Fired Heaters: Nitrogen Oxides Emissions and Controls

摘要

The report gives results of a study of nitrogen oxide (NOx) emissions from, and controls for, fired heaters. The petroleum refining and chemical manufacturing industries account for most of fired-heater energy use with an estimated 4600 fired heaters in operation, in these two industries. The report gives a brief description of the design and operation of fired heaters. Descriptions of the two major industries with fired heaters and the various heater applications are presented. An estimate is made of the growth in fired heater energy demand and the number of new fired heaters to be built in the next 5 years in these industries. The factors affecting NOx emissions from fired heaters are discussed, and quantitative relationships are presented, where available. Combustion modifications and flue gas treatment controls for NOx emissions are described. Low excess air (LEA) operation and low-NOx burners are discussed in detail. Long-term continuous NOx emissions data for 12 petroleum refinery heaters are presented. Results of a regression model to predict the effect of stack oxygen level on NOx emissions are used to evaluate LEA performance. The study also presents capital and annualized costs for LEA and low-NOx burner controls.