Simple material balance programs

This program helps calculate the rate of methanol formation in mol/m s at any specified temperature, and at different hydrogen, carbon monoxide and methanol concentrations. This simulates the working of a perfectly mixed CSTR specified at discharge condition, which is the same as these conditions are inside the reactor at steady-state operation. Corresponding feed compositions and volumetric rates can be calculated from simple material balances. 

Simple material balance programs requiring only a relatively small core size. 

The computer program for the material balance contains several parts. First, a description ofeach item of equipment in terms of the input and output flows and the stream conditions. Quite complicated mathematical models may be required in order to relate the input and output conditions (i.e. performance) of complex units. It is necessary to specify the order in which the equipment models will be solved, simple equipment such as mixers are dealt with initially. This is followed by the actual solution of the equations. The ordering may result in each equation having only one unknown and iteration becomes unnecessary. It may be necessary to solve sets of linear equations, or if the equations are non-linear a suitable algorithm applying some form of numerical iteration is required. 

Simple material balance programs need only a small memory and can be run on personal computers. 

We have called these material balance functions the a fractions. They equal the equilibrium a fractions only at one value of H at which equilibrium and material balance conditions are simultaneously satisfied. This can be found graphically or programmed for computer solution. For pure acid and base, Cj, or C zero, a simple, invariant shaped curve results in the logarithmic plots. 

The use of computer programs or packages to carry out material and energy balances is now commonplace, and probably one of the first encounters the student has with CAD. Unless the equipment or process is fairly simple, hand calculations become difficult and time consuming due to the iterative nature of the method. The design project may be the... 

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