CHE Seminars  


Speaker Prof. Ajay Kumar Dalai
Department of Chemical and Biological Engineering College of
Engineering, University of Saskatchewan, Saskatoon, Canada.
Arrested Wet Chemical Precipitation of Noble Metal Nanoparticles
Date 28, January 2015 (Wednesday)
Place L5
Time 4.00 PM - 5.00 PM


The heavy gas oil derived from Athabasca oil sands contain higher level of sulfur (~4.0 wt.%) and nitrogen (~0.4 wt.%) content, which needs to be lowered before it becomes suitable as a feedstock for refinery. The most widely used upgrading process is hydrotreating and the conventional catalyst used for hydrotreating is Ni/Co and Mo/W supported on γ-Al2O3. However, the improvement of hydrotreating catalyst is mandatory in view of stringent environment regulations and available oil sands containing high amount of sulfur. Therefore, in this work, several mesoporous support materials such as modified SBA-15 (Zr-SBA-15), mesoporous mixed metal oxides (TiO2-Al2O3 ZrO2-Al2O3) and large pore mesoporous metal oxides (ZrO2, Al2O3) were synthesized and utilized as a support material for NiMo hydrotreating catalyst. All catalysts were characterized by N2 adsorption and desorption isotherms, CO-chemisorption, X-ray diffraction, FT-IR, H2-temperature programmed reduction, NH3-temperature programmed desorption, Raman, XANES (X-ray absorption near edge spectra), HRTEM and ICP-MS. XANES technique was used as predominant method for atomic level study of various structural changes in sulfided and oxide catalysts. All catalysts were tested for hydrotreating of bitumen derived heavy gas oil in a fixed bed reactor at industrial conditions. It was also observed that nitrogen containing compounds cause inhibition and deactivation of hydrotreating catalyst, thereby, reducing the catalytic activity. Therefore, a pretreatment process employing porous polymer support coupled with electron withdrawing π-acceptors has been developed for the selective removal of refractory nitrogen compounds from gas oil via charge transfer complex (CTC) mechanism. The pretreated gas oil is then subjected to hydrotreating in a fixed bed reactor at industrial conditions and increase in hydrodesulfurization activity was observed.


Dr. Ajay K. Dalai is working as a Full Professor in the Department of Chemical Engineering at the University of Saskatchewan. In 2001, he was awarded a Tier 2 Canada Research Chair in Bioenergy and Environmentally Friendly Chemical Processing, and Tier 1 in 2009. In 2009 until 2014, Dr. Dalai accepted the position of Associate Dean of Research and Partnerships for the College of Engineering, in addition to his professorship and supervisory role. His research focus is the novel catalyst development for gas to liquid (GTL) technologies, biodiesel productions and applications, hydrogen/syngas production from waste materials, hydroprocessing of heavy gas oil, and value-added products from biomass. He is currently working on the production and applications of activated carbon and carbon nanotubes (CNTs). The worldwide impact of this research is tremendous in terms of combating pollution and finding alternate energy resources, and has generated much interest and collaborative projects with research institutes and universities around the world. Dr. Dalai has published over 300 research papers mostly in heterogeneous catalysis and catalytic processes in international journals and conference proceedings. He has submitted several patent applications. He is an active board member, reviewer, and guest editor for several international journals. He is a life member of the Indian Institute of Engineers, the Indian Catalysis Society, the American Institute of Chemical Engineers, and an active member of the American Chemical Society and the Chemical Institute of Canada. He is a Fellow of CIC, CAE, EIC, AIChE and IIChE. He is the winner of 2014 CSChE Bantrel Award in Design and Industrial Practice. He is also recently became a fellow of Royal Society of Canada.