A novel approach to process crude oil membrane concentrate using a centrifuge

摘要

The present work discusses an alternative process to handle crude oil membrane concentrate during a degumming process. In this process, the membrane concentrate, which typically consists of 15-30% phospholipids (PL) by weight of oil, is first stripped of hexane and then centrifuged to produce two phases-supernatant (PL < 0.6%) and lecithin concentrate (PL > 62%). The main advantages of this method are limited oil loss, potential lecithin by-product, and a supposedly simpler process. In this work, we first show that the phase behavior of an oil-PL-hexane system can be exploited to identify the various steps of the process. The steps include membrane degumming, hexane evaporation, and centrifugation. Although much knowledge already exists on these unit operations for miscella degumming, it is the combination and sequence of these steps that is proposed here. Since the novelty of this process lies in using a centrifuge after the membrane separations, we focus on this step. Here, we evaluate the dependence of hexane removal, moisture, temperature, hexane amount, residence time, centrifuge g-force, and nonhydratable PL on the phase separations.