if only biogas could be used as a fuel..., page-5

There is one thing you must be wary of if anyone wants to repeat my system. You must release the first two tubes of gas to the air. Methane and oxygen are highly explosive when mixed together. You'd end up with a shit bomb!!!!
( a Tee piece screwed into the small bung on the drum takes the gas to the delivery pipe or to the tractor tube. The large bung takes the mixed slurry via a funnel and then screwed in to seal the system.)