Quarg-making by ultrafiltration using polymeric and mineral membrane modules: a comparative performance study

Abstract

The present study was conducted to evaluate the performance of Hollow Fiber (HF-43 and 60), Carbosep S7 and Ceraver (P-19-40) modules for ultrafiltration of coagulated skim milk at pH 4.6 for making quarg. Three basic parameters, ie permeate flux, energy consumption/m3 permeate and retention coefficients of total solids, protein, lactose and calcium, were taken for comparative evaluation. The average permeate flux in case of Hollow Fiber-43 to achieve concentration factor (CF) = 2 was 31.52 l.h-1.m-2 and in case of Hollow Fiber-60 to obtain CF = 4 from CF = 2 concentrate was 23.19 l.h-1.m-2. The average flux to reach CF = 4 in case of Carbosep and Ceraver modules was 27.75 and 86.13 l.h-1.m-2, respectively. The retention of protein by all types of membranes at CF = 4 was the same. The energy consumption in the case of Hollow Fiber-43 and -60, Carbosep and Ceraver to obtain CF = 4 was 3.14, 16.78 and 7.12 kWh/m3 permeate collected. The lower energy consumed by Hollow Fiber modules was due to the lower operating velocity, ie 0.6 m/s as compared to 4.7 m/s in 1 the, other 2 modules. The Ceraver microfiltration module P-19-40 was found to be the best for making quarg by ultrafiltration of coagulated skim milk of all the modules investigated. Although this module has a double energy requirement as compared to Hollow Fiber modules, its average flux is much higher. This module is easy to clean. On the other hand, Hollow Fiber membranes fouled by coagulated skim milk require vigorous cleaning with additional energy expenditure.