Electronic Thesis and Dissertation Repository

Degree

Doctor of Philosophy

Program

Chemical and Biochemical Engineering

Supervisor

Dr. Charles (Chunbao) Xu

2nd Supervisor

Madhumita Ray

Co-Supervisor

Abstract

Each day large volumes of oil sands process-affected water (OSPW) are being produced during the extraction of bitumen in oil sands industry in northern Alberta. OSPW contains different polyaromatic hydrocarbons which not only are the major source of toxicity in OSPW, but also create operational problems such as corrosion of the equipment during bitumen recovery process. Therefore, these compounds need to be removed prior to the recycle of the OSPW. In this research, petroleum coke (PC) as an abundant, inexpensive adsorbent was selected as an adsorbent for recovery of chemicals from OSPW. The surface area and adsorption capacity of PC were increased through several processes such as KOH activation, surface modification, and optimization. The Box-Behnken design and response surface methodology were employed to optimize KOH activation parameters for the production of activated petroleum coke (APC). APC adsorbent with a BET surface area of 1726 m2/g and total pore volume of 0.85 cc/g was produced at the optimum activation conditions (KOH/coke mass ratio of 3.0, activation temperature 790 °C, and activation time 3.47 hr). The produced APC at optimum condition was tested in batch and bench scale continuous adsorption column for adsorption of model compounds and treatment of OSPW. Furthermore, two different amination processes including a single stage treatment with ammonia gas at an elevated temperature and a two-step treatment of nitration followed by reduction were adopted. The results showed an excellent adsorption capacity for the model NAs and OSPW at pH= 4.0. Ammonia treatment was more effective on improvement of adsorption capacity than the nitration followed by reduction method. The results of the PLS model shows that the pH of the solution and the NH3 surface modification are the most important contributors that affect the adsorption capacity of APC. The result of this study provides an effective treatment method for OSPW by using APC. The TOC of OSPW could be reduced by 96 percent after a two steps treatment including pH adjustment and adsorption by APC. The APC could be regenerated easily using a solution of methanol and sodium hydroxide and could be reused in several cycles.


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