Not quite the same thing, but our metro landfill is used as a source for methane for the city. The city has been doing this for twenty years. Most of the city buses as well as heavy municipal trucks (like garbage trucks or snow plows) were converted to run on methane. The methane recovered from the landfill powers all of these city vehicles and even has excess production that is piped into the municipal natural gas pipelines so that retail, commercial and industrial consumers can use it too.