Synthesis of a Multiperiod C-H-O Symbiosis Network for the Potential Valorization of Glycerol to PHA Production

The synthesis of the carbon-hydrogen-oxygen symbiosis network (CHOSYN) provides a structured framework for dealing with multiscale integration of hydrocarbon processing industries to improve resource efficiency and reduce waste generation. However, the earlier CHOSYN design approaches presumed that the networks operate in a single mode throughout the year. This may not be the case in real-world situations where the production of certain plants such as polyhydroxyalkanoates (PHAs) from bio-based glycerol may require multiple operational modes to accommodate the seasonal variability and availability of raw material. PHAs are biodegradable polymers produced by bacterial fermentation of carbon sources, which are the potential substitutions for petrochemical-based plastics. Hence, this work aims to propose a systematic approach to optimize multiperiod mass integration in the development of a CHOSYN. The central principle of the proposed approach is the incorporation of a storage and dispatch system into the conventional CHOSYN design for the supply of chemical species needed in the network throughout different operational periods. A case study considering glycerol valorization and other chemical plants using the devised CHOSYN model was conducted to evaluate the performance of the proposed design against the conventional CHOSYN in terms of sustainability metrics. The results demonstrate the advantages of the CHOSYN model with a storage and dispatch system by exhibiting a better profitability outcome than the conventional multiperiod CHOSYN through operating cost savings.