Water is an essential substance in most biopharmaceutical processes. It can be used both as an ingredient or to clean equipment and materials. It is also used in the form of steam for sterilization. Water that is not used as an ingredient in preparation is called process water. This water is used for heat exchange in the plant, for steam generation, and for cleaning equipment. The flow diagram of process water in a plant is shown below. Potable water enters the process at a flow rate of 10 kg/h and at 25C. In order to avoid limescale formation, two softeners are used to remove Ca2+ and Mg2+ ions, which contribute to the hardness of the water. At the outlet of the furnace, the water exits as saturated steam at 162C. From the water leaving the softeners, 3.8 kg/h is recirculated and preheated in a heat exchanger that recovers the energy contained in the water following sterilization. After sterilization, the water is at 85C. Just before entering the furnace, the water is at 35C. a) What rate of energy (in kW) must combustion in the furnace generate in order for water to be in the desired condition for sterilization? Consider that 85% of the energy from the combustion is transferred to the water. b) If the recirculated water upstream of the softeners exits the heat exchanger at 45C, how much energy is transferred from the sterilization water to the recirculated water (in kW)? c) At what temperature will the water used for cleaning the equipment be? What will be the mass enthalpy of this water? Specify the reference used.

Potable water ATM Softeners Potable water tank Furnace Sterilization Ultrafiltration Fuels To the purification unit Equipment cleaning