(300b) Predicting Reboiler Operations Using Fluid Dynamic Modeling

Due to the heat sensitivity of amine solutions, the temperature profile of the radiant heating tubes in an Acid Gas Removal Unit regenerator is critical. Localized heat zone formation inside the reboiler may overheat and reduce the amine absorption efficiency. This may reduce result in CO2 and H2S leak into the process. In addition, the burned amine becomes viscous and reduces the flow rate inside the tubes which leads to mechanical problems. In order to prevent such problem, Computational Fluid Dynamics (CFD) was used in the design phase to predict the amine reboiler heat flux and tube skin temperature profile. To ensure the accuracy of the results, the heat flux and temperature profiles were compared to the result produce by another furnace modeling software, PFR Direct Fired Heater Computer Program

Several simulations were done to include different operating conditions. Most of the cases were run under steady state condition, but a transient simulation was conducted to predict the cooling rate of the reboiler during shut down. This paper presents the details of the CFD modeling work that were utilized to mitigate the risk to the reboiler operations under normal and emergency conditions.