It is well known that urbanization and industrialization have resulted in the rapidly increasing emissions of volatile organic compounds (VOCs), which are a major contributor to the formation of secondary pollutants (e.g., tropospheric ozone, PAN (peroxyacetyl nitrate), and secondary organic aerosols) and photochemical smog. The emission of these pollutants has led to a large decline in air quality in numerous regions around the world, which has ultimately led to concerns regarding their impact on human health and general well-being. Catalytic oxidation is regarded as one of the most promising strategies for VOC removal from industrial waste streams. This Review systematically documents the progresses and developments made in the understanding and design of heterogeneous catalysts for VOC oxidation over the past two decades. It addresses in detail how catalytic performance is often drastically affected by the pollutant sources and reaction conditions. It also highlights the primary routes for catalyst deactivation and discusses protocols for their subsequent reactivation. Kinetic models and proposed oxidation mechanisms for representative VOCs are also provided. Typical catalytic reactors and oxidizers for industrial VOC destruction are further discussed. We believe that this Review will provide a great foundation and reference point for future design and development in this field.

/pdf/recent-advances-in-the-catalytic-oxidation-of-volatile-zw2c35dbg7.pdf

Recent Advances in the Catalytic Oxidation of Volatile Organic Compounds: A Review Based on Pollutant Sorts and Sources.

https://engineering.purdue.edu/BTPFL/BTPFL%20Publications/92.pdf

Flow boiling heat transfer in two-phase micro-channel heat sinks––I. Experimental investigation and assessment of correlation methods

The lack of stability is a challenge for most heterogeneous catalysts. During operations, the agglomeration of particles may block the active sites of the catalyst, which is believed to contribute to its instability. Recently, titanium oxide (TiO2) was introduced as an alternative support material for heterogeneous catalyst due to the effect of its high surface area stabilizing the catalysts in its mesoporous structure. TiO2 supported metal catalysts have attracted interest due to TiO2 nanoparticles high activity for various reduction and oxidation reactions at low pressures and temperatures. Furthermore, TiO2 was found to be a good metal oxide catalyst support due to the strong metal support interaction, chemical stability, and acid-base property. The aforementioned properties make heterogeneous TiO2 supported catalysts show a high potential in photocatalyst-related applications, electrodes for wet solar cells, synthesis of fine chemicals, and others. This review focuses on TiO2 as a support material for heterogeneous catalysts and its potential applications.

/pdf/titanium-dioxide-as-a-catalyst-support-in-heterogeneous-3aez80fim6.pdf

Titanium Dioxide as a Catalyst Support in Heterogeneous Catalysis

Recent literatures in the field of cold thermal energy storage (CTES) are reviewed. First, the concept of the CTES is explained. Examples of load leveling of electrical energy in various countries are presented. Various types of the CTES are defined and compared as for their merits and demerits. The compared systems are a cold water storage vs. an ice-making storage, a static ice-making storage vs. a dynamic ice-making storage, and direct ice-making vs. indirect ice-making. Approximately 140 papers are reviewed and divided into five categories: (1) performance of successful systems, (2) simulation and control, (3) cold water storage, (4) static ice-making storage, and (5) dynamic ice-making storage. Finally, suggestions for future research are provided.

Recent advances in research on cold thermal energy storage

An impressive amount of investigation has been devoted to enhancing overall thermal and hydrodynamic performance of microchannel heat sinks. The small size of microchannel heat sinks and their ability to dissipate heat generated by modern electronics makes them the first choice for the electronic cooling systems in most devices. In this paper, a comprehensive review of available studies regarding non-circular microchannel heat sinks, with emphasis on rectangular microchannels, was presented and analyzed. This review looked into the methodologies used to analyze and optimize the overall performance of microchannel systems along with channel geometries, flow conditions, the coolants used, structural materials, optimization tools and finally, the form in which the final outcome of each study was presented. The review showed that earlier studies (from 1981 to 1999) were largely conducted using experimental or analytical approaches while more recent studies (from 2000 to the end of 2012) showed a dependency on numerical simulations and evolutionary algorithms. In addition, they also showed that laminar was the prevailing flow condition as out of the 69 articles reviewed, 54 employed laminar flows. Furthermore, the use of liquid coolants was preferable over gaseous coolants. Recent developments in nanofluids are providing alternative coolants that are quickly establishing as coolants to be reckoned with.

Thermal and hydrodynamic analysis of microchannel heat sinks: A review

Catalytic conversion of 1,2-dichlorobenzene using V2O5/TiO2 catalysts by a thermal decomposition process

Oxygen-enriched air for co-incineration of organic sludges with municipal solid waste: a pilot plant experiment.

In present study a methodology has been developed and applied for the optimum design and performance evaluation of microchannel heat sinks. The optimum design parameters include channel number and fin thickness. For a trial model of 127mm in length, 52.5mm in width, 16mm in height and 2.5mm in base thickness, the optimum channel number and the fin thinckness have been determined to be of 194 and 0.08359mm, respectively in laminar flow region. Performance of the optimally designed microchannel heat sinks has been compared with those having 50% and 150% of the number of channels. The results showed that the 50% and 150% designs increased the pumping power by 200% and 150%, respectively.

Optimum Design of Microchannel Heat Sinks

Heat transfer characteristics of gaseous flows in micro-channel with constant heat flux

The Poiseuille number, the product of a friction factor and the Reynolds number (f Re) for a quasi-fully developed high speed flow in a micro-channel of Re < 2300 and Mach number Ma < 0.7, was obtained numerically. The numerical methodology is based on the arbitrary-Lagrangian–Eulerian (ALE) method. Two-dimensional compressible momentum and energy equations with no-slip and slip boundary conditions were solved for constant wall temperatures that are lower or higher than the inlet temperature. The channel height ranges from 10 to 100 µm and the channel aspect ratio is 200. The stagnation pressure, pstg, is chosen such that the exit Mach number ranges from 0.1 to 0.7. The outlet pressure is fixed at atmospheric conditions. In the case of fast flow for both no-slip and slip boundary conditions, the value of f Re is higher than 96 due to compressibility effects. However, in the case of slow flow for slip boundary conditions (Maout < 0.3), the value of f Re is slightly lower than 96 due to rarefaction effects, even the flow is accelerated. The f Re correlation for slip boundary conditions is obtained from that for no-slip boundary conditions and incompressible theory as a function of the Mach number and the Knudsen number. The f Re correlation obtained for no-slip boundary conditions is also compared with that obtained for slip boundary conditions. The values of f Re obtained for no-slip and slip boundary conditions almost coincide within 3% for the channel height in the range 10–100 µm.

http://iopscience.iop.org/article/10.1088/0022-3727/41/10/105111/pdf

Jae-Heon Lee

Papers

Catalytic conversion of 1,2-dichlorobenzene using V2O5/TiO2 catalysts by a thermal decomposition process

Oxygen-enriched air for co-incineration of organic sludges with municipal solid waste: a pilot plant experiment.

Optimum Design of Microchannel Heat Sinks

Heat transfer characteristics of gaseous flows in micro-channel with constant heat flux

Poiseuille number correlation for high speed micro-flows