Mathematical Modeling of Fixed Bed Adsorption: Influence of Main Parameters on Breakthrough Curve

Abstract

Dynamic modeling and simulation of fixed bed adsorption process was carried out by explaining the behavior of breakthrough curve parameter. Adsorption of sulfur compound, present in road fuel, has posed a great challenge. A model of fixed bed adsorption of benzothiophene from fuel was formulated with non-ideal plug flow behavior and considered velocity variation along a column. The model was solved using the Method of Line (MOL) numerical solution - a technique for solving PDEs - in which all but one dimension is discretized; as a result, the set of ODEs can be solved by highly accurate methods and low computational cost. The effects of various factors, such as flow rate (4-10 cc/min), inlet concentration (125-500 ppm), and bed height (10-40 cm), on adsorption performance, were investigated. Specific characteristics, typical of breakthrough curve, were analyzed in terms of degree of bed utilization, break point time, film mass transfer coefficient, and height of adsorption zone. High bed column, high flow rate, and high inlet concentration happened to be better conditions, in term of used overall bed capacity percent for adsorption system.

Keywords

• adsorption
• benzothiophene
• breakthrough curve
• fixed bed
• modeling