Homogeneous Nucleation in Barium Sulfate Precipitation.

Nielsen, Arne E.; Hope, Henry B.; Sørensen, Nils Andreas; Dam, H. van; Sjöberg, Berndt; Toft, Jens

doi:10.3891/acta.chem.scand.15-0441

Cited by 84 publications

(62 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…A minimum in the product particle size vs. the stirring rate was found. Due to lower solubility, the maximum supersaturation ratio in the experiments of Tosun (1988) is approximately 1,900; however, the estimated corresponding induction time still is approximately 0.02 s (Nielsen, 1961). The range of mean specific power input seems to have been approximately the same as in the present study.…”

Section: Interpretation Of Experimental Resultsmentioning

confidence: 40%

Semibatch reaction crystallization of benzoic acid

Slund

Rasmuson

1992

AIChE Journal

View full text Add to dashboard Cite

Section: Interpretation Of Experimental Resultsmentioning

confidence: 40%

Semibatch reaction crystallization of benzoic acid

Slund

Rasmuson

1992

AIChE Journal

View full text Add to dashboard Cite

“…If the critical supersaturation is crossed (S a [ 550), homogeneous nucleation is the dominant nucleation mechanism, which leads to a continuously decreasing particle size with increasing supersaturation. 19 As can be seen in Figure 9, using fitted nucleation data measured by Nielsen 1 for the heterogeneous and the homogeneous region (solid line), a good qualitative correspondence between simulation and experiment is already achieved. It is remarkable that in the heterogeneous region in particular, the simulation overestimates the mean particle size, although fewer particles are created by this nucleation mechanism and nucleation takes place on a more moderate timescale in comparison to the homogeneous nucleation region.…”

Section: Offline Measurementsmentioning

confidence: 89%

“…Nucleation kinetics of barium sulfate have been studied by several authors (Nielsen, 1 Mohanty et al, 2 and Angerhöfer 3 ) under stoichiometric conditions (R 5 1). Although all three authors studied the same crystalline substance, namely barium sulfate, their reported experimental data and the proposed models are not very consistent ( Figure 7).…”

Section: Supersaturationmentioning

confidence: 99%

“…Numerous theoretical and experimental research studies are reported on nucleation and growth kinetics [1][2][3][4] and on the influence of reactor geometries and mixing conditions on the resulting particle size or to test precipitation models. [5][6][7][8] Most of these studies were carried out as batch or semi-batch processes, where mixing of the reactants has a dominant influence due to the very fast nucleation and growth kinetics of barium sulfate.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

In situ WAXS synchrotron radiation study on particle formation of precipitated barium sulfate

2008

View full text Add to dashboard Cite

in Wiley InterScience (www.interscience.wiley.com).The particle formation process during the precipitation of barium sulfate from aqueous solutions of barium chloride and sodium sulfate was studied experimentally and numerically. Particle formation was examined offline and in situ on timescales ranging from 55 ms to 1 s. Precipitation experiments were performed in a tubular reactor of adjustable length equipped with a flow-through cuvette. The mass fraction of the crystalline precipitate was followed time-resolved using wide-angle X-ray scattering (WAXS), performed at the synchrotron radiation facility ANKA of FZK Karlsruhe GmbH. A high degree of correspondence between numerical and experimental results was achieved using nucleation kinetics based on experimental findings in combination with diffusion-controlled growth kinetics in the population balance equation. Furthermore, the online measurements showed that the lattice ion ratio (educt ratio) has no influence on nucleation kinetics, which means that the adsorption of lattice ions on pre-nuclei has no influence on their respective interfacial energy.

show abstract

“…In precipitation research nucleation rates are generally measured according to the method developed by Nielsen [2,3] for barium sulfate. Two flows of reactant solutions are intensively mixed in a mixing tee and nuclei form in the outlet tube.…”

Section: Introductionmentioning

confidence: 99%

An Analysis of Mixing in a Typical Experimental Set‐up to Measure Nnucleation Rates of Precipitation Processes

Roelands¹,

Derksen

Horst

et al. 2003

Chem Eng & Technol

View full text Add to dashboard Cite

Mixing in a typical experimental setup to measure nucleation rates in precipitation processes was assessed. To determine these rates as a function of the driving force for concomitant polymorphs, it is necessary to perform these experiments at constant supersaturation. Therefore, the mixing time must be shorter than the time for the first nuclei to appear. For fast precipitation processes complete mixing has to be achieved within milliseconds. The mixing performance of a wide angle Y-mixer was studied to see whether this is possible. An analysis of characteristic mixing times as a function of the average energy dissipation rate showed that turbulent dispersion of the feed streams determined the rate of the mixing process. The characteristic time for turbulent dispersion was of the same order as an arbitrarily set residence time in the Y-mixer. However, CFD simulations of the flow showed large variation in the spatial distribution of the dissipation rate and revealed unsatisfying macromixing.

show abstract

Homogeneous Nucleation in Barium Sulfate Precipitation.

Cited by 84 publications

References 0 publications

Semibatch reaction crystallization of benzoic acid

Semibatch reaction crystallization of benzoic acid

In situ WAXS synchrotron radiation study on particle formation of precipitated barium sulfate

An Analysis of Mixing in a Typical Experimental Set‐up to Measure Nnucleation Rates of Precipitation Processes

Contact Info

Product

Resources

About