Take the 2-minute tour ×  Is Hydrogen gas present in biogas? As
it is highly inflammable, may it ignite the other gases like
methane?  share|improve this question What's your question here?
Are you asking why biogas with hydrogen doesn't spontaneously
ignite? –  Oreotrephes Jul 10 '13 at 6:51 first question is
whether Biogas constitutes Hydrogen and if yes why doesn't then
the biogas spontaneously ignite? –  sk1 Jul 10 '13 at 6:57  2
Answers 2  The constitution of the biogas depends greatly on its
source and the fermenting microbe. But in general, it does
contain hydrogen about 0-1%. Even if it did contain large
amounts, the mixture would be inflammable, but it would not
burst into flames without any external igniter, which could be
any small fluctuation of heat if the mixture is too unstable.
But in general, an inflammable gas doesn't start burning on its
own.  share|improve this answer  The auto ignition temperature
of a combustible mixture of hydrogen in air is 500 degrees C
source - Wikipedia. It will not