(363b) Synergy of Technological and Ecological Systems for Self-Reliant Process Design

Traditionally, chemical engineers apply man-made technological principles to design processes that solve practical industrial problems. However, the multitude of goods and services that are extracted as well as those that could be used from nature are usually ignored. This has led to the deterioration of many ecosystems due to industry operating outside the constraints applied by nature and unnecessarily forced engineers to look past the industrial application of nature's unit operations. For example, the natural carbon cycle has been overwhelmed by anthropogenic sources beyond its carrying capacity causing an increase in greenhouse gas concentrations in the atmosphere. Natural goods that were once considered free and infinite such as water and air are now recognized as prized resources and should be considered as such in process design. To responsibly manage these resources and ensure their sustainability, the design and use of natural processes may be required. For example, a beverage plant that depends on large flow rates of water from existing pools may benefit from the design of a wetland system that allows for the on-site generation and filtration of water. This research aims to capture the industrial and ecological connection and design sustainable processes through the Synergy of Technological and Ecological Systems (STEMS). Instead of using technology alone to design processes, STEMS will consider industry and ecology to be one cohesive system with the goal of designing an optimum system that is self-reliant and minimizes ecological impact while maintaining industrial effectiveness. Instead of limiting the design palette to tools ordinarily used by engineers, such as traditional unit operations, STEMS would encourage the usage of natural systems to perform industrial tasks as well as stress the "waste equals food" principle where byproducts from one process are inputs to another. Wetlands can be used for water filtration and storage, trees and turfgrass for carbon sequestration, riparian buffers to prevent nutrient runoff, and various microbial activities for waste conversion into usable fuels. The smart integration of processes can integrate flows of material and energy such that there are minimal wastes of both. The concept of STEMS is demonstrated through the design of two systems: A residential home and a corn ethanol system that uses both technological and ecological systems as design elements. Optimization methods are applied to determine the impact of design alternatives on multiple objectives, such as economic potential and net carbon emissions. The results yield a Pareto optimal solution set that indicates the trade-offs between objectives under the various design variables. These results can extrapolated to process design in general, suggesting that STEMS can yield both economically and ecologically sound designs that minimize waste and promote self-sufficiency.