ABSTRACT
Heat transfer is a frequently occurring process operation. Within a process two general types of heat exchange occur. One type is the exchange of heat between two process streams. The heat exchanger where this occurs is frequently called an interchanger. In the second type, heat exchange occurs between the process and the surroundings, which requires a heat-transfer fluid. Water is the most common fluid. If the temperature is sufficiently high, then it may be economical to recover work from a process stream by generating high pressure steam and then expanding the steam through a turbine. This occurs in processes for synthesizing methanol where superheated steam is generated when cooling the reformer exit stream.
