Ar

(Whcorakt Powor « UghQ

100%

%TDF In Fuel

100%

05 O

Ohio Edison

United Power Assoc.

Illinois Power

Wisconsin Power & Light

Modesto Energy Project (100% Tires)

Figure 6-1. Particulate emissions while burning TDF or whole tires at coal-fired electric utilities.

On day 4 (1SX TOf) Ohio Edison experienced tire feed supply probte» that resulted In several Interruptions of tire sifiply to the boiler.

particulate emission rates for these four companies by TDF level. The fifth company, Northern States Power, had significant operational problems with their particulate control device during their test.9 Their particulate data are not included in Figure 6-1 for this reason, and also because the boilers primary fuel is wood waste, not coal.9

Wisconsin Power and Light reported that, when burning certain high-sulfur coals, opacity from their ESP's increased by about 1.5 percent for each 1 percent incremental increase in the TDF blend rate.18

Ohio Edison reported that the higher emission rates at lower tire feed rates may be related to the non-uniform Btu supply associated with slower whole tire feed rates. To achieve a 5 percent TDF rate, on a Btu basis, whole tires were added one per 34 seconds. Tires were added every 8.5 seconds to result in a 20 percent TDF input. As Btu supply from tires approached a uniform and fairly constant feed rate during their tests, operating conditions appeared to stabilize and emission rates to decline. On day 4 of the test (15 percent), for example, tire feed problems caused interrupted tire supply, and the report states that data from that day support the view that uniform tire feed results in lowered emissions.12

6.3.2 SO.. Emissions

As shown in Figure 6-2, S02 emission results showed variable emission rates over different TDF levels at different facilities. Variations in the sulfur level of the primary coal fuel could account for some of these inconsistent results.

1.41

1.14

S.47

"A (OHoEdtoon) 8.94

1.53

(United Power Association)

-O (Wisconsin Power & Light)

(Modesto)

100%

o"

"i

Ohio Edison United Power Assoc. Illinois Power Wisconsin Power & Light Modesto Energy Project

Figure 6-2. S02 emissions while burning TDF or tires at coal-fired electric utilities.

Note: On dey 4 (15X I0F) Ohio Edison experienced tire feed supply probles» that resulted In severs! interactions of tlrs supply to the boiler.

6.3.3 NO^ Emissions

Two tests showed decreased NOx emissions, and one, WP&L showed increased NOx emissions. Figure 6-3 graphs these emission data. The levels emitted at WP&L were still only 60 percent of the facilities' emission limit.18 WP&L personnel theorize that the emissions increase is due to higher flame temperatures in the cyclone caused by the TDF and a subsequent increase in thermal nitrogen oxide formation.18 Cyclone boilers tend to have high NOx emissions because of high flame temperature, relative to other boiler configurations, even when burning coal.

6.3.4 CO Emissions

Data from WP&L were the only information to compare CO emission rates over varied TDF levels. WP&L found that CO increased, indicating that additional excess air may be required when utilizing TDF, but levels were still less than 50 percent of the permitted level.18

6.3.5 Trace Metal Emi?gi<?ng

WP&L provides the only data showing trace metal concentrations in flue gas. Changes in trace metal emissions during testing at WP&L were reported to be small and statistically insignificant.18 Figure 6-4 shows trace metal emission rate comparisons for WP&L. Figure 6-5 shows change in rate for trace metals at WP&L.

6.3.6 Other Air Emissions Information

Ohio Edison reported emissions of lead during their test; lead remained relatively constant throughout the tests from 0 percent to 20 percent TDF.12 WP&L reported that HC1 and

.430

.443

(Untad Power Assoc)

(Modesto)

Ohio Edison Untied Power Aasoc. Wlnsconsln Power & Ughl Modeslo Energy Project

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