A novel hydrazine oxidation technique for the determination ofka in gas—liquid and gas—liquid—solid reactors

́rquez, Alejandro Lara Ma; Nguyen, Chau; Poncin, Souhila; Wild, Gabriel; Midoux, N.

doi:10.1016/0009-2509(94)00285-1

Cited by 7 publications

(2 citation statements)

References 9 publications

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“…Mass transfer measurements (k L a) were carried out using the steady-state hydrazine oxidation technique reported by Onken et al 23 and Marquez et al 24 During the experiment, hydrazine solution (NH 2 NH 2 ‚H 2 O) was fed continuously to the tank using a peristaltic pump. The hydrazine flow rate was measured with 1% accuracy.…”

Section: Methodsmentioning

confidence: 99%

Hydrodynamic and Mass Transfer Characteristics of Single and Multiple Impeller Hollow Self-Inducing Reactors

Kasundra

Kulkarni

Joshi

2008

Ind. Eng. Chem. Res.

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In the present work, hydrodynamics and mass transfer characteristics of a gas-liquid stirred tank provided with hollow self-inducing impellers were investigated. Critical impeller speed for the onset of gas induction, gas induction rate, power consumption, and mass transfer coefficient (k L a) were measured using two types of self-inducing impellers, viz., hollow pitched-blade downflow turbine and double-disk impeller. Experiments were carried out in 100 and 800 L tanks. Mass transfer coefficient was measured with steady-state hydrazine oxidation technique with air-water as the gas-liquid system. The impeller speed was varied from 2.5 to 14 rps, and power input per unit volume was varied from 0.5 to 10 kW/m 3 . Further, the performance of a multiimpeller hollow self-inducing system has been investigated. Four different hollow impellers in combination with three axial flow impellers have been studied in an 800 L tank using three impeller diameters and three liquid submergences. Suitable correlations have been proposed that also take into account all the published k L a data in the literature.

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Section: Methodsmentioning

confidence: 99%

Hydrodynamic and Mass Transfer Characteristics of Single and Multiple Impeller Hollow Self-Inducing Reactors

Kasundra

Kulkarni

Joshi

2008

Ind. Eng. Chem. Res.

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“…Several compounds, R, have been used to determine k^a, each one designating a different chemical method, including the oxidation of sodium dithionite (Na 2 S 2 O 4 ) to sodium sulphite (Na2SO 3 ) and sodium sulphate (Na 2 SO 4 ) in aqueous alkaline solutions [69], the oxidation of cuprous chloride (CuCl) to cupric chloride (CuCl 2 ) in dilute acidic solutions [70], and the catalytic oxidation of hydrazine (N 2 H 4 ) to nitrogen gas (N 2 ) [71]. An alternative chemical method has been also proposed recently [72] whereby k^a values are determined from the catalytic decomposition rate of hydrogen peroxide (H 2 O 2 ) to oxygen gas and water, that is from a reduction and not an oxidation.…”

Section: Chemical Methodsmentioning

confidence: 99%

Gas–Liquid Oxygen Mass-transfer; from Fundamentals to Applications in Hydrometallurgical Systems

Filippou

Cheng

Demopoulos

2000

Mineral Processing and Extractive Metallurgy Review

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Oxygen gas is used as a reactant in many hydrometallurgical processes. However, oxygen is sparingly soluble in aqueous electrolyte solutions, and the driving force for its masstransfer from the gas to the aqueous phase is also very low. Hence, the mass-transfer of oxygen depends significantly on the interfacial area between the gas and the liquid phase, which in turn depends on the mixing conditions inside the reactor. A change in the solution composition or the presence of solids can further alter the rate of oxygen masstransfer. All such phenomena related to the gas-liquid oxygen mass-transfer in hydrometallurgical unit operations are critically reviewed in the present article -from the basic thermodynamics and kinetics of oxygen dissolution in aqueous solutions to the most recent advances in oxygen mass-transfer systems.

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Simultaneous measurement of gas hold-up and mass transfer coefficient by tracer dynamic technique in “Emulsair” reactor with an emulsion-venturi distributor

Gourich¹,

Soulami²,

Zoulalian³

et al. 2005

Chemical Engineering Science

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A novel hydrazine oxidation technique for the determination ofka in gas—liquid and gas—liquid—solid reactors

Cited by 7 publications

References 9 publications

Hydrodynamic and Mass Transfer Characteristics of Single and Multiple Impeller Hollow Self-Inducing Reactors

Hydrodynamic and Mass Transfer Characteristics of Single and Multiple Impeller Hollow Self-Inducing Reactors

Gas–Liquid Oxygen Mass-transfer; from Fundamentals to Applications in Hydrometallurgical Systems

Simultaneous measurement of gas hold-up and mass transfer coefficient by tracer dynamic technique in “Emulsair” reactor with an emulsion-venturi distributor

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