It can be hard to imagine household food waste producing anything more than a putrid odour. But it's also a potential energy source.
In Canadian municipalities with green bin programs, household organics are collected at the curb and sent to a central facility where they are broken down by microorganisms. One result of this process is something called raw biogas.
A growing number of these cities are upgrading that biogas (from a methane concentration of 55 to 60 per cent to 90 per cent or more) to produce what is called renewable natural gas (RNG). RNG is similar in quality to conventional natural gas and can be injected into a natural gas pipeline to heat buildings and fuel vehicles.
By CBC News