Reaction engineering: The supercritical water hydrothermal synthesis of nano-particles

Lester, Edward; Blood, Paul; Denyer, Joanne P; Giddings, Donald; Azzopardi, B.J.; Poliakoff, Martyn

doi:10.1016/j.supflu.2005.08.011

Cited by 222 publications

(170 citation statements)

References 16 publications

Supporting

Mentioning

163

Contrasting

Order By: Relevance

“…It is well known from visualization experiments that the flow inside a hydrothermal reactor is unsteady in most cases [40,41]. This phenomenon is the result of natural convection influencing the flow field, as the extreme temperature gradients lead to strong buoyancy forces.…”

Section: Model Validationmentioning

confidence: 99%

“…Continuous hydrothermal synthesis is a relatively new method for the preparation of inorganic nanomaterials, which offers a cheap, green, and highly scalable route [8,9]. The process is relatively straightforward; it involves the mixing of an aqueous metal salt stream with a superheated water stream (hydrothermal) within a continuous reactor to produce nano-size particles [10]. If the superheated water reaches its critical point, it changes from a polar liquid to a fluid with a low dielectric constant and low ionic product, which is necessary for some materials [11] but not all [12].…”

Section: Introductionmentioning

confidence: 99%

“…Thus, a suitable design for the mixing device in the supercritical synthesis of nanoparticles is a key parameter for obtaining particles characterized by a small size and narrow particle size distribution (PSD) [10]. Normally, the mixing in these types of devices occurs in a turbulent manner, where turbulent mixing involves the ability of a turbulent flow to effectively mix entrained fluids at a molecular scale [30].…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Understanding bottom-up continuous hydrothermal synthesis of nanoparticles using empirical measurement and computational simulation

et al. 2016

Self Cite

View full text Add to dashboard Cite

(2016) Understanding bottom-up continuous hydrothermal synthesis of nanoparticles using empirical measurement and computational simulation. Nano Research, 9 (11). pp. 3377-3387. ISSN 1998-0000 Access from the University of Nottingham repository: http://eprints.nottingham.ac.uk/41016/1/1215_proof.pdf Copyright and reuse:The Nottingham ePrints service makes this work by researchers of the University of Nottingham available open access under the following conditions. This article is made available under the University of Nottingham End User licence and may be reused according to the conditions of the licence. For more details see: http://eprints.nottingham.ac.uk/end_user_agreement.pdf A note on versions:The version presented here may differ from the published version or from the version of record. If you wish to cite this item you are advised to consult the publisher's version. Please see the repository url above for details on accessing the published version and note that access may require a subscription. ABSTRACTContinuous hydrothermal synthesis was highlighted in a recent review as an enabling technology for the production of nanoparticles. In recent years, it has been shown to be a suitable reaction medium for the synthesis of a wide range of nanomaterials. Many single and complex nanomaterials such as metals, metal oxides, doped oxides, carbonates, sulfides, hydroxides, phosphates, and metal organic frameworks can be formed using continuous hydrothermal synthesis techniques. This work presents a methodology to characterize continuous hydrothermal flow systems both experimentally and numerically, and to determine the scalability of a counter current supercritical water reactor for the large scale production (>1,000 T•year -1 ) of nanomaterials. Experiments were performed using a purpose-built continuous flow rig, featuring an injection loop on a metal salt feed line, which allowed the injection of a chromophoric tracer. At the system outlet, the tracer was detected using UV/Vis absorption, which could be used to measure the residence time distribution within the reactor volume. Computational fluid dynamics (CFD) calculations were also conducted using a modeled geometry to represent the experimental apparatus. The performance of the CFD model was tested against experimental data, verifying that the CFD model accurately predicted the nucleation and growth of the nanomaterials inside the reactor.

show abstract

Section: Model Validationmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Understanding bottom-up continuous hydrothermal synthesis of nanoparticles using empirical measurement and computational simulation

et al. 2016

Self Cite

View full text Add to dashboard Cite

show abstract

“…Continuous hydrothermal processes have a wide range of applications including: the synthesis of catalysts and photo-catalysts, electronic materials, bio-medical materials, fuel cell materials, thin films, inks, disinfectants, amongst others (Lester et al, 2006). The continuous hydrothermal flow synthesis (CHFS) process is relatively green as it uses water as a major reagent rather than organic solvents.…”

Section: Introductionmentioning

confidence: 99%

“…Moussiere et al (Moussiere et al, 2007) reported CFD simulation of impinging jet reactors for the oxidation of organic matter as a means of waste remediation. Lester et al (Lester et al, 2006) used CFD to simulate the velocity distributions inside a counter-current nozzle reactor. However, in the simulation, methanol and sucrose at ambient temperature and pressure were used to model supercritical water and metal salt solution at critical water condition.…”

Section: Introductionmentioning

confidence: 99%

Modelling and simulation of counter-current and confined jet reactors for hydrothermal synthesis of nano-materials

Cai

Chen

Wang

2014

Chemical Engineering Science

View full text Add to dashboard Cite

A confined jet mixer and a counter-current mixer for the continuous hydrothermal flow synthesis of TiO 2 nano-materials under supercritical water conditions have been investigated using computational fluid dynamics (CFD). The fluid flow and heat transfer behaviour, including velocity and temperature profiles in both reactor configurations, are studied using the CFD tool ANSYS Fluent. The tracer concentration profiles are also simulated via solving species equations from which the mixing behaviour in the reactors is examined. A combined CFD and population balance model is used to predict the size distribution. The predicted temperature distributions for both reactors were found to be in good agreement with experimentally measured data. Detailed comparison of the hydrodynamic and thermal behaviour, and particle size distributions between the two reactors helped in the identification of key factors that affect the reactor performance, and also provided suggestions for reactor design optimisation and scale-up.

show abstract

Applications of SCW

Marcus¹

2012

Supercritical Water

View full text Add to dashboard Cite

Reaction engineering: The supercritical water hydrothermal synthesis of nano-particles

Cited by 222 publications

References 16 publications

Understanding bottom-up continuous hydrothermal synthesis of nanoparticles using empirical measurement and computational simulation

Understanding bottom-up continuous hydrothermal synthesis of nanoparticles using empirical measurement and computational simulation

Modelling and simulation of counter-current and confined jet reactors for hydrothermal synthesis of nano-materials

Applications of SCW

Contact Info

Product

Resources

About