Quick Answer: Activated carbon purifies biogas by adsorbing hydrogen sulphide (H₂S), siloxanes, volatile organic compounds (VOCs), and other contaminants. Impregnated activated carbon offers enhanced H₂S removal, protecting engines, pipelines, and gas upgrading systems while improving biomethane quality.
Key Takeaways:
✔ Activated carbon removes hydrogen sulphide (H₂S) from raw biogas.
✔ Impregnated activated carbon provides superior H₂S removal efficiency.
✔ Purified biogas protects engines and pipelines from corrosion.
✔ Activated carbon also reduces siloxanes and VOCs.
✔ It is widely used in CBG, landfill gas, wastewater, and waste-to-energy plants.
Biogas is a clean, renewable fuel produced from organic waste, but in its raw form, it is far from pure. Along with the useful methane, raw biogas contains impurities, and the most troublesome of these is hydrogen sulphide (H₂S). This single contaminant is corrosive, toxic and foul-smelling, and if it is not removed, it damages engines, pipelines and equipment, and lowers the quality of the gas. Activated carbon is one of the most effective and widely used solutions for removing it.
What is in Raw Biogas?
Raw biogas is mainly a mixture of methane (CH₄) and carbon dioxide (CO₂), but it also carries several impurities that must be cleaned before the gas can be used efficiently:
➤ Hydrogen Sulphide (H₂S): Highly corrosive and toxic, it damages engines, boilers and pipelines and produces a strong rotten-egg odour.
➤ Moisture: Water vapour that can cause corrosion and reduce gas quality.
➤ Siloxanes: Compounds that form harmful deposits inside engines and turbines.
➤ Volatile Organic Compounds (VOCs): Trace contaminants that affect gas purity.
Removing these impurities, especially H₂S, is essential to protect equipment and produce clean, usable biogas or biomethane. At Western Adsorbents & Catalysts, as a leading coconut shell activated carbon manufacturer in India, we offer high-quality activated carbon in different source materials and forms, tailored in terms of pore size, surface area and other specifications for biogas purification applications.
How Activated Carbon Purifies Biogas
Activated carbon cleans biogas through "adsorption", where impurities attach to the surface of the carbon as the gas passes through the carbon bed. Its very large internal surface area, created by millions of tiny pores, gives it a high capacity to trap contaminants.
For biogas purification, impregnated activated carbon is often used. Here, the carbon is treated with chemicals such as potassium hydroxide or potassium iodide, which react with hydrogen sulphide and greatly improve its removal. This makes impregnated carbon far more effective at H₂S removal than ordinary activated carbon.
Why Activated Carbon is Preferred
As one of the top activated carbon suppliers in Malaysia, we provide activated carbon for biogas purification for several practical reasons:
➤ High Efficiency: It removes hydrogen sulphide and other impurities to very low levels.
➤ Simple Operation: The system is easy to install, operate and maintain.
➤ Protects Equipment: By removing corrosive H₂S, it extends the life of engines, pipelines and boilers.
➤ Improves Gas Quality: It helps upgrade biogas to cleaner biomethane suitable for power generation or vehicle fuel.
➤ Reliable and Proven: It is a well-established, trusted technology used across biogas plants.
Where is it used?
Activated carbon purification is used wherever clean biogas is needed, including:
➤ Biogas and biomethane (CBG) plants
➤ Sewage and wastewater treatment facilities
➤ Landfill gas recovery systems
➤ Food, agricultural and distillery waste-to-energy plants
In each of these, activated carbon helps turn raw, impurity-laden gas into a clean fuel that is safe for engines, grids and pipelines.
Conclusion
Activated carbon is a simple and highly effective way to purify biogas. By removing hydrogen sulphide and other impurities, it protects valuable equipment, improves gas quality and helps produce clean, usable biomethane. For biogas producers looking for a reliable purification solution, choosing the right activated carbon makes all the difference.
To purify your biogas with high-quality activated carbon, contact Western Adsorbents & Catalysts and let our team help you select the right grade.
FAQs
How does activated carbon purify biogas?
➤ Activated carbon purifies biogas through adsorption, where impurities like hydrogen sulphide attach to the surface of the carbon as the gas passes through the bed. Its large internal surface area gives it a high capacity to trap these contaminants.
Why is hydrogen sulphide removed from biogas?
➤ Hydrogen sulphide (H₂S) is corrosive, toxic and foul-smelling. If not removed, it damages engines, pipelines and equipment and lowers the quality of the gas, so removing it is essential for safe, efficient use.
What is impregnated activated carbon?
➤ Impregnated activated carbon is treated with chemicals such as potassium hydroxide or potassium iodide that react with hydrogen sulphide. This makes it much more effective at removing H₂S than ordinary activated carbon.
Can activated carbon remove other impurities besides H₂S?
➤ Yes. Along with hydrogen sulphide, activated carbon can help remove siloxanes and volatile organic compounds (VOCs), which also affect gas quality and can damage engines and turbines.
Where is activated carbon used for biogas purification?
➤ It is used in biogas and compressed biogas (CBG) plants, sewage and wastewater treatment facilities, landfill gas recovery systems, and food, agricultural and distillery waste-to-energy plants.