Waste streams ranging from agricultural byproducts to municipal
waste are excellent fuel sources for large scale gasification. In
many circumstances the gasification plant can receive disposal fees
along with sales of metal and glass slag and electricity fed to the
grid.

The upside to waste gasification is the destruction of landfill
materials. However the downside is the high cost and complexity
involved with running such a large plant.
Here is a video about a company having success with waste
gasification: