Landfill gas treatment system
First Claim
1. A method for treating a raw landfill gas stream to form a treated methane-based gas which may be used in lieu of natural gas as a fuel gas, said method comprising the steps of:
- a) passing said landfill gas stream through a hydrogen sulfide adsorption bed to reduce hydrogen sulfide content of the raw landfill gas stream to about five ppm or less;
b) cooling a resultant gas stream emanating from said adsorption bed to a temperature which is operable to condense water vapor and heavier hydrocarbon fractions in the resultant gas stream;
c) adsorbing condensed water vapor and heavier hydrocarbon fractions from the resultant gas stream to form a dried gas stream;
d) removing hydrocarbon contaminants from the dried gas stream by passing the dried gas stream through an activated carbon bed; and
e) removing contaminant particules from the dried gas stream.
3 Assignments
0 Petitions
Accused Products
Abstract
The gas stream which emanates from landfills is treated to produce a purified gas which is essentially a hydrocarbon such as methane which can be used as the fuel source in a fuel cell power plant, or can be used in other power plants which use natural gas as a fuel. The landfill gas passes through a system which removes essentially all of the hydrogen sulfide; water; organic sulfur and halogen compounds; and solid contaminants from the gas stream. The resultant purified gas stream can be cleanly flared; used to power an energy plant; or put to other useful purposes.
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Citations
14 Claims
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1. A method for treating a raw landfill gas stream to form a treated methane-based gas which may be used in lieu of natural gas as a fuel gas, said method comprising the steps of:
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a) passing said landfill gas stream through a hydrogen sulfide adsorption bed to reduce hydrogen sulfide content of the raw landfill gas stream to about five ppm or less; b) cooling a resultant gas stream emanating from said adsorption bed to a temperature which is operable to condense water vapor and heavier hydrocarbon fractions in the resultant gas stream; c) adsorbing condensed water vapor and heavier hydrocarbon fractions from the resultant gas stream to form a dried gas stream; d) removing hydrocarbon contaminants from the dried gas stream by passing the dried gas stream through an activated carbon bed; and e) removing contaminant particules from the dried gas stream. - View Dependent Claims (2, 3, 4)
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5. A system for treating a raw landfill gas stream to form a treated methane-based gas which may be used in lieu of natural gas as a fuel gas, said system comprising:
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a) a hydrogen sulfide adsorption bed for receiving the raw landfill gas stream, said hydrogen sulfide adsorption bed being operable to reduce hydrogen sulfide content of the landfill gas stream to about five ppm or less; b) a cooler condenser adsorption bed station for receiving an essentially hydrogen sulfide-free gas stream and cooling said hydrogen sulfide-free gas stream to a temperature which is operable to condense and adsorb water vapor and heavier hydrocarbon fractions from the gas stream; c) an activated carbon bed for receiving an essentially dry gas stream from the cooler condenser adsorption bed station, said carbon bed being operable to remove hydrocarbon contaminants from the gas stream; d) a particulate filter station for removing contaminant particles from the gas stream; and e) a gas stream line for transferring the treated gas to a fuel-consumption device which can produce environmentally-clean energy from the treated gas. - View Dependent Claims (6, 7, 8, 9, 10, 11, 12, 13, 14)
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Specification