Experimental Study on the Ignition and Extinction Characteristics of the Hydrothermal Flame

Zhang, Fengming; Zhang, Yong; Xu, Chunyan; Chen, Shouyan; Chen, Guifang; Ma, Chunyuan

doi:10.1002/ceat.201300571

Cited by 22 publications

(8 citation statements)

References 55 publications

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“…2. Xi'an Jiaotong University multi-function reactor [17] Shandong University also designed a 1.8L transpiring wall reactor which can be seen in Zhang et al [5] for hydrothermal combustion experiments. The reactor they designed was similar to the reactor at ETH.…”

Section: 2 Continuous Reactorsmentioning

confidence: 99%

“…Under the condition of 25 MPa, while the oxidant was pure oxygen, the methanol concentration was increased from 9.7mol% to 12.3mol%, and the ignition temperature is decreased from 490°C to 460°C. Zhang [5] used the TWR to measure the ignition temperature of methanol. The oxidant used was oxygen.…”

Section: Characterization Of Hydrothermal Flame Processes 1 Ignitionmentioning

confidence: 99%

“…The supercritical hydrothermal combustion experiment of WCHB of Weber [25] shows that under 25MPa, pure oxygen is used as oxidant, when the methanol concentration increased from 2.3mol% to 15.8mol%, and the extinction temperature decreased from 550°C to 100°C. Zhang's TWR [5] measured that under 23MPa with pure oxygen as oxidant, methanol concentration increased from 4.2mol% to 7mol%, and the extinction temperature decreased from 405°C to 301°C. It can be seen that under the same conditions, the extinction temperature decreases as the fuel concentration increases, and the temperature can drop to ambient temperature.…”

Section: Extinction Temperaturementioning

confidence: 99%

“…The supercritical hydrothermal combustion research results on coal of Ma [4] represent that when the surface temperature of coal particles is much higher than the temperature of the surrounding fluid (generally the surface temperature of the particles is more than 800 ℃), it is taken into account that the supercritical hydrothermal combustion reaction of coal occurs. Zhang [5] believes that supercritical hydrothermal combustion occurs when the temperature of fluid in the reactor rises sharply (at least 100 ℃ /min). Augustine [6] believes that the hydrothermal flame which operates in a regime of thermal runaway has the features of extremely fast reaction rates(with residence times being only 10-100ms) and high temperatures(usually more than 1000°C).…”

Section: Introductionmentioning

confidence: 99%

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Review of Supercritical Hydrothermal Combustion

Wang

Ren

et al. 2019

E3S Web Conf.

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Two major points in supercritical hydrothermal combustion were reviewed:(1) The structure of semi-batch reactors or continuous reactors used in different institutes and colleges. These investigations can be used to guide the design of reactors for later scholars and lay the foundation for the industrialization of supercritical hydrothermal combustion. (2) The research status of characterization of hydrothermal flame processes by various scholars. These investigations can be used to guide the process parameters of industrialization of supercritical hydrothermal combustion. The continuous reactor designed in each organization is very sophisticated, which can avoid the two major problems of reaction in the supercritical state: salt precipitation and corrosion. The ignition temperature, extinction temperature, and other characteristics of supercritical hydrothermal combustion studied by scholars are summarized and the laws are basically similar. The removal rate of different organic matters was also summarized under supercritical hydrothermal combustion, and the removal rate of more than 99% was basically achieved.

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Section: 2 Continuous Reactorsmentioning

confidence: 99%

Section: Characterization Of Hydrothermal Flame Processes 1 Ignitionmentioning

confidence: 99%

Section: Extinction Temperaturementioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Review of Supercritical Hydrothermal Combustion

Wang

Ren

et al. 2019

E3S Web Conf.

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“…However, reaction heat linearly increases with increasing feed concentration, and more heat can be recovered from the reactor effluent. Moreover, the preheating temperature of the feed at the starting and steady states can be reduced at a high feed concentration [40]. Thus, the total electricity consumption of the systems with and without OR decreased from 49.51 $•t −1 and 49.80 $•t −1 to 44.35 $•t −1 and 43.91 $•t −1 , respectively, when feed concentration was increased from 2 wt% to 8 wt% (Figure 12a).…”

Section: Effect Of the Feed Concentrationmentioning

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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Study on the uniformity of water film in a transpiring wall reactor for supercritical water oxidation

Zhang

2020

Can J Chem Eng

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A three‐dimensional computational fluid dynamic model of a transpiring wall reactor for supercritical water oxidation has been built to optimize the uniformity of water film. Results show that the temperature and species distributions at the nozzle outlet deviate from the reactor centre. The inner wall of the porous tube near the transpiring water injection tube displays low temperatures, while high temperatures are recorded far from the injection tube. The circumferential temperature distribution on the inner wall of the porous tube is uneven. This phenomenon is due to the uneven injection of the transpiring water, leading to the uneven protection of the water film and local overheating of the porous wall. The injection velocity of the transpiring water significantly decreases when the number of injection tubes is increased, and the circumferential velocity and temperature distributions on the porous wall gradually become even. Moreover, high pressure drops across the porous wall at low porosities are useful for the uniform injection of the transpiring water. This characteristic is also conducive to obtaining a more uniform water film protection.

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Experimental Study on the Ignition and Extinction Characteristics of the Hydrothermal Flame

Cited by 22 publications

References 55 publications

Review of Supercritical Hydrothermal Combustion

Review of Supercritical Hydrothermal Combustion

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

Study on the uniformity of water film in a transpiring wall reactor for supercritical water oxidation

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