Huan Jiang

Date of Award

Spring 2022

Document Type

Open Access Dissertation


Chemical Engineering

First Advisor

James A. Ritter


This work focused on both fundamental of adsorption and large-scale PSA design. Chapter 1 and 2 addressed the analysis of conditions for formation of adsorption azeotropes in binary systems. Chapter 1 theoretically assessed the necessary and sufficient conditions for the formation of an adsorption azeotrope in a binary gas mixture when this mixture exhibits either intersecting or non-intersecting single gas isotherms. Chapter 2 confirmed theoretically whether adsorption azeotropes can form in a binary mixture at a pressure below the intersection pressure of the corresponding single gas isotherms. Analytical expressions derived for both general and dual thermodynamically consistent process Langmuir (DPL) models, in terms of the single gas isotherm DPL model parameters, were used to find examples or to answer these questions.

Chapter 3 assessed the importance of incorporating a vacuum pump performance curve into a mathematical model that describes the regeneration steps in a vacuum swing adsorption (VSA) cycle. It was accomplished by evaluating the relationship between pressure and flow rate at the exit of a 13X zeolite bed initially and uniformly saturated with 70 vol% CO2 in N2 at 101.325 kPa and 333.15 K, which then undergoes just countercurrent depressurization (CnD) and light reflux (LR) steps. Four Parametric studies were carried out and revealed it is imperative to incorporate a realistic vacuum pump model in cyclic adsorption process simulation, which led to a more accurate VSA performance prediction and energy consumption estimation.

Chapter 4 and Chapter 5 addressed extremely large-scale pressure swing adsorption (PSA) process designs for CO2 capture from flue gas. Chapter 4 provided methods and a scaling procedure to design systems for multiple beds undergoing a feed step at the same time with the same feed flow rate and multiple beds undergoing a light reflux step at the same time with the same light reflux flow rate to process a gas stream in a multi-bed, multiunit PSA process using reasonably sized beds. Chapter 5, based on chapter 4, is generally directed to design a unique VSA cycle schedule containing multiple Feed and multiple light reflux (LR) beds to achieve the target performance, while meeting pressure drop requirements and bed design constraints. A brief overview of the scaling procedure will be given, along with the study on designing a VSA process that can meet all the required performance criteria.

Available for download on Friday, May 31, 2024