A Systems Evaluation on the Effectiveness of a Catalyst Retrofit Program in China

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• 作者：Mark Jones ; Ryan Wilson ; Joseph M. Norbeck ; Weijian Han ; Ronald Hurley ; and Dennis Schuetzle
• 刊名：Environmental Science & Technology
• 出版年：2001
• 出版时间：September 1, 2001
• 年：2001
• 卷：35
• 期：17
• 页码：3416 - 3421
• 全文大小：56K
• 年卷期：v.35,no.17(September 1, 2001)
• ISSN：1520-5851

文摘

A low-cost, rare-earth oxide (REO) catalyst has beenrecommended as part of China's retrofit program for Chinesecarbureted vehicles. This study evaluated: (1) theemission reduction efficiency of the REO catalyst duringchassis dynamometer testing on the FTP cycle; (2) the effectthat fuel properties had on tailpipe emissions and catalystefficiency; (3) the importance of vehicle premaintenanceas part of a retrofit protocol; and (4) the emission reductionsobtained following implementation of the program.Results also show that current in-use Chinese noncatalyst,carbureted vehicles operate excessively rich, resultingin extremely high emissions of CO, gaseous toxic compounds,and other non-methane hydrocarbon species (NMHC).Preretrofit maintenance alone has the potential to reducethese emissions by ~50%. Dynamometer emission testsshowed emissions reductions of >95% for hydrocarbons,CO, and gaseous toxics after retrofit of the REO catalyst.In particular, the relative unit health risk associated with thedecrease in emissions of airborne toxic compoundsusing unleaded Chinese fuel was reduced from 6.33 to0.30. (Use of low-sulfur California Phase II gasoline ratherthan current in-use Chinese fuel reduced emissionsfurther.) Following implementation of the program, a follow-up study showed that in-use emissions benefits wereconsiderably less than anticipated, primarily because ofpoor quality control at the retrofit service centers, a lessaggressive preretrofit maintenance procedure, andunauthorized modification to the recommended retrofitcontrol system. Overall results indicate that a carefullycontrolled retrofit program using REO catalyst technologycan reduce emissions significantly. However, well-defined implementation guidelines, and strict adherenceto these guidelines are needed to achieve maximum benefits.