Page 532 - Materials Chemistry, Second Edition

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Incineration of Hazardous Wastes 503
Takeshita, R. and Akimoto, Y., Control of PCDD and PCDF formation in fluidized bed incinerators,
Chemosphere, 19, 345–352, 1989.
Theodore, L. and Reynolds, J., Introduction to Hazardous Waste Incineration, Wiley New York, NY, 1987.
U.S. Congress, Office of Technology Assessment, Dioxin Treatment Technologies, Washington, DC, 1991.
U.S. Environmental Protection Agency, Permitting Hazardous Waste Incinerators, EPA/530-SW-88-024,
Office of Solid Waste, Washington, DC., April, 1988.
Wiley, S.K., Incinerate your hazardous waste, Hydrocarbon Processing, 66, 51–54, June, 1987.
Wood, R.W. and Bastian, R.E., Rotary kiln incinerators: the right regime, Mechanical Engineering, III, 78–81,
September, 1989.

QUESTIONS
1. Which two major sets of regulations are included in the federal standards for hazardous
waste thermal technologies? Under which specific acts are they administered? How do
they differ in terms of regulatory coverage?
2. Combustion involves chemical transformations in which solid materials are converted to
gases and solid residues. What factors, with regard to both incinerator design and oper-
ation and waste properties, affect the composition and quantities of gases produced?
What factors will influence the amount of solid residues produced, both carbonaceous
and inorganic?
3. Whenever an organic material is to be incinerated, air (oxygen) is necessary to complete
combustion. For what other purposes is air required? Be specific.
4. List the engineering and design factors that serve to enhance combustion in an incinerator.
5. Discuss how each of the major types of gaseous emissions from an incinerator may be
effectively removed from the flue.
6. Compare and contrast the rotary kiln injection system and the liquid injection incinera-
tor in terms of overall design, efficiency and problems during use. Which is most suited
to the destruction of organic sludges, organic solids, liquid solvents, and metal-enriched
acidic solutions?
7. A waste mixture consisting of benzene and chlorophenol is being incinerated. Is the unit
in compliance for each compound?

Compound Inlet (kg/h) Outlet (kg/h)
Benzene (C H ) 953 0.081
6 6
Chlorobenzene (C H OCl) 950 0.149
6 5
Xylene (C H ) 442 0.061
8 10
HCl — 0.95
Particulates (8.8% O ) — 48.1
2
Note: Flow rate 16,250 dscfm.
8. For the data in the previous question, determine if the emissions meet federal require-
ments for particulates.
9. Calculate the solids retention (θ) time in a rotary kiln incinerator with the following data:
kiln length 6 m
kiln rotational velocity 0.8 r/min
kiln diameter 1.8 m
kiln slope 0.085 m/m
10. For question number 9, if the desired retention time is actually 12.0 min, what should the
rotational velocity be adjusted to?
11. In a regulatory sense, how might hazardous waste incinerator ash be considered haz-
ardous? Consider both listed and characteristic hazardous wastes.