BiOXYGEN by SYSADVANCE makes use of the PSA technology to produce pure oxygen from air by selective adsorption of N2 on a special molecular sieve material. As a result, only O2 is injected in your bioprocess for H2S reduction avoiding the biogas dilution with contaminants.
A special O2 injection system developed by SYSADVANCE use proportional valves injecting O2 as a function of external process variable such as the H2S content in the raw biogas, raw biogas flow or even a combination of both is available.
Oxygen production cost per Nm3 of biogas treated is extremely low ranging from 0,0005€ to 0,0010€.
SYSADVANCE offers a wide range of O2 injection systems (PSA and VSA) covering the needs for anaerobic digestion plants with production capacities between 20 Nm3/h and 2000 Nm3/h of raw biogas.
Hydrogen sulphide is formed during the anaerobic digestion of organic material containing Sulphur. Its presence in the biogas significantly reduces the lifetime of pipework, instrumentation, analytical equipment, CHP, blowers, compressors or even the adsorbent material from biogas upgrading processes.
Hydrogen sulphide can be removed from biogas by different chemical, physical, and biological procedures. Most of them require small amounts of O2 to be effective.
Air injection with blower is currently the method used to supply O2 into the different H2S reduction processes. The major inconvenient is that Nitrogen (N2) – which corresponds to 79% of the air content - is introduced into the biogas has contaminant reducing its heating value.
This is even more problematic if the target is to upgrade biogas to biomethane due to the fact that most part of the upgrading technologies is not able to remove N2 from CH4 (e.g., scrubbing with amines, water or chemical solvent), except for Vacuum-Pressure Swing Adsorption (VPSA) which can remove approximately half of the N2 content.