Determination of gas-liquid partition coefficients of volatile methyl siloxanes by vapor phase calibration method

The presence of siloxanes in biogas can remarkably reduce the efficiency of energy recovery from biogas. Hence, pretreatment processes have been applied to remove siloxanes from biogas. The gas-liquid mass transfer of siloxanes was characterized using L2, L3, lA, D4, and D5 which are often presented in biogas. The vapor phase calibration method using head space analyses by GC was used to directly measure the gas-liquid partition coefficient of siloxanes. Gas-liquid partition coefficients of siloxanes tended to become smaller as molecular weight increased. For both linear and cyclic siloxanes, the vapor pressure and the aqueous solubility decreased as the compound molecular weight increased. The results obtained provide a useful database for estimating behaviors of volatile methyl siloxanes. These results can be utilized as design and operational parameters to develop the siloxanes removal processes in biogas utilization systems. This is an abstract of a paper presented at the AWMA's 107th Annual Conference & Exhibition (Long Beach, CA 6/24-27/2014).