Coalescence efficiency model including electrostatic interactions in liquid/liquid dispersions

Kamp, Johannes; Kraume, Matthias

doi:10.1016/j.ces.2014.11.045

Cited by 18 publications

(19 citation statements)

References 47 publications

(100 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…To avoid a violation of conservation of mass due to numerical loss of mass, a narrower normal daughter drop size distribution ( , ′ ) than proposed by Coulaloglou and Tavlarides (1977) was used (see Equation (12) in Table 1) using a standard deviation tolerance of = 5 (instead of 3) within . According to Coulaloglou and Tavlarides (1977) binary drop breakup was assumed ( = 2) (Kamp and Kraume, 2015). In some parts of this work other submodels for breakage rate and coalescence efficiency were applied (see section 1.3).…”

Section: Simulationsmentioning

confidence: 99%

“…It was found that variations of the initial drop size distribution had only minor influence on the simulation results within the first milliseconds of the simulations. Hence, a Gaussian initial drop size distribution with mean value = 1 mm and standard deviation = 50 μm was used arbitrarily (Kamp and Kraume, 2015). All variables and parameters are given in SI units if dimensional; 2, of the Coulaloglou and Tavlarides (1977) model has the dimension [m -2 ].…”

Section: Simulationsmentioning

confidence: 99%

“…However, empirical scale-up rules are used up to now which require geometric similarity and constant impeller tip speed or power input (Ghotli et al, 2013). Apart from that, a mechanistic approach using population balance equations (PBE) Lucas, 2010, 2009) was established in the past years using single drop investigations to describe the fundamental phenomena breakage and coalescence in PBE (Bart et al, 2006;Kamp and Kraume, 2015;Kopriwa et al, 2012;Maaß and Kraume, 2012;Villwock et al, 2014b). Using PBE, which describe the breakage and coalescence rate by separate submodels, a bottom-up approach from small scale single drop experiments to droplet swarms in technical applications can be performed directly omitting empirical scale-up and pilot plant scale investigations.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

From single drop coalescence to droplet swarms – Scale-up considering the influence of collision velocity and drop size on coalescence probability

Kamp

Kraume

2016

Chemical Engineering Science

Self Cite

View full text Add to dashboard Cite

Coalescence modelling in liquid/liquid dispersions is a challenging task and field of investigations up to now, which becomes apparent when comparing the various existent models with their different and partly even contradictive implementation of influencing factors. In this work, systematic investigations of single drop coalescence were used to compare and validate different coalescence efficiency models regarding the important influencing parameters relative collision velocity and drop size. The impact of these parameters could be analysed independently from each other for the first time and used to identify the best modelling approach. Moreover, the numerical parameter of the coalescence efficiency model could be obtained based on single drop experiments. Using this determined parameter the simulation of drop size distributions within a lab scale stirred vessel was possible. The presented method offers the possibility of independent parameter estimation for population balance equation simulations based on single drop experiments. The application of this systematic approach allows the separate validation of submodels and reliable parameter determination by small scale investigations. On this basis a sound scaleup is possible using population balance equation simulations. Postprint: Kamp, J.;, From single drop coalescence to droplet swarms -Scale-up considering the influence of collision velocity and drop size on coalescence probability, Chemical Engineering Science, 156, 162-177, https://doi.org/10.1016/j.ces.2016.08.028 2 the drop breakage (Maaß and Kraume, 2012), this work focusses on drop coalescence and its modelling in PBE. Drop CoalescenceCoalescence describes the confluence of two disperse droplets or a drop with the corresponding continuous phase. Before coalescence between two droplets occurs, the interfaces approach each other and a thin film of surrounding continuous phase has to drain between the interfaces. At a certain critical distance the continuous phase film ruptures and the drops confluence. However, a collision of droplets does not end in coalescence necessarily, but may also results in a repulsion or agglomeration of the droplets. The probability of coalescence after droplet collision is described by the coalescence efficiency in PBE. The coalescence efficiency is influenced by numerous factors especially surface active components in already small amounts (Kamp et al., 2016b). Due to the involved complex interactions in distances of several orders of magnitude, numerous modelling approaches can be found in literature (Liao and Lucas, 2010) which implement influencing factors differently and in parts even contradictorily (Kamp et al., 2016b;Kopriwa et al., 2012). Postprint: Kamp, J.;, From single drop coalescence to droplet swarms -Scale-up considering the influence of collision velocity and drop size on coalescence probability, Chemical Engineering Science, 156, 162-177, https://doi.org/10.1016Science, 156, 162-177, https://doi.org/10. /j.ces.2016.08.028 3 Population Balance Equation (PBE...

show abstract

Section: Simulationsmentioning

confidence: 99%

Section: Simulationsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

From single drop coalescence to droplet swarms – Scale-up considering the influence of collision velocity and drop size on coalescence probability

Kamp

Kraume

2016

Chemical Engineering Science

Self Cite

View full text Add to dashboard Cite

show abstract

“…The presence of additives with different size, wettability and shape such as surfactants, nanoparticles, ions or enzymes can severely change the interface characteristics, e.g., by affecting the breakage and coalescence phenomena due to a change from mobile to rigid interfaces , . The description of these effects often necessitates additional experimental investigations, such as the determination of the zeta potential in case of ions in liquid/liquid systems . For an exact description, all relevant characteristics of the interface need to be implemented into the respective modeling approaches.…”

Section: Interface Characterizationmentioning

confidence: 99%

Description of Disperse Multiphase Processes: Quo Vadis?

Hohl

Panckow

Schulz

et al. 2018

Chemie Ingenieur Technik

Self Cite

View full text Add to dashboard Cite

The experimental accessibility of disperse systems often is a critical factor when it comes to the development of modeling approaches that intend to converge towards an exact solution. Often, integral or pseudo‐homogeneous values are used to reduce the complexity of the system, but a detailed single particle or interface analysis is crucial to understand relevant effects that also affect the swarm behavior. A high number of experimental techniques with respective limitations and advantages is available to quantify these effects. In this work, an overview on measurement techniques for momentum, heat and mass transfer in particle swarms as well as for the particle size distribution and interface characterization is provided. The industrial applicability is addressed by pointing out the vicinity to the process and the costs of different measurement techniques.

show abstract

“…Especially if additives or impurities barely affect the physical properties of the systems, common approaches might fail to predict the resulting droplet sizes with an acceptable accuracy since not all existing effects on droplet breakup and coalescence are taken into account. Examples are the influence of different molecular structures of surfactants with the same resulting interfacial tension or electrostatic forces induced by ions .…”

Section: Introductionmentioning

confidence: 99%

Mass Transfer and Drop Size Distributions in Reactive Nanoparticle‐Stabilized Multiphase Systems

Petzold

Röhl

Hohl

et al. 2017

Chemie Ingenieur Technik

Self Cite

View full text Add to dashboard Cite

Mass transfer in stirred liquid-liquid systems with and without silica nanoparticles is investigated for the saponification of benzoyl chloride. The mass transfer area is positively affected by the nanoparticles which lead to an increase of the liquidliquid interfacial area due to droplet coalescence hindrance. However, an additional mass transfer resistance induced by particles at the liquid-liquid interface was observed for all particle concentrations, since the high occupancy diminishes the available area for mass transfer. The ratio of the two oppositional effects needs to be determined to identify suitable nanoparticle reaction systems.

show abstract

Coalescence efficiency model including electrostatic interactions in liquid/liquid dispersions

Cited by 18 publications

References 47 publications

From single drop coalescence to droplet swarms – Scale-up considering the influence of collision velocity and drop size on coalescence probability

From single drop coalescence to droplet swarms – Scale-up considering the influence of collision velocity and drop size on coalescence probability

Description of Disperse Multiphase Processes: Quo Vadis?

Mass Transfer and Drop Size Distributions in Reactive Nanoparticle‐Stabilized Multiphase Systems

Contact Info

Product

Resources

About