Systematic Design of Solvent Recovery Pathways: Integrating Economics and Environmental Metrics

Abstract

The increasing trend of solvent usage by chemical industries has caused an upsurge in hazardous waste solvents and, consequently, increased their toxicity potential within the environment. The increase in overall carbon and ecological footprints due to conventional waste handling techniques such as incineration and onsite and offsite disposal can hardly be overstated. Even though solvent recovery methods present a better alternative to these techniques, analysis is generally centered on economics. This paper presents a framework that evaluates the economic and sustainability metrics of solvent recovery processes. In the first approach, standalone software (SimaPro) was used to evaluate the impact of the recovery process. The framework was extended by incorporating the economics, Sustainable Process Index (SPI), and Emergy metrics. Thus, solvent recovery challenges have been transformed into a multiobjective optimization problem that is solved through superstructure and mixed-integer nonlinear programming techniques. The applicability of the framework is illustrated by two comprehensive case studies with varying complexities, and the results are compared with conventional methods. The results indicate that about 76−85% of the ecological and energy burden can be prevented if solvent recovery is the preferred option to incineration.

Material Flow Analysis and Occupational Exposure Assessment in Additive Manufacturing End-of-Life Material Management

“…However, it is worth investigating the effects of adding such a recovery loop, namely, solvent recovery and filament extruder, and analyzing the net cost to incentivize recycling efforts. At a minimum, in-house collection, sorting, and scrap reprocessing can minimize the need for material disposal. , …”

“…At a minimum, in-house collection, sorting, and scrap reprocessing can minimize the need for material disposal. 96,97 EoL material management challenges can be expected to begin at the generation point and propagate as these materials are transported to the EoL material management stage. The identity and purity level of these materials can also become lost, creating a disconnection between manufacturing and EoL material management.…”

Development of an Interactive Software Tool for Designing Solvent Recovery Processes

“…The last method, incineration, is very effective with regard to disposing of most materials. Although a constant feed flow is needed for maximum efficiency, incineration can thermally decompose nearly 100% of volatile organic compounds and can recover thermal energy to be used for other equipment within the process. − Although efficient, incineration is not environmentally friendly, because it can release harmful chemicals and pollutants into the atmosphere. , Solvent recovery is a better alternative than the previous methods because it can improve the sustainability and greenness of chemical processes. ,, In addition, solvent recovery poses economic benefits since fresh solvent will not need to be purchased in such high quantities anymore, because much of these recovered solvents can be reused. While many unique recovery methods have been researched, no standard solvent recovery method has been implemented. ,, …”

“…Because of the fast-paced nature of design projects, many engineers do not have the time to analyze all available options within a limited time frame. We have previously developed a superstructure-based solvent recovery framework capable of suggesting an optimal recovery pathway with minimal cost and environmental impacts , (refer to the Supporting Information for more details). The previous work can analyze multiple recovery options simultaneously within a short time frame.…”

“… 13 , 14 Solvent recovery is a better alternative than the previous methods because it can improve the sustainability and greenness of chemical processes. 13 , 15 , 16 In addition, solvent recovery poses economic benefits since fresh solvent will not need to be purchased in such high quantities anymore, because much of these recovered solvents can be reused. While many unique recovery methods have been researched, no standard solvent recovery method has been implemented.…”