Safety, sustainability and economic assessment in conceptual design stages for chemical processes

Abstract Safety and sustainability are commonly considered once the conceptual design of a process has been carried out. As an effect, modifications to the process to address safety and sustainability issues are more expensive and difficult to make. Several efforts to include safety and sustainability criteria during the process conceptual design have been made. The main challenge is to find a systematic way to reconcile these criteria with the economic objectives to provide an outcome easy to interpret by decision makers. The objective of this paper is to introduce a new safety and sustainability weighted return on investment metric, a tool that is intended to achieve such reconciliation. A case study dealing with the production of methanol from shale gas is presented. The results show how a design with suitable operating conditions that reconcile economic, environmental and safety criteria can be identified with the use of the new metric.