Biogas / RNG
Hydrogen Sulfide (H₂S) Removal
H2S is typically present in biogas. Waste streams that are high in proteins containing sulfur-based amino acids like methionine and cysteine, and construction waste can influence biogas H2S levels.
Our activated carbon effectively removes H2S and:
- Mitigates risk of poisons and foul odors
- Protects plant equipment from corrosion
- Ensures compliance with air permits, and
- Makes RNG profitable by meeting pipeline specifications or enabling use as vehicle fuel
Purifying biogas and concentrating the methane also requires the separation of carbon dioxide, water, nitrogen and the removal of other contaminants (siloxanes and VOCs) before it can be called RNG and used interchangeably with pipeline natural gas.
Our DARCO® BG 1, DARCO BG 1P, and NORIT® ROZ 3 are high performance activated carbons developed specifically for removing H2S from biogas streams.
Industry Leading
DARCO BG 1
- 4 x 10 GAC
- 65-100+%* Loading capacity
- Lower density / less fill cost
- Long life / Less changeouts
- Safe! Non-self heating
- Non-reversible reaction
- Easy and effective: No bricking
- Lowest $/lb of sulfur removed
Granular activated carbon
(*per operating conditions)
Pelletized Version
DARCO BG 1P
- 4mm pellet
- 55-85%* Loading capacity
- Low pressure drop
- Low dust
- Safe! Non-self heating
- Non-reversible reaction
- Easy and effective: No bricking
Extruded activated carbon
(*per operating conditions)
For Low Relative Humidity
NORIT ROZ 3
- 3mm KI Impregnated pellet
- 35-65%* Loading capacity
- Effective for low RH gas
- Easy and effective: No bricking
- Non-reversible reaction
Extruded activated carbon
(*per operating conditions)
Video: H2S Removal with DARCO BG1
Eliminating H2S from gas is easy, safe, and effective with DARCO BG1. Our animated video demonstrates how using DARCO BG1 activated carbon in a lead/lag (worker/polisher) vessel configuration optimizes loading capacities, decreases the cost per pound of sulfur removed, and allows system maintenance without interruption.
- DARCO BG1, NORIT's flagship H2S removal product, converts H2S into elemental sulfur and sequesters it in the activated carbon's network of pores.
- NORIT recommends a lead/lag vessel configuration to maximize loading capacity, enabling H2S loading capacity to exceed 85% by weight and reducing the $/lb of sulfur removed.
- A lead/lag vessel configuration keeps the H2S removal system online during change-outs, with the lag vessel becoming the lead.
- For optimal performance, DARCO BG1 requires a 1:1 ratio of O2 to H2S and relative humidity between 60-100%.
- As sulfur adsorption increases, the reaction slows but never stops, enabling optimal loading rates.
Changing out DARCO BG1 is safe and easy
In this video, you'll see the media change-out in action. Watch the steps for media replacement in a worker/polisher (lead/lag) vessel configuration to ensure safe, reliable, and compliant biogas operations.
- A lead/lag system ensures the H₂S removal process remains operational during change-outs, with the lag vessel becoming the lead.
- Advanced equipment ensures easy loading procedures and minimizes the need for manual handling.
- Low dust granules contribute to a cleaner change-out process and improved workplace safety.
- Quick and straightforward change-outs, reduce downtime and system interruptions.
RESOURCES
White Paper
5 Key Steps to Size Activated Carbon Vessels for Optimal H2S Removal.
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White Paper
Fate of Spent Specialty Non-Impregnated Activated Carbon in Landfills.
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Educational Video Series
Learn about activated carbon, adsorption fundamentals, and the value it creates in purifying RNG and biogas.
DARCO BG1 Info Sheet
Get the lowest $/lb of H2S removed and personalized technical support for your biogas purification needs.
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Case Study
SCS Energy substantially reduced costs, saved time, and significantly increased H2S loading capacity.
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Case Study
Casella removed more H2S while using less media and requiring fewer change outs.
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