The two-stroke solution

The roar of a chainsaw engine can shatter the silence of a peaceful day at the cottage, but in Karachi and Lahore, Pakistan, thousands of these two-stroke engines operate at once—powering the main mode of transportation known as the auto-rickshaw.

Kaleidoscopic paint jobs make it difficult to miss the huge fleet of auto rickshaws that operate as taxi cabs in Pakistan's cities. Unfortunately, the tiny vehicles are a major source of both air and noise pollution.

The most accessible and least expensive form of transportation in many major cities in Asia, the three-wheeled auto-rickshaw—combined with motorcycles and other vehicles that operate on two-stroke engines—has become a major environmental problem. Two-stroke engines operate in a similar manner to the four-stroke versions found in most automobiles; however, fuel is not burned as completely or as efficiently. The result is a noisy engine that emits high volumes of carbon dioxide and other pollutants.

Add the still-prevalent use of leaded fuel in Pakistan and the result is a pollution problem so great that one province in Pakistan has stopped issuing new permits for auto-rickshaws. Treating this now as an environmental priority, the Government of Pakistan has made a commitment to establish natural gas fueling centres in all major cities in the hopes of promoting the cleaner-burning fuel as an alternative to leaded gasoline.

For three years, researchers at Environment Canada's Environmental Technology Centre have been working with Yugo-Tech, a Mississauga-based company, to develop a technology that will allow two-stroke engines to run on cleaner-burning compressed natural gas instead of regular leaded gas. Already successfully tested at the Centre's labs, this technology will now be field tested in Lahore, Karachi and Quetta—a smoke-filled city in Pakistan once known for its clean air.

The demonstration project, which is funded under Canada's Climate Change Action Fund, will involve converting 35 auto-rickshaws, creating conversion and emission test centres in Quetta, and providing training and education for rickshaw drivers on the importance of using cleaner fuel. Raja Group in Pakistan, a manufacturer of the auto-rickshaw, will collaborate in converting the engines.

Over the two years it is scheduled to run, the demonstration project will result in a reduction of 76.5 tonnes of carbon dioxide, a greenhouse gas that contributes to climate change. Based on estimates that the typical rickshaw driver logs 200 kilometres a day, 360 days a year, converting all new and in-use vehicles in Pakistan to compressed natural gas would reduce annual carbon dioxide emissions by 21 per cent, or 370,000 tonnes. In addition, the conversion would greatly reduce emissions of lead, benzene and other pollutants that affect the health and environment of city dwellers.

This demonstration project is intended to prove the viability of this Canadian-made technology and simplify its transfer to other Asian countries—making it possible for people in these countries to breathe easier, and contributing to global efforts to minimize the human impact on climate change.

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