Mr Teslonian is a great tech channel that not too many know about.  I didn't realize it was possible to get gasoline from wood, until he demonstrated his gasifiers.  He also does crazy stuff like building a powered exo-suit out of an old wheelchair.  Definitely a post apocalyptic kind of channel.  

https://yewtu.be/channel/UCVP1PTBbRGpmTQE1oQx8xNw