May 16, 2004

With supplies running low, now is the time to bring in alternative fuel supplies to power the global industrial setup

THE engines of global economy are being run by crude oil. However, as experts have been warning for years, the crude oil reservoirs of the world are fast receding. And there is every possibility that the current levels may prove too insufficient to sustain the increasing demand of these fossil fuels. But these aren’t the only worries. Pollution is yet another headache that needs to be taken care of. That is why, scientists continue to look into ways of developing fuel form, from other organic sources.

Increasing requirement for gasoline has been the driving force in the utilization and depletion of crude petroleum, which is a non-renewable resource. There exist many possible alternative fuels. These alternatives include, but are not limited to, various solar power batteries, alcohols and both liquefied and gaseous natural gas, as well as hydrogen. Nevertheless, drawbacks do exist; the chief drawback being cost of adaptation/implementation, engineering and cost of the fuels themselves.

According to recent findings in the UK, pollutions in vehicle emissions cause atmospheric contamination. The UK government has been urged to double the retail price of petrol and triple the use of public transport by 2005. The findings have raised interest in possible alternative fuels.

These alternatives involve modified internal combustion engines (ICE’s) modified fuel delivery systems, as well as advancements in the field of electrical storage capacities.

There have been much advancement in reducing emissions of gasoline and diesel powered vehicles. Every month we hear of another vehicle running on petroleum fuels, reducing emissions and increasing efficiency.

There is also much advancement in the non-petroleum field, as well as advancements in engines burning gasoline in addition to other fuels such as alcohol and various combustible gasses such as butane, propane, methane.

NATURAL GAS: The alternative has a lot fo promise. Currently there are an estimated one million natural gas vehicles in service, many of them used by natural gas companies, as city busses. Two-hundred and fifty thousand of them are used in Italy alone. A CNG (compressed natural gas) vehicle currently emits less toxic fumes than do gasoline powered vehicles. CNG vehicles are one of the most viable alternative options in the US. In addition, natural gas would be cheaper to purchase than gasoline. The natural gas option is certainty not without its drawbacks. The most significant drawback would be a retrofit of existing vehicles with high pressure tanks. Natural gas needs to be highly compressed and requires a special high-pressure fuelling station. Natural gas fuel is stored on the vehicle in either compressed or liquefied form. CNG autos, store at 16 to 25MPa, and LNG’s (liquefied natural gas vehicles) use pressures of 70 to 210kPa and -160xC.

However, this installation of high pressure fuelling stations is not an unrealistic idea; for example, Italy’s countryside is inundated with high-pressure natural gas fuelling stations for their 250,000 natural gas powered automobiles. Many Italian citizens with CNG vehicles purchase compressors so that they may fuel their vehicles overnight.

LPG (LIQUEFIED PETROLEUM GAS): Propane, or LPG (liquefied petroleum gas) is one other option similar to CNG but with less viability (due to vehicle manufacturers, not for technical reasons). LPG has been used in vehicles since the 1920’s and powers nearly 500,000 vehicles. Conversions to LPG powered vehicles peaked in the early 1980’s due to the gasoline price increase. Benefits include the potential to reduce CO and hydrocarbon emissions, and the fuel is readily available. Propane does, however, have its disadvantages and does not burn as cleanly as CNG. And vehicle collisions that cause leaks can create dangerous situations.

ALCOHOL: The next category of proven viable alternative fuels are alcohols, specifically methanol and ethanol both obtainable from petroleum and natural (biomass) sources, many domestic resources, fossil and renewable resources, natural gas, and coal.

Replacing gasoline with pure methanol or natural gas as fuels could cut ozone levels by as much as 40 per cent. Methanol has certainly proved that it is a desirable fuel whose combustion products are much less harmful to the environment than those of gasoline.

Methanol also has many other positive aspects of use both for the environment and for conversion of current vehicles to run with it as fuel. There have been many arguments against methanol; however, technology has rendered many of these arguments void. Methanol first does have the best potential for widespread use of all of the aforementioned fuels.

A methanol-powered vehicle is ‘fundamentally’ the same as a gasoline powered car. Fuel-flexible vehicles that automatically adjust to operate on alcohol fuels, gasoline or combinations of both are excellent choices for methanol fuel use. Methanol also has a 100 per cent octane rating and results in overall lower emissions and higher energy efficiency than gasoline-fuelled vehicles.

Needless to say, methanol has had its drawbacks, which petroleum companies have fought to make known. The main problems involve aldehyde emissions, cold starting, low energy density, and corrosiveness.

Aldehyde emissions, specifically acetaldehyde, occur with the incomplete combustion of alcohol, which is inevitable in an ICE. In high concentrations, this chemical can cause skin and eye irritations along with serious lung damage. The chemical also has an offensive odour and harms vegetation.

Cold starting is also a drawback to alcohol fuel as alcohol has a higher vaporization temperature than does gasoline and it has a lower calorific value than does gasoline.

ETHANOL: It is very similar to methanol and can be used in all of the same ways as its close cousin, with all of the same drawbacks and advantages. The only differences to discuss are production of ethanol versus methanol, and drawbacks concerning this process.

Brazil has been powering vehicles with ethanol since the seventies. The decision was made to switch from gasoline to ethanol quickly by the government due to rising cost and dependence on gasoline importation. Cost is the major drawback. An ethanol powered vehicle is on average 10 per cent more expensive than a gasoline powered vehicle. Pollution is another problem. Pollution not from the ethanol combustion, but from the ethanol synthesis.

ELECTRIC POWERED VEHICLES: Electric powered vehicles also qualify as alternatively powered vehicles. Three types of vehicles are currently being developed, not including solar powered vehicles. These include 100 per cent electric vehicles, vehicles with range extending generators and regenerative braking devices, and electric, ICE hybrids. Battery powered vehicles have the advantage of zero emissions. This does not necessarily make them environmentally friendly. Power does not come from the air (unless it is solar). Electric must be generated at some point. In the east, 50 per cent of power is produced with coal. Power plants are not located in cities; they are located outside of city limits, which help the local smog situation, but not the environment. In addition, batteries wear out and have to be replaced. They contain heavy metals, which must be recovered so as not to be released to the environment. Electric vehicles also have a limited driving range, are still technically inferior, and are not consumer familiar.

According to a new analysis by the International Energy Agency (IEA), Cars and Climate Change, it is estimated that an electric car operated on coal power could contribute as much as 200 per cent more emissions than a petrol car over its life cycle.

HYDROGEN: This is the last alternative fuel, warranting significant attention and it will quite possibly be the fuel of the future one century from now, if no new methods of propulsion and/or power are discovered till then. Hydrogen has many advantages and disadvantages most of which seem solvable by existing technology. The most obvious advantages are that it is by far the most abundant element in the Universe, it packs more energy per unit of weight than any other fuel, and it burns cleanly.

Leading car companies have been researching the hydrogen alternative for the past decade. Hydrogen fuel cells are the most popular area of research at the moment in an attempt to deal with the dangerous hydrogen storage problem. Cells convert a fuel’s energy directly into electricity, without combustion and without moving parts. The main feature of the fuel-cell system are a fuel supply, an oxidant (typically oxygen from the air), and two electrodes with an electrolyte sandwiched between them. A type of fuel cell that promises to be both compact and inexpensive enough for a practical automobile is the proton-exchange-membrane fuel cell.

Aside from cost, the features of the fuel-cell car of greatest interest to the consumer are fuel economy, performance, refuelling time and range between refuelling. Fuel-cell cars operated directly on hydrogen would be three times as energy-efficient as comparable gasoline cars. They would also be much quieter and require less maintenance than ICE’s.

Ammonia can also be used as a hydrogen carrier, spawning ammonia fuelled vehicles. Ammonia also has the advantage of being carbon free and has a substantial infrastructure. Engineers at Johns Hopkins are researching the concept.

Automobile makers in Germany have been experimenting with hydrogen-burning cars for two decades, and it will be years before they come to market. Burning it mainly creates steam, most of which condenses and trickles out the tail pipe with only a few nitrous oxides left over. Nevertheless, the main problem is how to produce and distribute hydrogen. So far, prototypes are using gasoline engines that have been modified for hydrogen, although not yet optimized. The key question is, how the fuel should be stored?

Most of the problems associated with the use of fossil fuels fall into two general categories: availability and pollution. The availability problems stems form the fact tat fossil fuels are not renewable. All the coal, oil and natural gas that will ever be available to humans are already formed. To reach these resources, people have to keep looking deeper beneath Earth’s surface an exploring farther into natural areas.

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