global environmental impacts including land use change in life cycle optimization: Studies on biofuels

Session: Design, Analysis, and Optimization of Sustainable Energy Systems and Supply Chains I, Tuesday, October 20, 12:52 PM: Methods for Quantitative Consideration of Ecosystem Services in Supply Chain Design and Optimization

Session: Sustainable Energy Generation and Utilization in System Design, Wednesday, October 31, 12:30 PM: Addressing Uncertainty in Large-Scale Bioconversion Product and Process Networks with Two-Stage Adaptive Robust Optimization

Selected Peer-Reviewed Journal Publications

Garcia, D., Lovett, B., You, F., Applying Ecosystem Service Valuation Methods in the Food-Water-Energy-Waste Nexus, In Preparation.

Garcia, D., Mozaffar, M., Ren, H., Correa, J., Ehmann, K., Cao, J., You, F. Sustainable Manufacturing with Cyberphysical Manufacturing Networks: Overview and Modeling Framework, Submitted.

Garcia, D. & You, F. (2018) Addressing global environmental impacts including land use change in life cycle optimization: Studies on biofuels. Journal of Cleaner Production, 182, 313-330.

Garcia, D. & You, F. (2017). Systems Engineering opportunities for agricultural and organic waste management in the food-water-energy nexus, Current Opinion in Chemical Engineering, 18, 23-32.

Gong, J., Garcia, D., You, F. (2016). Unraveling Optimal Biomass Processing Routes from Bioconversion Product and Process Networks under Uncertainty: An Adaptive Robust Optimization Approach, ACS Sustainable Chemistry & Engineering, 4, 3160-3173. Cover article, June 2016 issue

Garcia, D. & You, F. (2016) The Water-Energy-Food Nexus and Process Systems Engineering: A New Focus, Computers & Chemical Engineering, 4, 3160-3173.

Garcia, D. & You, F. (2015) Network-based Life Cycle Optimization of the Net Atmospheric Carbon Ratio (NACR) of Fuels and Chemicals Production from Biomass, ACS Sustainable Chemistry & Engineering, 3, 1732-1744.

Garcia, D. & You, F. (2015) Supply Chain Design and Optimization: Challenges and Opportunities, Computers & Chemical Engineering, 81, 153-170.

Garcia, D. & You, F. (2014) Multiobjective optimization of product and process networks: General modeling framework, efficient global optimization algorithm, and case studies on bioconversion, AIChE Journal, 61, 530-554.