Salt deposition problems in supercritical water oxidation

Xu, Donghai; Huang, Chuanbao; Wang, Shuzhong; Lin, Geng; Guo, Yang

doi:10.1016/j.cej.2015.05.040

Cited by 95 publications

(27 citation statements)

References 82 publications

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“…Another interesting design is the sonochemical reactor [27] (c.f. Figure 4 Regarding the oxidative process eciency, the reviews written by BRUNNER [5,28,29] [12] is focused on the deposition of sticky salts (Na 2 CO 3 , Na 2 SO 4 . .…”

Section: (B))mentioning

confidence: 99%

Solubility of inorganic salts in sub- and supercritical hydrothermal environment: Application to SCWO processes

Voisin

Erriguible

Ballenghien³

et al. 2017

The Journal of Supercritical Fluids

102

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The supercritical water oxidation process (SCWO) is of great interest today in recycling toxic and/or complexed chemical wastes with very good eciency. When reaching the critical conditions (374°C, 22.1 MPa), polarity collapses and water becomes a very good solvent for organic compounds. However, these interesting properties for organics turn to be problematic regarding dissolved inorganics. Commonly present in the aqueous waste, those inorganics precipitate easily when approaching the critical domain, leading to plugs in the process. In order to better understand the precipitation of salts in supercritical water, their solubility behaviour is of main interest. However, lots of relevant data are still missing in the literature. The aim of this review is to summarise most of the existing data regarding salt solubility in sub-and supercritical water as well as the dierent set up and methods developed over the past 50 years, including predictive theoretical modeling.

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Section: (B))mentioning

confidence: 99%

Solubility of inorganic salts in sub- and supercritical hydrothermal environment: Application to SCWO processes

Voisin

Erriguible

Ballenghien³

et al. 2017

The Journal of Supercritical Fluids

102

View full text Add to dashboard Cite

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“…Salt management was identified as a critical issue for the success of SCWO technology. Except for the inorganic salts initially present in the feedstocks, a majority of inorganic salts derive from the SCWO treatment of high-concentration, stubborn organic matters including hetero-atoms such as chlorine, sulfur, and phosphorus [50]. Solubility of salts is reduced evidently in SCW, which is usually lower than 100 mg/L, and thus they are prone to deposition.…”

Section: Salt Precipitationmentioning

confidence: 99%

“…In general, different salts own different deposition characteristics [51]. Salt deposition principles and the corresponding solutions have been systemically presented in the previous literatures [50,52,53]. In a commercialized SCWO plant, reactor plugging can be avoided by particular reactor designs, special instruments, and operation means [18].…”

Section: Salt Precipitationmentioning

confidence: 99%

“…Salts in SCWO are classified into Type 1 or Type 2, according to their solubility [54], Type 1 salt has a high solubility in the range of water's critical temperature, while Type 2 salt has a low solubility in this region. Type 2 salt can be separated by properties of SCW [50], and the suitable supercritical conditions should be controlled at approximately 400°C and 25 MPa according to the solubility of salts mentioned in the previous studies [52,55]. Hydro cyclone or centrifugal reactor helps to remove soluble salts under the abovementioned supercritical conditions, but severe wearing problem is inevitable.…”

Section: Salt Precipitationmentioning

confidence: 99%

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Supercritical Water Oxidation for Environmentally Friendly Treatment of Organic Wastes

Li¹,

Wang²

2020

Advanced Supercritical Fluids Technologies

Self Cite

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Supercritical water oxidation is a promising, environment-friendly technology to efficiently deal with a wide variety of organic wastes such as wastewaters, industrial and municipal sludge, etc. As for the two key problems, i.e., corrosion and salt plugging, generally encountered in supercritical water oxidation plants, this chapter firstly reported the related mechanism analysis, solutions, research status, and development trends, respectively. From the perspectives of corrosion prevention and control, safety and automatic control, economic improvements, and development of novel reactors, a number of advanced technologies and equipment such as on-line desalination in supercritical water, new operation scheme assisted secondary traditional treatment, produced-gas recovery and oxygen reuse and novel TWM reactor, etc., were introduced systematically. Finally, this chapter summarizes the implementation status of industrial plants and the technological features of several firms being active in the construction of full-scale supercritical water oxidation plants. This chapter will provide very valuable information for the researchers and engineers who are interested in supercritical water oxidation for the harmless treatment of organic pollutants.

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“…Supercritical water (SCW) (P > 22.1 MPa, T > 374 • C) has unique thermo-physical characteristics [1], which can dissolve organic compounds and gases to form a homogeneous mixture without mass transfer resistance [2,3]. SCW has been widely used to treat organic waste by supercritical water oxidation (SCWO) or supercritical water gasification (SCWG) for high efficiency and low residence time [3][4][5].…”

Section: Introductionmentioning

confidence: 99%

Energy Consumption and Economic Analyses of a Supercritical Water Oxidation System with Oxygen Recovery

Zhang

Chen

et al. 2018

Processes

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Oxygen consumption is one of the factors that contributes to the high treatment cost of a supercritical water oxidation (SCWO) system. In this work, we proposed an oxygen recovery (OR) process for an SCWO system based on the solubility difference between oxygen and CO2 in high-pressure water. A two-stage gas–liquid separation process was established using Aspen Plus software to obtain the optimized separation parameters. Accordingly, energy consumption and economic analyses were conducted for the SCWO process with and without OR. Electricity, depreciation, and oxygen costs contribute to the major cost of the SCWO system without OR, accounting for 46.18, 30.24, and 18.01 $·t−1, respectively. When OR was introduced, the total treatment cost decreased from 56.80 $·t−1 to 46.17 $·t−1, with a reduction of 18.82%. Operating cost can be significantly reduced at higher values of the stoichiometric oxygen excess for the SCWO system with OR. Moreover, the treatment cost for the SCWO system with OR decreases with increasing feed concentration for more reaction heat and oxygen recovery.

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Salt deposition problems in supercritical water oxidation

Cited by 95 publications

References 82 publications

Solubility of inorganic salts in sub- and supercritical hydrothermal environment: Application to SCWO processes

Solubility of inorganic salts in sub- and supercritical hydrothermal environment: Application to SCWO processes

Supercritical Water Oxidation for Environmentally Friendly Treatment of Organic Wastes

Energy Consumption and Economic Analyses of a Supercritical Water Oxidation System with Oxygen Recovery

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