1. School of Engineering Science, Industrial Engineering and Management, Lappeenranta University of Technology, P.O. Box 20, FI-53851, Lappeenranta, Finland
2. School of Energy Systems, Lappeenranta University of Technology, P.O. Box 20, FI-53851, Lappeenranta, Finland
3. Pöyry Finland Oy, P.O. Box 4, FI-01621, Vantaa, Finland
4. Faculty of Process and Environmental Engineering, Lodz University of Technology, Poland