Effect of Operating Parameters and Cleaning on the Performance of Ceramic Membranes Treating Partially Clarified Sugar Cane Juice

Abstract

The performance of ceramic membranes with pore sizes of 0.05 and 0.10 µm in purifying limed and partially clarified sugar cane juice was investigated under different operating conditions. From various operating conditions and strategies, switching off the permeate for 5 seconds for every 5 minutes (S5sT5 m) by an automated control valve provided higher flux. From the three pH experiments conducted on the 0.05 µm membrane, the best performance was observed at a pH of 7.5. Amongst the four fouling models tested, the cake filtration model fitted the performance of both membranes with higher accuracy at a transmembrane pressure of 0.5 bar. Filtering the cane juice through the membrane reduced the turbidity by 99.7%, color by 15%, and the starch concentration by 80% as well as increased the purity by 1.4%. The effective cleaning chemical composition from experimental results showed that 1% NaOH and 3000 ppm NaOCl solution performed the best but only for the experiments that were treating limed and partially clarified juice at pH 7.5.

Keywords:

• Ceramic membrane
• membrane fouling
• purity rise
• sugar cane juice
• transmembrane pressure (TMP)

ACKNOWLEDGEMENTS

Sugar Research and Development Corporation (SRDC) funded a project entitled “JCU029: evaluation of membrane technology for clarification of sugar cane juice (2007–2009)” to carry out this work. Mr. Bryn McDonagh of ATA Scientific Pty Ltd, NSW, Australia carried out particle size analysis on the permeate samples and provided valuable suggestions. Messrs. Curt Arrowsmith, Stuart Petersen, and John Ellis of the School of Engineering and Physical Sciences, James Cook University, are also acknowledged for providing assistance in purchasing and installing the membrane system.

Notes

F-Feed; P-Permeate.

• Cost calculated using: NaOH = AU$ 8.6/kg (technical grade) and NaOCI = AU$1.4/liter (active chlorine 12%).

• Constant operating protocol for all cleaning runs: TMP = 0.2 bar, cross-flow velocity = 1.5 m/s Temperature = 50°C, Duration = 30 minutes.