Position Professor Emeritus Qualifications PrEng MEng(Pret) PhD(Pret) FSAIChE MSAIT Telephone +27-12-420-6748 Fax +27-12-420-5048 Office Engineering I, 8-11 E-mail [email protected]

Current research interests

Modelling and control

Tribology

Use of laboratory techniques related to performance characteristics of fuels and lubricants.

Current projects

Use of advanced control techniques for improved performance of control systems

This project addresses the following:

• Obtaining nonlinear process models
• Design of nonlinear MPC-controllers for continuous processes
• Automated start-up and shutdown of continuous process

Completed projects

Control of batch digesters used for the manufacturing of dissolved pulp

This project was run in collaboration with SAPPI-SAICCOR and PITEC and was supported by the THRIP-initiative of the NRF.

• Development of a Model Predictive Control software package This project was run in collaboration with PITEC and was supported by the THRIP-initiative of the NRF as well as the TIPTOP-scheme supported by the Department of Trade & Industry through the NRF.
• Advanced Milling Control. This project was run with the support of MINTEK.
• Abnormal Situation Management. This project was run with the support and collaboration of SASTECH.

Publications

Scopus researcher ID: 6603186692

Process modelling and control:

1. Gous, G.Z., de Vaal P.L.; Using MV overshoot as a tuning metric in choosing DMC move suppression values; ISA Transactions 51 (2012) 657–664
2. De Clerk, N, de Vaal, P.L.; A holistic approach to control and optimization of a PGM concentrate flash drying unit; Journal of The Southern African Institute of Mining and Metallurgy, 112, January (2012), 45-53.
3. De Klerk, A, de Vaal, PL; Alkylate Technology Selection for Fischer-Tropsch Syncrude Refining; Industrial and Engineering Chemistry Research (2008), 47(18), 6870-6877
4. de Vaal, P.L Sandrock, C.; Implementation of a Model Based Controller on a Batch Pulp Digester for Improved Control; Computers and Chemical Engineering 31 (2007) 1222–1230
5. de Vaal, P.L., Sandrock, C.; Implementation of a Model Based Controller on a Batch Pulp Digester for Improved Control; pp 1013-1018 in 'Computer-aided Process Engineering. Vol.14: European Symposium on Computer Aided Process Engineering –13'; Kraslawski, A., Turunen, I. (Ed), Elsevier, Amsterdam, 2003 (ISBN 0-444-51368-X)
6. Muller, B., de Vaal, P.L.; Development of a Model Predictive Controller for a Milling Circuit; Journal of the South-African Institute of Mining & Metallurgy; Nov/Dec. 2000, pp.451-456.
7. de Vaal, P.L.; What is Classical Control and when is it better than AI?; South-African Journal of Chemical Engineering; Vol.11 No.2., 2000, pp.10-26
8. Kilian, A. de Vaal, P.L.; Potential for improved control of an acid sulphite batch digester using a fundamental model; TAPPI Journal, Vol. 83 No.11, November 2000.
9. Fourie, S., de Vaal, P.L.; Advanced Process Monitoring using an On-line Multiscale Principal Component Analysis Methodology; Computers & Chemical Engineering, July 2000, Vol.24, pp.755-760.
10. de Vaal, P.L.; An overview of advanced control techniques; Chemical Technology SA; September/October 1999, pp. 13-19.
11. de Vaal, P.L., Fourie, S., Oosthuizen, N.; Creating an integrating learning environment in a control systems laboratory; SACAC Workshop on control engineering education, Cape Town University, 10 September 1999.
12. Greeff, P., de Vaal, P.L.; Robust control of a triple-effect evaporator: A desktop case study; 1999 International Symposium on quantitative feedback theory and robust frequency domain methods; 26-27 August 1999, University of Natal, Durban.
13. de Vaal, P.L.; Assignments for Process Dynamics and Control ; AECI/Wits Conference, 5-6 July 1999, University of Natal.
14. Greeff, P., de Vaal, P.L.; Dynamic modelling of unit operations - a modular approach applied to distillation columns; South-African Journal of Chemical Engineering, Vol. 10 No.2 1998, pp.15
15. Greeff, P. de Vaal, P.L.; Dynamic modelling of unit operations using SIMULINK - an object-oriented approach applied to distillation columns; Proceedings of the 8th National meeting of SAIChE, 16-18 April 1997, Cape Town, p.48-49.
16. de Vaal, P.L., Vermaak, J.L.; Implementation of a scheduled adaptive internal model controller; Proceedings of the 8th National meeting of SAIChE, 16-18 April 1997, Cape Town. p.85-86.
17. Vermaak, J.L., de Vaal, P.L.; Temperature control of a nonlinear process with variable dead time: Implementation of scheduled adaptive internal model control; South-African Journal of Chemical Engineering, Vol.9 No.1 1997, pp.30-44
18. de Vaal, P.L.; An overview of control system design software; South-African Journal of Chemical Engineering, Vol.8 No.2 1996, pp. 34-48
19. de Vaal, P.L. Controlling a non-linear process with variable dead-time: a computer-based laboratory experiment; ESCAPE 6, 26-29 May 1996 Rhodes, Greece; Computers and Chemical Engineering Vol.20 Supplement, pp.S1359-S1364, 1996.
20. Braae, M., Boje, E., Craig, F.K., de Vaal, P.L., Gouws, J., McClaren, S.G., Swartz, C.L.E., Ungerer, C.P., van Niekerk, J.L. and Wigdorowitz, B., Control Engineering Education in South-Africa, IEEE Control Systems Magazine, April 1996, pp. 41-47.

Tribology

1. de Vaal, P.L., Barker, L.F., du Plessis, E., Crous, D.; Biorefining - A Green Tribological Perspective; in M. Nosonovsky and B. Bhushan (eds.), Green Tribology, Green Energy and Technology, DOI: 10.1007/978-3-642-23681-5_20, Springer-Verlag Berlin Heidelberg 2012, pp. 565-605. 
2. Massinga, P.H. Jr., Focke, W.W., de Vaal, P.L., Atanasova, M.; Alkyl ammonium intercalation of Mozambican bentonite. Applied Clay Science 49 (2010) 142–148 
3. de Vaal, P.L. & Phillpotts, D.; Comparison of test methods to determine diesel fuel lubricity; Proceedings of the ECOTRIB 2007 Conference; 12-15 June 2007; Ljubljana, Slovenia pp 895-905 (ISBN 978-961-90254-8-2 
4. Burger, N.D.L., de Vaal, P.L., Meyer, J.P.; Failure analysis on retrieved ultra high molecular weight polyethylene (UHMWPE) acetabular cups; Engineering Failure Analysis 14 (2007) 1329–1345
5. Burger, N.D.L., de Vaal, P.L., Meyer, J.P.; Failure criteria for polyethylene acetabular cups; South African Journal of Science 102, Nov/Dec (2006) pp.572-574.
6. Vavruch, P., de Vaal, P.L.; Selecting a new formulation of industrial gear oil - focus on EP performance; Lubrication Engineering, Vol. 59 No 7, July 2003, pp.22-27.   
7. de Vaal, P.L.; Open-Gear Lubrication: Meeting Industrial Requirements using Laboratory Techniques; Tribotest Journal, Vol. 5 No. 1, September 1998, pp.79-91.
8. de Vaal, P.L.; Girth Gear Lubrication: Laboratory-based Performance Norms; Journal of the Balkan Tribological Association, Vol.4 No.4 1998, pp.245-252
9. de Vaal, P.L; The Development of an FZG Test for Open gear Lubricants: The South-African Experience; Proceedings of the World Tribology Congress, 8-12 September 1997, London, p.284. 1
10. de Vaal, P.L.; Lubricant Performance Test Simulation in the Laboratory; SAIT Seminar on "Lubricants analysis, Condition Monitoring & Performance Evaluation"; BIFSA Conference Centre, Midrand, 26 August 1997. 1
11. de Vaal, P.L.; Open Gear Lubrication: Meeting Industrial Requirements using Laboratory Techniques; Proceedings of the 10th LAWPSP Symposium, IIT Bombay, Mumbai, India, 30 Jan - 1 Feb 1997, Vol.10, No.10, pp.FF2.1 - FF2.8 1
12. de Vaal, P.L., Girth gear lubrication: Laboratory-based performance norms; Proceedings of the BALKANTRIB '96-Conference, 5 - 7 June 1996, Thessaloniki, Greece, pp.893-900. de Vaal, P.L., Lubricant Performance Testing on a Laboratory Test Bench - Does it Contribute?; Proceedings of the 10th International Colloquim on Tribology, Vol. 3, pp 2041-2045, Esslingen, Germany, 9-11 January 1996. 1
13. de Vaal, P L, Laboratory performance testing of open-gear lubricants - fact or fiction?, South-African Journal of Chemical Engineering, Vol. 7, No. 2, pp. 25-38, October 1995. 1
14. de Vaal, P.L., Le Roux, H.J., Barker, L.F., Performance evaluation of girth-gear lubricants, The South African Mechanical Engineer, Vol. 45, pp. 11-15, August 1995. 1
15. de Vaal, P.L.; Performance of open-gear lubricants using a modified FZG test; STLE/ASME Tribology conference, 11-13 October 1999, Kissimmee, Florida, USA. 1
16. de Vaal, P.L., Le Roux, H.J.; Evaluation of Open-Gear Lubricants on the FZG Machine; Lubrication Engineering, Vol.51 No.3 March 1995 pp.198-202.