Ozonizer-type discharge

Other Arsenic Hydrides. Diarsine [15942-63-9] AS2H4, occurs as a by-product in the preparation of arsine by treatment of a magnesium aluminum arsenide alloy with dilute sulfuric acid and also may be prepared by passing arsine at low pressure through an ozonizer-type discharge tube (19). Diarsine is fairly stable as a gas but quite unstable (above — 100°C) in condensed phases. The for diarsine is +117 4 kJ/mol (28 1 kcal/mol) and... 

The usual procedure in preparations of polysilanes and polygermanes is to circulate the simple hydride through an ozonizer-type discharge until practically all of it has decomposed and the gas being circulated is principally hydrogen. The product hydrides are trapped out in a suitable cold trap in the gas circuit. If the desired product vapors were allowed to circulate continually through the discharge, the product would... 

Trisilane. Trisilicopropane trisilicon octahydride silicopropane trisilicane. HtSi9 mol wt 92.33. H 8.73%, Si 91.27%. SijHj. Obtained by separation of mixed silanes prepared from magnesium silicide and hydrochloric acid Stock. Somlesky. Ber. 49, 111 (1916) 54B, 524 (1921) S6B, 247 (1923) Culbertson. UA pat. 2,551,571 (1951 to Union Carbide) prepared by conversion of silane to higher silanes in an ozonizer type of electric discharge Spanier, MacDiar-mid, In org. Chem. 1, 432 (1962). 

The corona discharges produces oxygen ions and ozone, which may react with the photoconductor [634], As a means to circumvent possible degradation of the surface layer, an extra, protective thin layer was proposed, with high carbon content [101, 635, 636]. This would reduce silicon-oxygen reactions at the surface. Excellent electrophotographic characteristics have been obtained with a thin device comprising a 0.1-/rm-thick n-type a-Si H layer, a 1.0-/rm intrinsic a-Si H layer, a 0.1-/irm undoped a-SiCo i H layer, and a 0.014-/xm undoped a-SiCoj H layer [101]. 

Many wastewater flows in industry can not be treated by standard aerobic or anaerobic treatment methods due to the presence of relatively low concentration of toxic pollutants. Ozone can be used as a pretreatment step for the selective oxidation of these toxic pollutants. Due to the high costs of ozone it is important to minimise the loss of ozone due to reaction of ozone with non-toxic easily biodegradable compounds, ozone decay and discharge of ozone with the effluent from the ozone reactor. By means of a mathematical model, set up for a plug flow reactor and a continuos flow stirred tank reactor, it is possible to calculate more quantitatively the efficiency of the ozone use, independent of reaction kinetics, mass transfer rates of ozone and reactor type. The model predicts that the oxidation process is most efficiently realised by application of a plug flow reactor instead of a continuous flow stirred tank reactor. 

Water or waste water ozonation - regardless of the scale of equipment - is mostly performed in directly gassed systems, where the ozone containing gas is produced by an electrical discharge ozone generator and is introduced into the reactor by some type of gas diffuser. Since two phases, the gas and the liquid, are required for the oxidation reaction to proceed as it does, they are also called heterogeneous systems. 

Figure 80 Types of treater for applying corona discharge (a) for non-conductive substrates, with an earthed base roll covered with a dielectric (b) for material of all types, with a bare, earthed base roll and the dielectric on the discharge electrode The main components are (1) Multi-fin electrode (2) Electrode tube in ceramic or quartz (3) Earthed base roll covered with dielectric (4) Bare, earthed base roll (5) Housing for the electrode assembly, enabling the extraction of ozone and cooling of the electrode (6) Path of material being treated...

It thus appears that a possible and fast mechanism for the production of ozone is by way of oxygen atoms which act as catalysts for the conversion of 02 O3. Because oxygen atoms are essentially slow in destruction of ozone, the limiting stationary process must be the destruction of ozone via the same type of process which is responsible for oxygen destruction—e.g., electron bombardment—or else the increase in temperature of the discharge which would finally provoke the thermal decomposition of ozone and make Reaction 3 a limiting process. 

T1he water-gas shift reaction was chosen for study in a Siemens type ozonizer discharge with the aim of establishing the important variables associated with the conversion of carbon monoxide. 

Thus, there are at least two important chemical differences between these reactions in (a) the radiofrequency discharge in an annular ozon-izer-type reactor at pressures near 200 torr, and (b) the microwave discharge in a cylindrical reactor at pressures of 12 or 50 torr. Under the microwave conditions, C2H2 is always produced (together with CH4) from H2 + CO and H2 + C02 (without cooling) form CO but no hydrocarbons. Obviously, it would be extremely useful to understand these phenomena. We have explored this situation a bit further, in the following manner. 

Ozone generator type feedstoek gas Dew point, °C Cooling fluid Discharge gap, mm Voltage, kV Frequeney, Hz Dieleetrie barrier, mm Energy cost, kWh/kg... 

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