Dr. Yassir T. Makkawi

Chemical Engineering and Applied Chemistry (CEAC)

European Bioenergy Research Institute (EBRI) 

Dr. Yassir T. Makkawi

I obtained my PhD in Chemical Engineering at Heriot-Watt University in Edinburgh (2003). Prior to that, I worked as a process engineer for eight years, serving the oil and gas industry sectors in the Middle East. My first academic post was at Heriot-Watt University, where I worked as a Research Associate. I then moved to the University of Edinburgh as a Research Fellow, then to the University of Sheffield as a Teaching and Research Fellow. I joined the academic staff at Aston University as a lecturer in 2008.

My research is focused on the broad areas of particle technology and biomass thermochemical conversion. I have particular current interest in wet suspension and particle-particle interactions, experimental and CFD modelling of biomass gasification and pyrolysis in fluidized bed reactors, adsorption for gas separation and purification.

Position: Senior Lecturer in Chemical Engineering 

Phone:  0121 204 3398
Email: y.makkawi@aston.ac.uk
Room: MB124

  • Postgraduate Certificate of Professional Practice (PGCPP) in Higher Education, Aston University, Birmingham, UK, 2012.
  • PhD in Chemical Engineering, Heriot-Watt University, Edinburgh, UK, 2003.
  • MSc in Chemical Engineering, King Fahd University of Petroleum and Minerals (KFUPM), Dhahran, KSA, 1995.
  • BSc in Chemical Engineering, University of Khartoum, Khartoum, Sudan, 1991
  • Aug 2013 – present: Senior Lecturer, Chemical Engineering and Applied Chemistry, Aston University, Birmingham
  • Aug 2008 – Jul 2013: Lecturer, Chemical Engineering and Applied Chemistry, Aston University, Birmingham
  • Nov 2006 – Jul 2008: Teaching and Research Fellow, Chemical and Process Engineering, University of Sheffield, Sheffield
  • Jun 2006 – Oct 2006: Research Fellow, Chemical Engineering, University of Edinburgh, Edinburgh
  • Jun 2003 – May 2006: Research Associate, Chemical Engineering, Heriot-Watt University, Edinburgh
  • Separation Processes ( 2nd and 3rd year levels)
  • Introduction to Transfer Processes (1st year level)
  • Advanced Transfer Processes (3rd year level)
  • Advanced Process Design (3rd year level)
  • Process Laboratory (2nd year level)
  • Research projects (4th year level)
  • Industrial Placement Tutor for chemical engineering and applied chemistry (since 2008)

  • Mathematical modelling and simulation of particle-gas systems
  • Fluidized bed chemical, thermal and physical processing
  • Energy conversion and renewable energy sources
  • Biomass thermal conversion (gasification and pyrolysis)
  • Computional Fluid Dynamic (CFD) modelling 
  • Adsorption and desorption processes
Current research grants
  • EPSRC grant- Project title: Real time control of gasifiers- increase tolerance to biomass and reduce emissions (2015-2018); £281.322; in collaboration with Dr Ian Watson (Project lead from Glasgow University (Aston principal investigator: Makkawi )
  • KTP (Knowledge Transfer Partnership) with Aylesford Newsprint Ltd - project title: A novel process for the thermochemical conversion of paper mill waste into clean energy (2014-2017); £175.024 (Lead academic: Makkawi)
  • EPSRC case-award with Dow Corning Ltd- Project title: Gas purification for the silicone industry (2012-2015); £92,000 (Principal Investigator: Makkawi)
  • The Leverhulme Trust- Project title: Wet and dry particle flow at the intermediate regime (2012-2015); in collaboration with Prof Raffaela Ocone (Heriot-Watt) and Sotos Generalis (Aston University); £175.162 (Principal Investigator: Makkawi)
  • Industrial collaboration fund with Dow Corning Ltd- Project title: gas purification by adsorption (2012-2015); £25,000 (Principal Investigator: Makkawi
Research sponsors
  • The Engineering and Physical Sciences Research Council (EPSRC, UK)
  • The Leverhulme Trust, UK
  • Dow Corning, UK
  • Technology Strategy Board, UK
Particle Suspension and Processing (PSP) 

In the process industry, particles suspension is of particular interest due to the enhanced heat and mass transfer characteristics. This is found in most of the chemical processes, including food production, pharmaceutical, petrochemicals and energy. Our research is uniquely combining knowledge on particle technology and energy conversion in order to solve challenging engineering problems and develop novel and sustainable processes for future industrial applications.

We are particularly interested in applying mathematical modelling and Computational Fluid Dynamic (CFD) for studying the physical, chemical and thermal processing of particles during suspension. This is of direct relevance to fluidized bed processing such as in granulation, drying, gas cleaning, chemical looping, catalytic cracking and biomass thermal conversion. We are currently looking at (i) developing new models for the interaction of wet/dry particles at the micro-scale level (ii) working with industrial collaborator on novel processes on adsorption for gas separation and thermal conversion of paper mill waste to energy (iii) Building 3D predictive models of biomass gasification and pyrolysis in fluidized bed reactorsOur theoretical approach is supported by state of the art experimental facilities including a range of modern fluidized bed systems, gas adsorption unit, biomass gasifiers and analytical techniques. 

We have established links with national and international institutions including Heriot-Watt University (UK), Glasgow University and the institute for chemicals and fuels from alternative resources (Canda). In addition, our research is funded by UK industrial collaborators such as Dow Corning Ltd and UK research funders such as the EPSRC, The Leverhulme Trust and the Technology Strategy Board.


Resaerch figure

  1. Dr Mohamed Hassan - CFD modelling and simulation of biomass thermal conversion in fluidized bed reactors.
  2. Mr. Maxwell Ozonoh- PhD (2014-2017): Gasification of municipal solid waste and sewage sludge in a circulating fluidized bed reactor.     

  3. Mr Jai Lad - PhD (2011-2014): A greener approach for the purification of methyl Chloride for silicone industry.
  4. Dr Xi Yu - Postdoctoral Research Fellow (2012-2015): Wet and dry particle flow at the intermediate regime.
  5. Mr Muktar Bashir - PhD (2013-2016): A novel approach for the integration of concentrated sold energy with biomass thermochemical conversion.  
  6. Mr Francis Elewuwa - PhD (2012-2015): Modelling and simulation of a novel adsorption/desorption process for gas purification and hydrogen production. 


  1. Yassir Makkawi, Lead inventor, “Syngas production from paper mill waste”. UK application (filled in 2013) 
  2. Yassir Makkawi, Sole inventor, “Process and apparatus for thermochemical conversion”. UK application (filled in 2011) 

Book Chapters:

  1. Yassir Makkawi and Raffaella Ocone "Mass transfer in fluidized bed drying of moist particulate” a chapter published in a new book under the title “Mass Transfer”, ISBN 978-953-307-215-9, INTECH, 2011.
  2. Yassir Makkawi "Reactor design and its impact on performance and products” a chapter in a new book under the title “Transformation of Biomass: Theory to Practice”, ISBN 978-1-119-97327-0, John Wiley & Sons Ltd, 2014.

Journal papers (* corresponding author): 


  1. Yu, X., Hassan, M., Ocone, R., Makkawi, Y.*, A CFD study of biomass pyrolysis in a downer reactor equipped with a novel gas-solid separator- II: Thermochemical performance and products, Fuel Processing Technology (submitted)
  2. Yu, X., Makkawi, Y.*, Ocone, R., Berruti, R., Beriens, C., Huard, M., A CFD study of biomass pyrolysis in a downer reactor equipped with a novel gas-solid separator- I: hydrodynamic performance, Fuel Processing Technology, 2014, 366-382.
  3. Lad, J. and Makkawi, Y.*, Adsorption of Dimethyl ether (DME) on zeolite molecular sieves, Chemical Engineering Journal, 2014, 335-346.


  1. Kelwin, C, Makkawi, Y.*, Hounslow, M., A Priori prediction of aggregation efficiency and rate constant for fluidized bed melt granulation, Chemical Engineering Science, 2013, Volume 98, 291-297. 


  1. Kelwin, C, Makkawi, Y.*, Hounslow, M., Time scale analysis for fluidized bed melt granulation- I: granule-granule and granule-droplet collision rates, Chemical Engineering Science 2011, Volume 66, Issue 3, 318-326.
  2. Kelwin, C, Makkawi, Y.*, Hounslow, M., Time scale analysis for fluidized bed melt granulation- II: binder spreading rate,Chemical Engineering Science 2011, Volume 66, Issue 3, 327-335.
  3. Kelwin, C, Makkawi, Y.*, Hounslow, M., Time scale analysis for fluidized bed melt granulation- III: binder solidification rate,Chemical Engineering Science 2011, Volume 66, Issue 3, 336-341.              


  1. Makkawi, Y.* and Ocone, R., Mass transfer coefficient for drying of moist particulate in a bubbling fluidized bed. Chemical Engineering Technology 2009, 1-10. 


  1. Makkawi, Y. and Ocone, R.*, Integration of ECT measurements with hydrodynamic modelling of conventional gas-solid bubbling bed. Chemical Engineering Science, 2007. 4304-4315. 4


  1. Makkawi, Y. and Ocone, R.*, A model for granular flows in a horizontal duct with a smooth merge of rapid-intermediate-dense flows. Chemical Engineering Science, 2006. 4271-4281.
  2. Makkawi, Y., Wright, P. C. and Ocone, R.*, The effect of friction and inter-particle cohesive forces on the hydrodynamics of gas-solid flow: a comparative analysis of theoretical predictions and experiments. Powder Technology 2006, 163. 69-79.


  1. Makkawi, Y. and Ocone, R.*, Modelling of particle stress at the dilute-intermediate-dense flow regimes: A review. KONA - Powder Science and Technology 2005, No.23. 49-63.


  1. Makkawi, Y. and Wright, P. C.*, Electrical Capacitance Tomography for conventional fluidized bed measurements- remarks on the measuring technique. Powder Technology 2004, 148. 142-157.
  2. Makkawi, Y. and Wright, P.*, Tomographic analysis of dry/semi-wet bed fluidization: the effect of small liquid loading and particle size on the bubbling behaviour. Chemical Engineering Science 2004, 59 (1), 201-213.


  1. Makkawi, Y. and Wright, P. C.*, The void function and effective drag force for fluidized beds. Chemical Engineering Science 2003, 58 (13), 2035-2051.


  1. Makkawi, Y. and Wright, P. C.*, Fluidization regimes in a conventional fluidized bed characterized by means of Electrical Capacitance Tomography. Chemical Engineering Science, 2002, 57 (13), 2411-2437.
  2. Makkawi, Y. and Wright, P. C.*, Optimisation of experiment span and data acquisition rates for reliable Electrical Capacitance Tomography measurement in fluidization studies- a case study. Measurement Science and Technology 2002, 13 (12), 1831-1841.
  3. Makkawi, Y. and Wright, P. C.* (2012). Tomographic analysis of dry and semi wet fluidization, Short article. The Chemical Engineer Journal.


  1. Demirel, Y.*, Abu-Al-Saud, B. A., Al-Ali H. H. and Makkawi, Y., Packing size and shape effects on forced convection in large rectangular packed ducts with asymmetric heating, International Journal of Heat and Mass Transfer 1999, 42 (17), 3267-3277.


  1. Makkawi, Y., Y. Demirel* and H. H. Al-Ali, Numerical analysis of convection heat transfer in a rectangular packed duct with asymmetric heating, Energy Conversion and Management 1998, 39 (56), 455-463.

Conference presentations and papers:  


  1. Yu. X, Hassan, M., Ocone, R., Makkawi, Y., CFD modelling of biomass pyrolysis in a downer reactor, 3rd International Conference on Chemical and Biological Processing (ICCBP 2014), 19-21 December, 2014, Dubai, UAE  
  2. Yu, X., Ocone, E., Sotos, G., Makkawi, Y., Improved two-fluid model for bubbling fluidized bed. 12th UK Particle Technology Forum, 17-19 Sep 2014, Manchester, UK
  3. Bashir, M., Makkawi, Y., Modelling of biomass fast pyrolysis in a solar trough/reactor, 2nd international symposium on Energy Challenges and Mechanics, 19-21 Aug 2014, Aberdeen, UK.
  4. Yu, X., Ocone, R., Makkawi, Y., A CFD study of biomass pyrolysis in a downer reactor equipped with a novel gas-solid separatoor. The 20th International Symposium on Analytical and Applied Pyrolysis (Pyro2014), May 19-23, Birmingham, UK.


  1. Makkawi, Y., Ocone, R., Geldart Classification and limitations for the Kinetic Theory of Granular Flow in Solid-Gas Modelling. AICHE Annual meeting, Nov 3-8, 2013, San Francisco, USA.
  2. Yu, X., Ocone, E., Sotos, G., Makkawi, Y., A new constitutive equation for solid stress in a slightly wet particulate flow, UK-China International Particle Technology Forum IV, October 15-19, 2013, Shanghai, China.
  3. Yu, X.., Ocone, R., Makkawi, Y., CFD study of gas-solid behaviour in a downer pyrolysis reactor: An Eulerian-Eulerian approach. BioEnergy IV: Innovations in Biomass Conversion for Heat, Power, Fuels and Chemicals, June 2-7, 2013, Otranto, Italy.
  4. Makkawi, Y., Hassan, M., Modelling and simulation of biomass thermal conversion to hydrogen-rich gas in a short circulating fluidized bed riser. BioEnergy IV: Innovations in Biomass Conversion for Heat, Power, Fuels and Chemicals, June 2-7, 2013, Otranto, Italy.
  5. Yu, X., Ocone, R., Sotos, G., Makkawi, Y., Inter-particle force and stress models for wet and dry particulate flow at the intermediate flow regime. 2nd IMA Conference on Dense Granular Flows, July 1-4, 2013, Isaac Newton Institute for Mathematical Sciences, Cambridge, UK.


  1.  Makkawi, Y. Particle to gas heat transfer coefficient in a circulating fluidized bed riser. International Conference on  Circulating Fluidized Beds and Fluidization Technology- CFB 10, 01-06 May 2011, USA, Oregon.


  1. Makkawi, Y. Prediction of the hydrodynamics in slightly wet suspended particles. IMA Conference on Dense Granular Flows, 5-9 Jan 2009, Cambridge, UK. 


  1. Nitert, B. J., Makkawi, Y., Hounslow, M. J.. Product engineering for crystallization: A step by step process. 17th International Symposium on Industrial CrystallizationISIC 17, 14-17 September 2008, Maastricht, The Netherlands.


  1. Makkawi, Y., Duncan, J., McAndrew, M., Ocone, R.. Drying of moist particulate in bubbling fluidized bed. AICHE annual meeting, 4-9 Nov 2007. Salt Lake Utah- USA.


  1. Makkawi, Y., Wright, P. C., Ocone, R., Experimental observations of wet bed fluidization hydrodynamics. 5th World Congress on Particles Technology, 23-27 April 2006. Orlando FL- USA.
  2. Makkawi, Y. and Ocone, R., Validation of CFD model for fluidized bed over broad ranges of operating conditions. 5th World Congress on Particles Technology, 23-27 April 2006. Orlando FL- USA.


  1. Makkawi, Y. and Ocone, R., Simulation of dense and intermediate granular flow in a horizontal duct. Proceedings of the 7th World Congress of Chemical Engineering- 2005. Galsgow- UK.
  2. Chuntanapum, A, Makkawi, Y, Arrighi, V, Ocone, R., Particles suspension in viscous fluids. 7th World Congress of Chemical Engineering- 2005. Galsgow- UK.


  1. Makkawi, Y. and Ocone, R., Hydrodynamic simulation of gas-solid flow in a horizontal duct using kinetic-frictional stress models. AICHE annual meeting, 7-11 Nov 2004. Austin TX- USA.
  2. Makkawi, Y. Wright, P. and Ocone, R., Comparative analysis of experimental and modelling of gas solid flow hydrodynamics: Effect of friction and interparticle cohesion forces. AICHE annual meeting, 7-11 Nov 2004. Austin TX- USA.


  1. Makkawi, Y. and Wright, P. C., Hydrodynamics in a conventional fluidized bed analyzed by electrical capacitance tomography.4th World Congress on Particles Technology,Sydney-Australia,20-25 July 2002.
  2. Makkawi, Y. Wright, P. C. Meeyoo, V., Dechsiri, C., Zwan, E., Paans, A.M.J. and Hoffmann A.C., Observations on cross-sectional non-uniformity on fluidized beds using two different imaging techniques. 4th World Congress on Particles Technology, Sydney-Australia, 20-25 July 2002.
  3. Makkawi, Y., Tomographic analysis of semi-wet bed fluidization. Particle Technology UK Forum IV. The University of Leeds, UK. 11-12 April 2002.


  1. Makkawi, Y. and Wright, P., Application of Process Tomography as a tool for better understanding of fluidization quality in fluidized beds, Proceedings of 2nd World Congress on Industrial Process Tomography, Hanover, Germany, 28-31 August 2001. 

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