The present invention reduces the amount of oxygen in an oxygen-containing gas within a closed environment. A selected amount of hydrogen gas is mixed with a portion of the oxygen-containing gas from the closed environment to form a first gas mixture. A catalyst exposed to the first gas mixture causes a reaction between the hydrogen and at least a portion of the oxygen therein. The resulting second gas mixture, which is returned to the closed environment, has a lower percentage of oxygen. At least one oxygen sensor is positioned in the closed environment to determine when oxygen levels in the closed environment reach a threshold level. The output signal from the sensor is used to control when and/or how much hydrogen is mixed in the first gas mixture.

An integrated process and apparatus for integrating an alkene derivative process, such as ethylene oxide process, with an ethylene process so that any ethylene entrapped in the purge stream of the alkene derivative process can be effectively recovered through the ethylene process portion of the integrated process.

A non-cryogenic system for producing ultra-pure nitrogen includes a pressure swing adsorption (PSA) unit for converting incoming ambient air into a process stream containing mainly nitrogen. The process stream is combined with hydrogen, in a reactor, to remove residual oxygen. The process stream is then cooled, and the cooled process stream is directed through a dryer. The output of the dryer is ultra-pure, dry nitrogen. The dryer contains at least two sections, one being the active section and the other section being regenerated. A portion of the output nitrogen leaving the active section is directed back into the section being regenerated, where it absorbs moisture, and is then recycled to the PSA unit. The result is an ultra-pure and dry product. The invention avoids the need for providing heat to the dryer, and also eliminates the need for many of the components used in prior art systems. The invention is economically operated even for small or medium-sized flow rates.

In an electrolysis cell wherein powdered material are added to a bath of molten electrolyte, the anode is provided with a duct through which the powdered material may be fed to the electrolyte. Simultaneously, a gas which is preferably inert, is also fed together with the powdered material through the duct, and both are injected beneath the surface of the electrolyte.

The process and system according to the present invention are used for the production of an atmosphere. The process involves feeding an impure nitrogen stream, combined with a hydrocarbon to a catalytic reactor having a non-noble metal catalyst to produce a gas which is suitable for use as an atmosphere in furnaces for thermal treatment of metals. The impure nitrogen stream, contains less than 21% oxygen and is preferably produced by a gas membrane system. The system for producing the atmosphere preferably includes a membrane separator, one or more heat exchangers and a catalytic reactor preferably having a nickel catalyst on an alumina support.