Development of a simultaneous mass-water carbon-hydrogen-oxygen symbiosis network

The carbon-hydrogen-oxygen symbiosis network, which deals with hydrocarbon chemical species, is considered a special case of the eco-industrial park. The carbon-hydrogen-oxygen symbiosis network is based on the atomic targeting technique, which can be defined as a multi-scale approach to minimize resources and wastes. Nevertheless, previous works neglected the opportunity to perform water integration within the carbon-hydrogen-oxygen symbiosis network to minimize wastewater discharged to the environment. In this work, a rigorous model for the design of simultaneous mass and water carbon-hydrogen-oxygen symbiosis network is introduced. The objective of this model is the utilization of multi-objective optimization to maximize the economic and the environmental performance of the mass-water carbon-hydrogen-oxygen symbiosis network simultaneously to reach a sustainable design. The simultaneous mass-water carbon-hydrogen-oxygen symbiosis network is performed in a single-step model using the sustainability weighted return on investment metric. The solution from the model indicates which plants participate and the extent of participation, the chemical pathways to convert the incoming chemical species into value-added chemicals, the allocation of the products to the usersand the mass and water network configuration. Three scenarios were investigated to show the merits of the developed model. Scenario one was solved using a single-objective function of minimum external species to design separate mass and water networks in a two-step model. Scenario two was solved using sustainability weighted return on investment metric, in which economic and environmental indicators were incorporated in the model to achieve multi-objective optimization to design a simultaneous mass-water CHOSYN in one single step. Scenario three was solved using a single-objective function of minimum purchased chemical species to synthesize a simultaneous mass-water CHOSYN in a single step. The results indicated that scenario two achieved better overall environmental and economic performance where the return on investment and sustainability weighted return on investment metrics reached 29 and 36%/yr. In conclusion, the multi-objective optimization of simultaneous mass-water CHOSYN provided eminent results and outstanding performance in terms of economic (annual net profit, total operating costs, return on investment metric) and environmental (carbon dioxide and wastewater discharge) aspects, leading to significant advantage compared to either separate mass and water network integration or single-objective optimization.