Cross flow microfiltration of oil–water emulsions using kaolin based low cost ceramic membranes

Abstract

Emphasizing upon the need to develop and target applications of low cost ceramic membranes, this work addresses the cross flow microfiltration (MF) of oil–water emulsions. Membranes prepared using uniaxial dry compaction method and possessing higher average pore sizes (3.06–2.16μm) and porosities (30.1–37.4%) have been used for cross flow MF studies. Cross flow runs were conducted using a feed oil concentration of 400mg/L of for various combinations of trans membrane pressure differentials (138–207kPa) and cross flow velocities (Reynolds number=3417 to 6835). The fitness of various fouling models indicates that combination fouling models could only represent the observed flux decline data which refers to existence of one of the pore blocking phenomena (complete/intermediate/standard pore blocking) during the first 10min of experimental run followed with cake filtration for the data obtained for later time periods. Experimental investigations inferred that the membrane performance is optimal for maximum combinations of trans membrane pressure (ΔP=207kPa), fabrication pressure (73MPa) and minimal cross flow velocity (Re=3417) at which conditions, an optimal combination of fouling index, steady state flux and rejection were obtained as 11.58%, 22.14×10−6m3m−2s and 98.52%, respectively.