I have already considered to perform experiences with a "gas bag" like that, but I would rather try biomethane. Only downside is that it would be nearly impossible to license a setup like that in my country.
i've still planned to put a gasifier on a trailer to power a two-wheel tractor.
That sounds cool. But would you dare to drive it during the winter there? Have you already seen some video footages of Chinese 2-wheel tractors converted into some sort of rudimentary truck with an enclosed cabin? Maybe it could be a good approach to overcome this issue...
Look at this one from Brazil, without a cabin but it has a driven trailer (which would be desirable to overcome the disadvantage inherent to the rear weight bias when fully-loaded under certain terrain conditions):