2002年-世界发展银行全球_Bangladesh___Reducing_Emissions_from_Baby-Taxis_in_Dhaka_76页_511kb

Summary of "Reducing Emissions from Baby-Taxis in Dhaka"

Core Content

This document outlines a program aimed at reducing emissions from baby-taxis in Dhaka, Bangladesh, which are a major contributor to air pollution in the city. The initiative, supported by the Joint UNDP/World Bank Energy Sector Management Assistance Programme (ESMAP), includes mechanical training, an auto clinic, and efforts to improve lubricant and gasoline quality standards.

Main Points

• Air Pollution in Dhaka:
  Dhaka, the capital of Bangladesh, has experienced rapid population growth (6.4% annually from 1992 to 1999) and vehicle population growth (8.9% annually). Air quality has deteriorated significantly, with much of the pollution attributed to the transport sector.

  • The most serious pollutants are respirable and fine particulate matter (PM10 and PM2.5), which are 2–3 times higher than standards in the US and other countries.
  • PM10 and PM2.5 concentrations vary with rainfall, being highest during low rainfall seasons and lowest during high rainfall seasons.
  • PM10 is responsible for approximately 20% of total particulate matter, while PM2.5 contributes about 40%.
  • High PM10 concentrations are linked to health impacts, including 6,000 premature deaths and 50,000 cases of chronic bronchitis annually.

• Vehicular Emissions:

  • Vehicular emissions are a major source of PM10 and PM2.5 in Dhaka.
  • Baby-taxis, which are three-wheelers, account for over one-third of all vehicle kilometers traveled, despite being only one-tenth of the total kilometers.
  • Two-stroke engines, commonly used in baby-taxis, are more prone to high particulate and hydrocarbon emissions due to scavenging losses and the use of incorrect lubricants.

• Lubricant and Gasoline Quality:

  • Two grades of gasoline are available in Bangladesh: RON 80 and RON 95.
  • The minimum required octane number for three-wheelers is 87 RON, while modern passenger cars require 91–92 RON.
  • Straight mineral oil, which is not designed for use in vehicles, is commonly used by baby-taxi drivers and leads to high emissions.
  • The use of mineral-oil-based 2T oil and low-smoke synthetic lubricants can significantly reduce emissions.

• Emission Testing and Results:

  • Three baby-taxis were tested for particulate matter, hydrocarbons, CO, and NOx.
  • Emissions were found to be most strongly affected by the mechanical condition of the vehicle and the type and quantity of lubricant used.
  • Switching from straight mineral oil to 2T oil reduced particulate emissions, but low-smoke lubricants had no additional effect.
  • Reducing lubricant concentration from 8% to 3% significantly lowered emissions.
  • Opacity measurements showed a reasonable correlation with particulate emissions above 1 g/km.
  • An oxidation catalyst was found to reduce particulate emissions when they were high.

• Mechanics Training and Auto Clinic:

  • Over 400 mechanics were trained on proper vehicle servicing and lubricant use.
  • A free auto clinic was held for 1,000 drivers, offering vehicle inspections, minor servicing, emissions testing, and health checks.
  • Many drivers were found to be using excessive amounts of straight mineral oil, leading to high emissions.
  • The clinic helped raise awareness about the health and environmental impacts of incorrect lubricant use.

• Regulatory Change and Consensus-Building:

  • A seminar was held in 2000 to build consensus on improving lubricant and gasoline quality.
  • It recommended banning the sale of straight mineral oil and setting API TC or JASO FB as the minimum standard for 2T oil.
  • In January 2001, the Bangladesh Petroleum Corporation (BPC) implemented the ban on straight mineral oil for two-stroke engines.
  • The sale of 2T oil in 60 ml sachets was encouraged to reduce excess lubricant use.
  • A follow-up auto clinic was held in 2001–2002 to assess the impact of these measures.

Key Information

• Impact of Lubricant Use:

  • Excessive use of straight mineral oil significantly increases particulate emissions.
  • Correct lubricant use (e.g., 2T oil) and reduced quantity (3%) can lower emissions.
  • Mechanical condition and servicing also play a major role in emission levels.

• Health and Environmental Impacts:

  • Many drivers suffer from health issues due to exposure to high emissions.
  • Emissions from baby-taxis contribute heavily to air pollution, particularly PM10 and PM2.5.
  • Poor vehicle maintenance and ad hoc repairs exacerbate emissions.

• Program Outcomes:

  • The program successfully raised awareness among drivers and mechanics about emission reduction.
  • Statistical analysis showed a strong correlation between lubricant quantity and emissions.
  • The ban on straight mineral oil and promotion of 2T oil are critical steps in reducing emissions.

• Challenges and Lessons Learned:

  • Measurement errors were common due to equipment handling, poor reproducibility, and exhaust leakage.
  • Drivers and mechanics sometimes circumvent emission tests by reducing lubricant use.
  • Unidentified factors, such as air filter and spark plug conditions, also significantly affect emissions.
  • More work is needed to identify and address these factors to improve emission control.

Conclusion

The "Reducing Emissions from Baby-Taxis in Dhaka" program highlights the importance of improving lubricant and gasoline quality, providing mechanical training, and implementing regulatory changes to combat air pollution. These measures have shown promising results in reducing emissions, but continued enforcement and public education are essential for long-term success.