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Show NOx AND CO PEMS ON A 100 MW COGENERATION GAS TURBINE AT DOW CHEMICAL, FREEPORT, TEXAS The PEMS in this application was built from data collected on 184 process variables. The final model was reduced to 17 important inputs and 3 outputs, NOx ppm, CO ppm and O2,%. The NOx emission model achieved an R2 correlation of 0.997 (accuracy of 99.7%). Figures 4 and 5 display the accuracy for the NOx and CO emission test sets. The original RATA on this turbine for NOx was 2 %, 3 % and 4% at the low, medium and high ranges respectively compared to a requirement of 20%. This PEMS has been in operation for approximately 2 years. It has passed all RATA tests (5 t<Xal to date), with better than 98% up-time. Eight other units at this facility have had PEMS installed and all have demonstrated the same exceptional performance. A total of fifteen will eventually be installed. The savings of these 15 PEMS versus 15 hardware CEMS is estimated at over $3 million for installation and over $150,000 in annual operation and maintenance costs. Figure 4. NOx Emissions from a 100 MW Gas Turbine at Dow 140~=====T======T=====~======~=====r====~~====~~ 120 ~ : ' · M iii ( i ! I! CEMS PEMS I I ~ i r-- ~ i! I i! III ;' I l · I 1 ~ I ! ~ \ l 1 ! 1 on i L.i '1 I ! n i .~ 1 ! I! i ~ .1 p{-i ~f i ; : ! ~ I d I ,/i.'· i :, I I I I ! I 1,,11 i i ! i ! · ~ I I L ! ! l! ~~. 40 I I':!I~ " \Vt I~ 1I ;~ .~i ! I~ I 20 ! It 1 I ,i \, I ~ fl ! j . ) ~ ! I I ! ~ ; ! ~ ; " o~====~====~======~====~====~====~======~ 6-2-93 6-6-93 11 |