Abstract: A system and method for the purification of biogas, the system comprising: a gas compressor for increasing the pressure of the biogas for processing; a gas processor for removing any CO2, volatile organic compounds, and H2S, from the gas; an optional biological sulfur removal system for treating offgas from the gas processor; a regenerative thermal oxidizer system for treating gas from the biological sulfur removal system for thermal destruction of volatile organic compounds, H2S, and CH4 slipped from the gas processor; a catalytic oxygen removal system for receiving product gas from the gas processor and removing oxygen from the product gas; and a caustic scrubber for receiving product gas from the catalytic oxygen removal system and neutralizing any acid formed during catalytic oxygen removal.

Abstract: The present invention provides a regenerative thermal oxidizer system, comprising: a recuperative heat exchanger that receives process exhaust gas from an anaerobic digestion process and boosts an inlet temperature of the gas to a second gas temperature; and a regenerative thermal oxidizer that receives the gas from the heat exchanger, further heats/combusts the gas to a third gas temperature, and feeds the gas back through the recuperative heat exchanger, which recoups heat from the gas such that the gas exits the heat exchanger at a fourth gas temperature.

Abstract: Systems and methods are presented for the purification of a biogas. The systems comprise: a gas processor for reducing CO2, volatile organic compounds, and H2S in the biogas, the gas processor comprising a scrubber tank and a scrubber liquid; and a scrubber liquid processor in fluid connection with the gas processor for reducing the amount of absorbed gas in the scrubber liquid. The scrubber liquid processor comprises a stripper tank, and is configured to reduce or eliminate airflow through the stripper tank.

Abstract: The present invention provides a method and apparatus for the treatment of process gas from an anaerobic digestion system or a landfill gas system. In one embodiment, the system comprises a caustic scrubber including a vertical column having a top and a bottom and including a counter current flow system, wherein a process gas stream flows up vertically through the column in counter current flow to a caustic liquid solution that flows downward through the column. The caustic liquid solution removes at least one acid from the process gas stream, wherein treated gas that is substantially free of acids bubbles out through an opening at the top of the vertical column.

Abstract: The present invention provides a biological H2S removal system for the treatment of process gas, comprising: a housing that receives a process gas stream through a gas inlet, the housing comprising a plurality of layers through which the process gas stream flows while it is treated for H2S removal, and a gas outlet through which a treated gas stream exits; wherein air is added to the process gas stream prior to the process gas stream entering the housing.

Abstract: The present invention provides a method and apparatus for the treatment of process gas from an anaerobic digestion system or a landfill gas system. In one embodiment, the system comprises a caustic scrubber including a vertical column having a top and a bottom and including a counter current flow system, wherein a process gas stream flows up vertically through the column in counter current flow to a caustic liquid solution that flows downward through the column.

Abstract: The present invention provides a biological H2S removal system for the treatment of process gas, comprising: a housing that receives a process gas stream through a gas inlet, the housing comprising a plurality of layers through which the process gas stream flows while it is treated for H2S removal, and a gas outlet through which a treated gas stream exits; wherein air is added to the process gas stream prior to the process gas stream entering the housing.

Abstract: The present invention provides a method and apparatus for the treat en of process gas from an anaerobic digestion system or a landfill gas system. In one embodiment, the system comprises a caustic scrubber including a vertical column having a top and a bottom and including a counter current flow system, wherein a process gas stream flows up vertically through the column in counter current flow to a caustic liquid solution that flows downward through the column. The caustic liquid solution removes at least one acid from the process gas stream, wherein treated gas that is substantially free of acids bubbles out through an opening at the top of the vertical column.

Abstract: The present invention provides a method and apparatus for the treatment of process gas from an anaerobic digestion system or a landfill gas system. In one embodiment, the system comprises a caustic scrubber including a vertical column having a top and a bottom and including a counter current flow system, wherein a process gas stream flows up vertically through the column in counter current flow to a caustic liquid solution that flows downward through the column. The caustic liquid solution removes at least one acid from the process gas stream, wherein treated gas that is substantially free of acids bubbles out through an opening at the top of the vertical column.

Abstract: The present invention provides a regenerative thermal oxidizer system, comprising: a recuperative heat exchanger that receives process exhaust gas from an anaerobic digestion process and boosts an inlet temperature of the gas to a second gas temperature; and a regenerative thermal oxidizer that receives the gas from the heat exchanger, further heats/combusts the gas to a third gas temperature, and feeds the gas back through the recuperative heat exchanger, which recoups heat from the gas such that the gas exits the heat exchanger at a fourth gas temperature.

Abstract: The present invention provides a biological H2S removal system for the treatment of process gas, comprising: a housing that receives a process gas stream through a gas inlet, the housing comprising a plurality of layers through which the process gas stream flows while it is treated for H2S removal, and a gas outlet through which a treated gas stream exits; wherein air is added to the process gas stream prior to the process gas stream entering the housing.

Abstract: The present invention provides a method and apparatus for the treat en of process gas from an anaerobic digestion system or a landfill gas system. In one embodiment, the system comprises a caustic scrubber including a vertical column having a top and a bottom and including a counter current flow system, wherein a process gas stream flows up vertically through the column in counter current flow to a caustic liquid solution that flows downward through the column.

Abstract: A system and method for the purification of biogas, the system comprising: a gas compressor for increasing the pressure of the biogas for processing; a gas processor for removing any CO2, volatile organic compounds, and H2S, from the gas; an optional biological sulfur removal system for treating offgas from the gas processor; a regenerative thermal oxidizer system for treating gas from the biological sulfur removal system for thermal destruction of volatile organic compounds, H2S, and CH4 slipped from the gas processor; a catalytic oxygen removal system for receiving product gas from the gas processor and removing oxygen from the product gas; and a caustic scrubber for receiving product gas from the catalytic oxygen removal system and neutralizing any acid formed during catalytic oxygen removal.

Abstract: The present invention provides a method and apparatus for the treatment of process gas from an anaerobic digestion system or a landfill gas system. In one embodiment, the system comprises a caustic scrubber including a vertical column having a top and a bottom and including a counter current flow system, wherein a process gas stream flows up vertically through the column in counter current flow to a caustic liquid solution that flows downward through the column.

Abstract: The present invention provides a biological H2S removal system for the treatment of process gas, comprising: a housing that receives a process gas stream through a gas inlet, the housing comprising a plurality of layers through which the process gas stream flows while it is treated for H2S removal, and a gas outlet through which a treated gas stream exits; wherein air is added to the process gas stream prior to the process gas stream entering the housing.