A Novel and Cost-Effective Removal of Siloxanes From Wastewater Digester Biogas Using Regenerable Polymeric Adsorbents
biogas, a fuel used to generate electricity, contains siloxanes that can damage combustion engines, leading to expensive repairs and service interruptions. Thermal swing adsorption (regeneration at 250 �c) using silica gel is an effective method to remove siloxane from biogas. In the present study, a novel polyacrylic acid (paa)-based polymer adsorbent was studied as a biogas siloxane adsorbent exposed to adsorption/regeneration cycles. The exhausted polymer adsorbent was regenerated by washing with heated air at 60�80 �c, which afforded a similar capacity for siloxane (d5) adsorption. At room temperature (25 �c), the siloxane adsorption capacity of this polymer was ~80% of that of silica gel. In addition, the thermal desorption of siloxane (d5) from the polymer was more than 95% at a low regeneration temperature of 80 �c, where no siloxane regeneration was observed using conventional silica gel.
Index Terms- Biogas, Siloxane, Adsorbent, Polymer