Burners vs. SCRs

As air emission rulings continue to become more stringent, NOx emission requirements are reaching levels as low as 5 ppm and are expected to decrease even further.  The CataStak™ SCR system is proven technology that not only meets 5 ppm NOx, but outperforms burner technology and provides emissions limits as low as 2½ ppm NOx for many demanding applications. The CataStak™ SCR system also provides substantial cost-savings and valuable energy efficiency gains, above and beyond available burner technology.

System Comparisons

There are two technology choices used for lowering NOx emissions: 
(1) front-end burner technology or (2) back-end selective catalytic reduction (SCR) technology. SCR technology has multiple advantages over ultra low NOx burner technology, as illustrated in the table below:

  Standard Burner & SCR System Ultra Low NOx Burner
NOx Emissions 2.5 ppm 9 ppm
Turndown 10:1 5:1
Excess Air 3% ~8.5%
Flue Gas Recirculation 0% ~40%
Forced Draft Fan HP X 2X or More
Carbon Footprint Lowest Highest

SCR technology is the most economical, efficient, reliable and easy to operate solution, capable of exceeding 9 ppm. In contrast to users with 9 ppm boiler burner controls, equipment outfitted with the CataStak™ SCR system easily performs at current NOx levels and will easily meet future levels as low as 2.5 ppm, without additional costly burner upgrades. Also, when packaged with EconoStak economizers it provides energy efficiency gains (the E2Stak).

Advantages of the CataStak™ SCR System Include:

  • Low operating cost
  • Easy field retrofit – no burner or fan changes required
  • Ammonia-free option – no special permits required
  • Stand-alone operation – minimum operator intervention
  • Dramatic reduction in stack emissions – NOx, VOC and CO
  • Proven to reduce up to 99% NOx emissions
The choice between a 9ppm burner and our CataStak™ SCR system is easy:  do you want your boiler to follow your plant load or do you want your plant load to have to follow your boiler?
  • When evaluating a low NOx solution call Nationwide Environmental Solutions, your partner in achieving compliance. For complete, worry-free NOx compliance, select the CataStak™ SCR system - the one time compliance investment that will provide proven results year-after-year.