Everyone here is right that you can sub for propane with little modification. Propane actually has higher energy density than methane, too, so it creates higher

Everyone here is right that you can sub for propane with little modification. Propane actually has higher energy density than methane, too, so it creates higher heat with less fuel. Seems like the best solution — allow restaurants to install propane tanks and even subsidize conversion. Could be challenging in dense cities though.