Removal of siloxane from digestion gas of sewage sludge

This paper studies the way to remove siloxanes from digestion gas of sewage sludge by adsorbents. Many adsorbents were tested by using the model gas of siloxane in nitrogen. The adsorption ratio was 0.056–0.192 for the activated carbons, 0.004–0.077 for the molecular sieve and 0.104 for the silica gel. An observed tendency was that the activated carbons showed high adsorption ratio, and that the adsorption ratio was increased when BET surface area was higher, and the pore volume was higher and the pH value was higher. Finally, we found a few kinds of activated carbons with the superior ability of adsorption, and we tested the ability of them by using the real digestion gas. All of the siloxanes were found to be removed in the 1000 h test.