Process integration methods allow one optimizing industrial processes. The main goals are decreasing energy demand and operating costs as well as reduction of pollutants emissions. High fuel costs promote installations of heat pumps. In a heat pump process waste energy is valorized by electrical power to produce higher quality energy. This energy is used to satisfy a part of the process demand so that less fuel is required and CO2 emission will decrease. The combination of appropriate refrigeration and heat pump cycles leads to an important energy saving potential. The respective flow rates are defined by optimization. The application case of a dairy is used to calculate the energy and operating cost savings potential.