Evaluation indicators for energy-chemical systems with multi-feed and multi-product

Multi-feed multi-product (MFMP) operation is a characteristic and significant trend in the development of novel energy-chemical systems. The complicated characteristics of an MFMP system coupled with multiple materials, energy and information flows are difficult to assess on the basis of conventional thermal indicators. In this paper, a feasible evaluation framework for MFMP systems is proposed. Based on the traditional single-feed single-product (SFSP) systems selected as the reference sub-systems, the evaluation indicators for an MFMP system are constructed. The indicators, including primary energy saving ratio (PES), primary installed capital cost saving ratio (PIS), primary cost saving ratio (PCS), waste emission avoidance ratio (EmR) and CO2 avoidance cost (CostA), can be obtained through calculations via a simulation software or industrial data. They are valuable to assist process design, selection and optimization for energy-chemical systems and provide a powerful tool for sustainability analysis as well. A typical case of an MFMP system for producing methanol and power from coal and natural gas is studied and optimized using the proposed evaluation indicators.