Alternative Control Techniques Document— Nitric And Adipic Acid

higher NO reductions than can extended absorption. However,
x
rapid fuel price escalations caused a decline in the use of NSCR
for new nitric acid plants, many of which opted for extended
absorption.
Despite the associated high fuel costs, NSCR offers
advantages that continue to make it a viable option for new and
retrofit applications. Flexibility adds to the attractiveness of
NSCR, especially for retrofit considerations. An NSCR unit
generally can be used in conjunction with other NO x control
techniques. Furthermore, NSCR can be operated at any pressure.
5
Additionally, heat generated by operating an NSCR unit can be
recovered in a waste heat boiler and a tail gas expander. The
heat recovered can supply the energy for process compression
needs with additional steam available for export. 11
The following sections discuss NSCR used as a NO control
x
technique for nitric acid plants. Section 5.1.2.1 describes an
NSCR system including its components and operation. Factors
affecting the performance of NSCR units are discussed in
Section 5.1.2.2, while Section 5.1.2.3 presents data and
discusses NO control performance.
x
5.1.2.1 Description of Nonselective Catalytic Reduction
Systems. Figure 5-3
5-10