Submitted to: Journal of Air and Waste Management Association
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/4/1996
Publication Date: N/A
Interpretive Summary: The San Joaquin Valley of California exceeds Federal standards for ozone pollution. Nitrous oxides (NOx) which are created from burning fossil fuels are precursors of ozone. Cotton gins in the Valley use fossil fuels (propane or natural gas) to dry and condition cotton during the ginning process. The State of California has proposed a burner NOx emission limit of 60 ppm or less as part of the licensing criterion for cotton gins. The emission levels of conventional gin burners as well as that of newer lo-NOx emission range from a low of 2.4 ppm to a high of 51 ppm for a lo-NOx and conventional burner, respectively. An economic analysis of the cost per ton of NOx reduction substituting a lo-NOx burner for a conventional burner showed an annual capitalized cost of $16,711/ton. The State air control district has an upper cost limit of $9,700/ton of NOx reduced to require an equipment change. Therefore, using this economic criterion, gins do not have to replace their conventional burners for lo-NOx burners to meet operational licensing requirements.
Technical Abstract: The San Joaquin Valley of California is in the San Joaquin Valley Unified Air Pollution Control District (SJVUAPCD), which is a nonattainment area for ozone of which NOx is a precursor. Because of the Federal Clean Air Act, the SJVUAPCD recently began defining Best Available Control Technology (BACT) for NOx emissions from cotton gin drying system gas fired burners in nits jurisdiction. The NOx emission levels of conventionally used direct fired burners were unknown. It was also unknown how these conventional 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 conventional direct fired and lo-NOx burner designs. NOx emission levels during the test ranged from a low of 2.4 ppm for one of the lo-NOx designs to a high of 51 ppm for a conventional burner depending on the firing rate. An economic analysis of the cost per ton of NOx reduction substituting a lo-NOx burner for a conventional burner showed an annual capitalized cost of $16,711/ton. The SJVUAPCD has an upper limit of $9,700/ton of NOx reduced to qualify for definition as BACT. Therefore, using this economic criterion, the conventional gas fired burners will presently remain as BACT for cotton gins for the SJVUAPCD.