Steady-State Economic Comparison of Alternative Tubular Reactor Systems

Abstract

This paper presents a comparison of the steady-state economics of alternative tubular reactor systems. These alternative designs use different tubular reactor configurations including single adiabatic, multistage adiabatic with interstage cooling, multistage adiabatic with cold-shot cooling, single cooled, multistage cooled with interstage cooling, and multistage cooled with cold-shot cooling. The design considers the entire plantwide process: reactor(s), heat exchangers, gas recycle compressor, preheat furnace, condenser, and separator. The chemistry is the exothermic, irreversible, solid catalytic, gas-phase reaction A + B → C, which is carried out in a packed-bed tubular reactor. The economic objective function is total annual cost, which includes annual capital cost (reactor, catalyst, compressor, and heat exchangers) and energy cost (compressor work and furnace fuel). Design and optimization procedures are developed for each alternative design. Optimum operating conditions and equipment sizes are determined. The effect of catalyst cost on the steady-state design is considered. The steady-state design results indicate that the single cooled reactor configuration is the best from the standpoint of steady-state economics.