Modeling and simulation of a multistage absorption hydration hybrid process using equation oriented modeling environment

• An absorption hydration method is established using ACM® and Aspen Plus®.
• Key parameters of the absorption hydration process are analyzed.
• Based on optimization calculation, optimal operation conditions are found.
• Effect of hydrate structure on separation of dry gas is discussed.
• Based on economic evaluation, aspects need further investigation are pointed out.

Separation of light hydrocarbon mixtures is one of the most important topics in chemical engineering research. With development of theories on hydrate equilibriums and kinetics, researchers are trying to apply hydration based separation technology to industrial applications. It is increasingly important to develop the corresponding simulation strategies for process design purposes. In this work we use an equation oriented modeling environment, named Aspen Custom Modeler® (ACM®), which enables rapid model development and provides powerful simulation solvers. With the help of ACM®, a multistage absorption hydration hybrid process (AHHP) for refinery dry gas separation is modeled and simulated. Sensitivities of key parameters such as water content and absorbent flow rate, are analyzed. Features of the multistage AHHP are discussed. For comparison, based on an industrial data, a butane absorption process is established and simulated. Economic evaluation shows that the multistage AHHP is competitive compared to current absorption process.