Abstract
In ammonia reactor system, a feed-effluent heat exchanger (FEHE) is typically installed to utilize reaction-generated heat to heat the reactor’s feed. Utilizing energy from exothermic reaction to the incoming feed stream is often called “autothermic operation”. Despite the advantage of FEHE, there is a risk of utilizing FEHE in a reactor system such as instability of process temperature or known as hysteresis. Hysteresis phenomena in chemical process could cause operational problems, for example it could damage the integrity of the equipment’s material. This paper aims to evaluate the dynamic behavior of a single-bed ammonia reactor with FEHE, particularly to propose a way to prevent instability within the system. The dynamic simulation of the single-bed ammonia reactor with FEHE was performed with Aspen HYSYS v8.8. The result of the simulation result shows that hysteresis phenomenon in the ammonia reactor system occurs when the feed’s temperature is below a certain value. If the feed temperature reaches that value, the temperature of the reactor’s outlet oscillates. One of the solution to keep the feed temperature above that critical value is by installing a trim heater within the system. Based on the simulation, trim heater installation within the system is able to prevent hysteresis in the system evaluated.
Highlights
Ammonia production process is the one of the most important industrial-scale chemical process
The catalytic reforming reaction is usually supported by feed-effluent exchanger (FEHE) to make energy usage more efficient [2]
Feed-effluent heat exchanger (FEHE) is a kind of heat exchanger that widely used to utilize reactiongenerated heat carried by reactor outlet as reactor inlet heating media
Summary
Ammonia production process is the one of the most important industrial-scale chemical process. One part of the ammonia synthetic process, catalytic reforming reaction of nitrogen and hydrogen is the most energy consuming process that requires massive amount of heat to ensure the reaction is presented [2]. The catalytic reforming reaction is usually supported by feed-effluent exchanger (FEHE) to make energy usage more efficient [2]. Using FEHE is the one of the practical ways to optimize energy consumption in chemical plant. This system could be implemented in the process that involve exothermic reaction such as ammonia and methanol synthesis. Releasing energy from exothermic reaction to the incoming reactant stream is often called “autothermic operation” [4]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
