1. A Feasibility Study on Retrofitting Diesel Oxidation Catalyst (DOC) to in-use old Diesel Vehicles in Hong Kong AWMA Conference June, 2003 Wing-tat HUNG, Chun-shun CHEUNG The Hong Kong PolyU Wai-Chuen MOK, Kong HA and Allan HUNG EPD, Hong Kong SAR Government

2. Hong Kong Population: about 7 millionPopulation: about 7 million Area: 1,099 square kmArea: 1,099 square km Road: 1,991 kmRoad: 1,991 km Licensed vehicles: 525,000Licensed vehicles: 525,000 275 vehicles per km275 vehicles per km

3. Vehicle Emission Problems Taxis, goods vehicles, light buses and buses were diesel vehiclesTaxis, goods vehicles, light buses and buses were diesel vehicles 29 % of vehicle population - (17% Singapore, 10 % UK, 4 % USA)29 % of vehicle population - (17% Singapore, 10 % UK, 4 % USA) 98 % PM and 75 % NOx from diesel vehicles98 % PM and 75 % NOx from diesel vehicles 100 % of excessive smoky vehicles100 % of excessive smoky vehicles Cause record high Air Pollution IndexCause record high Air Pollution Index

4. Vehicle Emission Control Strategy Clean alternatives to diesel vehiclesClean alternatives to diesel vehicles Stringent new vehicle emission standards and fuel specificationStringent new vehicle emission standards and fuel specification Strengthen in-use vehicle emission inspectionStrengthen in-use vehicle emission inspection Strengthen enforcement against smoky vehiclesStrengthen enforcement against smoky vehicles

5. Vehicle Emission Control Strategy Promote environmentally friendly driving and awareness of vehicle maintenancePromote environmentally friendly driving and awareness of vehicle maintenance Retrofitting in-use vehicles with emission reduction deviceRetrofitting in-use vehicles with emission reduction device

6. Retrofit DOC on Buses Started Diesel Oxidation Catalyst (DOC) trial in 1995Started Diesel Oxidation Catalyst (DOC) trial in 1995 Fuel sulphur content: 2000 ppm to 500ppmFuel sulphur content: 2000 ppm to 500ppm Trial Result :Trial Result : *FAS Test: Free Acceleration Smoke Test, similar to snap idle test Up to (HSU)Up to (%) Manufacturer A 0.24165Clogged Manufacturer B 0.23966Passed 0.21851Clogged 0.2 and 0.05 1846Normal 0.05922Running 0.05612Running Manufacturer C with muffler State of catalyst Sulphur content in diesel(%) Smoke reduction (FAS Test*)Catalyst Manufacturer C

7. Custom design catalyst offers good resultCustom design catalyst offers good result Voluntarily installing DOC on Pre- Euro and Euro I buses (2,600 units)Voluntarily installing DOC on Pre- Euro and Euro I buses (2,600 units) The trial of 400+ passive particulate traps ongoingThe trial of 400+ passive particulate traps ongoing Retrofit DOC on Buses

8. Implementation of Retrofit Technologies Government actions: Grants for Pre-Euro (pre-1995) diesel vehicle owners to install approved devicesGrants for Pre-Euro (pre-1995) diesel vehicle owners to install approved devices Light Diesel Vehicle (below 4 tonnes) Retrofitting ProgramLight Diesel Vehicle (below 4 tonnes) Retrofitting Program 2 approved devices with over 30% PM reduction and 3 years warranty2 approved devices with over 30% PM reduction and 3 years warranty Low efficiency trap requires regular cleaningLow efficiency trap requires regular cleaning CatalystCatalyst Completed on October 2001 (about 24,000 vehicles retrofitted)Completed on October 2001 (about 24,000 vehicles retrofitted)

9. Trial of Retrofitting DOC on HDDV Heavy Duty Diesel Vehicles (over 4 tonnes) Heavy Duty Diesel Vehicles (over 4 tonnes) Started a trial in Dec 1999 Started a trial in Dec 1999 59 trial vehicles were retrofitted with DOCs of different makes 59 trial vehicles were retrofitted with DOCs of different makes Test Fuel 500 ppm sulphur (Before Aug 2000) 500 ppm sulphur (Before Aug 2000) 50 ppm sulphur (After Aug 2000) 50 ppm sulphur (After Aug 2000)

10. Trial of Retrofitting DOC on HDDV 23 Government vehicles (all comply with Euro-1 standard23 Government vehicles (all comply with Euro-1 standard 36 non-government vehicles (all except three are pre-Euro standard)36 non-government vehicles (all except three are pre-Euro standard) Among non-government vehicles, 4 China trade vehicle, fueled with high sulphur diesel from China MainlandAmong non-government vehicles, 4 China trade vehicle, fueled with high sulphur diesel from China Mainland 7 brands of DOC with 200 cpi to 300 cpi7 brands of DOC with 200 cpi to 300 cpi

11. Emission Testing FAS before and after the DOC (200 and 300 cpi) installed;FAS before and after the DOC (200 and 300 cpi) installed; Measure CO and HC before and after the DOC at high idle, on road and at lug down test modeMeasure CO and HC before and after the DOC at high idle, on road and at lug down test mode Monitor exhaust gas temperature and backpressure before the DOC at high idleMonitor exhaust gas temperature and backpressure before the DOC at high idle Trial of Retrofitting DOC on HDDV

12. Fittings for DOC in-use Test

13. Test Results (1) Test Results (1) Average 72% CO reduction

14. Test Results (2) Average 36% HC Reduction

15. On-road CO test results VehicleCO before DOC (ppm) CO after DOC (ppm) % reduction V3294698 V34 (test 1)197498 V34 (test 2)200199

16. CO test results – Chassis Dyno Lug-down Vehicle CO (ppm) before DOC CO (ppm) after DOC % CO reduction V3104397 V41502087 V201504073

17. Test Results (3)

18. Test Results (4)

19. TestDOC Maximum power for vehicle V3V4V20 AYes49.1 kW at 2895 RPM94 kW at 2779 RPM141 kW at 2032 RPM BNo48.4 kW at 2938 RPM94 kW at 2768 RPM141 kW at 2018 RPM CYes52 kW at 2738 RPM142 kW at 2053 RPM DNo50 kW at 2752 RPM143 kW at 2039 RPM Test Results (4) Effects of DOC on Power Output under Lug-down Tests

20. Associated Issues –White Smoke White smoke observed after extensive long idling 5 concrete mixers 5 concrete mixers 3 lifting trucks 3 lifting trucks Under prolonged idling working conditions

21. Associated Issues - NOx VehicleSampling point CO (ppm) NO (ppm) NO 2 (ppm) NOx (ppm) V3Before DOC29411911.1130 After DOC61139.1119 V4Before DOC197449.653 After DOC44410.754 V4Before DOC200679.276 After DOC1587.265 On-road NOx measurements

22. Associated Issues – High Sulphur Fuel VehicleCO Conc. (ppm) Smoke Opacity (HSU) Efficiency of CO Reduction (%) Efficiency of Smoke Reduction (%) Before DOC After DOC Before DOC After DOC V263618520 77-2 V262352854458817 V277589520118845 V2733827334231932 V28446254223543-58 V2847471637385-15 V2241138639516-29 V22300120395260-33 V233963715952611 V23204180696112 Average392186.342 48 Sulphur content: 2700 – 3400 ppmSulphur content: 2700 – 3400 ppm

23. Conclusions DOC was found to be effective in reducing: Smoke opacitySmoke opacity Average 72% COAverage 72% CO Average 36% HCAverage 36% HC DOC was found to have minimal effects on Maximum PowerMaximum Power NOxNOx There may be problems of white smoke

24. Grants for Pre-Euro long diesel vehicle owners for installationGrants for Pre-Euro long diesel vehicle owners for installation Retrofitting Program started December 2002 (non cross-boundary diesels)Retrofitting Program started December 2002 (non cross-boundary diesels) Complete retrofitting of 30,000 vehicles in 18 monthsComplete retrofitting of 30,000 vehicles in 18 months Tender for cross-boundary diesels in progressTender for cross-boundary diesels in progress Installation Program for local Pre-Euro Diesel Vehicles (0.005 % sulphur diesel)