MTBE has long been the best, most widely available oxygenate for gasoline. It increases combustion efficiency resulting in reduced tailpipe emissions of carbon monoxide, volatile organic compounds (VOC), nitrogen oxides (NOX), and particulate. The European Fuel Oxygenates Association (EFOA) states, "Of all the options for replacing lead and aromatics in petrol, MTBE is the most effective from both octane supply and air quality perspectives." In spite of its benefits, MTBE use is being phased out in North America, and popular opinion is that ethanol should replace it because ethanol is renewable. The Canadian government is committing $60 million to the Ethanol Expansion Program to increase ethanol supply. Before everyone jumps on the green bandwagon, it is important to understand why this change is occurring and whether it really is an improvement.
MTBE is being phased out in North America because of groundwater contamination. The problem with MTBE is that it has a turpentine smell and taste at very low concentrations. A person can detect its presence long before it reaches concentrations that could impact health. Ethanol makes a nice replacement because you can't taste or smell it at really low concentrations. Ethanol also biodegrades more quickly than MTBE. The switch to ethanol sounds logical until you ask yourself how MTBE got into the groundwater in the first place. Gasoline is kept in underground storage tanks. As the tanks age they leak and no one knows they are leaking. MTBE is more water soluble than most gasoline components so it travels faster and farther underground. MTBE was the canary that told of a gasoline tank leak. It would signal contamination of a water source before the carcinogenic gasoline components entered the water supply in harmful, but difficult to detect, quantities. Cleaning up gasoline and MTBE that have leaked through a large area of soil is an expensive business. Some areas have responded with regulations requiring better storage systems for gasoline with early leak detection. Others have responded by phasing out the use of MTBE. Enforcement of leak detection and clean-up regulations is lax, and MTBE allows companies to be caught red handed. Instead of focussing on preventing leaks and spills, MTBE was labeled the bad guy and exiled.
Ethanol is a marketer's dream. It rides in wearing the renewable energy cape to save us from the evil MTBE. Everyone is so happy about this new biofuel that nobody asks for the test results. Air quality testing shows that ethanol-reformulated gasoline is an improvement over conventional gasoline; however, it is not as good as MTBE-reformulated gasoline. According to the US EPA-appointed Blue Ribbon Panel on Oxygenates in Gasoline, ethanol increases volatile organic compound emissions contributing to ground level ozone and greenhouse gases. Very little research has been done on ethanol-blended gasoline and groundwater; however, a simple science experiment shows that ethanol increases the solubility of benzene, toluene and xylene (all among the most hazardous components of gasoline) in water by 25 percent. When an underground ethanol-blended gasoline storage tank leaks ethanol, then benzene, toluene, and xylene dissolve in the groundwater and move through the ground faster than the gasoline. For a long time no one will know the groundwater is contaminated because the taste and smell of MTBE are not there. Ethanol is not better than MTBE.
Groundwater contamination and air pollution are awful. All of the work to reformulate gasoline is a bit like a fad diet. It doesn't matter if you eat a sack of potatoes or a side of beef. The fundamental problem is over consumption. A simpler and more effective way to meet Canada's Kyoto targets would be to put that $60 million dollars into public transportation. Gasoline will always be hazardous. Treat it like black gold. Use it carefully and sparingly.
Links:
EFOA
Ethanol Expansion Program News Release
CEPA
Ethanol Woes
EPA
Ethanol Spill
Text of CBC article on Ontario Ethanol Spill:
Maxville's water tested after ethanol spill
Last updated May 3 2005 08:04 AM EDT
CBC News
OTTAWA – People living in Maxville, Ont., are being told not to drink water from their wells after a train car leaked 60,000 litres of ethanol in the area.
Ontario's Environment Ministry made the order on Monday, hours after the leak caused a state of emergency that forced about 200 people from their homes.
Analysts will test well water samples to see if the ethanol contaminated groundwater in the community about 70 kilometres east of Ottawa.
Residents will have to drink bottled water until the test results are back.
That could take several days.
Highly flammable ethanol or combustion alcohol began spilling from a freight car just after 1:45 a.m. ET Monday, forcing evacuation of the Maxville Manor nursing home. The 120 residents took refuge in the banquet hall of the local sportsplex until the all-clear was given.
FROM MAY 2, 2005: Nursing home evacuated after train mishap
The spill also caused Via Rail to cancel its Montreal-Ottawa train service for several hours. Passengers were transported to their destinations by bus instead.
"A freight train from the Ottawa Central Railway sideswiped another car that had [combustion] alcohol in it," said Via Rail Canada spokesperson Seychelle Harding.
Environment Canada, the fire department and the Ontario Provincial Police worked to neutralize the liquid.
OPP spokesperson Joel Dorion said the surrounding area was evacuated "for emergency and precautionary reasons."
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