In the paper is presented the way of Process Integration application for waste heat utilisation from exhaust gases streams with partial condensation. It is based on the construction of Hot Composite Curve representing the gaseous mixture cooling with accounting for the gas-liquid equilibrium of condensable vapour part. With Cold Composite Curve for streams requiring heating, the Pinch Point is determined. Then the structure of Heat Exchanger Network (HEN) for utilised Heat Integration into the energy system of the factory is developed accounting for the possible splitting of two-phase flow on gas and liquid streams and selection of plate heat exchanger (PHE) types for specific positions in HEN. The method is illustrated by a case study of heat utilisation from exhaust gases after superheated steam tobacco drying and flue gases from natural gas-fired boiler. The heat transfer areas of PHEs in HEN are optimised with the total annualised cost as an objective function. The payback period of the received solution is less than four months with a substantial saving of energy, reduction of greenhouse gases and other harmful emissions of combustion processes.