Director, UBC Clean Energy Research Centre (CERC)
CHBE 411

Research Summary

Particle Technology, Fluidization and Multiphase Reactors, Clean and Renewable Energy, Sustainability and Systems Analyses


University of British Columbia, 1994, Ph.D.
Tsinghua University, China, 1988, M.A.Sc.
Tsinghua University, China, 1985, B.A.Sc.

Research interests + projects

Green Engineering, Clean Energy and Sustainability: Green Engineering is the design, commercialization and use of processes and products, which are feasible and economical while minimizing impacts on ecosystems over the full life-cycle. Traditional engineering focuses on the technical and economic aspects of a technology.  In contrast, Green Engineering extends our research and development beyond product manufacturing to include the ecological impacts of a process/product or a technology on the renewability and sustainability of the raw materials, the toxicity and health risks of the product use, and the recycleability and degradability at the end of the product use. We are developing environmental systems and life cycle analysis tools to model and evaluate biomass energy systems, including Canadian wood pellets, BC forest residues, animal wastes, agricultural residues and municipal wastes, as well as integrated impact assessments of biomass combustion, gasification, torrefaction and pyrolysis processes. At the same time, we are developing novel thermo-catalytic technologies to convert biomass residues to bio-fuels, biochar, torrefied pellets and renewable natural gas, with a focus on reactor design and catalyst development. Both clean energy and green engineering are key areas of my research and teaching.

Fluidization and Multiphase Reactors: Fluidized bed reactors have been widely used in industrial processes for conducting both catalytic and non-catalytic reactions, fuel combustion, particulate drying, powder coating and granulation, electrolysis etc. I started my research career on fluidization in 1985, and have conducted research over many areas, including hydrodynamics, flow patterns and flow regimes, heat transfer, mass transfer, reactor performance testing, modeling and simulation, scaling and scale-up, commercial reactor trouble-shooting etc. covering gas-solids, liquid-solids, gas-liquid-solids bubbling, turbulent and circulating fluidized beds. My current fluidization research is focused on electrostatic charging of dielectric particles in gas-solids fluidized beds and novel fluidized bed reactors for biomass thermo-catalytic conversion.

Awards and honours

CSChE Industrial Design and Practice Award , 2020
PSRI Lectureship Award, AIChE , 2012
Killam Senior Faculty Research Fellowship, UBC , 2011

Selected publications + presentations

BA Mohamed, N Ellis, CS Kim, X Bi, WH Chen, Engineered biochars from catalytic microwave pyrolysis for reducing heavy metals phytotoxicity and increasing plant growth, Chemosphere 271, 2021

H Wang, X Bi, R Clift, A case study on integrating anaerobic digestion into agricultural activities in British Columbia: Environmental, economic and policy analysis. Environmental Pollution, 271, 2021.

H Yun, Z Wang, R Wang, X Bi, W Chen, Identification of suitable biomass torrefaction operation envelops for auto-thermal operation. Frontiers in Energy Research 9, 2021.

W Ao, J Fu, X Mao, N Wahab, C Ran, Q Kang, Y Liu, Z Jiang, J Dai, X Bi, Characterization and analysis of activated carbons prepared from furfural residues by microwave-assisted pyrolysis and activation. Fuel Processing Technology, 213, 2021.

JR Grace, X Bi, N Ellis, Essentials of Fluidization Technology, Wiley-VCH, 2020.

G Zhang, Z Chen, J Bao, W Wei, X Bi, A revisit to saturation carrying capacity and saturated solid fraction in gas-solid upward flow, Powder Technology 373, 627-636, 2020.

H Yun, R Clift, X Bi, Process simulation, techno-economic evaluation and market analysis of supply chains for torrefied wood pellets from British Columbia: Impacts of plant configuration and distance to market. Renewable and Sustainable Energy Reviews, 127, 2020.

Y Zhang, Y Liang, M Wang, X Bi, C Lu, Experimental study and CPFD simulation on circumferential flow heterogeneity in a disc-donut catalyst stripper, Chemical Engineering Journal, 391, 2020.

Y Yang, Y He, X Bi, JR Grace, H Wang, F Fotovat, W Xie, S Wang, Effect of moisture on energy-size reduction of lignite coal in Hardgrove mill. Fuel 270, 2020.

BA Mohamed, N Ellis, CS Kim, X Bi, Synergistic Effects of Catalyst Mixtures on Biomass Catalytic Pyrolysis. Frontiers in bioengineering and biotechnology 8, 2020

H Piri, H Li, HJ Wang, XT Bi, 3D-printed fuel cell bipolar plates for evaluating flow field performance. Clean Energy, 4(2), 142-157, 2020.

X Zhuang, Y Song, H Zhan, XT Bi, X Yin, C Wu, Pyrolytic conversion of biowaste-derived hydrochar: Decomposition mechanism of specific components. Fuel 266, 2020.

HM Yun, R Clift, XT Bi, Environmental and economic assessment of torrefied wood pellets from British Columbia. Energy Conversion and Management, 208, 2020.

H Wang, S Zhang, X Bi, R Clift, Greenhouse gas emission reduction potential and cost of bioenergy in British Columbia, Canada. Energy Policy 138, 2020.

Y Nie, S Zhang, RE Liu, DJ Roda-Stuart, AP Ravikumar, A Bradley, MS Masnadi, AR Brandt, J Bergerson, XT Bi, Greenhouse-gas emissions of Canadian liquefied natural gas for use in China: Comparison and synthesis of three independent life cycle assessments. Journal of Cleaner Production, 2020.

A Stefanova, XT Bi, CJ Lim, JR Grace, A probabilistic heat transfer model for turbulent fluidized beds. Powder Technology, 365, 163-171, 2020

L Cheng, Z Wu, Z Zhang, C Guo, N Ellis, X Bi, AP Watkinson, JR Grace, Tar elimination from biomass gasification syngas with bauxite residue derived catalysts and gasification char. Applied Energy 258, 2020.

A.P. Ravikumar, D. Roda-Stuart, R. Liu, A. Bradley, J. Bergerson, Y.H. Nie, S.D. Zhang, X.T. Bi and A. Brandt, Repeated leak detection and repair surveys reduce methane emissions over scale of years. Environ. Res. Letter. 15(3), 2020

MH Rahman, XT Bi, JR Grace, CJ Lim, Comparison of techniques for measuring CFB solids circulation rates at low and high temperatures. Powder Technology 360, 43-54, 2020.

W Guo, X Bi, CJ Lim, S Sokhansanj, Investigation of wood pellets self‐heating kinetics and thermal runaway phenomena using lab scale experiments. The Canadian Journal of Chemical Engineering 98 (1), 127-137, 2000.

S Yewalkar, T Wu, D Kuan, H Wang, D Li, A Johnson, D Posarac, S Duff, X Bi, Applicability of differential fluorescein diacetate and propidium iodide fluorescence staining for monitoring algal growth and viability Waste Disposal & Sustainable Energy 1 (3), 199-206, 2019

BA Mohamed, N Ellis, CS Kim, X Bi, Understanding catalytic effects of bentonite/clinoptilolite on biomass pyrolysis. Renewable Energy 142, 304-315, 2019

BA Mohamed, N Ellis, CS Kim, X Bi, Microwave-assisted catalytic biomass pyrolysis: Effects of catalyst mixtures. Applied Catalysis B: Environmental 253, 226-234, 2019

MH Rahman, L Daniel, U Shah, X Bi, JR Grace, CJ Lim, Estimation of solids circulation rate and char transfer rate from gasifier to combustor in a dual fluidized-bed pilot plant for biomass steam gasification. Particuology, 46, 22-29, 2019

S Zhou, M Liu, X Yao, Z Yan, C Lu, X Bi, Gas phase flow hydrodynamics in the feed injection zone of a fluidized bed reactor. Industrial & Engineering Chemistry Research, 2019

G Liu, A Bonakdarpour, X Wang, X Bi, DP Wilkinson, Antimony-Doped Tin Oxide Nanofibers as Catalyst Support Structures for the Methanol Oxidation Reaction in Direct Methanol Fuel Cells. Electrocatalysis 10 (3), 262-271, 2019

H Wang, F Fotovat, XT Bi, JR Grace, Tribo-charging of binary mixtures composed of coarse and fine particles in gas–solid pipe flow. Particuology 43, 101-109, 2019

A Bakhurji, X Bi, JR Grace, Hydrodynamics and solids mixing in fluidized beds with inclined-hole distributors. Particuology 43, 19-28, 2019

Q Hu, H Yang, Z Wu, CJ Lim, XT Bi, H Chen, Experimental and modeling study of potassium catalyzed gasification of woody char pellet with CO2. Energy 171, 678-688, 2019

C Zhang, SH Ho, WH Chen, Y Fu, JS Chang, X Bi, Oxidative torrefaction of biomass nutshells: Evaluations of energy efficiency as well as biochar transportation and storage, Applied Energy 235, 428-441, 2019

D Jia, X Bi, CJ Lim, S Sokhansanj, A Tsutsumi, Heat transfer in a tapered fluidized bed of biomass particles with pulsed gas flow. Particuology 42, 2-14, 2019

A Stefanova, XT Bi, CJ Lim, JR Grace, A probabilistic heat transfer model for turbulent fluidized beds. Powder Technology, 2019

JS Lee, S Sokhansanj, CJ Lim, AK Lau, XT Bi, AK Lau, A Comparative Analysis of Sorption Isotherms for Wood Pellets and Solid Wood. Applied Engineering in Agriculture, 2019