Oxygen-containing gas

Most applications of commercial significance require some elevation of temperatures and pressures. A range of about 125 C (257 F) and 5 atm. to 320 C (608 °F) and 200 atm covers most cases. Frequently, air is the oxygen-containing gas, in which case the process may be termed wet-air oxidation (WAO). In the general case, including the use of pure oxygen, the broader term of wet oxidation (WO) is used. 

The oxidation reaction is generally described with Pt or Pd as catalyst, eventually on active coal, in aqueous alkaline solutions at temperature from 40°C to 100°C. The oxidation reaction is mostly carried out with oxygen or with an oxygen-containing gas such as air [17,18]. 

Roberts and Laine [25] describe a process for electrochemically transferring oxygen with the scheme shown as Fig. 11. Air or other oxygen-containing gas is drawn into the left side of the vessel. The solution contains an organic solvent such A-methyl pyrrolidine with a supporting electrolyte as tetrabutyl ammonium tetrafluroborate. The carrier, one of the two Schiflf bases shown as Fig. 12, is dissolved to about 3 volume percent. 

Pyrolysis processes differ primarily in the means used to supply the required heat to the coal. Invariably, the heat is generated by burning a portion of the coal with an oxygen-containing gas. In some cases, a circulating stream of char is used to carry the heat to the fresh coal. Alternately, an inert solid is used as heat carrier although, in this case, means must be provided to separate heat carrier from product char. 

Gasification. The extent of carbon removal from coal by pyrolysis is relatively limited. As a result, the yields of secondary fuels having increased H/C ratio are not large. Essentially complete control of the amount of carbon removed can be achieved, however, by complete gasification of coal with an oxygen-containing gas and steam ... 

Very little information was located in the literature concerning the disposal of 1,2-diphenylhydrazine. Dietrich et al. (1985) reported that wet air oxidation (heating wastewater under pressure with the addition of an oxygen-containing gas such as air) would remove 99.88% of the... 

An oxygen-containing gas mixture at 1 00 atm is subjected to the action of yellow phosphorus, which removes the oxygen In this way it is found that oxygen makes up 35 0% by volume of the mixture What is the partial pressure of 02 in the mixture0... 

Beuther et al. (1978) claimed that excellent yields of acrylonitrile could be obtained by using an FFB reactor instead. The reactant gases can be added into the reactor in stages, while the lower part of the reactor serves as a regeneration zone. For example, an oxygen-containing gas, such as air, can be introduced stepwise to improve selectivity and to maintain a low partial pressure of oxygen in the reactor. 

Another way of using plastics as fuels is their direct combustion. The oxidative pyrolysis of PET has been investigated in several cases. Oxidative pyrolysis means that instead of an inert atmosphere an oxygen-containing gas was used. In this case pyrolysis can occur, if oxygen can not reach the particle surface due to efflux of volatiles or diffusional resistances at boundary layers, or if oxidative conditions do not affect the kinetics and mechanism of the pyrolytic processes [41]. 

H.J.A. van Helden and J.E. Naber (Shell Internationale Research Mij. N.V), Removal of sulfur dioxide from an oxygen-containing gas, Brit. Pat. 1,160,662 (1969). 

Gas Analysis.—One use of it is in gas analysis for the determination of oxygen. When air or an oxygen containing gas mixture is passed through an alkaline solution of pyrogallol all of the oxygen is... 

NHj. Influences on the conversion of fuel-bound nitrogen to HCN and tar were not found. A main conclusion is that the feeding point and therewith the contact between the fuel particles and the surrounding oxygen-containing gas is of great importance for the formation and destruction of NH3,... 

Oxidation and hydrolysis reactions are two common methods of producing oxide films. In this class of reaction, the metal precursor contains metal atoms in a reduced valence state, usually a metal hydride or metal halide. The oxidizing agent is an oxygen containing gas such as O2, O3, CO2, H2O, or N2O. The reaction is a simple oxidation scheme. Examples of such reactions are ... 

Because the details of processing in each class of CMCs (e.g., oxide, carbide, or nitride matrix) are slightly different, the appropriate thermochemical approach for each class may also be different. For example, in the formation of alumina matrix materials by directed metal oxidation, the alumina product grows from a molten aluminum alloy by reaction with an oxygen-containing gas phase. On the other hand, in the formation of platlet-reinforced zirconium carbide, the gas phase is not involved in the reaction at all, being inert to the reactants and products. Thus, a general approach to deal with the myriad of possible products formed by the... 

The single cells consist of a dense solid electrolyte membrane and two porous electrodes. In most cases, at least one of the electrodes is exposed to an oxygen-containing gas (often, ambient air), while the other electrode is exposed to an inert gas, a liquid metal, a partial vacuum, or a reacting mixture (hydrogen, water vapor, hydrocarbons, CO, CO2, etc.). The single-chamber reactor (SCR) has been also proposed either as a membrane reactor or as a fuel cell. In this case, the solid-electrolyte disk, with two different electrodes that are coated either on opposite sides or on the same side of the pellet, is suspended in a flow of the reacting mixture (see Section 12.6.3). 

---