Scope and Method of Study. This research is focused on adopting a systematic methodology for address sustainability concerns during early stages of engineering design. Traditionally, engineers designed processes to achieve beneficial operations and economic goals. However, given the need to balance the economic benefits of chemical engineering processes, safety, health and environmental impacts, the improved focus on sustainability of production processes has introduced more complex dimensions to consider. When it comes to addressing the three conflicting dimensions of sustainability, there is no well-defined methodology or tool for achieving this. A thorough review was completed to investigate the applications and limitations of existing economic, environmental, health and safety evaluation tools. Therefore, the methodology combines already established approaches, concepts and tools into a novel systematic technique that addresses sustainability concerns during early stages of chemical process design.

Findings and Conclusions. A methodology that involves the use of the SUSTAINABILITY EVALUATOR and ASPEN PLUS was developed for evaluating processes for sustainability. The SUSTAINABILITY EVALUATOR is a novel impact assessment tool developed for this research. This tool applies selected metrics that address economic, environmental as well as health and safety concerns. The SUSTAINABILITY EVALUATOR is a Microsoft Excel based tool that uses mass and energy balance inputs from ASPEN PLUS to evaluate the sustainability of a process. This impact assessment tool equips the process designer with a framework to design industrial processes for sustainability. The objective is for processes designers to use the results generated from the tool to assess and improve the sustainability of a process. The proposed framework involved the use of ASPEN PLUS to simulate processes, calculate mass and energy balances, complete sensitivity analysis and lastly optimize processes An overall sustainability impact which has been incorporated into the SUSTAINABILITY EVALUATOR was developed to quantify sustainability issues in process design. The methodology was demonstrated on two case studies: the acrylonitrile process and the allyl chloride process. The application of the methodology on the two case studies resulted in a more economic, environmental and socially acceptable processes.