Decision framework for chemical process design including different stages of environmental, health, and safety assessment

Abstract

in Wiley InterScience (www.interscience.wiley.com).In recent years, many chemical companies have adopted the concept of sustainable development as a core business value. In this context and with focus on early phases, we present a novel design framework that comprises four stages of process modeling and multiobjective evaluation considering monetary and nonmonetary aspects. Each stage is characterized by the available information as a basis for process modeling and assessment. Appropriate modeling approaches, and evaluation indicators for economy, life-cycle environmental impacts, environment, health, and safety (EHS) hazard, and technical aspects are selected for each defined stage. The proposed framework is demonstrated on the design of a methyl methacrylate (MMA) process: considering 17 synthesis routes, the framework is mimicked step-by-step, to select the route with the best multiobjective performances, and to produce an optimized process flowsheet. As a validation of the framework, evaluation profile of six routes over all stages are compared, and crucial points are identified that should be estimated considerably well in early stages of the framework.

Application of environmental and economic metrics to guide the development of biocatalytic processes

“…The energy loss index was introduced on a decision framework for process design developed by Sugiyama and co-workers [21]. This metric is an indicator to estimate the energy-related efforts associated to the process, using only the available reaction information forecasting the energy and utilities that will be required in a large scale.…”

“…This metric is an indicator to estimate the energy-related efforts associated to the process, using only the available reaction information forecasting the energy and utilities that will be required in a large scale. This index has a value of 0 (low) to 1 (high estimated energy demand) according with: reaction medium (aqueous or organic solvent), [P], difference of boiling points, inherent waste and reaction energy [21]. However, this metric only gives a qualitative score of the process energy demand and it was thought to be applied exclusively for a process requiring distillation processes on their recovery and purification processes, whereas the impact of the reaction adjuvants (such as co-solvents and catalysts), operating conditions and other unit of operations are not accounted for in the process energy demand.…”

“…In fact, over the development life cycle of a new process, the tools can serve three very distinct roles: (1) route selection, where the tools are a key to decision-making eliminating of synthetic routes where the reaction chemistry prevents the environmental and economic competitiveness of the process, (2) early development, where the tools are used for benchmarking (i.e., to set the targets required to achieve a competitive process) thus assisting in the selection between different process alternatives and (3) late development (following process selection, but prior to scale-up), where the tools can be used for go/no-go decision-making by assessing process profitability and the environmental profile ( Figure 1). It is crucial to differentiate the goals and the tools for each process development stage, since the more design-variables are fixed (e.g., reaction chemistry, final [P], biocatalyst dosed in the reactor, downstream equipment), the smaller the weight of the other design-variables (e.g., heat integration) becomes on the environmental and economic performance [21]. Hence, the presented environmental and economic tools vary in detail and we suggest that it is necessary to use different tools to deal with the different objectives at different stages of the process development.…”

Safety, health, and environmental assessment of bioethanol production from sugarcane, corn, and corn stover

“…Scaling schemes are proposed, which quantify these dangerous properties for all substances involved in a process and result in substance-specific indices with values between 0 and 1. Sugiyama et al [25] have extended the work of Koller et al [23] by combining the substance-specific indices with the respective process mass flows and introducing a weighting scheme for calculating first categorical scores for the EHS hazards and finally an overall EHS hazard assessment score. Both substance-specific indices and process mass flows can result from basic information about the process layout and operating conditions complemented with process modeling, wherever is necessary.…”

“…Two hazard assessment methods were applied: the inherent safety index (ISI) [22] method and the environmental, health, and safety (EHS) method [23]. These methods have also been recently integrated into process retrofitting [24] and conceptual design frameworks [25]. Although both methods consider substance properties and process conditions and can provide categorical and aggregated results to a single metric, they also quantify different aspects of process hazards.…”