Page 411 - Air Pollution Control Engineering

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384 Lawrence K. Wang et al.

5. MANAGEMENT

5.1. Evaluation of Permit Application
Table 7 can be used to compare the results from the calculations and the values
reported by the permit applicant. The calculated values in Table 7 are based on the
example case presented in Table 1. If the calculated values agree with the reported
values, then the design and operation of the proposed catalytic incinerator system may
be considered appropriate based on the assumptions used in this handbook.
In the case of a permit review for a catalytic incinerator, the following data at standard
conditions (77ºF, 1 atm) should be supplied by the applicant. The calculations in this
chapter will then be used to check the applicant’s values.
1. Reported destruction efficiency, DE (%)
reported
2. Temperature of the emission stream entering the incinerator (oxidizer):
If no heat recovery, T (ºF)
e
If emission stream preheated, T (ºF)
he
3. Temperature of flue gas leaving the catalyst bed, T (ºF)
co
4. Temperature of combined gas stream (emission stream plus supplementary fuel combustion
products) entering the catalyst bed, T (ºF)
ci
−1
5. Space velocity through catalyst bed, SV (h )
6. Supplementary fuel gas flow rate, Q (scfm)
f
7. Flow rate of combined gas stream entering the catalyst bed, Q (scfm) (Note that if no
com
supplementary fuel is used [i.e., Q = 0], the value of Q will equal the emission stream
f com
flow rate)
8. Dilution airflow rate, Q (scfm)
d
3
9. Catalyst bed requirement, V (ft )
bed
10. Fuel heating value, h (Btu/lb)
f
5.2. Operation and Manpower Requirements
The total annual cost (TAC) of a catalytic incinerator consists of direct and indirect
annual costs. Direct annual costs include fuel, electricity, catalyst replacement operating
and supervisory labor, and maintenance labor and materials.
Fuel usage is calculated in Section 3. Once the fuel gas flow rate is calculated, multiply
it by 60 to covert flow rate from standard cubic foot per minute (scfm) to standard cubic
foot per hour (scfh). The annual fuel usage can be calculated by multiplying the hourly
fuel gas flow rate by the annual operating hours. Then, simply multiply the annual fuel
usage by the cost of fuel to obtain this annual cost.
Electricity costs are primarily associated with the fan needed to move the gas through
the incinerator. Use Eq. (11) to estimate the power requirements for a fan assuming a
combined motor fan efficiency of 65% and a fluid specific gravity of 1.0:

−4
F = 1.81×10 (Q )(P)(HRS) (11)
p fg,a
where F is the power needed for the fan (kWh/yr), Q is the total emission stream
p fg,a
flow rate (acfm), P is the system pressure drop (in. H O) (from Table 6), and HRS is
2
the operating hours per year (h/yr).
In general, catalyst replacement costs are highly variable and depend on the nature of
the catalyst, the amount of poisons and particulates in the emission stream, the temperature