Development of novel adsorbents for carbon dioxide capture
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Development of novel adsorbents for carbon dioxide capture
Wed, 02/11/2016 - 16:00 to 17:00
Location:
Speaker:
Dr. Ajay Kumar Dalai
Affiliation:
University of Saskatchewan
Synopsis:
Research on the CO2 adsorption on activated carbon (AC) adsorbents has gained significant interest due to their low cost, low regeneration energy, and eco-friendly characteristics. The current research is focused on the systematic development of AC using different types of biomass, pyrolysis conditions and activation condition to prepare adsorbent with tailored textural properties for CO2 separation under simulated flue gas conditions. The work is divided into two phases. The first phase of the work was focused on the synthesis of activated carbon using steam, CO2 and potassium hydroxide (KOH) as activation agents and evaluation the CO2 adsorption performance under a range of temperature and inlet CO2 concentrations (CCO2). The KOH treated activated carbon had the highest CO2 adsorption capacity of 1.8 mol/kg due to its microporous structure under the optimized experimental conditions of 30 mol% CO2 and 25°C. However, all prepared activated carbon samples had a poor performance at high temperature (~65°C) and/or low CCO2 (~10 mol%). The KOH activation conditions in the first phase was then used for the activated carbon preparation using three different types of biomass (forest residue, agricultural residue and animal manure) as precursor and two different pyrolysis processes (fast and slow pyrolysis). The main finding in this phase was that activated carbons have different sensitivity to CO2 separation according to their micro-pore distributions and total pore volume and surface area are not significant factors for CO2 adsorption on ACs. Overall, the pinewood sawdust derived ACs showed the best adsorption capacity of 78.1 mg/g (at 15 mol% CO2 in N2 and 25°C). An isothermal mass transfer model for CO2 adsorption in a mixture of CO2/N2 is developed. The adsorption equilibrium data of CO2 and N2 on KOH activated carbon are determined at 273, 298, 323 and 348 K. The model is used to reproduce the CO2 adsorption breakthrough curves in CO2/N2 gas mixture and can be considered for designing a fixed-bed adsorption process to separate CO2 and N2 using microporous and mesoporous carbon materials.
Biography:
Professor Dalai holds a Ph.D. in Chemical Engineering from the University of Saskatchewan where he is currently employed as a Full Professor and Canada Research Chair in Bioenergy and Environmentally Friendly Chemical Processing. His research focus is the novel catalyst development for gas to liquid (GTL) technologies, development of carbon adsorbents for CO2 capture, biodiesel production, hydrogen/syngas production, hydroprocessing of gas oil, and value added products from biomass. Dr. Dalai holds several patents and has published over 300 research papers mostly in heterogeneous catalysis and catalytic processes in international journals and conference proceedings. He has received several national and international awards. He served as Chair of Catalysis Division of Chemical Institute of Canada and and served as Chair of Canadian Catalysis Foundation. Professor Dalai has become fellow of Canadian Academy of Engineering (CAE), Chemical Institute of Canada (CIC), Engineering Institute of Canada (EIC), American Institute of Chemical Engineers (AIChE) and Indian Institute of Chemical Engineers (IIChE), and more recently Royal Society of Canada and Royal Society of Chemistry (UK). He has served in Editorial Board of Can. J. Chem. Eng., and serves on Editorial Board of J. Biobased Materials and Bioenergy, J. of Engineering Chemistry and Fuel, and Recent Patents on Materials Science.