Spreadsheets mass balance calculations

Figure 6.11 Spreadsheet for the mass balance calculation of a HCR process.

Figure 6.11 illustrates an Excel spreadsheet that we develop to do the mass balance calculations. We have included all of the Excel spreadsheets mentioned in the DVD accompanying this book. Although we have developed the spreadsheet and the formulas for a specific HCR process, the reader can generalize the steps described above and apply the spreadsheet to do mass balance of any HCR process with only minor changes. 

The fractional conversions in terms of both the mass balance and heat balance equations were calculated at effluent temperatures of 300, 325, 350, 375, 400, 425, 450, and 475 K, respectively. A Microsoft Excel Spreadsheet (Example6-ll.xls) was used to calculate the fractional conversions at varying temperature. Table 6-7 gives the results of the spreadsheet calculation and Eigure 6-24 shows profiles of the conversions at varying effluent temperature. The figure shows that die steady state values are (X, T) = (0.02,300), (0.5,362), and (0.95,410). The middle point is unstable and die last point is die most desirable because of die high conversion. 

Once process design is complete and each of the process steps characterized, the process is ready for scale-up to pilot or manufacturing scale. A spreadsheet template for scale-up calculations is important and provides a mass balance of buffer volumes, column volumes, priming volumes, product volumes, and waste volumes as well as the tank size and column size. Product volumes can be expressed relative to column volume or can be calculated from a constant concentration, depending on the process step. In addition, starting volumes and titers of conditioned medium as well as step yields and gel or membrane capacity are necessary to cal-... 

Recommended procedure From the mass balance for sulfate, find an expression for [SO]-] in terms of [Cu2+] and fH+]. Set up a spreadsheet with pH values between 2 and 12 in column A. From pH, compute [H+] and [OH ] in columns B and C. Guess a value for [Cu2+] in column D. From [HT] and [Cu2+], calculate [S04] from the equation derived from the mass balance for sulfate. From [HT], [OH, [Cu2+], and fSO ], calculate all other concentrations by using equilibrium expressions. Find the total concentration of... 

Note that this 12-line calculation would have required setting up a recycle and three stream-adjusts in a process simulator, illustrating that simple problems can often be solved more easily by hand or spreadsheet calculations if the boundaries for mass balances are chosen carefully. 

These spreadsheet calculations are very intuitive they helped in the understanding of inverse mass balance modeling. We strongly recommend readers to practice using a... 

The final step is to calculate the conversion that belongs to the individual entries in the spreadsheet. The calculation of conversion ( is carried out by means of a mass balance for the two comonomers. The necessary equation is shown as eqn [36] ... 

The core of this problem concerns the specification of an acceptable plate arrangement, Le. length, width, spacing and number. The calculations are easier if they are done on a spreadsheet so that the interdependence of the variables can be seen instantly. The flowrates and concentrations are related by mass balance equations ... 

Figure 9.8 shows the flowsheet of an algae-based biorefinery case study. The mass balance was determined using spreadsheet calculations, and the conversion and yield factors of the various process units are presented in Table 9.8. The production of lOOOkgh" of dry algae biomass is used as basis. The composition of algae biomass is shown in Table 9.9. 

Figure 5.15 Microsoft Excel-based spreadsheet tool for mass and hydrogen balance calculations.

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