Rebuttal of Alvarez on Gas Vans
Part II: Producer Gas
Lacking sufficient concrete evidence to show the Holocaust did not happen and to build their own narrative, Holocaust deniers are forced to resort to their personal incredulity as a main line of attack: the Germans wouldn't have done it this way, therefore it didn't happen. It's always fascinating to see with what incredible certainty Holocaust denier think to contradict historical facts established by multiple, corroborating sources by just presenting their poorly substantiated incredulity. A prime example is the claim that the Germans would have used the exhaust of producer gas generators instead of engine exhaust for homicidal gassing.
"But not even gasoline engines would have been the choice of a potential mass murder, since Germany had an even cheaper, less complicated, and more efficient method readily at hand: wood gas or producer gas generators." (p. 101)"Hence, if the Germans had used the Saurer trucks mentioned in the Gaubschat exchange as gas vans – or any other truck – they would have been equipped with wood gas generators, and this very gas – before(!) entering the engine – would have been used to kill the inmates locked up on the cargo box." (p. 272)
(Santiago Alvarez, The Gas Vans)
This argument is also advanced by the Holocaust deniers Friedrich Berg, Jürgen Graf, Thomas Dalton (Debating the Holocaust, p. 84) and Nicholas Kollerstrom (Breaking the Spell, p. 63).
Actually, the choice for gasoline engine exhaust can be well understood. The use of producer gas generators to drive combustion engines with solid fuels was more dirty, dangerous, complicated and inconvenient and hardly anybody would used them for transport if it were not because of political intervention due to the shortage of liquid fuels during the war. The producer gas generators had to be mounted in addition to the combustion engine and were therefore reducing the space/load available and the number of people to be gassed per batch in the cargo box. Last but not least, producer gas is not only toxic but also potentially explosive.
Here is the composition of producer gas according to Imbert, the leading producer gas generator company in Germany at the time (Eckermann, Fahren mit Holz, p. 17):
Here is the composition of producer gas according to Imbert, the leading producer gas generator company in Germany at the time (Eckermann, Fahren mit Holz, p. 17):
Nitrogen: 47%
Carbon monoxide: 23%
Hydrogen: 18%
Carbon dioxide: 10%
Methane: 2%
And here are some lower explosive limits of gases:
Carbon monoxide: 12.5%
Hydrogen: 4%
Accordingly, this mixture of carbon monoxide and hydrogen has a lower explosive limit of about 6% in air (Le Chatelier's mixing rule) and makes up about 40% of producer gas. Its safe use for homicidal gassing could have required technical regulation and training not necessary for gasoline engines as its concentration of carbon monoxide is around the lower explosive limit in air. Gasoline engine exhaust contains 10 - 14% carbon monoxide when running idle, which is more than one order of magnitude of what is fatal within 20 minutes, yet with much less risk of ignition than there was with producer gas.
From the choice of gasoline engine exhaust over producer gas one may conclude that the Germans in charge of the gas van development did not consider the higher content of carbon monoxide in producer gas beneficially enough to outweigh the lower effective payload of the trucks, the extra effort for its technical implementation and/or the safety issues and that gasoline engine exhaust was seen as the best compromise between toxicity and safety for this kind of application.