On August 26, the first “green” bus route (Saigon – Binh Tay) running on compressed natural gas was inaugurated. This marks a turning point for public passenger transport toward sustainability and environmental friendliness.
A clean fuel
According to Dr. Nguyễn Hữu Hường, Head of the Transportation Engineering Department, Ho Chi Minh City University of Technology, compressed natural gas (CNG) is a clean fuel that, when burned, does not emit toxic gases such as CO, NO, or SOx. Therefore, it does not negatively affect human health or the environment. In addition, since it is compressed gas, in case of leakage during transportation, CNG released into the atmosphere is not harmful to the environment like gasoline, oil, or other liquid fuels.
The main component of CNG is methane (CH₄), extracted from natural gas fields, then processed and compressed at high pressure (250 atm) for storage. Because it contains no benzene or aromatic hydrocarbons, burning this fuel releases fewer toxic gases and produces no particulate matter.
CNG also offers several other advantages, such as being 10–30% cheaper than other fuels. Compared with FO, DO, and LPG, using CNG in production reduces fuel costs by 10–15%, and in transport by 30–40%. Thus, using this fuel helps minimize fuel expenses.
According to some scientists’ calculations, the price of 1 ton of CNG is about USD 318, equivalent to only 53.5% of gasoline and 42% of diesel prices. Therefore, each bus running on CNG can save about USD 8,308 in fuel annually compared to diesel.
Another advantage is that this fuel can be used in both gasoline and diesel engines. CNG burns completely, preventing deposits in combustion equipment and carburetors, thereby improving efficiency, extending maintenance intervals, and lengthening machinery lifespan.
Not ready for mass adoption yet
Despite its many advantages, the widespread adoption of CNG in transportation cannot happen overnight and requires time and preparation. “The first condition for large-scale deployment is adequate infrastructure. Specifically, more pipelines and refueling stations must be built,” Mr. Hường said.
Currently, there are only two CNG refueling stations in the South: one in Phú Mỹ (Đồng Nai) and one near Tân Sơn Nhất Airport in Ho Chi Minh City.
CNG technology has only been introduced in Vietnam since 2008. Due to its technical characteristics, CNG supply has so far been limited to some southern regions, and is not yet widely applied. Previously, this fuel was mainly used in large industrial facilities such as Thủ Đức Steel, Biên Hòa Steel, Pomina Steel, Bạch Thanh Ceramics, and some food companies.
More than three years ago, Ho Chi Minh City began considering CNG for public transport, with two CNG buses introduced in 2009–2010. However, due to refueling challenges, the “green bus” project has only now been officially implemented.
Currently, each CNG bus can travel less than 300 km per full tank before having to refuel at one of the two available stations. Therefore, although cars and motorbikes can technically run on CNG after installing a conversion kit, it will take more time before CNG can be applied widely in transportation.
At a recent seminar on energy efficiency in transportation, Mr. Lê Trung Tính from the Ho Chi Minh City Department of Transport also emphasized that using CNG helps save fuel and minimize environmental pollution. However, achieving this requires long-term preparation. For now, practical feedback should be gathered after the “green bus” route begins operation.
(Dat Viet 6/9)
