The scope of this paper is to discuss some process integration options for enhancing the energy systems in pulp and paper industries. The focus is on the recovery of heat of the exhaust air streams from the paper machine dryer section and on the utilisation of eventual excess heat from thermo-mechanical pulping (TMP). With optimal heat recovery systems substantial savings can be obtained. New papermaking technologies like improvements in the press section and impingement drying have opened up new possibilities for utilisation of secondary heat energy. Production of electrical power with organic Rankine cycle (ORC) can be an option in that respect.