Fluidization, Reactor Design, Electrostatics, PEM Fuel Cells, Pollution Control, Biomass Processing, Green Engineering
Director, UBC Clean Energy Research Centre (CERC)
CHBE 411
University of British Columbia, 1994, Ph.D.
Tsinghua University, China, 1988, M.A.Sc.
Tsinghua University, China, 1985, B.A.Sc.
Research Interests

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.

Select Publications
  • JR Grace, X Bi, N Ellis, Essentials of Fluidization Technology, Wiley-VCH, 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, …, 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.
  • 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, 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 Stefanova, XT Bi, CJ Lim, JR Grace, A probabilistic heat transfer model for turbulent fluidized beds,  Powder Technology 365, 163-171, 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, 2020.
  • 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
  • Ehsan Oveisi, Shahab Sokhansanj, Anthony Lau, C Jim Lim, Xiaotao Bi, Mahmood Ebadian, Fernando Preto, Cliff Mui, Robby Gill. In-depot upgrading the quality of fuel chips for a commercial gasification plant. Biomass and Bioenergy. 108: 138-145, 2018
  • Nie, Y, X Bi, Life-cycle assessment of transportation biofuels from hydrothermal liquefaction of forest residues in British Columbia. Biotechnology for biofuels 11 (1), 23, 2018.
  • Fotovat, F, XT Bi, JR Grace, A perspective on electrostatics in gas-solid fluidized beds: Challenges and future research needs. Powder Technology 329, 65-75, 2018.
  • Hu, Q, H Yang, H Xu, Z Wu, CJ Lim, XT Bi, H Chen, Thermal behavior and reaction kinetics analysis of pyrolysis and subsequent in-situ gasification of torrefied biomass pellets. Energy Conversion and Management 161, 205-214, 2018.
  • Chen, WH, BJ Lin, B Colin, JS Chang, A Pétrissans, XT Bi, M Pétrissans, Hygroscopic transformation of woody biomass torrefaction for carbon storage. Applied energy 231, 768-776, 2018.
  • Yan, Z, Y Fan, XT Bi, C Lu, Effects of Different Gaseous Nozzle Injections on Gas–solid Dynamic Mixing in FCC Riser. Industrial & Engineering Chemistry Research 58 (2), 1055-1067, 2018.
  • Yan, Z, Y Fan, XT Bi, C Lu, Dynamic behaviors of feed jets and catalyst particles in FCC feed injection zone. Chemical Engineering Science, 189, 380-393, 2018.
  • Masnadi, MS, HM El-Houjeiri, D Schunack, Y Li, JG Englander, … Global carbon intensity of crude oil production. Science 361, 851-853, 2018.
  • Lopes, GC, X Bi, N Epstein, SA Baldwin, JR Grace, Hydrodynamic characteristics of particles with different roughness and deformability in a liquid fluidized bed. Chemical Engineering Science 185, 50-63, 2018.
  • Oveisi, E, S Sokhansanj, A Lau, J Lim, X Bi, F Preto, C Mui, Characterization of Recycled Wood Chips, Syngas Yield, and Tar Formation in an Industrial Updraft Gasifier. Environments 5 (7), 84, 2018.
  • Nie, Y, XT Bi, Techno-economic assessment of transportation biofuels from hydrothermal liquefaction of forest residues in British Columbia. Energy 153, 464-475, 2018.
  • Rezaei, H, S Sokhansanj, CJ Lim, A Lau, X Bi, Effects of the mass and volume shrinkage of ground chip and pellet particles on drying rates. Particuology 38, 1-9, 2018.
  • Li, YH, Z Chen, P Watkinson, X Bi, J Grace, CJ Lim, N Ellis, A novel dual-bed for steam gasification of biomass. Biomass Conversion and Biorefinery, 8(2), 357-367, 2018.
  • Zhou, S, S Liu, Y Wei, X Li, C Lu, M Liu, X Bi, Coupled fluidized bed reactor for pyridine synthesis. Industrial & Engineering Chemistry Research 57 (22), 7466-7475, 2018.
  • Liu, W, XT Bi, Q Zhu, H Li, Usefulness of multi-solids pneumatic transport bed data for evaluation and validation of binary solids computational simulation models. Powder Technology 327, 70-78, 2018.
  • Fotovat, F, XT Bi, JR Grace. Electrostatics in gas-solid fluidized beds: A review. Chemical Engineering Science. 173: 303-334. 2017.
  • Hejazi, B, JR Grace, X Bi, A Mahecha-Botero, Kinetic model of steam gasification of biomass in a bubbling fluidized bed reactor, Energy & Fuels, 31 (11): 12141–12155, 2017.
  • Badr A Mohamed, Naoko Ellis, Chang Soo Kim, Xiaotao Bi. The role of tailored biochar in increasing plant growth, and reducing bioavailability, phytotoxicity, and uptake of heavy metals in contaminated soil. Environmental Pollution. 230: 329-338. 2017.
  • Fotovat, F., K Gill, JR Grace, XT Bi, Impact of Column Material on Electrostatics and Entrainment of Particles from Gas-Solid Fluidized Beds. Chem Eng Sci, 167: 120-134. 2017.
  • Olga Petrov, Xiaotao Bi, Anthony Lau. Impact assessment of biomass-based district heating systems in densely populated communities. Part II: Would the replacement of fossil fuels improve ambient air quality and human health? Atmospheric Environment. 161: 191-199. 2017.
  • Rahman, MH, XT Bi, JR Grace, CJ Lim, Measurement of solids circulation rate in a high-temperature dual fluidized bed pilot plant, Powder Technology, 316: 658-669. 2017..
  • D Jia, Xi, CJ Lim, S Sokhansanj, A Tsutsumi, Gas-solid mixing and mass transfer in a tapered fluidized bed of biomass with pulsed gas flow. Powder Technology. 316: 373-387. 2017.
  • Farzam Fotovat, John R. Grace, Xiaotao T. Bi, Particle entrainment from gas-solid fluidized beds: Conductive vs. dielectric fines. AIChE Journal. 63(4): 1194–1202. 2017.
  • Jia, D., XT Bi, CJ Lim, S Sokhansanj, A Tsutsumi, Heat transfer in a pulsed fluidized bed of biomass particles. Ind & Eng Chem Res. 56(13): 3740-3756. 2017.
  • Bijan Hejazi, John R Grace, Xiaotao Bi, Andrés Mahecha-Botero. Kinetic model of steam gasification of biomass in a bubbling fluidized bed reactor. Energy & Fuels. 31(2): 1702-1711. 2017.
  • YH Li, Z Chen, P Watkinson, X Bi, J Grace, CJ Lim, N Ellis. A novel dual-bed for steam gasification of biomass. Biomass Conversion and Biorefinery. 1-11. 2017.

For more publications, visit my Google Scholar Profile.


Canadian Academy of Engineering, Fellow
Engineering Canada, Fellow
Association of Professional Engineers and Geoscientists of BC (APEGBC), Member
Canadian Society of Chemical Engineers (CSChE), Member
American Institute of Chemical Engineering (AIChE), Senior member
Clean Energy Research Centre (CERC), Director
China-Canada Bioenergy Centre (C-CBC), Director
Fluidization Research Centre (FRC), Manager
Biomass and Bioenergy Research Group (BBRG), Member


CHBE 370 Fundamentals of Sustainable Engineering
CHBE 561 Particle Technology
CEEN 523 Energy and the Environment