Encyclopedia of Environmental Science and Engineering, Volume I and II

656 MANAGEMENT OF SOLID WASTE

take advantage of the economics of size. However, small skid-

mounted units with capacities in the range of 20 ton to 50 tons

per day are available at a cost which will make central incinera-

tion for smaller communities economical possible. The first of

these units that met most air pollution codes was marketed by

Combustion Engineering in the late ’60s. It was ahead of its

time and did not enjoy success. However, similar size units with

energy recovery are now finding a good acceptability. Another

development will be the installation of more combined sewage

sludge-refuse incineration facilities using the Nichols multiple

earth rotating grid or similar installations.

Rotary kiln incinerators have been successfully utilized

in handling mixed wastes, often predominantly industrial

wastes. They are particularly useful where long residence

times are required to insure complete combustion. Their

disadvantages center primarily around high maintenance

costs. One of these incinerators has been in operation at Dow

Chemical, Midland, Michigan for almost 30 years.

Incineration in fluidized beds was demonstrated by

Black and Clawson in a facility in Franklin, Ohio, as well as

by Combustion Power Co. which combined a fluid bed com-

bustor with a gas-turbine generator to produce power from

400 tons per day of refuse. The latter demonstrations had

technical difficulties and fluidized bed technology has not

been commercialized.

Numerous on-site incinerators are operated with satis-

factory results for the reduction of industrial wastes. These

facilities are usually specially designed to handle one type of

refuse. Typical materials that are incinerated include plastics,

rubber, wood scrap and paper. The economics of waste recov-

ery are changing so that often these materials are no longer

burned. For example wood chips and sawdust at sawmills

are often sent to paper-mills or composition board producers

as feed, where formerly they were burned. Insulated copper

wire and automobiles are incinerated to remove the organic

components prior to recovery of the metal. Special liquid

TABLE 17

Incinerator effl uent gas composition d

Combustion Products

Feed Product Gas composition vol. %

Component Wt. % Excess air component 0% 50%

Carbon 30.0 CO 2 16.00 9.86

Hydrogena 6.1 H 2 O 19.5 12.04

Oxygene 43.3 O 2 — 7.94

NOx — ~700 ppmb

Nitrogen 0.5 N 2 64.5 70.15

Sulfur 0.1 SO 2 0.02 0.01

Noncombustible 20.0c —— —

a Includes moisture of 20%.

b Not computed.

c No combustion of metal assumed, in actuality same takes place.

d Excluding particular matter.

e Based on theoretical required less O 2 contained in feed.

a potential recovery of $10 to $15 per ton or refuse for the

steam sold.

In addition to the installation of units with waste heat

recovery facilities the trend will be to longer installations to

TABLE 18

Incinerator stack gas contaminants

Component Amounts reported

Organic Acids

Formic 25–133 ppm (31)

Palmitic 0.6 lbs/ton of refuse (32)

Acetic (all organics) 40–600 mg m^3 (33)

Esters

Methyl acetate 5–137 ppm (32)

Ethyl acetate —

Aldehydes

Acetaldehyde 2.8  10 –4 (33)

Formaldehyde 1.1 lbs/ton refuse (32)

Hydrocarbons 4 mgm/gm of particulate (29a)

Halogenated Hydrocarbons

(depends on plastics and aerosols) 6–120 mg m^3 (33)

0.44–10 ppm (31)

0.3 lbs/ton refuse (32)

Ammonia 0.15–1.5 ppm (31)

Nitrogen Dioxide 0.15–5 mg m^3 (33)

Nitrogen Trioxide 4–100 mg/m^3 (33)

HCl 300–1200 mg/kg refuse (33)

30–350 mg/m^3 (33)

SO 2 0.25–1.2 ppm (31)

1.9 lbs/ton refuse (32)

a When burning rubber.

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