Oxygen separation process

The amount of work used in a practical oxygen separation process is much greater than this minimum because of irreversibility. Figure 1 illustrates the process flow for one type of oxygen production cycle. The process quantities refer to separation of... 

The absolute oxygen fluxes through these materials may not be as high as in a cobaltite, but they have better robustness for the oxygen separation process. 

For the same production capacity, the oxygen-based process requires fewer reactors, all of which operate in parallel and are exposed to reaction gas of the same composition. However, the use of purge reactors in series for an air-based process in conjunction with the associated energy recovery system increases the overall complexity of the unit. Given the same degree of automation, the operation of an oxygen-based unit is simpler and easier if the air-separation plant is outside the battery limits of the ethylene oxide process (97). 

Anodic programs without a separate oxygen scavenging function are entirely suitable for all these system types, provided makeup (MU) requirements remain consistently low. Where MU water volumes are too high, the risk of oxygen corrosion processes is also high. Classically, this is evidenced by rapid pitting corrosion in boiler tubes. 

Many technologies have been proposed for detoxifying waste by processes that destroy chemical bonds pyrolytic biological and catalyzed and imcatalyzed reactions with oxygen, hydrogen, and ozone. The following sections deal only with research opportunities in the areas of thermal destmction, biodegradation, separation processes, and wet oxidation. 

Double Substitution In such processes, two substitutions take place simultaneously. For example, in perovskite oxides, La may be replaced by Sr at the same time as Co is replaced by Fe to give solid solutions Lai Sr Coi yFey03 5. These materials exhibit mixed ionic and electronic conduction at high temperatures and have been used in a number of applications, including solid oxide fuel cells and oxygen separation. 

Electropox [Electrochemical partial oxidation] Also called Pox. An electrochemical process for oxidizing methane to syngas. It combines the partial oxidation and steam reforming of methane with oxygen separation in a single stage. Invented in 1988 by T. J. Mazanec at BP Chemicals. An industrial-academic consortium to develop the process was formed in 1997. 

VAROX An air separation process, allowing for variable oxygen demand. Developed by Linde from 1984. 

It is known that fluorinated compounds dissolve considerable amounts of oxygen and that membranes containing ultrahydrophobic moieties show a high selectivity in gas-separation processes, e.g., in O2/N2 separation. 

---