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

Abstract

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.

Fundamental insights into barium sulfate precipitation by time-resolved in situ synchrotron radiation wide-angle X-ray scattering (WAXS)

“…The aqueous reactants are prepared with the salts barium chloride dihydrate (Roth, 4453.4, pro analysis) and sodium sulfate (Roth, 8560.2, pro analysis) dissolved in deionized water. The reactant solutions are continuously mixed in a Y-mixer (jet diameter of 0.5 mm, jet angle of 1501, 2 mm in the mixing zone, 7 mm length of mixing zone, see Kucher et al, 2008). Reaction tubes of varied lengths and diameters can be connected to the mixer.…”

“…Hence, the surfactant concentration after mixing is always 1 g/l. The points of time for reaching the solution's SLE are estimated by experimental and simulated results from Kucher et al (2008).…”

“…Haselhuhn et al (2006) have studied the pseudo polymorphic behavior of precipitated calcium oxalate by using a fast Y-mixing device, coupled with a reaction tube of variable length. Kucher et al (2008) have quantitatively determined the transient increase of the crystalline mass during barium sulfate precipitation and found that the nucleation rate does not depend on the initial free lattice ion ratio. In context with oil and gas processing, Jones et al (2008), Mavredaki et al (2011) and Webster et al (2014) have investigated surface deposition Contents lists available at ScienceDirect journal homepage: www.elsevier.com/locate/ces and its prevention on stainless steel due to barium sulfate precipitation.…”

“…(6)) and free lattice ion ratio R (see Eq. (7)) have been studied off-line in great detail by Judat and Kind (2004), Kucher et al (2008Kucher et al ( , 2006, Nielsen (1961), and Peukert (2004, 2005) at high supersaturation. These authors preferred impinging jet mixers in millimeter scale to investigate the influence of fundamental process parameters at the precipitation of barium sulfate.…”

Precipitation of barium sulphate in a hollow fiber membrane contactor: Part II The influence of process parameters

“…In addition to its economic value, barium sulphate has been used largely as a model system to investigate the effect of various process conditions in precipitation (especially related to mixing) and to validate precipitation models, since the kinetics of the primary process is quite well known (Nielsen and Toft, 1984;Aoun et al, 1996;Kucher et al, 2008). Its crystal structure is orthorhombic and one unit cell consists of four units of barium sulphate, i.e.…”