1. Polytechnique Montr�al, Department of Mathematics and Industrial Engineering, Montr�al, Qu�bec, H3T 1J4, Canada
2. CanmetENERGY Varennes, Varennes, Qu�bec, J3X 1P7, Canada
3. CanmetENERGY Devon, Devon, Alberta, T9G 1A8, Canada
4. Polytechnique Montr�al, Department of Chemical Engineering, Montr�al, Qu�bec, H3T 1J4, Canada