Oxygen gas stream

Reactor Conceptually the application of 03/UV and 03/H202 is quite simple. In the first case the water is treated by UV lamps while or before ozone/oxygen gas stream is bubbled through the solution. In the second case hydrogen peroxide is added while ozone is bubbling through the solution. In practice however it necessary to pay attention to several details. 

Spherical particles of ZnS of size 2.0 /un are reacted in an 8% oxygen gas stream at 900°C. A reaction takes place according to equation... 

Oxygen gas stream is heated from 300 K to 900 K with pressure dropping from 300 kPa to 150 kPa. Calculate the change in enthalpy, change in entropy, and change in Gibbs fimction of the gas stream. 

During this period, each film acquired a moisture content in equilibrium with that in the nitrogen stream. The initial time was marked when an oxygen gas stream at the selected A value, equal to A of the film in the cell, was introduced. The amount of oxygen that permeated per unit of time was continuously monitored with a Mocon... 

It U better to employ the special palladium catalyst which is incorporated in the Deoxo catalytic gas purifier (obtainable from Baker Platinum Limited, 52 High Holbom. London, W.C. 1). 1 his functions at the laboratory tamperature and will remove up to 1 per cent of oxygen. The water vapour formed is carried away in the gas stream and is separated by any of the common desiccants. 

The catalytic vapor-phase oxidation of propylene is generally carried out in a fixed-bed multitube reactor at near atmospheric pressures and elevated temperatures (ca 350°C) molten salt is used for temperature control. Air is commonly used as the oxygen source and steam is added to suppress the formation of flammable gas mixtures. Operation can be single pass or a recycle stream may be employed. Recent interest has focused on improving process efficiency and minimizing process wastes by defining process improvements that use recycle of process gas streams and/or use of new reaction diluents (20-24). 

Toxic or malodorous pollutants can be removed from industrial gas streams by reaction with hydrogen peroxide (174,175). Many Hquid-phase methods have been patented for the removal of NO gases (138,142,174,176—178), sulfur dioxide, reduced sulfur compounds, amines (154,171,172), and phenols (169). Other effluent treatments include the reduction of biological oxygen demand (BOD) and COD, color, odor (142,179,180), and chlorine concentration. 

Oxygen-enriched air is sometimes used in spent acid decomposition furnaces to increase furnace capacity. Use of oxygen-enriched air reduces the amount of inerts in the gas stream in the furnace and gas purification equipment. This permits higher SO2 throughput and helps both the heat and water... 

Other components in the feed gas may react with and degrade the amine solution. Many of these latter reactions can be reversed by appHcation of heat, as in a reclaimer. Some reaction products cannot be reclaimed, however. Thus to keep the concentration of these materials at an acceptable level, the solution must be purged and fresh amine added periodically. The principal sources of degradation products are the reactions with carbon dioxide, carbonyl sulfide, and carbon disulfide. In refineries, sour gas streams from vacuum distillation or from fluidized catalytic cracking (FCC) units can contain oxygen or sulfur dioxide which form heat-stable salts with the amine solution (see Fluidization Petroleum). 

Copper Oxides. Coppet(I) oxide [1317-39-17 is a cubic or octahedral naturally occurring mineral known as cuprite [1308-76-5]. It is ted or reddish brown in color. Commercially prepared coppet(I) oxides vary in color from yellow to orange to ted to purple as particle size increases. Usually coppet(I) oxide is prepared by pytometaHutgical methods. It is prepared by heating copper powder in air above 1030°C or by blending coppet(II) oxide with carbon and heating to 750°C in an inert atmosphere. A particularly air-stable coppet(I) oxide is produced when a stoichiometric blend of coppet(II) oxide and copper powder ate heated to 800—900°C in the absence of oxygen. Lower temperatures can be used if ammonia is added to the gas stream (27-29). 

Figure 3 shows a simple schematic diagram of an oxygen-based process. Ethylene, oxygen, and the recycle gas stream are combined before entering the tubular reactors. The basic equipment for the reaction system is identical to that described for the air-based process, with one exception the purge reactor system is absent and a carbon dioxide removal unit is incorporated. The CO2 removal scheme illustrated is based on a patent by Shell Oil Co. (127), and minimises the loss of valuable ethylene in the process. 

High destruction efficiencies for oxygen-rich, low-contaminant concentration gas streams... 

Biomters are most economic when apphed to low-concentration gas streams (<1000 ppm) that are also oxygen rich. Greater than 90 percent destruction efficiencies can be obtained for water-soluble organics such as alcohols, aldehydes, and amines. Water-soluble inor-... 

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