Thursday, March 26, 2009

CNG clears Dhaka's air

From: Christian Science Monitor:

Muhammad Mokles plies the busy Dhaka streets in his green-painted auto-rickshaw. But when it’s time to refuel, he skips the traditional gas pump and goes straight to a compressed natural gas (CNG) station. It’s not only much cheaper than gasoline but it’s also much better for the environment.

Here in Bangladesh’s capital, the streets overflow with thousands of noisy honking vehicles, pedestrians, beggar children, food vendors, and stray animals. Millions of people need to move around this crowded and sprawling metropolis of 11 million each day, and many do so in an auto-rickshaw that can dart around larger or slower forms of transport.

Auto-rickshaws are cheap, convenient, and in use all over Asia. Up until recently, the ones here in Bangladesh all were powered by two-stroke gasoline engines; (also found in many motorcycles and larger three-wheelers), which alone were responsible for 60 percent of all vehicle-related pollution here, according to the Asian Development Bank.

That’s because two-stroke engines don’t use gasoline efficiently. Up to 40 percent of the fuel emerges from the tailpipe unburned, as smoke and soot. Burning gasoline and diesel produces carbon dioxide, carbon monoxide, sulfur dioxide, nitrogen oxides, hydrocarbons, and soot that warm the climate, threaten human health, and pollute water, air, and soil. In Bangladesh, soot levels in 1997 were found to be 10 times higher than World Health Organization guidelines permit. This resulted in an additional 15,000 deaths and millions more illnesses, according to World Bank estimates.

Spurred by these findings, the government of Bangladesh took action in the mid-1990s to clear the air. Leaded gasoline, which can pollute groundwater, was banned in 1999. Strict regulations were placed on the sulfur content in diesel fuel. An import ban was placed on two-stroke three-wheelers to help phase out older-model auto-rickshaws, and a widespread CNG program was launched.

Compressed natural gas is “known to be a fuel with lower air pollutant emissions,” says Sameer Akbar, senior environmental specialist at the World Bank. Natural gas is 95 percent methane and releases significantly fewer tailpipe emissions than does gasoline or diesel fuel.
“The combustion of CNG does release more methane than gasoline [does], but those emissions are minor compared with the emissions released from gasoline combustion,” says Andrew Burnham of the US Department of Energy’s Argonne (Ill.) National Lab. Unburned methane itself is a powerful greenhouse gas.

Cheap fuel, expensive conversion
CNG programs work well in countries with abundant natural gas reserves like Bangladesh. Italy started using CNG in the 1930s and was the first country to put a viable program in place. Other countries now using CNG successfully include India, Pakistan, Iran, Argentina, and Brazil.
CNG has been around in Bangladesh since 1982. “At that time it wasn’t an issue of environmental concerns,” says Iftikar “Sabu” Hussain, CEO of CNG Distribution Company.

Compressed natural gas was initially introduced as a domestic fuel alternative to expensive imports, but did not catch on then because converting to the cheaper fuel involved an expensive engine conversion. The increasing cost of imported petroleum, however, plus a rising concern for the environment made CNG a stronger choice in the early 2000s.

CNG began to succeed in Bangladesh at this time because of the push for a cleaner environment plus the availability of millions of dollars in loans from international agencies to encourage a long-term program.

In 2000, the United Nations Devel­op­ment Program (UNDP) created a training scheme with Rupantarita Prakritik Gas Company Ltd to expand the alternative-fuel program (cost: $1.2 million). At about the same time the World Bank created the Air Quality Management Project (cost: $5 million) to help reduce vehicle emissions as well as introduce air-quality monitoring.
International help puts CNG in placeAdditional CNG projects to strengthen infrastructure were put in place by the Asian Development Bank in 2002 ($113 million) and the UNDP in 2004 ($1.5 million). These initiatives involved extending natural gas pipelines and more CNG technology development (including training engineers and mechanics to do CNG conversions and ­filling-station installations).

The price of CNG also dropped substantially. CNG now sells for 16 taka per liter, the equivalent of about 87 cents a gallon. Gasoline, on the other hand, is currently $4.33 per gallon, while diesel is $2.38. CNG represents a drastic savings, but gives about the same miles per gallon as gas for the auto-rickshaws. There are some 300 CNG filling stations around the country and almost 200,000 of the 1 million vehicles on the road are now CNG-fueled, according to the Bangladesh Road Transport Authority.

“I converted to save taka and the environment, but the main factor is for the environment,” says a truck driver at a CNG filling station who says he used to spend 2,000 taka per day (about $30) on gas, but now spends only one-quarter of that on CNG.

Payback is less than one year
Although conversions are relatively costly at around $800 per vehicle (the average per capita yearly income here is $600), the cheaper price of CNG relative to gas and diesel makes for a rapid payback. According to M. Khaliquzzaman, an environmental consultant at the World Bank, those who travel about 60 miles per day can break even on the cost of the conversion in less than a year.

Two-stroke engines were banned completely in 2003; all must be cleaner-burning four-stroke or CNG-fueled engines now.

When this happened, “there was a 30 to 40 percent drop in particulate pollution in Dhaka,” says the World Bank’s Mr. Akbar. In addition, an estimated $25 million in health costs are avoided each year by the cleaner environment, says Quamrul Islam Chowdhury, chairman of Forum of Environmental Journalists of Bangladesh.

The name CNG has become synonymous with the auto-rickshaws, which are painted green and referred to simply as CNGs. More than 14,000 of them now crisscross the streets of Dhaka. So even though Muhammad Mokles says that he’s not happy to be driving for a living (a job he’s done for 30 years), he is still happy to be helping the environment.

Some caution that, for all the good news, CNG isn’t the perfect solution. The tanks are bulky. Prices doubled last year. Reports also point to shoddy conversion stations springing up and vehicle traffic expanding 10 percent every year here.

“That positive impact on the overall quality of environment in Dhaka city has been eroded especially by other modes of transport,” says Mr. Chowdhury. “Especially old buses; those are still emitting CO2.

1 comment:

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