Estimated Cost of Emission Reduction Technologies for Light-Duty Vehicles

March 2012 Estimated Cost of Emission Reduction Technologies for Light-Duty Vehicles FRANCISCO POSADA SANCHEZ ANUP BANDIVADEKAR JOHN GERMAN www.theicct.org Written by Francisco Posada Sanchez, Anup Bandivadekar, and John German. The authors thank Tim Johnson and Joe Kubsh for their invaluable help in gathering information and reviewing this report. The International Council on Clean Transportation 1225 I Street NW, Suite 900 Washington DC 20005 USA www.theicct.org © 2012 The International Council on Clean Transportation Funding for this work was generously provided by the ClimateWorks Foundation and the William and Flora Hewlett Foundation. EXECUTIVE SUMMARY There are great opportunities around the globe to reduce conventional pollutant emissions from light-duty vehicles (LDVs), with positive effects on air quality and public health. Even though the benefits of more stringent standards have been demonstrated and the technologies to achieve those benefits are readily available, there are still large differences in the implementation schedules for increasing emission stringency (Figure ES-1). Among the reasons for delaying the implementation of stricter emission levels is the extra cost added to the vehicle by the emission control system. This report directly addresses the cost to LDV manufacturers of deploying technology in order to meet more stringent emission regulations. Costs were assessed by government agencies during the rulemaking process establishing each new standard in the US and Europe. However, some of these standards were established many years ago. There have been substantial improvements in emission control technology since then, which are not reflected in the original cost estimates. This report updates the cost of meeting each emission standard level so that countries considering adoption of more stringent standards can make a more informed decision. The objective of this study is to assess the technology requirements’ costs, in current terms, derived from advancing to more stringent regulatory standards on LDVs. Emission control costs for diesel and gasoline vehicles are assessed separately. Gasoline engine emission control is based primarily on precise air-fuel control and catalytic aftertreatment. These emission control technologies have reached a significant level of maturity, which results in very modest incremental compliance costs for even the most stringent existing 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 Brazil PROCONVE L-3 PROCONVE L-4 PROCONVE L-5PROCONVE L-6 China(1) China II China III China IV Europe Euro 4Euro 5 Euro 6 India(1) Bharat II Bharat III Japan FY 2005 Emission Regulation Post New Long Term Emission Regulation Mexico Standard A (US 1994) Standard B: Tier 2 Bin 10, 11 / Euro 4-Euro 3 (diesel) Standard C(2) Russia Euro 1 Euro 2EEuro 3 uro 4 S. Korea US NLEV CARB K-ULEV and Euro 4 (diesel) CARB LEV-2 and Euro 5 (diesel) Taiwan Euro 3 Euro 4 – Tier 2 Bin 7 Euro 5 Thailand Euro 2 Euro 3 Euro 4 U.S. US Tier 2 (1) Major cities have introduced accelerated adoption schedules – timelines in this table reﬂect nationwide adoption (2) Implementation schedule dependent on the availability of low sulfur fuel nationwide Figure ES‑1 Global schedule for implementation of emission regulations in light‑duty vehicles i EXECUTIVE SUMMARY standards. Nitrogen oxides (NOX) and particulate matter (PM) emission control from diesel engines is far more complex and requires the implementation of relatively new technologies involving air management, fuel injection control, aftertreatment and system integration. The implementation of new technologies for diesel engine emissions control has a significant impact compared with the cost associated with gasoline engine emissions control. Emission control technologies for gasoline and diesel vehicles are presented first, and later the technology requirements for each regulatory level and its cost are estimated. It should be noted that the US and EU regulatory programs were used to estimate costs because sources of information and technical literature about them is more widely available than that for other country-specific regulatory programs. In addition, most countries/regions have modeled their regulatory programs using the European and the US as regulatory models, so the technology steps are very similar. This implies that cost findings from this report can be used as benchmarks in other countries/regions. ES-1. EMIssION REDUCTION TECHNOLOGIES Technologies required for control of regulated pollutants are presented below for gasoline and diesel vehicles. Emissions control technologies can be divided into two groups: in-cylinder control and aftertreatment control. A brief description of each technology, including operational principle, appli- cability, reduction capabilities and special conditions, is provided. ES-1.1 GASOLINE VEHICLES Almost all gasoline, spark-ignited (SI) engines run at stoichiometric conditions, which is the point where available oxygen from the air is completely consumed, oxidizing the fuel delivered to the engine. Stoichiometric SI engines use a homogenous air-fuel mixture with early fuel introduction for good fuel vapor- ization. Gasoline fuel delivery systems have evolved from carbureted systems to throttle body injection (TBI), multipoint fuel injection (MPFI), and sequential MPFI. The latest evolutionary step, stoichiometric direct injection, represents a significant improvement for spark-ignited engines and when combined with turbocharging and engine downsizing makes them competitive with diesel engines in terms of fuel economy and performance. Air-fuel control has a major impact on the formation of hydrocarbons (HC), or unburned fuel, and carbon monoxide (CO), which is partially oxidized fuel. In contrast, NOX is a byproduct of combustion, created when nitrogen and oxygen in the air combine during the combustion process. The higher the cylinder temperature, the more NOX is formed. Thus, the primary strategy to reduce the formation of NOX in the engine is to reduce combustion temperatures, using faster burn combustion chamber design and exhaust gas recirculation (EGR). ii COST OF EMIssION REDUCTION TECHNOLOGIES Aftertreatment emissions control for stoichiometric engines is based on the three-way catalytic converter (TWC). The TWC is capable of oxidizing HC and CO, and simultaneously reducing NOX if the air-fuel ratio is controlled very precisely at stoichiometry. Improvements in SI emission control have focused on extreme precision in air-fuel control, maintenance of stoichiometric conditions at all times, and catalyst improvements. The latest systems can simultaneously reduce all three pollutants by more than 99% after the catalyst has reached normal operating temperature. Catalyst improvements have focused on ways to quickly bring the catalyst to operating temperature and minimize emissions following cold starts, while significantly reducing the amount of precious metals required for proper operation. ES-1.2 DIESEL VEHICLES Unlike gasoline SI engines, which always control both the amount of air and the amount of fuel close to complete combustion conditions, the diesel engine runs unthrottled with an excess of air (lean operation). HC and CO emissions are not usually a concern with diesel engines, as the lean operation reduces engine-out HC and CO emissions and enables high oxidation efficiency in simple oxidation catalysts. PM and XNO emissions are more challenging to control and are the main focus of diesel emissions control research, as well as the main source of technology costs. Engine-out PM emissions are also much higher than on SI engines due to direct in-cylinder fuel injection. The timing of fuel combustion is controlled when fuel is injected and the fuel ignites almost immediately after injection. This allows little time for the fuel to vaporize and mix with air, creating flame plumes. During this combustion process, carbonaceous particulates grow by aggregating with other organic and inorganic particles. Thus, particulate matter (both mass and number) is also much more challenging to control in a CI diesel engine. In-cylinder emission control of NOX and PM in CI diesel engines is associated with three systems: fuel injection, air handling, and EGR. Fuel injection system improvements involve the use of high-pressure fuel injection with variable injection fuel timing and metering, as well as redesigned nozzle and piston bowl. The fuel injection pressure and the rate of fuel injection are used to control both NOX and PM. The high-pressure injection improves diesel fuel penetration and atomization, improving the mixing of air and fuel. Advancing fuel injection timing increases combustion pressures and temperatures, improving efficiency and reducing PM, but increasing XNO emissions. Delaying the injection of fuel has the opposite effect. Multiple injections of fuel, including pilot, main and post injections, minimize the trade-off between NOX and PM emissions. Multiple fuel injection strategies can only be performed with high-pressure unit injectors or common-rail fuel iii EXECUTIVE SUMMARY injectors. Electronically controlled fuel metering and timing are also required for aftertreatment devices with active regeneration. Air handling is focused on the use of variable geometry turbochargers to provide the right amount of air under specific engine operational conditions. The availability of additional air reduces PM emissions, and has positive effects on power output. EGR is the most significant technology for

Load more