Alternative drives: concept overview

Alternative drives
Subscriptions & booklets

W eg from crude oil is the motto. Alternative forms of propulsion must be found that have less impact on the climate and protect the shrinking oil reserves - or ideally do without them at all. But what fuel will we fill up in 20 years, what technology will power our cars?

Combustion engines with savings potential

One thing is already clear: In 2028, internal combustion engines fueled by gasoline or diesel will still dominate. However, they will be much more economical than their current ancestors. Because downsizing, direct injection and turbocharging will also prevail across the board with gasoline engines. In the case of diesel, ever higher injection pressures should ensure further increases in efficiency.

Both processes will also come closer in further developed engines such as the diesel motto from the Mercedes F 700. This means that the diesel, like the gasoline engine, works with a homogeneous fuel-air mixture at part load, which above all prevents the formation of particles and nitrogen oxides and reduces consumption. With the same goal, the mixture in the gasoline engine should be ignited simultaneously in the entire combustion chamber solely by the heat of compression. At least in the partial load range, the spark plug is superfluous.

The processes are called HCCI (Homogeneous Charge Compression Ignition) or CAI (Controlled Auto Ignition). While the developments by Mercedes and GM based on gasoline engines run on conventional gasoline or E85, the so-called CCS process from VW (Combined Combustion System) requires tailor-made, synthetic diesel, preferably made from biomass.

Purely electric driving longer distance

Full hybrids with their significantly more powerful e-machines and larger batteries also allow pureelectric driving over short distances. To extend the range, more powerful batteries - in future lithium-ion instead of nickel-metal hydride - and external charging connections will be installed. In these so-called plug-in hybrids, the electricity for charging the batteries is no longer generated exclusively by the combustion engine while driving, but should be able to be drawn from the network at any socket.

No combustion engine at all pure electric vehicles, which will occupy a small but stable niche, especially in cities with entry restrictions. Most commuters should have a range of up to 115 kilometers, such as that offered by the Smart Fortwo ed (electric drive), to get to work in the morning and back home in the evening. The batteries are recharged overnight at the domestic socket.

Oxygen and hydrogen react on board

However, the spread of electric vehicles could increase rapidly if - as in the USA - the manufacturers fixed quotas for emission-free cars are prescribed. Fuel cell vehicles are one of them. The electricity is generated on board by reacting oxygen and hydrogen (H2) in the cell. Apart from water vapor, no exhaust gases are produced. The range should be comparable to today's gasoline-powered vehicles, which is why fuel cell cars are also suitable for long journeys. However, this assumes that sufficient hydrogen is carried.

But that is only where the problems begin. Because hydrogen can only be stored in the vehicle with considerable effort. In addition, an infrastructure would first have to be built from scratch. Above all, however, the question of H2 production has not yet been clarified. Because in order to be really environmentally friendly, the large amounts of energy required for this process must come exclusively from renewable sources.

Nobody can say with certainty whether this will be possible in the future. That is why the manufacturers, suppliers, mineral oil companies and specialists surveyed by auto motor und sport do not give hydrogen as a fuel for mobile use any great opportunities for the time being.

Renewable raw materials point the way out of oil dependency

Biofuel could offer a further alternative to crude oil: The public image of these alternative fuels is currently rather crooked: they are to blame for the rise in food prices and therefore make the poor even poorer. In addition, they threatened the Malay rainforest and its biodiversity of plants and animals because of the overflowing palm oil plantations. The debate about whether empty plates are the price for full tanks caused increasing nervousness, especially among politicians.

Nevertheless: Energy from renewable raw materials is a model for success. 'The use of biomass to generate fuels is in addition to vehicle technologyMeasures to increase efficiency are the only option in the transport sector today to replace fossil raw materials and save greenhouse gases ', according to the current analysis of the FNR on the potential of biofuels. Whether from biomass, gas or coal - the good product properties of designer fuels are almost Identical. They significantly reduce pollutant emissions. A special charm of biomass fuel: It is almost CO2-neutral.

Gas is also an inexpensive fuel alternative to petrol and diesel in order to escape rising fuel costs. In Germany offers two gas variants: the naturally occurring natural gas in compressed form, hence the name CNG (Compressed Natural Gas) and the liquid gas LPG (Liquefied Petroleum Gas). The latter is also known as autogas and is a refinery product that is used in the distillation of crude oil accrues.


Leave a reply

Name *