NOx Emissions from Cement Mfg - US Environmental Protection ...

for different kiln types. This figure also includes NOx 10
emissions measurements at 9 cement kilns in Germany, and
measurements at 18 kilns performed by F.L. Smidth and Company in
1
several other countries. As seen from this figure, there are
substantial variations in NO emissions even for cement kilns of
x
the same type. The spread is greater with a greater number of
kilns sampled. This survey provided average NO emission factors
x
for four different kiln types: 4.97 lb/ton of clinker for wet
process kilns, 5.7 lb/ton of clinker for dry process kilns, 2.98
lb/ton of clinker for kilns with SPs, and 3.86 lb/ton of clinker
for kilns equipped with a precalciner.
Table 4-2 includes data collected by PCA during a recent
12
revision of the AP-42 emission factors for the cement industry.
This table also includes data from other available emission test
reports. The revised emission factors adopted for the AP-42
document for the same four kiln types mentioned above are
somewhat different than the earlier PCA survey: 8.2 lb/ton of
clinker for wet process kilns, 5.7 lb/ton of clinker for dry
process kilns, 5.5 lb/ton of clinker for kilns with preheaters,
and 4.8 lb/ton of clinker for kilns with precalciners. The NO x
emission rates given in Table 4-2 also exhibit substantial spread
similar to that in Figure 4-2: long wet-kiln emissions ranged
from 3 to 20 lb/ton of clinker, long dry-kiln emissions ranged
from 3 to 17 lb/ton of clinker, preheater-kiln emissions ranged
4-17