Mass and energy balance

The species (methane and carbon dioxide) mass balance and energy conservation in the cylindrical ring element at steady state lead to the following 2D partial differential equations ... 

From mass balance and energy balance calculations, the raw material and energy costs are... 

The calculation of multi-stage separation processes involves the solution of phase equilibrium relationships, mass balances, and energy balances. Energy balances require the computation of enthalpies of streams entering and leaving an equilibrium stage. The enthalpy is a function of state, defined in Section 1.1.2 as H = U -i- PV. It is a function of the stream composition, its temperature, and its pressure. 

The column section can be solved by simultaneous solution of the component mass balance and energy balance equations and the vapor-liquid equilibrium relations. Additional equations include the temperature, pressure, and composition dependence of the equilibrium coefficients and enthalpies. The equations for stage j are as follows ... 

DISCUSSION ON MASS BALANCES AND ENERGY EFFICIENCIES IN AN ELECTROCHEMICAL REACTOR... 

Now using mass balance and energy balances with M t =100 kg yields... 

This chapter will explain the principles underlying chemical reactions, and it will go on to generalize these principles to the case of several concurrent reactions with large numbers of reagents and products. Then we shall extend to the case of chemical reaction the principles of mass balance and energy balance presented in Chapter 3. Finally we shall explain in detail how to simulate a gas reactor and a continuous stirred tank reactor (CSTR). 

The basic model for a countercurrent separation process needs to consider equilibrium and kinetic relationships, as given in chemical engineering textbooks. For SFE processes, equilibrium relationships include phase equilibria, mass balances, and energy balances, whereas kinetic relationships refer to mass transfer. 

We will now use the binary equilibrium data to develop graphical and analytical procedures to solve the combined equilibriurn, mass balance and energy balance equations. Mass and energy balances are written for the balance envelope shown as a dashed line in Figure 2-1. For a binary system there are two independent mass balances. The standard procedure is to use the overall mass balance,... 

INTERFACIAL SPECIES MASS BALANCE AND ENERGY BALANCE... 

By convention when analyzing plants with steam extraction, energy balances are normalized by the flow exiting the steam generator. The fraction of steam extracted is defined as M = wie/ms. Using the mass balance and energy balance from Equation 23.103... 

Using mass balance and energy balance equation to calculate the math model of the... 

The stage equations are the traditional equations based on mass balances and energy balances in the bulk phase for each stage (see Taylor Krishna (1993)). These equations take into account reactions, and there are no restrictive hypotheses as to the nature and the localisation of the chemical reactions. The bulk variables (composition, molar flux, temperature, energy flux) are different to the interface variables. The temperature of the vapour and the liquid phases are not assumed to be equal. The entire column represented as a sequence of such stages. 

Physically this phenomenon can be explained as follows. Since the inlet temperature is lower than the temperature in the tank, an increase in inlet flow will lead to a decrease in temperature. However, the increased inlet flow will eventually lead to an increase in outlet flow since a new equilibrium will be found and outlet flow will become equal again to the increased inlet flow. This means that the temperature will increase as well as the level. In addition, the pressure will increase, resulting in the increased outlet vapor flow. The oscillatory behavior is a result of the interaction between mass balance and energy balance. 

The preceding text discussed the required functions and critical issues on the road to commercialization with regard to catalyst, membrane, MEA, stack, and system technologies. However, much of this chapter focuses on details of the proton-conducting membrane, which has a major role in enhancing energy and power density and also affects the catalyst, mass balance, and energy balance of DMFC systems for mobile applications. 

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