Integrated Approach of Safety, Sustainability, Reliability, and Resilience Analysis via a Return on Investment Metric

The process design and technology selection are driven by multiple objectives including technical, economic, environmental, safety, and resilience drivers. Traditionally, technoeconomic analyses have been used to select and optimize the process design. Subsequently, environmental, safety, and resilience issues have been included in post-design analysis. With the recognition of the importance of including various objectives during the early stages of the process design, there has been a growing interest in the development of systematic methods for the multi-objective conceptual design. Recently, novel concepts have been proposed for the incorporation of sustainability and safety in designs through financial frameworks. In the current work, an extended approach is proposed for the incorporation of reliability, resilience, safety, and sustainability aspects during the conceptual design of the process system. In this proposed methodology, safety and sustainability weighted return on investment metric (SASWROIM) is extended to include impacts of resilience and reliability aspects with different design changes and configurations. For this purpose, a safety, sustainability, reliability, and resilience weighted return on investment metric (S2R2WROIM) is introduced. Multi-objective decision-making can thus be carried out for the optimal design based on this augmented method over the convention economic return on investment metric. The general methodology to screen process alternatives through S2R2WROIM begins with the synthesis and simulation of base case and alternative case flowsheet in Aspen HYSYS. This is followed by performance analysis, evaluation of various metrics, and applications of integrated metric to select the recommended design. A compressor process system case study in a hydrocracking process plant is demonstrated to illustrate the applications and benefits of the proposed methodology. The new approach provides decision makers with meaningful information and insights about safety, reliability, resilience, and sustainability along with the economic aspect.