Process Synthesis and Simultaneous Heat and Electricity Integration to Reduce Consumption of Primary Energy Sources
Abstract A synthesis of an industrial utility system considering cogeneration options together with heat exchanger network synthesis has been developed. It consists of boilers at different temperature and pressure levels, steam turbines, condensers, cooling tower, deaerator and a heat exchanger network system, connecting the utility system with the process heat and electricity requirements. A mixed-integer nonlinear programming (MINLP) model was used for synthesis. A sensitivity analysis has been performed considering the price ratio of natural gas to electricity, while also estimating primary energy consumption and GHG emissions. The results indicate that the cogeneration is economically viable at different ratios of natural gas and electricity price. In addition, the sensitivity analysis shows the relationship between cogeneration and electricity purchase for obtaining the minimal primary energy consumption and consequently to reduce GHG emissions.