The next morning, as I turned into the spacious and immaculately kept grounds of a complex of low-rise buildings in Clinton Township, N.J., I might have been entering a rural estate in England. This pastoral site was, however, the headquarters of ExxonMobil Research and Engineering Company (EMRE), a subsidiary of Exxon Mobil Corporation, the world’s largest integrated oil company and the majority shareholder of Imperial Oil. The affiliation allows Imperial to benefit from all research carried out by EMRE. The value of this is enormous, for the research focuses on a variety of areas central to our lives, from improvements to fuels, lubricants and refining processes to advanced "pure" research into future energy sources and how they might be used.

The question that led me to the EMRE laboratory was one that intrigues many of us as we move into a new century: what will the car of the future be like? More specifically, from what kind of engine and from what fuel or other energy source will it derive its motive power?

Since the first "motor car" was built by the German inventor Karl Benz in 1885, automobiles have been powered almost exclusively by the internal-combustion engine. A vaporous fuel is inducted into a cylinder, compressed by a piston and ignited by an electric spark. The resulting explosion drives the piston down the cylinder and rotates a crankshaft, which then returns the piston to the top of the cylinder, expelling the burned fuel. More fuel is inducted into the cylinder during the piston’s downstroke and compressed on the upstroke, and the cycle is repeated.

From its inception, the fuel for the internal-combustion engine in automobiles has almost exclusively been either gasoline or its first cousin, diesel fuel.

Is that situation changing? As we move into the 21st century, will the traditional gasoline-fuelled internal-combustion engine be replaced to a significant degree? As governments, motivated by environmental concerns, set increasingly stringent rules regarding emissions, automobile manufacturers around the world are striving to design vehicles that use dramatically less gasoline or diesel fuel than the conventional engine, or none at all.

It might surprise some to know that helping automakers find ways of powering vehicles with fewer emissions but without sacrificing efficiency is a major goal of EMRE researchers, my host Gilbert (Gib) Jersey tells me in his office at the Clinton facility. The soft-spoken Jersey, who earned a master’s degree in meteorology, is a member of EMRE’s strategic planning group, which tries to foresee future energy and technology needs and how they might be met. He is quick to point out that gasoline became the dominant transportation fuel for sound reasons: "Gasoline is plentiful, readily available, relatively cheap, easy to transport and store, and safe compared with other liquid fuels and gases. It does not require pressurized or otherwise special containers or tanks, evaporates quickly when spilled, is easily detectable by its odour, doesn’t dissolve readily in water or corrode metals." But most of all, he says, gasoline is a highly efficient fuel, containing more latent energy by volume than the alternatives (40 percent more than ethanol, for example), which translates into fuel economy for the consumer.

"To overtake gasoline on a large scale," Jersey adds, "an alternative fuel would need to match most, if not all, of these properties while remaining economically attractive. That’s a tall order, especially since gasoline is constantly being reformulated to reduce emissions."

Energetic, animated and articulate, Jack Johnston, who holds a PhD in polymer science and is head of advanced fuels and engine research at EMRE, agrees that it would be premature to write off the gasoline-powered internal- combustion engine just yet. "Refinements to conventional engines and fuels, along with improvements to pollution-control technologies in automobiles, have dramatically improved both fuel economy and exhaust emissions over the last 20 years or so, to the point where a new car today produces about one percent of the emissions per kilometre driven that a new car of the mid-1970s did," says Johnston. "And there’s considerably more improvement to come."

So-called "hybrid" or "dual-drive" power systems, now available in two vehicles being sold in Canada and the United States, represent a significant breakthrough, Johnston tells me. The hybrid car utilizes two power sources, a small internal-combustion engine and a battery. The wheels are driven by an electric motor or the engine, or both at once, with a computerized controller choosing which method will be used at a particular moment. At low speeds, the hybrid’s battery is the primary source of power (the engine drives a generator to keep the battery charged). When extra power is needed, for acceleration or heavy loads, the computer diverts power from the engine to help drive the wheels. As a final touch, the system also captures kinetic energy generated during braking to help recharge the battery.

"Hybrid vehicles," says Johnston, "dramatically increase fuel efficiency and reduce emissions, with no loss of performance or driving range. The two models currently available with the hybrid system are the compact Honda Insight and the four-door Toyota Prius sedan. In the city, the Toyota Prius achieves 100 kilometres per 4.5 litres, making it up to twice as efficient as similar-sized conventional vehicles – with only about 10 percent of the tailpipe emissions."

As for drivability, Johnston says, "I’ve driven the Toyota Prius, and its performance is comparable to a conventional car. The only difference is that when it’s running on the electric motor or at a stop, it’s very quiet."

On a tour of the EMRE laboratories (rooms packed almost to overflowing with apparatus, control panels and monitoring screens for tracking, in millionths of seconds, how fuels flow, ignite and release their energy), Johnston describes another advancement with the potential for significantly increasing fuel economy and thereby reducing overall emissions: "direct injection," which is essentially a new way of mixing air with gasoline or diesel fuel vapour in an internal-combustion engine.

"Traditionally," Johnston says, "air and gasoline have been mixed in a carburetor or intake system to produce a fine mist that is inducted into the combustion chamber just before ignition. Using a high-pressure injector, the new system injects fuel directly into the combustion chamber, where it mixes with air drawn in through the intake ports. This results in the ability to use a ‘leaner’ [less fuel, more air] mixture that, when combined with specially designed pistons and combustion chambers, can generate the power of a traditional system while burning 10 to 25 percent less fuel."

Direct injection vehicles have been widely marketed in Japan and Europe, and in the United States a joint partnership of automakers and the federal government has identified direct injection as the leading engine technology for use in high-efficiency hybrid vehicle designs.

The technology that has most captured the attention of environmentalists, the media, governments and the public alike, however, is the so-called electric fuel-cell vehicle, which holds the promise of "zero-emitting" automobiles.

The fuel-cell vehicle is an electric car with a difference. In the past, attempts to build electric cars have foundered when confronted with the problem of how to generate and store sufficient electricity within the vehicle to provide an acceptable combination of power, performance and driving range. On-board batteries need frequent recharging, which not only is inconvenient to the motorist but also requires considerable electricity. Since the electricity utility may burn natural gas, oil or even coal, the environmental benefits of the zero-emitting vehicle may be negated. Moreover, battery performance is strongly diminished by cold conditions, a major drawback for Canadians.

The advantage of fuel-cell technology is that it does not require special batteries to store electricity. Instead, it generates an electrical current directly through an electrolytic process that uses hydrogen as a fuel. Explains Johnston: "Fuel-cell technology uses a chemical reaction to separate hydrogen atoms into protons and electrons. The protons pass through a membrane while the electrons generate an electrical current that drives a motor. The electrons then recombine with hydrogen ions and oxygen in the air to form water, which is the only emission from the process.

Fuel cells are not exactly new technology (they have been used in spacecraft since the 1960s), but their use in automobiles was hampered by their size and weight and the fact that the chemical reaction requires the use of platinum, a precious metal, as a catalyst. As recently as the early 1990s, a stack of fuel cells that could generate enough power to drive a car would have taken up as much space as a minivan and would have required $30,000 (U.S.) worth of platinum to function. For these reasons, early fuel-cell powered vehicles were buses, which had room to accommodate the hardware.

Today, mainly as a result of refinements introduced by Vancouver-based Ballard Power Systems, a stack of fuel cells can be accommodated in a normal-sized passenger car and requires only about $150 (U.S.) worth of platinum. Consequently, a number of auto manufacturers have built prototypes and say they will market fuel-cell cars by 2005. In fact, according to ExxonMobil sources, auto manufacturers representing more than 50 percent of current vehicle sales have active programs to develop and market fuel-cell vehicles.

That is not to say that fuel-cell powered vehicles will soon be crowding conventional automobiles out of car dealer showrooms and off the roads. Some significant challenges remain before this much heralded "car of the future" becomes the car of today.

One, Jersey tells me, is cost. "Although the cost of manufacturing fuel-cell engines has come down dramatically in recent years, they still cost about 10 times as much to make as conventional, internal- combustion engines," he says. "We believe that fuel-cell technologies will evolve and eventually become commercially significant for vehicle power trains because of their inherent efficiency and environmental benefits, but it will take some time."

A more complicated challenge to both automakers and petroleum companies, Jersey says, is deciding where the hydrogen that fuel cells need – in the huge volumes that will be required if fuel-cell vehicles are to supplant traditional, gasoline-powered automobiles to any significant degree – will come from. "Finding the right source of hydrogen for fuel-cell vehicles," he says, "will likely be the most critical factor in determining the success of these vehicles in the marketplace."

This requires some explanation. Fuel cells run on hydrogen and emit only water vapour. Although hydrogen is one of the most plentiful elements on earth, it occurs only in combination with another element, notably with oxygen in water and with carbon in many hydrocarbon compounds, including gasoline, natural gas, methanol and ethanol. As Professor Jim Wallace, chair of the department of mechanical and industrial engineering at the University of Toronto, explains, "To be used in a fuel cell, hydrogen must first be separated from the other elements it’s bonded with in nature. That could be difficult and expensive to do on a large scale."

One option is to "crack" hydrogen from water using electricity, but this is a relatively inefficient and energy-intensive process. A more practical and cost-effective alternative is to extract hydrogen from one of the readily available hydrocarbons – probably natural gas, gasoline or methanol – through a process used in petroleum refining known as "reforming." Yet this, in turn, raises another question of whether to extract hydrogen somewhere in the supply system so that the vehicle carries pure hydrogen, or build a small reformer into the vehicle itself. In the latter case, drivers would simply fill the fuel tank and drive away, as they do today.

Johnston and his colleagues at EMRE believe that on-board reforming is the safest and most practical option. "Pure hydrogen, whether in liquid or compressed-gas form, is highly volatile – in fact, explosive," Johnston says. "The less it has to be handled and stored, the lower the risk of explosion. Generating the hydrogen as you need it significantly decreases the risk."

Moreover, the costs of building networks of facilities to transport, store and dispense pure hydrogen would be enormous. Studies by the U.S. Department of Energy and consultants Arthur D. Little estimate that infrastructure to produce and distribute enough hydrogen to meet just 10 percent of today’s U.S. road fuel consumption would cost about $100 billion (U.S.).

Using gasoline as the primary source of hydrogen would appear to make the most economic and practical sense. First, the age-old advantages of gasoline – plentiful supply, relatively low price, ease and safety of handling and high energy density – continue to apply. And second, a highly efficient production and distribution infrastructure is already in place around the world.

The essential requirement for using gasoline in fuel-cell vehicles is, of course, a reliable, economical and lightweight on-board reformer, and it’s this challenge that Johnston and his research team at EMRE have tackled head-on. In collaboration with automotive researchers at General Motors Corporation and Toyota Motor Corporation, the EMRE team is working to design and build an on-board reformer that, combined with the fuel cell, will take about the same amount of space as a conventional engine. The reformer extracts hydrogen from gasoline, emits only water and carbon dioxide, and, according to Johnston, is more than twice as fuel efficient as a conventional automobile engine. In August 2000, General Motors vice-chairman Harry J. Pearce announced that his company plans a vehicle demonstration using the new technology within 18 months, and said that it could be producing gasoline-reforming fuel-cell vehicles on a commercial scale within this decade.

IN THE TESTING FACILITY AT EMRE headquarters in Clinton, Johnston takes me into a small laboratory. It is crammed to capacity with electronic and other scientific equipment – pipes, wires, dials, valves, monitoring screens and so on. At the epicentre, so to speak, is a metal cylinder wrapped in insulation that appears to be about the size of a large Thermos flask. This is the hydrogen-extracting gasoline reformer – in effect a "minireactor" – that may be the final, critical piece of technology that will make the fuel-cell vehicle an everyday reality.

It may at first seem self-defeating that the world’s biggest oil company would develop technology that could dramatically reduce the amount of gasoline needed to move the family automobile from one place to another, and might ultimately render the gasoline-powered internal-combustion engine obsolete, but at second glance it is not so.

"We see engine and fuel technologies constantly evolving in what you might call an energy-transportation continuum," says Jersey. "We expect simultaneous developments in fuel cells, in conventional engines, in hybrid power systems and in other areas such as using composite materials for lighter, more fuel-efficient cars. Some of these technologies will be in competition with one another; others will be complementary. And, ultimately, the key choices will be made by the motoring public, who clearly expect a combination of vehicle performance, fuel economy and lower emissions, all at an affordable price. We see ourselves as in the energy business, and we’re determined to meet the motoring public’s energy needs, however they may evolve."

Professor Wallace foresees a transportation marketplace that will cater to a variety of needs with a variety of solutions, rather than one that is essentially homogeneous, with one form of technology dominating. "With so many parallel developments going on at the same time, I don’t think there will necessarily be one winner," he says. "I think we’ll see different power sources matched to different transportation applications or sectors, just as different airplanes use different engines and fuels today. Buses and large vehicle fleets may run on fuel cells with tanks of pure hydrogen derived from water and distributed from large, central fuelling stations, which some of them do today. As for automobiles, we may see different engine types and technologies, with different fuels, meeting different needs. For example, we could have electric cars for urban commuting, hybrids and conventional cars running on reformulated gasoline or diesel fuel for longer touring and so on."

In short, a wider range of choice for the motoring consumer will mean improved fuel economy and a cleaner environment for all of us.

Illustration: Ninon