SULEVs

Supertwisted nematic display, 15 114 Super twisted nematic liquid crystal display (STN-LCD), 9 340 Super ultra-low emissions vehicle (SULEV), 13 855... 

Super ultra-low emission vehicle standard (SULEV), 10 57... 

Abbreviations HCHO = Formaldehyde NMOG = non-methane organic gas LEY = low-emission vehicle ULEY = ultra-low-emission vehicle SULEV = super-ultra-low-emission vehicle. 

SCO SCPC SD SEC SMR SNG SOFC SPE SRES SULEV SUV Synthetic crude oil Super-critical pulverised coal System dynamics US Securities and Exchange Commission Steam methane reformer Synthetic natural gas Solid-oxide fuel cell Society of Petroleum Engineers IPCC Special Report on Emissions Scenarios Super-ultra-low-emission vehicle Sport utility vehicle... 

The five categories of California Low-Emission Vehicle Program standards, from least to most stringent, are TLEV, LEV, ULEV, SULEV and ZEV. 

The CNG vehicles were a technical success and included the first vehicles certified to the strict California low emissions vehicle (LEV) and ultra low emissions vehicle (ULEV) standards. They were also certified to the inherently low emissions vehicle (ILEV) category, and the full-sized van was certified to the California super ultra low emissions vehicle (SULEV) standard. 

LEV = Low emission vehicle ULEV=ultra low emission vehicle SULEV=Super ultra low emission vehicle... 

Air pollution, mainly contributed by the emission from automobiles, has become the most serious urban environmental problems in many eountries. In this study, so as to meet the SULEV regulation, the main idea has been focused on the utilization of HCA(Hydro-Carbon Adsorber) in order to adsorb the excess hydrocarbons emitted during the period of engine cold-start. As a main recipe of HCA materials, many types of zeolite as well as the combination of alumina, precious metals were used. In this study, physico-chemical factors of zeolite such as acidic properties and hydrophobic properties etc. has been characterized, and tried to find the optimum recipe of HCA materials. As results, among the acid properties of zeolites, the Si/Al ratio is found to be the most important factor to get higher hydro-carbon adsorption capacity. 

To meet the future legislation requirements (such as SULEV in California), modem TWC technologies have recently taken the lead with different washcoat architectures to enhance the activity including inorganic carriers able to resist temperatures as high as 1100°C. Highly thermally-stable ternary (Ce/Zr/X) and even quaternary (Ce/Zr/X/Y) mixed oxides are emerging [10-12]. 

Even stiffer regulations apply to so-called Zero Emission Vehicles (ZEV), available to carmakers since 2003 for reduction of their average fleet emissions figures - also regulated by California law. ZEVs have to meet very tough exhaust standards ( SULEV ), in addition to which their HC emission from structural components ( nonfuel emissions ) must not exceed 0.35 g/test. Evaporative emissions from fuel and other liquid supplies ( fuel emissions ) are absolutely prohibited in these vehicles. 

LEV stands for low emission vehicle, T for transitional, U for ultra, S for super, and P for partial, and Z for zero. NMOG is nonmethane organics. A partial zero-level emission vehicle (PZEV) is a SULEV with evaporative emission controls (HC emissions from a nonoperating vehicle)... 

To accomplish the low emissions formulated by GARB for LEV and ULEV, and now SULEV and PZEV, a number of approaches have been investigated in the 1990s. With the underfloor catalyst technology of the 1990s, most HC emissions (60-80% of the total emitted) were produced in the cold start portion of the FTP,... 

All of these approaches contain vmderfloor catalysts of various compositions. It has become clear with the development of high-temperature, close-coupled catalyst that this is the leading technology for LEV, ULEV, and SULEV applications. It is used in combination with underfloor catalysts. A brief description of each of the various candidate technologies follows, along with details of the close-coupled catalyst development. 

Gasoline hybrid vehicles are becoming more available in the United States, and qualify for both SULEV and PZEV performance. Many of these vehicles operate with a stoichiometric engine and use TWC technology for emission control. Some vehicles operate the engine both in lean and stoichiometric modes. In the fuel efficient lean mode, a trap adsorbs the NO in an alkaline material, such as BaO, which is then desorbed and converted to N2 when the engine is commanded to the stoichiometric or TWC mode, which controls emissions over the entire driving cycle. 

Balland, J., Schreurs, B., Hardam, H., Yasui, Y. (2012) A New Clean Diesel Concept for US LEV III SULEV - Advanced Air/Fuel Control for NOx Reduction and for SCR Heat Up, presentation at 4th lAV MinNOx Conference 12-13 June 2012, Berlin. 

For simplicity, only California ULEV is shown in the table LEV and SULEV also were available (California LEV Low Emission Vehicle, ULEV Ultra Low Emission Vehicle, SULEV Super Ultra Low Emission Vehicle)... 

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