Location: Cotton Ginning Research
Title: Emissions from gas fired agricultural burners Authors
Submitted to: Applied Engineering in Agriculture
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: November 13, 2012
Publication Date: March 1, 2013
Citation: Baker, K.D., Armijo, C.B., Funk, P.A., Hughs, S.E. 2013. Emissions from gas fired agricultural burners. Applied Engineering in Agriculture. 29(2):269-277. Interpretive Summary: In order to improve the effectiveness of cleaning equipment, cotton is generally dried with heated air as it first enters the gin. Gas-fired burners are typically used to heat the air; however, these burners emit environmental pollutants in the process of heating the air. This study quantifies the amount of pollutants emitted from conventional gas-fired burners as well as from newly-designed lo-NOx burners. As expected, lo-NOx burners emit fewer pollutants than are emitted by conventional burners. An economic analysis was also done to determine the additional cost of using a lo-NOx burner rather than a conventional burner. The additional cost of operating a lo-NOx burner has been determined to be greater than the added benefit according to rules established by the U.S. Environmental Protection Agency. Therefore, cotton gins are not being required to replace conventional gas-fired burners with lo-NOx burners.
Technical Abstract: Because of the Federal Clean Air Act, the San Joaquin Valley Unified Air Pollution Control District (SJVUAPCD) began defining Best Available Control Technology (BACT) for NOx emissions from cotton gin drying system gas fired burners in its jurisdiction. The NOx emission levels of conventionally used direct-fired burners were unknown, as was how direct-fired burners would compare against newer lo-NOx burners or against the proposed SJVUAPCD NOx emission standard of 60 ppm or less. Replicated laboratory measurements were made of the emissions of both direct-fired and lo-NOx burner designs. NOx emission levels during the test averaged from 3 ppm for one of the lo-NOx designs to 36 ppm for a direct-fired burner when tested over four firing rates. An economic analysis of the specific cost of NOx reduction substituting a lo-NOx burner for a direct-fired burner showed an annual capitalized cost of $18,430/tonne ($16,710/T) of NOx reduction. The SJVUAPCD has an upper limit of $10,670/tonne ($9700/T) of NOx reduction to qualify for definition as BACT. Using this economic criterion, direct-fired burners meet the definition of BACT for cotton gins for the SJVUAPCD, as well as for the rest of the U.S.