Vacum Pressure Swing Adsorption
Using differential adsorption, this separation method efficiently separates methane (CH4) and carbon dioxide (CO₂) on an adsorbent material, offering low energy consumption. It also partially separates nitrogen (N₂) and minimises methane losses while handling biogas with high O₂ and N₂ concentrations.
Based on the differential diffusion behavior of chemicals through a specific membrane, this method offers simplicity, low energy consumption, and suitability for both small and large-scale productions. It ensures minimal methane losses.
Based on differential solubility in a washing liquid, this method separates biogas components. Those more soluble in amine or alkaline salt solutions (e.g., KOH) are absorbed and removed from the gas stream. Chemical absorption with amines is suitable for high flow rates, ensuring minimal methane losses.
Pressurized Water Scrubbing (PWS)
Based on differential solubility in water at low pressures and temperatures, this method separates compounds from the biogas. The most soluble components in the wash water are removed from the gas stream. The process regenerates the water by extracting air, which ensures low maintenance costs.