(461b) Hierarchical Activity Model Using Integrated Definition Language (IDEF0) for Generation of Green Retrofit Alternatives

In chemical industry owing to its capital intensive nature, retrofit design is an important key strategic decision. However, each sector of industry tends to act upon alternative generation by different approaches, therefore a standardized procedure as a business model is vital for retrofit design. Besides, due to high level of complexity, for practical implementation it is also advantageous to clarify the actual procedure of alternative generation by information flows. The objective of this paper is to address retrofitting actions to enhance both monetary and non-monetary aspects of chemical process design.  This is done by presenting a general template of type zero method of Integrated Definition Language (IDEF0) for identification of key activities. The developed IDEF0 method was based on a systematic Path Flow Decomposition (PFD) method for generation of design alternatives. In this study a set of Environmental, Health, and Safety (EHS) hazard assessment, Life Cycle Impact Assessment (LCIA) and economical indicators were used in order to exploit both monetary and non-monetary aspects of process design.

The above set of indicators has been associated with a table of heuristics based on EHS, LCIA, and cost as well as rules of thumb and established principles of green chemistry and engineering. The IDEF0 method is a useful framework to connect and visualize the aforementioned activities with information flows with a focus on green process alternative generation. Therefore, several activities were decomposed to sub-activities in a hierarchical manner in order to clarify exact activity definition, information, models, tools, and constraints. These step by step activities systematized the generation of retrofit alternatives, and customized and supported the appropriate implementation of alternatives in reality. Based on incoming information, resources, and constraints the outcome of alternative generation activity was a set of feasible options for improving process design. Furthermore, screening design alternatives as the next activity could bring sufficient understanding regarding constraints and alternative candidates for the multi-objective decision making.       

The developed methodology was applied to an existent batch production plant from pharmaceutical industry for production of an essential intermediate product. In pharmaceutical industry generating alternative design is getting especially important as a response to studies drawing attention to strong contribution of solvents for API manufacturing. Currently, the plant is running under solvent incineration, however, besides its EHS hazard potentials; the incineration of solvents is the main contribution of the fine chemical industry to the greenhouse effects. The IDEF0 activity model paved the way for green alternative generation by PFD methodology and mainly preserved for reduction in solvent use, seeking for novel recovery scenarios, use of alternative green solvents with reduced emissions and hazard potentials (both for reaction and separation system) for overall process improvements compared to base case of incineration.