API Publ 4667:1997 pdf download.Vehicle Emissions Testing of Rapidly Aged Catalysts
Over the past several years, interest in evaluating the effect of fuel sulfur content on motor vehicle emissions has prompted the initiation of a number of test programs which have focused on advanced technology vehicles. In 1993, for example, the Petroleum Environmental Research Forum (PERF) sponsored a study to evaluate the effect of fuel sulfur content on exhaust emissions from low-mileage production vehicles designed to meet California’s Transitional Low Emission Vehicle (TLEV) standards. (1) One of the TLEVs tested as part of that program was a 1993 Honda Civic VX. An identical catalyst from a 1993 Honda Civic VX TLEV model also was tested as part of a recent study sponsored by the Coordinating Research Council (CRC). (2) The CRC project was designed to measure the effect of fuel sulfur level on the conversion efficiencies and oxygen storage capacities of various rapidly aged automobile emissions control catalysts. The measurements in that program were performed using a steady-state bench reactor because three of the four catalyst formulations that were tested were prototypes for which no suitable vehicle platforms were available at the time for FTP emissions tests. Equivalent fuel sulfur levels were obtained in the CRC program by varying the content of the SO, feedgas to the bench reactor. However, this raised the question as to whether the results of steady-state emissions tests performed in a laboratory bench reactor were truly representative of those which would occur under in-use transient conditions as measured by the Federal Test Procedure.
Four catalysts designed for use on a production 1993 Honda Civic VX model were tested in this program. (See Table 2-2.) The “original” catalyst was the stock catalyst originally installed on the 1993 vehicle and used in the prior PERF study. It was included in the current program primarily to provide a connection to the PERF study and to determine whether normal aging had influenced its tolerance for sulfur. Two new catalysts were provided by HRA. These were stock replacements for the original catalyst. They were aged by Southwest Research Institute using the RAT-A cycle for 100 hours. One catalyst was aged using California Phase 2 Certification gasoline. The other was aged using the same gasoline with sulfur level raised to 1000 ppm. (See Appendix A for a description of the aging procedure used by SwRI.) HRA also provided a catalyst which they had obtained from a customer. This catalyst had been taken from a 1993 Honda Civic VX which had accumulated 107,000 odometer miles in customer service.
API Publ 4667:1997 pdf download
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