Enriched air oxygen

Oxygen-enriched air will be produced on the low pressure permeate side of the air-separating membranes. The oxygen-enriched permeate stream is usually vented, but there is an increasing interest in using this gas for combustion. High-purity oxygen 

FIGURE 4.27 Illustration of the approximate competitive range of current membrane nitrogen production systems. Many site-specific factors can affect the actual system selection. (From Baker R., Membrane Technology and Applications, McGraw-HiU, New York, 2000. With permission.) 

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Several studies of spherical and cylindrical detonation in acetylene—oxygen and acetylene—air mixtures have been reported (82,83). The combustion and oxidation of acetylene are reviewed extensively in Reference 84. A study of the characteristics and destmctive effects of detonations in mixtures of acetylene (and other hydrocarbons) with air and oxygen-enriched air in earthen tuimels and large steel pipe is reported in Reference 81. 

In the former USSR, there reportedly are two technologies in use one is old anthrahydroquinone autoxidation technology and the other is closed-loop isopropyl alcohol oxidation technology. Production faciUties include several smaller, 100-150-t/yr isopropyl alcohol oxidation plants and a larger, 15,000-t/yr plant, which reportedly is being expanded to 30,000-t/yr. Differences in this technology as compared to the Shell Chemical Co. process are the use of oxygen-enriched air in the oxidation step and, catalytic reduction of the coproduct acetone back to isopropyl alcohol per equation 21. 

Dried lead concentrate, flux, and return dust are added to the converter through a lance during the smelting cycle. Oxygen enriched air is injected at the same time to carry out the smelting reactions and maintain the temperature. Once smelting is completed, the air is shut off and the reduction carried... 

The oxidant preheater, positioned in the convective section and designed to preheat the oxygen-enriched air for the MHD combustor to 922 K, is located after the finishing superheat and reheat sections. Seed is removed from the stack gas by electrostatic precipitation before the gas is emitted to the atmosphere. The recovered seed is recycled by use of the formate process. Alkali carbonates ate separated from potassium sulfate before conversion of potassium sulfate to potassium formate. Sodium carbonate and potassium carbonate are further separated to avoid buildup of sodium in the system by recycling of seed. The slag and fly-ash removed from the HRSR system is assumed to contain 15—17% of potassium as K2O, dissolved in ash and not recoverable. 

Spiral-wound modules are much more commonly used in low pressure or vacuum gas separation appHcations, such as the production of oxygen-enriched air, or the separation of organic vapors from air. In these appHcations, the feed gas is at close to ambient pressure, and a vacuum is drawn on the permeate side of the membrane. Parasitic pressure drops on the permeate side of the membrane and the difficulty in making high performance hollow-fine fiber membranes from the mbbery polymers used to make these membranes both work against hollow-fine fiber modules for this appHcation. 

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... 

The constants DO 0o% and DO0% are the DO values measured by the probe at 100% or 0% saturation respectively. With this formulation one can readily analyze the operation with oxygen enriched air. 

Oxygen-enriched air or In-line Provides considerably higher Not practical except for low... 

The melt copper (matte) is further processed in a converter, where the remaining sulfur and iron is removed by underbath injection of oxygen-enriched air. The resulting so-called blister copper has a copper content of 98%. 

One of the most important industrial chemical processes is the manufacture of sulfuric acid. A major step in this process is the oxidation of SO, with air or oxygen-enriched air in the reversible, exothermic reaction corresponding to equation (A) in Example 1-2 ... 

Gas Separation (GS) pressure difference oxygen enriched air purification of natural gas... 

It should be noted that the sulfation reaction requires the presence of oxygen. This serves to highlight the importance of air/acid gas ratio control in the front end furnace feed and the prevention of oxygen breakthrough into the catalyst beds. This can be of particular importance when oxygen enriched air feed is used in the front end reaction furnace (31). 

In a number of industrial processes it is beneficial to replace combustion air with oxygen-enriched air to increase the temperature and/or enhance the overall energy efficiency. Since atmospheric N2 is also a source of nitrogen oxides through the thermal NO mechanism,... 

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