Professor Andrzej Pacek MEng, MSc, PhD

School of Chemical Engineering
Emeritus Professor in Multiphase Systems

Contact details

School of Chemical Engineering
University of Birmingham
B15 2TT

Andrzej Pacek is Professor of Multiphase Systems in the School of Chemical Engineering.

Andrzej has published over 100 research papers in a wide range of scientific journals, as well as reviews and a book chapter, in the fields of liquid-liquid and fluid-solid two phase systems. In the area of liquid-liquid two phase systems his works on organic/aqueous two phase systems are referred to as classic. He also carries fundamental research in kinetics of emulsification and in dynamics of aqueous-aqueous two phase systems. In solid-liquid two phase systems he investigates kinetics of de-agglomeration of nano-powders and stability of resulting nano-suspensions. Those processes have been investigated both in stirred vessels and in high shear mixers.

Andrzej has received major grants from EPSRC, BBSRC, EU and his work was also sponsored directly by industry.


  • PhD in Technical Sciences, 1983
  • MEng/MSc in Mechanical Engineering, 1973


Andrzej Pacek qualified with MSc in Mechanical Engineering from Warsaw University of Technology in 1973. He worked in the Institute of Gas Technology for two years and then he returned to Warsaw University of Technology as a lecturer while he worked towards his PhD. In 1983 he was awarded PhD in Simultaneous Mass and Energy Transfer and promoted to readership. In 1986 he started research in multiphase gas solid fluidization in the School of Chemical Engineering at the University of Birmingham. He has established a research group that carries out theoretical and experimental investigations of transport phenomena in dispersed systems, including multiphase gas/liquid/solid solid systems relevant to catalitical reactors, aqueous/aqueous two phase systems for low fat food and bio-separations, wet processing of nano-particles and heat transfer in nano-fluids. The video-technique for drop/bubbles size measurements developed by Andrzej has been recently improved and is used to investigate the relation between shear stress and morphology of multiphase systems. It also forms a part of the new instrument for simultaneous characterization of rheology and morphology recently filed for a patent.

In the School of Chemical Engineering Andrzej oversees undergraduate teaching and he also lectures in Advanced Transport Phenomena, Multiphase Flow, Heat Transfer and Advanced Chemical Reactors.


MEng in Chemical Engineering:

  • Momentum Heat and Mass Transfer
  • Advanced Chemical Reactors
  • Advanced Transport Processes

Postgraduate supervision

  • Simultaneous characterisation of morphology and rheology of complex multiphase products
  • Effect of catalyst particles on bubble size and overall reaction rate in mixed solvents in heterogeneous reactors at elevated pressure and temperature
  • Concurrent Product Process design using rotor stator devices
  • Solid/gas/liquid interfaces in multiphase catalitical reactors
  • Lignosulphonate as a source of fine chemicals


  • Multiphase catalytic reactors in manufacturing fine chemicals from bio-mass
  • Applications of high shear mixers in emulsification and dispersing of nano-powders in liquids
  • Modelling of multiphase systems: breakage, coalescence, phase inversion
  • Kinetics of de-agglomeration of nano-powders, rheology and stability of resulting suspensions
  • Aqueous/aqueous two phase systems: formation, morphology and rheology

Other activities

  • Editorial board of Polish Journal of Chemical Technology
  • Editorial board of Reports of Chemical and Process Engineering
  • Member of EPSRC College
  • Member of External Permanent Advisory Commission of research Center CIGAR (Research Centre on Geo-Environment and Resources) at University of Porto (Portugal) 
  • Member of Scientific committee of UK-China Particle Technology Forum III, 3-6th July 2011 University of Birmingham, Birmingham, UK


Pacek A.W., Ding P., Nienow A.W., Wedd M., (2000), Phase Separation and Drop Size Distributions in homogeneous Na-alginate/Na caseinate mixture, Carbohydrate Polymers, 42, 401-409.
Pacek A.W., Ding P., Nienow A.W.,(2001), The effect of volume fraction and impeller speed on the structure and drop size distribution in aqueous/aqueous dispersions of phases with different viscosities, Chem. Eng. Sci. , 56, 3247-3255
Baldyga J., Bourne J.R., Pacek A.W, Amanullah A., Nienow A.W., (2001), Effects of agitation and scale-up on drop size in turbulent dispersions: allowance for intermittency, Chem. Eng. Sci., 56, 3377-3387.
Hu B.J., Nienow A.W., Pacek A.W.,(2002), The effect of the type and concentration of protein, air volume fraction and hydrodynamic conditions on bubble size and coalescence rate in batch gas/liquid dispersions, International Journal of Colloids and Surfaces, B: Biointerfaces, 31, 3-11.
Ding P., Pacek A.W., Frith W.J., Norton I.T., Wolf B., (2005), Effect of Temperature and Composition on Interfacial Tension and Rheology of Separated Phases in Gelatine/Pullulan Mixtures, Food Hydrocolloids, 19, 567-574.
Ding P., Pacek A.W., Abinhava K., Pickard S., Nienow A.W.,(2005) A Process for the Manufacture of Produced Toner – I. Evolution of Structure and Rheology, Ind. Eng. Chem. Res. 44(16) 6004 –6012.
Hu B.J., Pacek A.W., Stitt E.H., Nienow A.W.,(2005). Bubble sizes in air-alcohol systems with and without particles: turbulent and transitional flow, Chem. Eng. Sci., 60, 6371 – 6377.
Hu B.J., Nienow A.W., Stitt H.E., Pacek A.W. (2006), Bubble sizes in agitated solvent/reactant mixtures used in heterogeneous catalytic hydrogenation of 2-butyne-1,4-diol, Chem Eng Sci. 61, 6765-6774
Pacek A.W., Ding P., Utomo A.T., (2007), Effect of Energy Density, pH and Temperature on De-aggregation in Nano-particles/Water Suspensions in High Shear Mixer, Powder Technology 173, 203-210,
Ding P., Pacek A.W., (2008), De-agglomeration of goethite nano-particles using ultrasonic comminution device, Powder Technology, 187, 1-10
Ding P., Norton I.T., Zhang Z., Pacek A.W., (2008), Mechanical properties of gelatin-rich micro-particles, Journal of Food Engineering, 86, 307-315
Spyropoulos F., Ding P., Frith W.J., Norton I.T.,Wolf B., Pacek A.W.,(2008), Interfacial Tension in Aqueous Biopolymer-Surfactant Mixtures, Journal of Colloid and Interface Science, 317, 604-610
Ding P., Pacek A.W.,(2008), Effect of pH on d agglomeration and rheology/morphology of aqueous suspensions of goethite nano-powder, Journal of Colloid and Interface Science, 325, 165-172,
Utomo A.T., Baker M., Pacek A.W., (2009),Effect of stator geometry on flow pattern and energy dissipation rate in a rotor-stator mixer, Chem. Eng. Res. Des., 87, 533 – 542,
Ding P., Pacek A.W., (2009) Ultrasonic processing of suspensions of hematite nano-powder stabilised with sodium polyacrylate, AIChE Journal, 55, 2796 – 2806,
Ding P., Orwa M.G., Pacek A.W. (2010), DE-Agglomeration of hydrophobic and hydrophilic silica nano-powders in a high shear mixer, Powder Technology, 195, 221-226,
Hall S., Pacek A.W., Kowalski A.J., Cooke M., Rothman D., 2011, Scaling Up of Silverson Rotor-Stator Mixers, Can J Chemical Engineering, in press

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