Photo: wood-burning cars (wikimedia.org) Author: Konstantin Shirokun
Cars that run on wood do exist – and despite all the nuances, they are of interest to motorists. How realistic is it to fuel a car with logs and pine cones in our time?
Read about how cars with firewood instead of a gas tank work in the RBC-Ukraine article.
No matter what progress is made by manufacturers of fashionable electric cars and super-fashionable hydrogen cars, a wide range of motorists are no less interested in wood-fueled cars. In the language of engineers, such power plants are called gasgens – gas generators.
What is gasgen
First of all, it should be understood that a wood-burning gas-generator car is not a relative of a steam locomotive. Such a car does not have a steam boiler, grates, valves and other components of a steam engine – the one that became a meme due to its pitiful seven percent efficiency.
The great success of gas generator designers is that they learned to “feed” typical cars with a standard internal combustion engine with firewood a hundred years ago. A serial gasoline car only needs to be equipped with a certain device – that same gas generator.
That is, any gasoline car can be converted from gasoline to firewood – approximately the same way as half of the current owners of gasoline cars converted them to liquefied gas by installing propane-butane LPG. Moreover, the “firewood” does not necessarily have to be literally firewood – these systems successfully operate on hard, brown and charcoal coal, peat and even cones of coniferous trees.
What is a gas generator for a car
The main difference of a gas generator car is the presence of a gas generator. This is a rather bulky structure, which, using the pyrolysis process, produces a mixture of combustible gases from firewood under conditions of incomplete combustion. Among which the main ones are CO (the same carbon monoxide) and hydrogen H2. And this simple mixture becomes combustible for the native engine of the car.
True, the gases obtained must undergo several preliminary procedures, so in addition to the gas generator, the car has additional devices. In particular, the gas obtained from the generator must be cleaned of resins and soot – this is done sequentially in two filters, coarse and fine cleaning. And the produced gas is very hot, so it must be cooled in a heat exchanger similar to the current intercooler, known from today's turbo engines. Finally, a gas generator car has several small elements – an air injection fan, a mixer, connecting tubes with valves, and the like.
The other side of gasgen
What is, is, most components of the gas generator fuel installation have impressive dimensions, but they are simple in design and therefore inexpensive. And besides, they are available for private production literally in the garage.
On the other hand, in the eyes of a modern motorist, gas generators have a whole set of disadvantages. Firstly, firewood must be prepared – it must be of a certain size, for example, the serial generator of the ZIS-21 car was loaded with firewood cubes of 5x6x6 cm caliber. Deviation in size was allowed, but not more than 20% – otherwise the firewood in the reactor will be used inefficiently, and the gas will contain many impurities.
Also, the firewood must be dry: the permissible humidity is no more than 20%, which means that in most cases the prepared firewood must be pre-dried. To make the generator less sensitive to humidity, it can be equipped with a forced air supply.
Finally, the fuel chamber, gas filters and heat exchanger-cooler must be cleaned of soot and resins and freed from condensate. Some operations are carried out daily, some – once every few days. It is clear that with a modern approach, most of the shortcomings of gas-generator cars could be leveled. However, liquid petroleum fuels are currently firmly holding their positions – not giving them up to either electricity or firewood.
In brief
The history of European countries knows several periods when, due to difficult economic circumstances, the main fuel for civilian cars was wood or coal. For example, during World War II, citizens of France, Germany and other warring countries drove almost exclusively on wood. At that time, gas generator sets were produced for trucks and cars, structurally designed, in particular, in stylish trunks or compact trailers. But at the first opportunity, those motorists returned to the usual gasoline – and this says a lot.
In preparing this article, materials from Autobild and Autocentre were used .
Let us recall that RBC-Ukraine recently reported why pedestrians are not always right.