
58 Oxygen-Enhanced Combustion
The pumped LOX cycle is typically lower cost, due to
the elimination of the oxygen compressor.
3.2.2.3 Coproduction of Nitrogen
From the material balances in Table 3.1, it is clear that an
air separation plant designed for oxygen production has a
waste nitrogen stream with a ow of approximately 80%
of the air ow to the plant. Waste nitrogen purity varies
based upon oxygen recovery, but would typically be in the
1%–5% O
2
range. Commercial nitrogen purity levels for
most usages are in the 1–10ppm O
2
range with some elec-
tronic customers requiring ppb contaminant levels. The
production of a pure gaseous nitrogen ( ...