Diesel Engines: Environmental Impact and Control

Transcription

1 Diesel Engines: Environmental Impact and Control Alan C. Lloyd, Ph.D. California Air Resources Board DEER Conference 2002

2 Diesels are an Important Part of the World s Economy Land and sea transport Electrical power Farming, industrial, and construction activities Introduction

3 Introduction Diesels Make Up One-Third of Passenger Car Sales in Europe Percent of New Car Sales 35% 30% 25% 20% 15% 10% 5% 0% Source: Walsh (2001) SAE paper Sales Year

4 Diesel Truck VMT is Growing in the U.S. Annual VMT (billions) <10,000 10,001 to 19,500 19,501 to 26,000 Truck Average Weight Category (pounds) Source: U.S. Department of Commerce >26,000 Introduction

5 Emissions Diesel Will be a Major Source of NO X in California Other Mobile Sources 32% On-Road HDD 18% Off-Road Diesel 19% Source: EMFAC2001 v2.082 Stationary 31% California in 2010

6 Diesel is a Majority of Air Toxic Risk in Los Angeles Risk (excess per million) Greater Los Angeles Other Toxics Diesel PM Emissions

7 CA Diesel Vehicle NO X Inventory NO X (thousand tons/year) Heavy-duty Vehicles Non-road Vehicles Medium-duty Vehicles ARB EMFAC 2001 v2.08 Year Emissions

8 CA Diesel Vehicle PM10 Inventory PM10 (thousand tons/year) Heavy-duty Vehicles Non-road Vehicles Medium-duty Vehicles ARB EMFAC 2001 v2.08 Year Emissions

9 Cancer Effects of Diesel Increased lung cancer incidence supported by 30+ population studies. WHO, U.S. EPA, NIOSH, and HEI acknowledge the cancer potential in humans. ARB identified diesel exhaust PM as TAC. Unit Risk Range: 130-2,400 per million. Health Effects

10 Association Between Lung Function of Children Living <300 Meters From Motorway and Intensity of Cargo Traffic Lung Function FEV1 (Liters) Number of Heavy Duty Vehicles Per Working Day Source: Brunekreef B, et al, Air Pollution from truck traffic and lung function in children living near motorways Health Effects

11 Diesel Contributes to Water and Soil Pollution Fuel spills and leaks. Deposition to water bodies and soils. Environmental Effects

12 Emissions From Diesels Can be Reduced New Engines Engine improvements / electronic controls Post-combustion clean-up Alternatives to diesel Fuels Cleaner diesel Alternatives Current fleet Proper maintenance Retrofit Emission Controls

13 Engine Technologies That Reduce Diesel Emissions In-Cylinder Air Handling Fuel Handling Aftertreatment PM Traps NOx Catalysts Electronic control Emission Controls

14 NO X (g/bhp-hr) Stringent NOx Standards Exist for New On-Road Engines Source: DieselNet. Emissions Standards: European Union, U.S./CA EU Current and Future Technologies

15 PM (g/bhp-hr) Stringent PM Standards Exist for New On-Road Engines Source: DieselNet. Emissions Standards: European Union, U.S./CA EU 98+% lower Current and Future Technologies

16 More Stringent Emission Standards For New Off-road Engines Needed hp g/bhp-hr HC+NOx PMx HDDE* Model Year *2007 HDDE Standards are 0.2 g/bhp-hr NOx and 0.14 g/bhp-hr NMHC Emission Controls

17 Diesel Fuels Low Sulfur Fuel Needed for aftertreatment U.S ppm (on-road) by mid-2006 CA/TX - 15 ppm (on and off-road) by mid-2006 EU - 50 ppm by 2005 (possibly 10 ppm) Alternative Diesel Fuels Fischer Tropsch - zero sulfur and aromatics Water emulsions - reduce PM and NO X Future Technologies

18 California Diesel PM Risk Reduction Plan Sets Aggressive Goals 75% risk reduction by Retrofit on- and offroad diesel engines with filters (80% of plan s benefit). Future Technologies

19 Maintaining Low Emissions In-use Through Enforcement Roadside smoke inspections. Reduced smoky trucks from 30% to 8%. Expand to include NO X and PM. Manufacturer-run in-use compliance program. Future Technologies

20 Diesel PM Traps Can Be Effective Trap Trap Trap Future Technologies

21 Alternative Fuels Can Reduce Emissions Natural Gas Lower NO X and PM. Nanoparticle formation being investigated. Methanol and Ethanol Poor durability and frequent overhauls. Future Technologies

22 Fuel Cells Have Promise Ultimate replacement for diesel engines: Zero Emissions High efficiency Cost reduction needed Initial transit buses in Near-term promise as truck APU. Future Technologies

23 Progress Means Continued Regulation and Monitoring Environmental regulations result in reduced emissions. Equal focus on off-road engines and fuels needed. Monitoring of in-use emission performance must continue. Conclusions and Recommendations

24 Summary Diesels are a key power source. Diesels are significant contributors to air pollution. Diesel exhaust is linked to cancer. Regulations are in place for new on-road diesels. Comparable regulations are needed for off-road, including cleaner fuel.

25 Summary (cont d) Technology is advancing to meet these challenges. Existing engines need to be cleaned up. Retrofit and replacement programs are being developed.