Municipal landfills collect household garbage. These landfills are predominately regulated by State and local governments. Research has, however, established minimum criteria that these landfills must meet in order to remain open. The only hazardous waste that municipal landfills can accept is household hazardous waste and waste that is exempt from hazardous waste regulation.
Gasification is a process that converts organic or fossil fuel based carbonaceous materials into carbon monoxide, hydrogen and carbon dioxide. This is achieved by reacting the material at high temperatures (>700 °C), without combustion, with a controlled amount of oxygen and/or steam. The resulting gas mixture is called syngas (from synthesis gas or synthetic gas) or producer gas and is itself a fuel. The power derived from gasification and combustion of the resultant gas is considered to be a source of renewable energy if the gasified compounds were obtained from biomass.The advantage of gasification is that using the syngas is potentially more efficient than direct combustion of the original fuel because it can be combusted at higher temperatures or even in fuel cells, so that the thermodynamic upper limit to the efficiency defined by Carnot's rule is higher or (in case of fuel cells) not applicable. Syngas may be burned directly in gas engines, used to produce methanol and hydrogen, or converted via the Fischer–Tropsch process into synthetic fuel. Gasification can also begin with material which would otherwise have been disposed of such as biodegradable waste. In addition, the high-temperature process refines out corrosive ash elements such as chloride and potassium, allowing clean gas production from otherwise problematic fuels. Gasification of fossil fuels is currently widely used on industrial scales to generate electricity.
Pyrolysis is a process in which tires can be subjected to high heat, under controlled conditions, resulting in steel, oil, and carbon black. Although it has been shown repeatedly to be scientifically possible, economically and practically it has not proven to be a viable process. High capital investment and operating costs typically inhibit tire pyrolysis from being made commercially available.
Incineration, or the burning of waste to produce energy, has also been an attractive waste processing approach for many communities and countries as a whole. Properly operated incineration projects can provide energy in the form of electricity or processed steam, while reducing the volume of waste that must be landfilled by a significant fraction.