This review presents the state of the art regarding the possible intensification of desorption processes by use of microwave irradiation. The most important experimental and modeling results reported in the literature on the laboratory scale as well as on the industrial scale were collected in this paper. It follows from the review that microwave heating is a powerful novel method proving many advantages when utilized for regeneration of loaded adsorbents. In general, a short penetration depth could be a drawback of this very efficient heating method. Hence, it seems that the fluidized bed adsorbers are better choice than the fixed-bed ones when the microwave-assisted desorption step is carried out because more homogenous temperature distribution would be guaranteed.

Intensification of desorption processes by use of microwaves—An overview of possible applications and industrial perspectives

A burner, particularly for a gas turbine, includes a catalytic combustion chamber and a performer/reformer (24). The combustion chamber has an essentially cylindrical extent in a flow direction of a fuel and a catalytically active coating (12) on a wall facing the fuel for oxidation of the fuel. A particularly low nitrogen oxide content of burner exhaust gas is achieved as a result of the catalytically induced combustion of the fuel. At the same time, in contrast to known primary measures for nitrogen oxide abatement, the flow resistance in the burner is not increased by the coating of the wall. Therefore, when the burner is used in a gas turbine, a particularly high efficiency together with a low nitrogen oxide emission can be achieved.

Catalytic combustion chamber operating on preformed fuel, preferably for a gas turbine

Pt-Al 2 O 3 , Al 2 O 3 and SnO 2 were deposited as thin films on a stainless steel support that was inserted into an annular reactor and heated using an electromagnetic induction device. Possibility of an accurate temperature control was demonstrated and heating rates up to 800 °C min −1 were obtained. Total abatement of 1000 ppm isopropyl alcohol (IPA) was achieved at low temperature (T50 about 80 °C) on 1 wt% Pt/Al 2 O 3 . Nevertheless, the strong IPA adsorption on the alumina support and the formation of large amounts of acetone dictated to select the other catalyst, SnO 2 . IPA 90% conversion into CO 2 and H 2 O was then obtained at 250 °C with a total flow of 100 NmL min −1 containing 1000 ppm IPA. Considering the volume of the very thin reactive sheath (hydraulic diameter about 3.6 mm), ghsv was as high as 2.6 × 10 3  h −1 . Total abatement to CO 2 and H 2 O of high amounts of IPA (about 1 vol%) in air was achieved in less than 30 s and near-room temperature was recovered quickly when the contaminant level at the reactor inlet felled again below a given threshold

Novel inductively-heated catalytic system for fast VOCs abatement, application to IPA in air

A portable catalytically heatable appliance is provided. The appliance includes a catalyst support structure to flamelessly combust liquid or gaseous fuel and thereby provide a lower temperature heat source than a heat source that combusts fuel via flame. The fuel is ignited inside the catalytic support structure by a spark electrode. The ignition of the fuel inside the structure obviates the need for separate flame arresters. The ignition system includes a piezoelectric device that causes a voltage potential to form between the electrode and the catalytic support structure. A spark jumps from the electrode to an interior surface of the structure and ignites the fuel inside the structure, causing a flame to propagate. The flame heats the catalytic structure to an activation temperature, after which the fuel is combusted flamelessly on the surface of the catalytic structure.

Portable heated appliance with catalytic heater with improved ignition system

The invention is directed to a heatable appliance, in particular a curling iron (10), including a device (18) for flameless combustion of a fuel/air mixture and an associated activation device (20, 21) for initiating the flameless combustion action, wherein the device (18) comprises a carrier means coated with a catalytically active material. According to the present invention, the carrier means is configured as a stable carrier structure (28) comprised in particular of a metal foil provided with perforations (32) or a wire lattice. At least one metal wire (36) preferably catalytically coated is arranged on the carrier structure (28) to serve as a starter catalyst (34). By this means, the activating ability of the catalytically coated carrier structure (28) is promoted.

Heatable appliance for personal use

A catalytic burner for oxidizing gaseous fuel in a catalytic combustion device having a gaseous fuel discharge tube, the burner comprises a tubular catalyst defining a catalytic combustion chamber and having an inlet opening at one end thereof for admitting gaseous fuel into the chamber, an outlet opening at the other end thereof for discharging products of combustion from the chamber, and a support for mounting the catalyst in coaxial relation on the discharge tube; and a gas distributor disposed within the inlet end of the catalyst proximate to but spaced from the discharge tube for uniformly distributing across the chamber gaseous fuel introduced into the chamber through the inlet opening

Catalyst structures and burners for heat producing devices

A method for the removal of trace quantities (0.2 to 10 ppm) of carbon monoxide in commercial hydrogen using a temperature-swing-adsorption system with 0.5 wt% Pt/Al2O3, adsorbent has been investigated. The adsorbent could be regenerated by treatment with air at 200°C to 250°C or by treatment with hydrogen at 270°C. The breakthrough curves have been described by a model which considers both the external-film resistance and the intraparticle diffusion resistance. The model has been validated at the high gas velocities expected in a commercial plant.



On a etudie une methode pour le retrait de traces d'oxyde de carbone (0.2-10 p.p.m.) dans de l'hydrogene commercial base sur un systeme d'adsorption a balayage de temperature avec un adsorbant contenant 0.5% en poids de Pt/Al2O3. L'adsorbant peut ětre regenere par un traitement a l'air a 200-250°C ou par un traitement a l'hydrogene a 270°C. Les courbes de rupture sont decrites par un modele tenant compte a la fois de la resistance du film exterieure et de la resistance de la diffusion intra-particulaire. Le modele a ete valide aux vitesses de gaz elevees typiques des installations cornmerciales.

Christopher Robert Aelick

Papers

Catalyst structures and burners for heat producing devices

Removal of trace quantities of co from H2 using temperature‐swing‐adsorption