project: a modern gasifier on a Volvo
My aim was to
equip a car
with a modern stainless steel gasifier. An American pickup truck was
the first option, because of the practical loading platform, where the
generator can find a spot. Also the low engine speed of oversized
V-8’s suits woodgas very well.
A neat truck would however cost a considerable amount of money. Both
the purchase and the vehicle holder's tax are high. Old-timers are even
more expensive and often require a major overhauling. And a large car
consumes more fuel, which has to be produced.
Therefore the only alternative was a strong sedan. Putting the
installation on a trailer was no option. It should be a practical car,
for which a parking lot could be found easy, even in the city.
I am Volvo-minded and a “brick” was still on the
“ever to possess cars”. Gradually and certainly
completion, the 240 has proven to be a right choice.
According to initiates, it has been the first serious attempt to build
a mobile wood gasifier since the second world war in the Netherlands.
The interest of biomass companies and the media forced me to build a
neat construction. Thereby it would be necessary to engage
First I phoned the Dutch Road Association questioning if there are
requirements with respect to driving on woodgas. There are none. Also,
there are no tax issues; although later it appeared to be a huge
problem…. But fortunately it could be solved.
The road association insisted on neat building and prevention of sharp
parts, which could hurt pedestrians. This gave me the courage to start.
Next: study of necessary literature and become member of two woodgas
forums for the necessary theoretical background. I recommend everyone
who wants to build a serious gasifier to read at least one book
concerning wood gasification. Without realizing what happens in the
generator and without correct calculation of the oxidation and
reduction zone, it is impossible a build a successful unit. Most of the
initiatives fail because of a surplus of enthusiasm and a lack of ready
knowledge. And lack of patience, a lot of patience….
In English there are several documents available, such as the FAO 72
paper: “Woodgas as Engine Fuel” and the
Biomass Downdraft Gasifier Engine Systems”. Both books are
outdated, but very useful for the basic knowledge and sufficient to
build a successful gas generator. And they can be downloaded from the
A tricky item was the weight at the back of the car. Every kilo on the
platform is one and a half kilos on the rear axle. A light construction
was necessary in order not overload the axle. Therefore a third part of
the installation is mounted in the front of the car, for better weight
A targeted search on the forums taught me how to carry out the
calculations. Calculations (for which the car must be either known or
present) led to construction drawings, which have been changed numerous
times. Meanwhile family members put my pencil drawings into Autocad.
Kepser Prometaal was contacted to cut, bend and roll the parts. Will,
neighbor and professional TIG welder, was asked to weld the critical
parts. Innumerable problems emerged, but were solved one by one. That
consumed a lot of time, but was very satisfying and enlightening .
Although building a house is way simpler.....
Even before all the drawings were definitively ready and put into
Autocad, I started building the details around the major components.
The ECU’s of ignition and injection had to be disconnected
driving on woodgas and an extra ignition distributor from an older
model had to be added. The gas/air mixer with four gas valves was a
time consuming part to build, as well as the connecting bowden cables
and levers. A new filter box with a separate compartment for the
woodgas could only find its spot before the radiator, which had to be
moved back towards engine. All in all I have spent more time under the
hood and the dashboard than on the rear of the car.
Collecting the components does cost a lot of time. Without an open
budget, the creative part of the brain conflicts with the rational
part. But an enrichment for both!
The gas cooler has been built before the front axle, to take away
weight from behind. I did not want the cooler being visible, because a
cooler with sufficient capacity needs much space and does not look very
elegant. It is also a sharp part that can wound pedestrians or cyclists
at a collision. That is why it is under the car. A disadvantage is a
smaller ground clearance. Still, it is a spectacular component. People
gladly get on their knees to have a look.
Also the reheater is moved to the front. It reheats the wet gas from
the cooler to get it dry into the final filter and engine. The reheater
substitutes for the grill. There are few stainless steel grills. And
none that weigh 25 kilo…
For a layman, the front therefore seems unchanged at first sight.
Every larger part is provided with puff lids or valves, to relieve a
Being bored at a certain point, I called the Tax and Customs
Administration with the question if wood or woodgas is taxed. A call I
regretted later… The first answer I got was that every
fuel is taxed. They would inform me how. After two weeks I received an
extensive e-mail with bad news. Wood and woodgas are indeed tax-free,
but because it concerns an engine fuel, the Tax and Customs
Administration took a known fuel which is near woodgas, being methane,
with nil tax. Well, good news, I thought…
Now, all taxed fuels have to be made on a place called AGP, where the
customs authorities can check if a producer sticks to the law. In my
case the car is the AGP. But an AGP is not allowed to be mobile.
Conclusion and recommendation to the commission of wise men of the
customs administration: “Gasification for mobile applications
Boy, did I regret my telephone call! Fortunately a senior official of
the ministry blew the whistle to his subordinates and wished me much
success with the project! Thus my call brought something good, although
the road to it was not very pleasant.
Doomsday was by the end of July 2008. After almost a year of
preparation and construction that day would be put to the test. Really
We filled the hearth with charcoal and chopped wood on top. The
electric lighting by means of a diesel glow plug was a wild guess of
mine and I had no idea if it would work. So I turned the blower on,
powered the glow plug and peered to the chimney for smoke: nothing.
Tried again: nothing. Frustrated, I pulled the plug from the hearth and
hot char flew out! And a minute later: flammable gas!
Thus we flared for an hour, in order to have the hearth settled.
Meanwhile I had to adjust the ignition with a stroboscope light,
whereas Diny, my wife, ran the starter motor. And believe it or not:
the engine started! Just like that…. Woodgas lights that
Anyone who has seen the woodgas videos on Youtube notices the face of a
woodgasser, ready for the maiden trip, at the same time cheerful and
anxious. For me that was no different.
I drove away carefully, but it ran so smooth, that after a couple of
kilometers a speed of 100 km/h was reached! More than I dared to dream
of. After thirty kilometers the party was over, because the high vacuum
between intake manifold and mixer drew a hole in the hose.
Weeks went by and many of the bugs were removed and modifications
added. Much of the theory can be found on the internet or in the
literature, but actual driving on woodgas and solving problems are an
attack on the self-educated mind. Or to put it bluntly, learn by damage
After 2000 kilometers on woodgas everything worked properly. Top speed
is 120 km/h. Cruising speed 100-110 km/h. Fuel consumption
approximately 30 kilos of wood for one hundred kilometers, which is
also one effective filling of the fuel bin. The back seat loaded with
sacks of wood make the total range approximately 400 kilometers.
The most beautiful compliments were given by the experienced Finnish
woodgassers. According to them, the Volvo is the first car which is
entirely built according to the current state or the art. The crown on
the job is a reference with photographs in Vesa Mikkonens well known
book: “Woodgas for mobile applications”.
Word of thanks
I want to pay my regards to the people who have cooperated in the
“Maxgasman” for his enormous knowledge of mobile
gasification. Without him I would have failed. Moreover he could temper
my over-enthusiasm to a lower, but more stable level.
Vesa Mikkonen for his fantastic book (I it should have purchased it way
earlier) and our frequent contact.
The members of the WoodGasforum and Woodgasbuildersforum
Chris, Bart and Stephan of Kepser Prometaal in Cuijk for providing the
Will for its excellent TIG welding; you do not know how many
compliments I have had to take for you!
Henry and Jacko for the Autocad drawings
Brother-in-law Toon for the use of the lathe
Car-electrics Van Dommelen, Wanroy and car company Wim Rische, Cuijk
for selecting and repairing the ignition. How can one have so much work
put into such a seemingly simple part?
Internetwebshop.nl for donating the inverter
Devobo, Deventer, for the supply of the carwood
TJ Houston for proofreading this manuscript and Birgit for proofreading
the German version
Mark Hendriks for building the website