Precipitation of sodium chloride and sodium sulfate in water from sub- to supercritical conditions: 150 to 550 °C, 100 to 300 bar

Armellini, Fred J.; Tester, Jefferson W.; Hong, Glenn T.

doi:10.1016/0896-8446(94)90019-1

Cited by 85 publications

(39 citation statements)

References 13 publications

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“…At these conditions, water is significantly less polar than at standard conditions, leading to a dramatic change of the dielectric constant (Leusbrock et al, 2008) and thus the solubility of inorganic ions is highly reduced (Schubert, 2010;Zhang et al, 2010). This decrease in the polarity results in a ''shock-precipitation'' and crystallization (Armellini et al, 1994), which could explain why the concentration of inorganic matter in the water and biocrude oil phases is higher at 250°C (milder conditions) than at 375°C (harsher conditions, less polar behavior of the water). These crystals seem to be thermally more stable, which is also consistent with the higher amount of ash recovered in the experiments at 375°C, compared to those at 250°C (despite using the same feedstock at both temperatures).…”

Section: The Role Of Water Soluble Inorganic Mattermentioning

confidence: 95%

“…In fact, when searching in the literature in view of the results obtained, it was found that hydrothermal processing has already been studied for the formation of more thermal stable crystals in the synthesis of ceramics (Byrappa and Yoshimura, 2013) or as a technique for solidification of thermal decomposable carbonate powders (Yamasaki and Weiping, 1993). Armellini et al (1994) reported the formation of NaCl and Na 2 SO 4 crystals by nucleation and agglomeration under hydrothermal conditions, leading to crystals with a particle size higher than 1 lm. Crystals with such a size would be part of the solid residue, given the separation procedure followed in our experiments.…”

Section: The Role Of Water Soluble Inorganic Mattermentioning

confidence: 97%

“…This would eventually explain why in other literature studies the yield of organics in the aqueous phase is so much higher (>60 wt%) than the ones reported in this paper, despite using similar experimental conditions. The understanding of the behavior of salts under hydrothermal conditions appears to be limited due to the significant number of parameters and complex phenomena involved (i.e., multicomponent multi-phase thermodynamics, crystal growth kinetics from highly supersaturated solutions, heat and mass transfer) (Schubert, 2010;Armellini et al, 1994). The change in the water properties at near critical conditions (Peterson et al, 2008) is the cause of the changes in the state and structure of the salts accompanying the algae slurries.…”

Section: The Role Of Water Soluble Inorganic Mattermentioning

confidence: 99%

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Influence of strain-specific parameters on hydrothermal liquefaction of microalgae

Barreiro¹,

Zamalloa²,

Boon³

et al. 2013

Bioresource Technology

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Section: The Role Of Water Soluble Inorganic Mattermentioning

confidence: 95%

Section: The Role Of Water Soluble Inorganic Mattermentioning

confidence: 97%

Section: The Role Of Water Soluble Inorganic Mattermentioning

confidence: 99%

See 1 more Smart Citation

Influence of strain-specific parameters on hydrothermal liquefaction of microalgae

Barreiro¹,

Zamalloa²,

Boon³

et al. 2013

Bioresource Technology

116

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“…11,[12][13][14] In contrast, inorganic salts are almost insoluble in SCW. 2,15 SCW also presents high diffusivities and low viscosities. In the region above the critical point these properties are only slightly affected by temperature and can be predicted.…”

Section: Properties Of Supercritical Watermentioning

confidence: 96%

Supercritical water oxidation: A technical review

2006

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Supercritical water oxidation (SCWO) technology presents important environmental advantages for the treatment of industrial wastes and sludges. The homogeneous reaction that takes place between the oxidizable materials and oxygen, at temperatures and pressures above the critical point of the water (647.3 K and 22.12 MPa), is well known. Specific equations of state for water and aqueous mixtures, gases, and organics have been developed. The process is not having the expected industrial development. Some new plants have been closed by corrosion and operational problems related with high temperature, high pressure, and oxidative atmosphere inside of the equipments. To overcome these technical difficulties more research focused on solving operational problems is necessary. This article presents an overview of the technical aspects of the supercritical water oxidation process. Reactors design, construction materials, corrosion, salts precipitation problems, and industrial applications are discussed. © 2006 American Institute of Chemical Engineers AIChE J, 2006

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“…Some effort has also been placed on characterizing nucleation rates and the solid salt morphology that appears during precipitation from highly supersaturated NaCl, Na 2 S0 4 , and Na 3 P0 4 brines (Armellini and Tester, 1991;Armellini, Hong, and Tester, 1994;DiPippo, 1997;DiPippo, Sako, and Tester, 1999;Hong et al, 1995). These studies have shown that the presence of liquid phases in Type I synthesis, in coexistence with lower density supercritical fluid or vapor phases, can greatly influence solid particle nucleation and morphology in the case of NaCl deposition.…”

Section: Chemical and Phase Reactions In Supercritical Watermentioning

confidence: 99%

Guidelines for Phase Separations in High-Temperature and Supercritical Water Solutions: A Report on a Workshop Organized by the U.S. Army Research Office and the Forschungzentrum Karlsruhe, 7-9 July 1999

Shaw¹,

Boukis²

2000

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Approved for public release; distribution unlimited. AbstractThe U.S. Army is developing supercritical water oxidation for destruction of military toxic materials. The properties of high-temperature aqueous solutions are not, in most cases, well known. Understanding the phase behavior of these solutions will facilitate design and efficient operation of high-temperature water reactors. A U.S. Army workshop held at the Forschungzentrum Karlsruhe in July 1999 assembled experts on phase behavior to develop guidelines that, in the absence of more complete knowledge of solution properties, will aid reactor designers and operators. The experts presented papers on model systems, properties of high-temperature aqueous solutions, and chemistry in high-temperature water. Following these presentations, the experts developed some of the desired rules of thumb and made recommendations for research to develop these guidelines further. This workshop report includes the presentation papers, guidelines, and recommendations for research. Distribution 67Report Documentation Page 71 Participants in the workshop 2Hong, Model Systems P-T-x diagram for Type la systems and Type lb systems 122. T-x diagram for NaCI-H 2 0 at 250 bar 13 3. P-T projection of solidus for NaCI-H 2 0 14 4. P-T-x diagrams for Type 2a systems, and Type 2b systems 14 5. T-x projection of phase diagram for ternary systems of Type 1: subtype A, subtype B, and subtype C 16 6. P-T projection of eutonic curve for NaCl-Na 2 S04-H 2 0 system ... 177. Temperature progression of phase diagrams at 225 bar for NaCINa 2 S04-H 2 0 system 17 Supercritical water (SCW) oxidation (SCWO) provides a powerful means to transform toxic organic materials into simple, relatively inert oxides. Water at high temperatures and pressures is an active medium, however, and its properties and those of its solutions are only partially understood. Indeed, two principal challenges to broad use of this technology are (1) the materials requirements for the reactor and the heatup and cooldown sections, and (2) the incomplete understanding of and ability to predict the phase behavior of SCW solutions.Phase separations have the potential to impair the operation of an SCWO reactor (1) by dramatically changing transport properties (especially in the presence of dynamically separating liquid and solid phases), (2) by generating solid particles that may plug reactor orifices and deposit on reactor surfaces, and (3) by producing a highly corrosive electrochemical environment. Objectives for This WorkshopWe sought to develop (or recommend methodologies to develop) guidelines/rules of thumb for phase separations in organic/salt/gas/aqueous solutions in SCWO processing for defined sets of feed compositions. Useful speculations about these phase separations are in the areas not only of equilibrium thermodynamics (e.g., solubility), but also of the kinetics of phase separation and growth (e.g., the problem of heterogeneous nucleation). The phase separation guidelines are intended to indicate regions of safe (pr...

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Precipitation of sodium chloride and sodium sulfate in water from sub- to supercritical conditions: 150 to 550 °C, 100 to 300 bar

Cited by 85 publications

References 13 publications

Influence of strain-specific parameters on hydrothermal liquefaction of microalgae

Influence of strain-specific parameters on hydrothermal liquefaction of microalgae

Supercritical water oxidation: A technical review

Guidelines for Phase Separations in High-Temperature and Supercritical Water Solutions: A Report on a Workshop Organized by the U.S. Army Research Office and the Forschungzentrum Karlsruhe, 7-9 July 1999

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