Diesel Construction Equipment Database and NO{sub}x Control Technology Evaluation for Greater Houston

摘要

Diesel engines are a pervasive source of ozone precursors and particulate matter throughout Texas. Based on the most current data available through the Texas Commission on Environmental Quality (TCEQ) TexAER database, roughly 75% of total on-road and nonroad mobile source NO{sub}x emissions are attributable to diesel engines operating in the Houston-Galveston-Brazoria (HGB) region. In order to reduce emissions from this largely uncontrolled source of emissions, the Texas Legislature adopted the Texas Low Emission diesel (TxLED) program, as well as the Texas Emission Reduction Plan program (TERP). The TERP is a voluntary program whereby owners of diesel equipment can receive grants to retrofit existing equipment, or replace older equipment, with newer units meeting cleaner emission standards. PM reduction through retrofits has become relatively commonplace. On the other hand, commercialized NO{sub}x-reduction technologies remain few, complex and relatively expensive. Consequently, widespread NO{sub}x-reduction through retrofits remains an unrealized goal at this time. The current study provides key information critical to the assessment and future implementation of diesel NO{sub}x retrofits. The State Implementation Plan (SIP) developed by the TCEQ for the HGB ozone non-attainment region relies heavily on anticipated NO{sub}x reductions resulting from future TERP-funded diesel engine retrofits. While significant emission reductions have been achieved to date, substantial additional reductions are still needed in the next few years in order to meet the required SIP targets. In order to meet the remaining emission reduction targets of the TERP, the New Technology Research and Development Program (NTRD) contracted with Eastern Research Group (ERG) and its teaming partner Emisstar LLC to conduct a Strategic Assessment of feasible NO{sub}x control retrofit strategies for diesel construction and marine sources operating in the 8-county HGB area. NTRD is a research-focused program jointly managed by the Texas Environmental Research Consortium (TERC) and the Houston Advanced Research Center (HARC). This assessment compiled highly detailed engine information with the latest data available concerning NO{sub}x retrofit technologies into a comprehensive database. The resulting database provides the fleet and engine-specific detail needed to identify additional cost-effective TERP targets in both regions. General findings can also be extrapolated to other non-attainment and near non-attainment regions across the state and beyond. The database may also be used to help characterize the potential financial return-on-investment resulting from development and EPA verification of various retrofit technologies. This information is crucial for emission reduction technology vendors in order to justify investments in new market areas like Texas. Work performed under this study also provides an extensive assessment of the potential emission reduction of a wide range of existing and developing technologies for the key emission sources identified. TERC may also use the data to target emissions reduction technology funding for development and verifications that will lead to the most cost-effective, and/or largest reductions from high emitting engines.