Removing hydrogen sulfide(H₂S) from carbon dioxide (CO₂) streams is vital in biogas production, natural gas processing, and carbon capture and storage applications. H₂S is a toxic and corrosive gas. Its removal from CO₂ streams is necessary to conform to pipeline injection standards and purity limits for CO₂ usage. Environmental and safety factors also play a role in the need for removal. Physical absorption, chemical absorption, membrane separation, amine separation, and biological consumption are all methods by which H₂S can be removed from CO₂ or biogas streams. While each method has pros and cons, physical absorption offers the most straightforward, robust, and lowest CapEx option while safely converting the H₂S into stable elemental sulfur for disposal or use as fertilizer.

Depending on the source, CO₂ waste streams may vary widely in their composition compared to traditional biogas sources. Waste CO₂ from plastic or chemical manufacturing sources may have no oxygen or moisture present and may contain exotic compounds not found in waste digestion. These are also typically generated at very high pressure and temperature. CO₂ streams generated from amine or membrane separation of biogas may also have a low relative humidity or oxygen content and high levels of H₂S due to the concentration effect after separation but are typically found at lower pressures. All these factors must be considered when selecting a versatile and cost-effective H₂S removal solution for your site’s needs.

FerroSorp® H₂S removal media has a base of iron hydroxide, which is the purest and most effective form of iron for H₂S reduction. Iron Hydroxide inherently contains more oxygen (O₂) within the molecule, making it more effective on CO₂ streams that do not have any O₂. FerroSorp® works on wet or dry gas, which makes it effective for CO₂ streams regardless of the source.

FerroSorp® does not bond with exotic VOC compounds that may be present in the gas, making it safe and non-hazardous for disposal or land application.

Treating H₂S in CO₂ –

• Pros:
  • Versatile applications for purified CO₂, turning waste CO₂ into a revenue stream
  • Enhanced oil recovery, food-grade additives, and chemical production
  • If the CO₂ stream is vented or routed through a flare, air can be injected to maximize the media’s H₂S absorption capacity

• Cons:
  • Higher operating pressures and temperatures may increase energy consumption
  • Higher H₂S concentrations per SCFM after CO₂ is concentrated out of biogas

Treating H₂S in Biogas –

• Pros:
  • Enhances biogas quality and energy content
  • Renewable energy applications like power generation and transportation fuel
  • Lower H₂S concentrations, simplifying the removal process

• Cons:
  • Presence of additional impurities in biogas may require extra treatment steps

The choice of treatment depends directly on industry and application requirements. CO₂ streams offer diverse utilization possibilities.

FerroSorp® SK is the only media in the industry that is pre-conditioned with CO₂ from the factory, so no initial heat-up is experienced when exposed to biogas or pure CO₂ streams.

Interra Global has media in stock in multiple warehouses across the US, coupled with rapid deployment options for the highly versatile VAV bulk media vessels that are made in America compliant.