By Jim Kerr
The automobile has been blamed for pollution for decades. In retrospect, vehicles did produce a lot of emissions, but stricter environmental regulations, improved computer controls and the quest for better fuel economy have reduced most of the tail pipe emissions. Hydrocarbons from unburned fuel and oil, Carbon Monoxide (a product of rich combustion mixtures) and Oxides of Nitrogen are almost non-existent out the tailpipe due to the combinations of engine design, fuel controls and post-combustion exhaust gas treatment in catalytic converters. That leaves only one major emission from the tailpipe that needs to be controlled: CO2.
CO2, Carbon Dioxide, is another byproduct of combustion. When an engine burns a fuel such as gasoline, it uses up the Hydrogen but leaves the Carbon behind. This Carbon combines with Oxygen to form CO2, and that gas is one of the main green house gas (GHG) emissions. Manufacturing, home heating and even lawn mowers and barbecues all contribute to the total green house gases, while Light Duty vehicles contribute only 12.5% of Canada's total GHG emissions. Even so, auto manufacturers are continually researching and developing new products to reduce CO2 emissions.
Improving fuel efficiency is an effective method of reducing GHG's. Use less fuel and less CO2 is produced. Direct fuel injection, smaller engine displacements, cylinder deactivation under light loads and multi-speed automatic transmissions are all helping reduce fuel consumption. Drivers can help too by keeping tires properly inflated, engines in good operating condition, avoiding aggressive driving habits and combining several short trip errands into one longer one.
Another method of reducing GHG's is to use ethanol as an alternative fuel. Because ethanol contains a lower percentage of Carbon compared to Hydrogen, there is less CO2 produced when it is burned. A vehicle running on E85 (85% ethanol/15% gasoline) produces about 50% less GHG's than the same vehicle operating on gasoline. There is still controversy over whether it uses more energy to produce Ethanol than can be derived from it, but it is a renewable resource that does reduce GHG's. Improved methods of producing ethanol are being developed and there are already millions of vehicles on the road capable of running on E85. Much of the gasoline sold across the country already contains small amounts of ethanol (up to 10%). As alcohol production increases, we should see E85 pumps at some filling stations.
Hybrid vehicles reduce GHG's by reducing fuel consumption and on some models by eliminating the combustion engine operation at times. Hybrids are seen as a transition vehicle, one that will eventually replaced by pure electrical power or fuel cell vehicles, but hybrids will be with us well into the future and are an effective method of reducing fuel consumption and emissions right now.
Plug-in electric vehicles will form part of the solution to reducing GHG's. These vehicles can be charged up overnight or at the workplace and perform well for short trip commuting. Some plug-in electric vehicles will also contain onboard generators that allow the vehicle to travel further. The vehicle itself doesn't produce GHG's when operating on electricity, but that electricity has to be produced somewhere. Coal and oil-fired electrical generating stations will still produce some GHG's but have the advantage of controlling smokestack emissions under a closed and stationary industrial environment. Of course, if that electricity is generated by wind or water power, it can be considered essentially green.
The final entry - as we see it now - will be Hydrogen powered fuel cell vehicles. Using a fuel that contains no Carbon, fuel cell vehicles have the technology to produce only water vapour out the tailpipe. Look to Vancouver and Whistler, B.C. as destinations on the "Hydrogen highway" planned to run up the West Coast during the 2010 winter Olympic Games. That's where I predict we will be exposed to a variety of Hydrogen-fueled vehicles for the first time. Some manufacturers are already predicating they will have production fuel cell vehicles for sale by 2012. That isn't very far away!
Future roadways will have a much different blend of vehicle types on them than what we have now. Gasoline-powered vehicles will still dominate for the foreseeable future, but rising fuel costs and environmental concerns will propel new technologies in our future. What will power your next vehicle?
Jim Kerr is a master automotive mechanic and teaches automotive technology. He has been writing automotive articles for fifteen years for newspapers and magazines in Canada and the United States, and is a member of the Automotive Journalist's Association of Canada (AJAC).
