Techno-economic evaluation of a thermochemical waste-heat recuperation system for industrial furnace application: Operating cost analysis

An operational cost analysis was conducted to determine the optimal parameters for achieving maximum net present profit value through thermochemical recuperation (TCR). The parameters of the TCR system (enthalpy, temperatures of exhaust gas and synthesis gas) were determined based on computational fluid dynamics (CFD) modeling. The results of the CFD modeling were verified using experimental data. The techno-economic evaluation of the TCR system was performed for two types of industrial furnaces with methane mass flow rate of 1.0 kg/s: a glass-melting furnace with an exhaust gas temperature of 1500 °C and a forging furnace with an exhaust gas temperature of 900 °C. The operational parameters of the steam methane reforming process varied during analysis: a residence time of 50–250 kgcat⋅s/molCH4, a feed steam-to-methane ratio of 1.0–3.0 mol/mol, and an operational pressure of 10 bar. Various prices for catalyst, electricity, and natural gas, as well as different replacement periods for the catalyst, were analyzed. It was found that the net present profit had an extreme value that depended on operational and cost parameters. The optimal residence time (specific mass of catalyst per mole flow rate of methane) was determined for various operational and cost parameters of the TCR system.