Alternative fuels and propulsion systems

3 Alternative fuels and propulsion systems 21.3.1 Getting on with liquid fuels 

Despite the considerable growth of the Canadian oil sands industry in recent years, there are still several difficulties that could impede the future development of this industry for instance, the heavy reliance on natural gas and water, which are necessary for both the extraction of bitumen from oil sands and its upgrading to synthetic oil, as well as the associated high emissions of C02. For nearly a century, the oil shale in the western United States has been considered a possible substitute source for conventional crude oil. If a technology can be developed to recover oil 

The alternative fuels and drive systems available only seem to be viable on the mass market, if the oil price stays above 60 to 70 /bbl for a sustained period. Oil prices peaked above 140 /bbl in summer 2008 and many experts believe that stable oil prices over 100 /bbl could be reached in the next one or two decades. The higher the market prices of fossil fuels, the more competitive low-carbon alternatives will become The principal choice here is between biofuels, electricity and hydrogen, provided that they are produced either from low/zero-carbon feedstock or that the C02 generated during their production is captured and stored. But higher priced conventional oil resources, on the other hand, can also be replaced by high-carbon alternatives such as oil sands, oil shale or synthetic fuels from coal and gas. 

Neither the use of hydrogen as an energy vector nor the vision of a hydrogen economy is new. Until the 1960s, hydrogen was used in many countries in the form 

Local air emissions, responsible for particulate matter, ozone and acid rain, as well as noise, could be significantly reduced by the introduction of hydrogen fuel-cell vehicles. Emissions of NOx, S02 and particulates can be reduced by 70% to 80% compared to a case without hydrogen. Especially in densely populated areas this is one major benefit of hydrogen, which is often underestimated. As there are a growing 

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An engine concept that utilizes a more efficient thermodynamic cycle that consumes less fuel, and is simple and capable of operation at both subsonic as well as supersonic speeds, would be an attractive alternative for future propulsion systems. Pulse detonation engines (PDE), in principle, can provide higher efficiency [9], and better performance over a wide range of operating conditions, with fewer moving parts. 

Other applications include car rental, shared-car ownership or public transport -these transfer the risk of ownership of a vehicle with a new propulsion system away from the private person. Once established, these niche applications can help to raise the profile of the new technology, increase public acceptance and provide opportunities for feedback that can lead to technology improvement. Once their commercial viability in the niche market has been proved, the vehicles can expand into wider markets. Particularly suitable for introducing hydrogen (or other alternative fuels) are buses, fleet vehicles and rental vehicles (Smith, 2001). 

Automotive-Mobile Applications. Hydrogen storage and delivery systems coupled to fuel cells have the potential to provide a propulsion alternative to batteries. This approach... 

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