Recent test results show that gasoline blended with methanol or acetone may be the cause of a series of mysterious fires that has destroyed about 50 motorbikes nationwide since last year, experts said at a conference in Hanoi yesterday.
According to the tests performed on old Honda Dream II motorbikes in well-ventilated locations without draughts, when the bikes were fuelled with gasoline containing 15 percent methanol and operated for various periods of time from 10 to 60 minutes, the heat of the engines, the outside surface of the cylinders and the exhaust pipes were higher than when they were fueled with RON92 standard gasoline.
The heat difference was 0.8 to 10 degrees Celsius, the Hanoi Standards, Metrology and Quality Sub-department, which carried out the tests, said.
Vu Huy Thanh, an expert from the Military Academy, said methanol and acetone could also erode the gasoline tubes and thereby cause gas leaks. They can also make the gasoline’s vapor pressure to increase and catch fire, since the combustion thresholds of the two fuels are very low.
According to the test results and related studies, the quality of gasoline is the possible leading cause of the bike fires, said Dr Hoang Manh Hung, deputy head of the Criminal Science Institute under the Ministry of Public Security.
Methanol is produced en mass at cheap cost in China, so fraudulent traders can add it to gasoline to get more profit illegally, Hung said.
Acetone can also be blended with gasoline for the same purpose, he added.
Both methanol and acetone can easily evaporate so when a fire has occurred, investigators will find it difficult to obtain their traces at the fire site, he said.
There has been a suggestion that gasoline tainted with ethanol or methanol in near-empty fuel tanks coupled with the cold weather may cause fires, but the theory was not very convincing.
He suggested the Hanoi Department of Science and Technology to establish a “task force” including scientists to identify the cause of the fire.
Dr Vu Thi Thu Ha, head of the petrochemical refinery laboratory at the Institute of Industrial Chemistry, said that methanol could cause damage to engines, gasoline tubes and then cause a gas leak, which may trigger a fire.
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