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Research

My research interests are in multiphase reactors with specific focus on gas-solid fluidized beds. My current research focuses on: (a) reactor fouling and particle agglomeration; (b) biomass gasification & fast pyrolysis; and (c)  CO2 capture

(a) Reactor Fouling and Particles Agglomeration

The overall focus of this research area is on the fundamental and applied research in the area of particle agglomeration and fouling due to electrostatic charge generation in multiphase reactors, pneumatic transport and powder handling.

Electrostatic charges are generated during particle handling, transport, and processing due to particle-particle and particle-wall contacts by triboelectrification. The charge build-up results in particle agglomeration, particle-wall adhesion and generation of high-voltage electrical fields, which can cause explosions and therefore be a major hazard.

In polymerization processes, electrostatic charge generation results in polymer particles agglomeration and reactor wall fouling (known as “sheeting”) in gas-solid fluidized bed reactors leading to the generation of waste/byproduct. In the oil and gas industry, fluid catalytic crackers provide a perfect setting for electrostatic charges to be generated in their risers or cyclones, which results in riser blockage or electrostatic discharge, and cyclones fouling. In powder handling operations such as pneumatic conveying, contanct charging occurs between solid particles and the pipe wall resulting in pipe or vessel fouling or blockage. Furthermore, electrostatic discharge can result in harmful electrical shocks to operating personnel and fires or explosions in commercial power-handling equipment and manufacturing facilities.

Projects:

Fundamental study of particle agglomeration and fouling due to electrostatic phenomena in gas-solid processes in industries such as polymerization (gas-solid fluidized bed  polyethyelne reactors).

Here are some of the specific projects of interest:

(1) Development of new and unique online electrostatic charge measurement techniques based on Faraday cup method to determine particles charge in three region of a gas-solid fluidized bed simultaineously; bed particles, those attahced to the reactor wall and the entrained fines.

(2) Study reactor wall fouling in an atmospheric fluidization system

(3) Investigation of reactor wall fouling in a high-pressure pilot-scale fluidization unit

(4) Computational Fluid Dynamics (CFD) modeling to predict the magnitude of electrostatic charge generation in gas-solid fluidized beds

Although current projects are in relation to gas-solid fluidized beds but fundamental knowledge gained can be applied to any gas-solid processes suffering from electrostatic charging.

(b) Biomass Gasification & Fast Pyrolysis

Reduction of world energy dependence on fossil fuels has significantly increased over the past few years. Renewable energy is a subject of significant interest as it would represent a diversification of the energy source. Biomass holds most promise for increasing use in the next few years.  In collaborations with NRCan CanmetENERGY (Ottawa, ON) we are to evaluate the effect sof various biomass feedstock pretreatment methods and reactor scale on gasification and fast pyrolysis processes performance.

Projects:

(1)  Evaluation of biomass feedstock pretreatment methods of drying, comminution level (related to particle size distribution), pelletization, and torrefaction on fluidized bed gasifiers.

(2) Bubbling fluidized bed co-gasification of biomass and refused derived fuel

(2) Fast pyrolysis fluidized bed reactor modeling.

(c) CO2 Capture

Calcium looping cycles (CaL) and chemical looping combustion (CLC) are promising technologies for the reduction of CO2 emissions from thermal power plants. Calcium looping is a two-stage process that uses oxy-fuel combustion for sorbent regeneration, i.e., generation of a concentrated CO2 stream. In collaborations with NRCan CanmetENERGY (Ottawa, ON) wer are  to investigate a new process integrating CaL and CLC for CO2 capture from post- and pre-combustion processes and to develope composite materials that use CuO as an oxygen carrier for the CaL sorbent regeneration stage via the exothermic reduction of CuO with a hydrocarbon (e.g., natural gas) or synthesis gas.

Projects:

(1) Sorbent developement and testing

(2) Cal-CLC Reactor modeling and process simulation

(d) Pressurized Chemical Looping Combustion-Reactor Modeling

(d) Heat Transfer and Entertainment in Pressurized Gas-Solid Fluidized Beds with Horizontal Internals

Heat transfer effects and particle residence time (i.e., entertainment rates) are being investigated at elevated pressures up to 2500 kPa in a gas-solid fludizied bed with horizontal internals. Binary system of fine and large particles is experimented replicating real systems such as pressurized oxygen-fired fluidized bed combustion (oxy-PFBC).

Projects:

(1) Investigation and modeling of fines residence time in pressurized fluidized beds with horizontal internals.

(2) Study of the influence of pressure and fines on heat transfer effects in a fluidized bed with horizontal heat exchanger tubes

Research Collaborations

  • Univation Technologies LLC, USA  ( the leading technology licensor to the worldwide PE industry)
  • NRCan CanmetENERGY, Bioenergy Systems Group, Ottawa, Ontario, Canada
  • NRCan CanmetENERGY, Fluidized Bed Combustion and Gasificaiton Group, Ottawa, Ontario, Canada
  • Gas Technology Institute-GTI, USA
  • Professor Rodney O. Fox, Chemical Engineering Department, Iowa State University, IA, USA
  • Professor Alberto Passalacqua, Mechanical Engineering Department, Iowa State University, IA, USA
  • Professor Arturo Macchi, Chemical and Biological Engineering Department, University of Ottawa, Onatrio, Canada.
  • Professor Jules Thibault, Chemical and Biological Engineering Department, University of Ottawa, Onatrio, Canada.

Research Funding

  • University of Ottawa Start-up
  • University of Ottawa, Chemical Engineering Department Star-up
  • NSERC Discovery
  • NSERC Research Tools and Instruments (RTI)
  • NSERC CRD
  • Canada Foundation for Innovation (CFI)
  • Ontario Research Fund (ORF)
  • Private Industry Funding
  • Carbon Management Canada (CMC)