138
H. Rehage and M. Kind
not experimentally proof the idea of a PFR-BF equivalent circuit, we developed the
concept of an “experimental simulation,” which compares experimental PSDs of the
equivalent circuit to the PSD resulting from semi-batch bulk experiments. Although
there is a small error introduced by the equivalent circuit concept, this concept proved
to be a suitable simulation strategy for process flowsheet simulation. To implement
the model, the steady-state model (with minor adaptations) was used to solve the PFR
with high computational speed. It was, furthermore, possible to increase the computational speed of the model significantly by developing a hybrid modeling technique.
Within this hybrid model design, which can be applied for every mechanistic model
using a BF-PFR equivalent circuit in literature, the PFR is not recalculated on each
iteration but, instead, most of the timesteps are approximated by simpler equations.
Simulation time scales suitable for dynamic process flowsheet simulation can be
reached by utilizing this new approximation method. The final dynamic semi-batch
model was implemented in Dyssol. Except for high feed volume flows, the model
predicted the experimental data well. The dynamic process simulations show that
the wide PSD obtained by semi-batch precipitation originates from the semi-batch
process dynamics. As an outlook to future work, it is, furthermore, demonstrated
that dynamic process parameters might be used to optimize semi-batch precipitation
processes.
References
1. Metzger, L., Kind, M.: Influence of mixing on particle formation of fast precipitation reactions—A new coarse graining method using CFD calculations as a “measuring” instrument.
Chem. Eng. Res. Des. 10, 176–185 (2016)
2. Metzger, L., Kind, M.: On the transient flow characteristics in confined impinging jet mixers—
CFD simulation and experimental validation. Chem. Eng. Sci. 133, 91–105 (2015)
3. Metzger, L., Kind, M.: The influence of mixing on fast precipitation processes—A coupled 3D
CFD-PBE approach using the direct quadrature method of moments (DQMOM). Chem. Eng.
Sci. 169, 284–298 (2017)
4. Metzger, L., Kind, M.: On the mixing in confined impinging jet mixers—Time scale analysis
and scale-up using CFD coarse-graining methods. Chem. Eng. Res. Des. 109, 464–476 (2016)
5. Rehage, H., Scherer, S., Kind, M.: A steady-state precipitation model for flowsheet simulation
and its application. Comput. Chem. Eng. 128, 524–537 (2019)
6. Barrett, M., O’Grady, D., Casey, E., Glennon, B.: The role of meso-mixing in anti-solvent
crystallization processes. Chem. Eng. Sci. 66(12), 2523–2534 (2011)
7. Jaworski, Z., Nienow, A.W.: CFD modelling of continuous precipitation of barium sulphate in
a stirred tank. Chem. Eng. J. 91(2–3), 167–174 (2003)
8. Jones, A., Rigopoulos, S., Zauner, R.: Crystallization and precipitation engineering. Comput.
Chem. Eng. 29(6), 1159–1166 (2005)
9. Vicum, L., Ottiger, S., Mazzotti, M., Makowski, Ł., Bałdyga, J.: Multi-scale modeling of a
reactive mixing process in a semibatch stirred tank. Chem. Eng. Sci. 59(8–9), 1767–1781
(2004)
10. Vicum, L., Mazzotti, M.: Multi-scale modeling of a mixing-precipitation process in a semibatch
stirred tank. Chem. Eng. Sci. 62(13), 3513–3527 (2007)
11. Wang, Z., Mao, Z., Yang, C., Shen, X.: Computational fluid dynamics approach to the effect of
mixing and draft tube on the precipitation of barium sulfate in a continuous stirred tank. Chin.
J. Chem. Eng. 14(6), 713–722 (2006)
H. Rehage and M. Kind
not experimentally proof the idea of a PFR-BF equivalent circuit, we developed the
concept of an “experimental simulation,” which compares experimental PSDs of the
equivalent circuit to the PSD resulting from semi-batch bulk experiments. Although
there is a small error introduced by the equivalent circuit concept, this concept proved
to be a suitable simulation strategy for process flowsheet simulation. To implement
the model, the steady-state model (with minor adaptations) was used to solve the PFR
with high computational speed. It was, furthermore, possible to increase the computational speed of the model significantly by developing a hybrid modeling technique.
Within this hybrid model design, which can be applied for every mechanistic model
using a BF-PFR equivalent circuit in literature, the PFR is not recalculated on each
iteration but, instead, most of the timesteps are approximated by simpler equations.
Simulation time scales suitable for dynamic process flowsheet simulation can be
reached by utilizing this new approximation method. The final dynamic semi-batch
model was implemented in Dyssol. Except for high feed volume flows, the model
predicted the experimental data well. The dynamic process simulations show that
the wide PSD obtained by semi-batch precipitation originates from the semi-batch
process dynamics. As an outlook to future work, it is, furthermore, demonstrated
that dynamic process parameters might be used to optimize semi-batch precipitation
processes.
References
1. Metzger, L., Kind, M.: Influence of mixing on particle formation of fast precipitation reactions—A new coarse graining method using CFD calculations as a “measuring” instrument.
Chem. Eng. Res. Des. 10, 176–185 (2016)
2. Metzger, L., Kind, M.: On the transient flow characteristics in confined impinging jet mixers—
CFD simulation and experimental validation. Chem. Eng. Sci. 133, 91–105 (2015)
3. Metzger, L., Kind, M.: The influence of mixing on fast precipitation processes—A coupled 3D
CFD-PBE approach using the direct quadrature method of moments (DQMOM). Chem. Eng.
Sci. 169, 284–298 (2017)
4. Metzger, L., Kind, M.: On the mixing in confined impinging jet mixers—Time scale analysis
and scale-up using CFD coarse-graining methods. Chem. Eng. Res. Des. 109, 464–476 (2016)
5. Rehage, H., Scherer, S., Kind, M.: A steady-state precipitation model for flowsheet simulation
and its application. Comput. Chem. Eng. 128, 524–537 (2019)
6. Barrett, M., O’Grady, D., Casey, E., Glennon, B.: The role of meso-mixing in anti-solvent
crystallization processes. Chem. Eng. Sci. 66(12), 2523–2534 (2011)
7. Jaworski, Z., Nienow, A.W.: CFD modelling of continuous precipitation of barium sulphate in
a stirred tank. Chem. Eng. J. 91(2–3), 167–174 (2003)
8. Jones, A., Rigopoulos, S., Zauner, R.: Crystallization and precipitation engineering. Comput.
Chem. Eng. 29(6), 1159–1166 (2005)
9. Vicum, L., Ottiger, S., Mazzotti, M., Makowski, Ł., Bałdyga, J.: Multi-scale modeling of a
reactive mixing process in a semibatch stirred tank. Chem. Eng. Sci. 59(8–9), 1767–1781
(2004)
10. Vicum, L., Mazzotti, M.: Multi-scale modeling of a mixing-precipitation process in a semibatch
stirred tank. Chem. Eng. Sci. 62(13), 3513–3527 (2007)
11. Wang, Z., Mao, Z., Yang, C., Shen, X.: Computational fluid dynamics approach to the effect of
mixing and draft tube on the precipitation of barium sulfate in a continuous stirred tank. Chin.
J. Chem. Eng. 14(6), 713–722 (2006)