Sunday, April 17, 2016

Landfill gas. Is there an environmental alternative?

...Historically, (click here) the explosion risk was managed simply by venting a landfill. Pipes were used to allow the landfill gas to escape so that it could not build up inside the landfill. Modern landfills may trap the gas after venting to avoid releasing it into the environment. Once trapped, the gas can be used in a variety of ways....

People actually think of landfill gas as renewable energy. Amazing.

...Converting Landfill Gas to Energy (click here)

Instead of escaping into the air, LFG can be captured, converted, and used as an energy source. Using LFG helps to reduce odors and other hazards associated with LFG emissions, and it helps prevent methane from migrating into the atmosphere and contributing to local smog and global climate change.

As landfill waste decomposes, it produces methane and other gases. More than 75 percent of this gas is available for use as “green” energy. Landfill gas can be used to generate electricity, or it can be piped directly to a nearby manufacturing plant, school, government building and other facility for heating and cooling.
LFG is extracted from landfills using a series of wells and a blower/flare (or vacuum) system. This system directs the collected gas to a central point where it can be processed and treated depending upon the ultimate use for the gas. From this point, the gas can be flared, used to generate electricity, replace fossil fuels in industrial and manufacturing operations, or upgraded to pipeline–quality gas where the gas may be used directly or processed into an alternative vehicle fuel.

Electricity Generation

The generation of electricity from LFG makes up about three–fourths of the currently operational projects in the United States. Electricity for on–site use or sale to the grid can be generated using a variety of different technologies, including internal combustion engines, turbines, microturbines, and fuel cells. The vast majority of projects use internal combustion (reciprocating) engines or turbines, with microturbine technology being used at smaller landfills and in niche applications. Technologies such as Stirling and organic Rankine cycle engines and fuel cells are still in development....