Effect of petrochemical industrial emissions of reactive alkenes and NO_<i>x</i> on tropospheric ozone formation in Houston, Texas

Abstract

Petrochemical industrial facilities can emit large amounts of highly reactive hydrocarbons and NO x to the atmosphere; in the summertime, such colocated emissions are shown to consistently result in rapid and efficient ozone (O 3 ) formation downwind. Airborne measurements show initial hydrocarbon reactivity in petrochemical source plumes in the Houston, TX, metropolitan area is primarily due to routine emissions of the alkenes propene and ethene. Reported emissions of these highly reactive compounds are substantially lower than emissions inferred from measurements in the plumes from these sources. Net O 3 formation rates and yields per NO x molecule oxidized in these petrochemical industrial source plumes are substantially higher than rates and yields observed in urban or rural power plant plumes. These observations suggest that reductions in reactive alkene emissions from petrochemical industrial sources are required to effectively address the most extreme O 3 exceedences in the Houston metropolitan area.