Title: Parametric effect of adsorption variables on CO₂ adsorption of amine-grafted polyaspartamide composite adsorbent during post-combustion CO₂ capture: a response surface methodology approach

Authors: Tafara L. Chitsiga; Michael Olawale Daramola; Nicola Wagner; Jacob Masiala Ngoy

Addresses: School of Chemical and Metallurgical Engineering, Faculty of Engineering and the Built Environment, University of the Witwatersrand, Johannesburg, South Africa ' School of Chemical and Metallurgical Engineering, Faculty of Engineering and the Built Environment, University of the Witwatersrand, Johannesburg, South Africa ' Department of Geology, University of Johannesburg, Auckland Park, Johannesburg, South Africa ' Clean Coal Research Group, School of Chemical and Metallurgical Engineering, Faculty of Engineering and the Built Environment, University of the Witwatersrand, Johannesburg, South Africa

Abstract: In this study, effect of operating variables (e.g., temperature, flue gas flow rate and pressure) on the CO₂ adsorption capacity of an amine-grafted polymer composite adsorbent, PAA, was investigated using a statistical approach (response surface methodology). A set of 25 experiments were designed using the central composite design (CCD) and six regression models were proposed to describe the behaviour of the materials for CO₂ capture under the influence of the operating variables considered in this study. The best model that adequately described the behaviour of the material displayed a mean error, a variance and a p-value of −2.6375 × 10⁻¹², 29 and 0.0006, respectively, indicating the statistical significance of the model to describe the behaviour of the material during CO₂ adsorption. In addition, results of the cross-validation of the model showed an error of about 5%, strengthening further the validity of the model. Under the main and interaction effects of the considered variables, a maximum amount of CO₂ adsorbed was approximately 45 mg CO₂/g adsorbent at a gas flowrate of 60 ml/min, a temperature of about 40°C, and at a pressure of 1.6 bar. [Received: October 5, 2016; Accepted: March 30, 2017]

Keywords: polyaspartamide; CO₂ capture; adsorption; post-combustion CO₂ capture; flue gas; coal-fired power plants; climate change.

DOI: 10.1504/IJOGCT.2018.090149

International Journal of Oil, Gas and Coal Technology, 2018 Vol.17 No.3, pp.321 - 336

Received: 05 Oct 2016
Accepted: 30 Mar 2017
Published online: 01 Mar 2018 *

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