Compressed Bio Gas (CBG)
Cleaned and conditioned, it makes a cost effective, green vehicle fuel
Municipalities and others have long been looking for ways to make the best possible use of landfill gas (LFG) created by anaerobic processes at their landfills. Now, landfill owners and operators with active LFG collection systems can use a Lanfill Gas to CNG system to convert LFG into CNG fuel – at about half the price of gasoline or diesel!
One other factor to consider is that CNG is ideally suited to fuel garbage trucks, because after the drivers unload at the landfill, they can pull up to the CNG fueling station and fill up with RNG fuel before returning to their assigned routes.
Landfill Gas/Bio Gas (LFG) basics.
LFG is generated during the natural process of bacterial decomposition of organic material contained in municipal solid waste (MSW) landfills. A number of factors influence the quantity of LFG generated and its composition, including the waste’s types and age, organic compounds, and moisture content and temperature.
LFG is about 50 percent methane (CH4) and 50 percent carbon dioxide (CO2) and water vapor. It also contains small amounts of nitrogen, oxygen, and hydrogen, as well as less than 1 percent nonmethane organic compounds (NMOCs) that include hazardous air pollutants and volatile organic compounds (VOCs).
Producing a fuel from LFG to meet engine specifications
To make a fuel that meets CNG engine specifications, the CBG system includes equipment that cleans and conditions the LFG.
Treatment systems remove H2S, volatile organic compounds (VOCs), siloxanes and CO2. After cleaning, filters remove particulates, and chillers and desiccants remove moisture. After conditioning, the fuel is routed to a CBG fueling station where it is dried more and compressed for use in CNG/CBG vehicles. Waste gas and condensate returns to the landfill’s existing environmental management systems. The CBG system is fully automated, and designed to allow the conditioned LFG to be used directly as vehicle fuel or mixed with natural gas to produce a CNG/CBG blend. This mixing of fuels is similar to vehicle fuels containing blends of biodiesel or ethanol.