A general methodology for energy efficiency of industrial chemical processes

This paper presents a general, practical and operational methodology to improve energy efficiency of chemical processes through a holistic approach. The required methods and tools have been developed based on a systematic approach for process energy integration and energy efficiency optimization. The objective is to develop a general methodology adaptable to any type of industrial chemical process, existing and under development. This methodology is summarized into six consecutive steps narrated as following: thermal data is collected first, in order to define the heating and cooling requirement of process. The composite curves are then established and the maximum energy recovery is calculated as a preliminary target. Technical improvement solutions are consequently proposed through integration of new technologies and modification of the process unit operations ( incremental and/or step changes). Suitable energy conversion units together with the proposed improvement options are then integrated and optimized. Among the feasible solutions, the most promising ones are selected; investment costs are evaluated and retrofit and re-designing of the heat exchangers network are performed for those solutions. Finally the profitability of the most promising proposals is evaluated and the best compromise is chosen. The application of the proposed methodology is demonstrated through a case study highlighting the different steps and the potential of the proposed approach.