Category: Energy Balance Computations

A chemical engineer has to perform a wide variety of energy balance computations for a large number of transformations and processes. These computations require application of the principles discussed in section 7.1. The myriad energy balance computations performed by chemical engineers can very broadly be classified into two types: those involving determination of heat effects in…

Enthalpy is a measure of the energy (or heat) content of a substance [3]. It is a thermodynamic quantity whose absolute value cannot be determined; however, enthalpy of a substance with respect to its value at some reference conditions can be calculated [4, 5]. The reference state, also called the standard state, is specified in terms of pressure and temperature of…

Consider an arbitrary process represented by the block flow diagram shown in Figure 7.1. Figure 7.1 Energy balance on a process unit; Streams: 1—Inlet, 2—Outlet, 3—Heat, 4—Work. This diagram is similar to the one shown in Figure 6.1 for the material balance, except for the following important differences: First, the streams represent energy flows rather than material flows. The…

Because energy can take several different forms, it is necessary for us to understand the forms that are of primary interest to a chemical engineer. These forms are briefly described in the following section. 7.1.1 Forms of Energy Three primary forms of energy are encountered in a chemical process [1]: 1. Kinetic energy (KE)—Energy associated with motion.…