Ozone preparation


Figure 10.2. Preparation of ozone Brodie s apparatus Figure 10.2. Preparation of ozone Brodie s apparatus
Addition compounds called ozonides are produced when alkenes react with ozone and reductive cleavage of these compounds is used extensively in preparative and diagnostic organic chemistry.  [c.264]

How would you obtain a sample of pure ozone Account for the conditions used in your method of preparation. What is the arrangement of oxygen atoms in an ozonide and what evidence would you cite in support of the structure you suggest  [c.308]

One of the chief uses of chloromethane is as a starting material from which sili cone polymers are made Dichloromethane is widely used as a paint stripper Trichloromethane was once used as an inhalation anesthetic but its toxicity caused it to be replaced by safer materials many years ago Tetrachloromethane is the starting mate rial for the preparation of several chlorofluorocarbons (CFCs) at one time widely used as refrigerant gases Most of the world s industrialized nations have agreed to phase out all uses of CFCs because these compounds have been implicated m atmospheric processes that degrade the Earth s ozone layer  [c.167]

Tetrafluoroethylene Oxide TFEO has only been prepared by a process employing oxygen or ozone because of its extreme reactivity with ionic reagents. This reactivity may best be illustrated by its low temperature reaction with the weak nucleophile, dimethyl ether, to give either of two products (47) (eq. 10).  [c.304]

The relevant properties of peroxide and superoxide salts are given in Table 4 (see Peroxides and peroxide compounds, inorganic). Potassium peroxide is difficult to prepare and lithium superoxide is very unstable. The ozonides, MO3, of the alkah metals contain a very high percentage of oxygen, but are only stable below room temperature (see Ozone).  [c.486]

Commercial production and utilization of ozone by silent electric discharge consists of five basic unit operations gas preparation, electrical power supply, ozone generation, contacting (ie, ozone dissolution in water), and destmction of ozone in contactor off-gases (Fig. 1).  [c.497]

Suppression of Nitrogen Oxides. The concentration of nitrogen oxides during preparation of ozone from air increases linearly with the energy density in the discharge, causing a decrease in the formation rate of ozone. Most commercial ozone generators produce 0.5 kg of nitrogen oxides for every 100 kg of ozone generated. The formation of nitrogen oxides at a given energy density is minimized by decreasing the residence time and temperature, increasing the pressure, and reducing the dew point of air.  [c.498]

Feed Gas Preparation. The use of oxygen for industrial ozone generation is significant and increasing. Oxygen provides a higher ozone concentration and more efficient ozone dissolution than air, and does not add nitrogen oxides to the water. It is prepared from dry, filtered air by hquefaction and fractional distiHation. Liquid oxygen (LOX) can be prepared on-site or purchased from vendors. Oxygen is sometimes used to enrich air-fed systems. Although oxygen-rich off-gases from ozone contactors can be recycled, more often they are discarded to avoid redrying costs.  [c.498]

Energy Requirements and Efficiency. The thermodynamics of ozone synthesis require the expenditure of 142.7 kj/mol (34.1 kcal/mol) thus the formation of 1 kg of ozone requires 2.97 MJ (711 kcal) or 0.85 kWh/kg at 100% efficiency. The more concentrated the ozone, the higher the specific energy (kWh/kg) and the lower the efficiency. The specific energy for ozone production from dry oxygen varies from 7—14 kWh/kg over the 1—6 wt % range. For dry air, the specific energy (15—22 kWh/kg for 0.5—3.0 wt % ozone) is lower than expected due to the contribution of atomic nitrogen to ozone formation. The higher-than-theoretical specific energy requirements are due to the fact that most of the suppHed energy is converted to heat resulting from ozone formation and decomposition reactions. These specific energy requirements correspond to ozone synthesis efficiencies from oxygen and air of 6—12% and 4—6%, respectively. Thus, the portion of the input synthesis energy dissipated as heat is 88—94% for oxygen and 94—96% for air. In addition to the power requirements for the ozone generator, the air-preparation unit requires 4.4—7.7 (kWh)/kg ozone, and the oxygen-recycle unit an additional 2—7 (kWh) /kg ozone.  [c.499]

The pharmaceutical industry employs ozone in organic reactions to produce peroxides as germicides in skin lotions, for the oxidation of intermediates for bacteriostats, and in the synthesis of steroids (qv) such as cortisone (see Disinfectants and antiseptics). Vitamin E can be prepared by ozonation of trimethyUiydroquinone.  [c.503]

The ozonides are characterized by the presence of the ozonide ion, O - They are generally produced by the reaction of the inorganic oxide and ozone (qv). Two reviews of ozonide chemistry are available (1,117). Sodium ozonide [12058-54-7] NaO potassium ozonide [12030-89-6] 35 rubidium ozonide [12060-04-7] RbO and cesium ozonide [12053-67-7] CsO, have all been reported (1). Ammonium ozonide [12161 -20-5] NH O, and tetramethylammonium ozonide [78657-29-1/, (CH ) NO, have been prepared at low temperatures (118).  [c.98]

The potassium salt is the best characterized. It is an orange-red paramagnetic soHd having a magnetic moment of 1.6 x 10 J/T (1.73 Xg). It reacts with water, yielding oxygen gas and potassium hydroxide. It decomposes to the superoxide, KO2, upon standing at room temperature. Potassium ozonide is prepared by ozonation of dry potassium hydroxide. It can be purified by extraction and recrystaUization from Hquid ammonia. Whereas the inorganic ozonides are of potential importance as soHd-oxygen carriers ia breathing apparatus, they are not produced commercially.  [c.98]

Efforts to raise the alpha-selectivity have been made. Thus nitration of anthraquinone using nitrogen dioxide and ozone has been reported (17). l-Amino-4-bromoanthraquinone-2-sulfonic acid (bromamine acid) [116-81 -4] (8) is the most important intermediate for manufacturing reactive and acid dyes. Bromamine acid is manufactured from l-aminoanthraquinone-2-sulfonic acid [83-62-5] (19) by bromination in aqueous medium (18—20), or in concentrated sulfuric acid (21). l-Aminoanthraquinone-2-sulfonic acid is prepared from l-aminoanthraquinone by sulfonation in an inert, high boiling point organic solvent (22), or in oleum with sodium sulfate (23).  [c.310]

Processing ndProperties. Neoprene has a variety of uses, both in latex and dry mbber form. The uses of the latex for dipping and coating have already been indicated. The dry mbber can be handled in the usual equipment, ie, mbber mills and Banbury mixers, to prepare various compounds. In addition to its excellent solvent resistance, polychloroprene is also much more resistant to oxidation or ozone attack than natural mbber. It is also more resistant to chemicals and has the additional property of flame resistance from the chlorine atoms. It exhibits good resiUence at room temperature, but has poor low temperature properties (crystallization). An interesting feature is its high density (1.23) resulting from the presence of chlorine in the chain this increases the price on a volume basis.  [c.470]

It is evident that for ordinary preparative work the careful calibration given in section G is not essential. It is only necessary to adjust the voltage of the transformer to about 10,000 to 11,000 volts and turn on the flow of oxygen to as rapid a rate as the absorption tubes will handle when surrounded by cooling baths. The amount of ozone produced in 5 minutes at the observed flowmeter reading is determined as in section F. By operating the ozonizer at this rate of flow and voltage the ozonization of organic compounds can be carried out.  [c.75]

A number of novel techniques have been attempted to provide (atomically) clean steel surfaces for optimal chemical bonding, but generally there has been no improvement over grit blasting. Ultraviolet light/ozone exposures have been used very successfully to provide extremely clean surfaces for semiconductor processing. However, when this technique was applied to oily steel, the cleaned surfaces showed no improvement in bond strength compared to control specimens [118]. Glow-discharge etching, which is another method of providing very clean semiconductor surfaces, was used to prepare steels for an anti-corrosion, polymer-film-coating process [119] but the results were no better than wiping with a solvent cloth. Neither was the result of another scheme [120] that incorporated cleaning components into the adhesive itself.  [c.985]

Such a sequence of snapshots, calculated in intervals of 4 fs, is shown as a series of double contour line plots on the left-hand side of figure A3.13.11 (tire outennost row shows the evolution of I equation (A3.13.68), the imremiost row is I I equation (A3.13.67), at the same time steps). This is the wave packet motion in CHD for excitation with a linearly polarized field along tlie the v-axis at 1300 cm and 10 TW cm after 50 fs of excitation. At this point a more detailed discussion regarding tlie orientational dynamics of the molecule is necessary. Clearly, the polarization axis is defined in a laboratory fixed coordinate system, while the bending axes are fixed to the molecular frame. Thus, exciting internal degrees of freedom along specific axes in the internal coordinate system requires two assumptions the molecule must be oriented or aligned with respect to the external polarization axis, and this state should be stationary, at least during the relevant time scale for the excitation process. It is possible to prepare oriented states [112. 114. 115] in the gas phase, and such a state can generally be represented as a superposition of a large number of rotational eigenstates. Two questions become important then How fast does such a rotational superposition state evolve How well does a purely vibrational wave packet calculation simulate a more realistic calculation which includes rotational degrees of freedom, i.e. with an initially oriented rotational wave packet The second question was studied recently by frill dimensional quantum dynamical calculations of the wave packet motion of a diatomic molecule during excitation in an intense infrared field [175], and it was verified that rotational degrees of freedom may be neglected whenever vibrational-rotational couplings are not important for intramolecular rotational-vibrational redistribution (IVRR) [ ]. Regarding the first question, because of the large rotational constant of methane, the time scales on which an initially oriented state of the free molecule is maintained are likely to be comparatively short and it would also be desirable to carry out calculations that include rotational states explicitly. Such calculations were done, for instance, for ozone at modest excitations [116. 117], but they would be quite difficult for the methane isotopomers at the high excitations considered in the present example.  [c.1075]

The superacid-catalyzed electrophile oxygenation of saturated hydrocarbons, including methane with hydrogen peroxide (via H302 ) or ozone (via HOs ), allowed the efficient preparation of oxygenated derivatives.  [c.166]

Phosphoms oxyfluoride is a colorless gas which is susceptible to hydrolysis. It can be formed by the reaction of PF with water, and it can undergo further hydrolysis to form a mixture of fluorophosphoric acids. It reacts with HF to form PF. It can be prepared by fluorination of phosphoms oxytrichloride using HF, AsF, or SbF. It can also be prepared by the reaction of calcium phosphate and ammonium fluoride (40), by the oxidization of PF with NO2CI (41) and NOCl (42) in the presence of ozone (43) by the thermal decomposition of strontium fluorophosphate hydrate (44) by thermal decomposition of CaPO F 2H20 (45) and reaction of SiF and P2O5 (46).  [c.225]

Many of the chemical reactions used to modify lignosulfonates are also used to modify kraft lignins. These include ozonation, alkaline—air oxidation, condensation with formaldehyde and carboxylation with chloroacetic acid (100), and epoxysuccinate (101). In addition, cationic kraft lignins can be prepared by reaction with glycidjiamine (102).  [c.145]

The unstable ammonium ozonide [12161 -20-5] NH O, prepared at low temperatures by reaction of ozone withHquid ammonia, decomposes rapidly at room temperature to NH NO, oxygen, and water (51). Tetrametbylammonium ozonide [78657-29-1] also has been prepared.  [c.493]

Synthesis. Hydroperoxides have been prepared from several types of peroxygen compounds including hydrogen peroxide or sodium peroxide, ozone, oxygen, and other organic peroxides (45). Hydrogen peroxide (H2O2) and its anions are powerful nucleophiles and react with reagents RX to form ROOH and HX, where X can be sulfate, acid sulfate, alkane- and arenesulfonate, chloride, bromide, hydroxyl, alkoxide, perchlorate, etc. RX can also be an alkyl orthoformate or alkyl carboxylate.  [c.104]

Monolayers of Organosilicon Derivatives. SAMs of aLkylchlorosilanes, alkylalkoxysilanes, and alkylaminosilanes require hydroxylated surfaces as substrates for their formation. The driving force for this self-assembly is the in situ formation of polysiloxane, which is connected to surface silanol groups (—Si—OH) via Si—O—Si bonds. Substrates on which these monolayers have been successfully prepared include siUcon oxide (125—130), aluminum oxide (131,132), quartz (133—135), glass (130), mica (136—138), zinc selenide (131,132), germanium oxide (130), and gold (139—141). OTS monolayers on siUcon oxide and on gold activated by uv-ozone exposure have been compared by in spectroscopy, eUipsometry, and wetting measurements showing identical average film stmctures (142).  [c.537]

Titanium oxide dichloride [13780-39-8] TiOCl2, is a yellow hygroscopic soHd that may be prepared by bubbling ozone or chlorine monoxide through titanium tetrachloride. It is insoluble in nonpolar solvents but forms a large number of adducts with oxygen donors, eg, ether. It decomposes to titanium tetrachloride and titanium dioxide at temperatures of ca 180°C (136).  [c.131]

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  [c.333]

Brassylic Acid. This acid is commercially available from Nippon Mining Company (Tokyo, Japan). It is made by a fermentation process (76). Several years ago, Emery Group, Henkel Corp. (Cincinnati, Ohio) produced brassyUc acid via ozonization of emcic acid primarily for captive use in making dimethyl brassylate and ethylene brassylate. A pilot-scale preparation based on ozonization of emcic acid has been described in which brassyUc acid yields of 72—82% were obtained in purities of 92—95%. Recrystallization from toluene gave purities of 99% (77).  [c.63]

Other Derivatives. Various derivatives have appeared on the market or reached the market development stage. A carboxy-terminated polyisobutylene (28) was prepared by ozonization of high mol wt butyl mbbet or poly(isobutylene-ff -pipetylene) [26335-67-1] in the presence of pyridine. The resulting polymers were viscous hquids with viscosity average mol wt about 2,000 to 4,000, and an average functionality of 1.8 COOH groups pet chain. This ptedominandy diacid could be converted to networks by various reactions, eg, with epoxides or aziridine. High mol wt  [c.481]

Ozone for laboratory use has always been prepared by the action of the silent electric discharge upon a stream of air or oxygen. Although dielectrics other than glass are nsed in commercial ozonizers, they do not give a percentage of ozone high enough for laboratory use, and practically all laboratory ozonizers employ the Berthelot tube and are modeled after the one originally constructed by Harries. Good ozonizers of this type have been described by Briner, Patry, and de Luserna, and by Church, Whitmore, and McGrew. The ozonizer described above is a modification of the one described by Smith, as improved by Herme, and by Smith and Ullyot and Greenwood. Henne and Perilstein described a modification of their ozonizer in which the inner electrode is a tube filled with mercury the outer electrode is water-cooled.  [c.76]

Silent electrical discharge at up to 15 kV may be used to create concentrations of about 5% ozone in an oxygen stream, which may then be reacted with a flammable or combustible substance for chemical synthesis. Laboratory preparations in (nonconductive) glass reactors have resulted in occasional explosions via static discharges in the oxygen enriched atmosphere, possibly exacerbated by residual vapor space ozone. An alternative to predilution with nitrogen, which forms nitrogen oxides in the ozonizer, is to add nitrogen downstream of the ozonizer. Other measures are to operate well below the flashpoint of any flammable liquid, typically at approximately -70°C using dry ice mixtures, and to select a more conductive solvent, as opposed to a hydrocarbon such as heptane. During shutdown of the system, a suitable inert gas such as argon should be used to thoroughly purge the system. Precautions should be taken to minimize the vapor space volume, avoid tightly closed containers that will not contain the pressure from an internal deflagration/detonation, and take appropriate measures for personnel protection if a flammable mixture might occur during operation. The hazards of unstable peroxides and ozonides, plus materials of construction suitable for oxygen service should be separately evaluated.  [c.162]

Ozone is an allotrope of oxygen eontaining three oxygen atoms. It oeeurs naturally in the upper atmosphere and is formed in small quantities during eleetrieal diseharges from eleetrieal maehines or when white phosphorus smoulders in air. In the laboratory it is most eonveniently obtained by subjeeting air to eleetrieal diseharges in ozonizers when some of tlie oxygen moleeules dissoeiate into oxygen atoms whieh then eombine with other oxygen moleeules. However, the yield of ozone is only 10% even when pure oxygen is used. It may also be prepared by eleetrolysis of iee-eold dilute sulphurie aeid using a high eurrent density. Here the eoneentration of ozone liberated at the platinum-in-glass anode is about 14%.  [c.303]

A typical ozone treatment plant consists of three basic subsystems feedgas preparation ozone generation and ozone/water contacting. Commercially, ozone is generated by producing a high-voltage corona, discharge in a purified oxygen-containing feedgas. The ozone is then contacted with the water or wastewater the treated effluent is discharged and the feedgas is recycled or discharged.  [c.485]


See pages that mention the term Ozone preparation : [c.27]    [c.95]    [c.293]    [c.294]    [c.294]    [c.294]    [c.101]    [c.492]    [c.494]    [c.498]    [c.111]    [c.113]    [c.304]    [c.41]    [c.75]    [c.340]    [c.40]   
Chemistry of the elements (1998) -- [ c.609 , c.611 ]