Quantification of Fine Particle Emissions From Petroleum Refining Operations in Houston, TX Using Rare Earth Elements as Markers

摘要

Fluidized bed catalytic cracking (FCC) is a critical activity of petroleum refining, which uses zeolite catalysts to convert heavier hydrocarbons to useful light hydrocarbons such as gasoline, diesel etc. Although, catalysts are repeatedly recovered and regenerated, some of it inevitably escapes to the local atmosphere, which can be an important source of PM_(2.5) especially in the immediate surroundings of the refinery. Additionally, large quantities of zeolite catalysts (which are enriched in rare earth elements (REEs) along with other metals) can be emitted to the atmosphere over short times (emission events) due to malfunctions in FCC units and substantially impact local air quality. These emission events often translate into elevated ambient PM_(2.5) levels. Characterization of such emission events is difficult due to their short duration and unexpected nature.