1. De-alcoholization and extraction of organic acids using
Liquid Emulsion Membranes
Dissertation work submitted in partial fulfillment of the requirement
For the degree of
Master of Technology in Chemical Engineering
Of
Visveswaraiah Technological University
Belgaum.
By
Chanukya B. S.
Reg No: 1SI07HCE01
Place of Investigation
Department of Food Engineering,
Central Food Technological Research Institute (C.F.T.R.I), Mysore
A constituent laboratory of Council of Scientific and Industrial Research, New Delhi, India
Under the Guidance of
Dr. P. Nirguna Babu Dr. Navin K. Rastogi
Professor and Head, Scientist,
Dept. of Chemical Engineering Dept. of Food Engineering
SIT, Tumkur-572 103 CFTRI, Mysore –570 020
Department of Chemical Engineering
Siddaganga Institute of Technology
Tumkur-572 103, KARNATAKA, INDIA
2008-2009

2. Synopsis
In the removal and the concentration of the product, the most preferred methods are
membrane separation processes. Despite the advantages, there are limitations with membrane
separations; such as loss of their activities in harsh conditions or not sufficiently effective or too
expensive or difficult to scale up. To overcome these limitations, Liquid emulsion membranes
(LEM), which has the potential advantages of having selectivity higher than those attainable by
current separation methods, saving on energy costs for final concentration of separated product,
was chosen.
Two kinds of LEM experiments are carried out here. First; deals with de-alcoholizing a
solution using liquid emulsion membranes, due to its simplicity in design and operation and
retains normal character of the feed solution. Effects of various parameters on the de-
aloholization rate were studied in detail. Extraction of alcohol from real solutions like
Anthocyanin extract solution and simulated pineapple wine has been carried out.
Second; extraction of organic acids from dilute solutions using LEM by tailoring the
emulsion composition for the purpose, the effect of various parameters on extraction has been
thoroughly studied. The extraction results have varied with different parameters.
This work traces the development of LEMs, discusses their key features, advantages and
limitations, and explains with experimentation how the LEM can be best used by optimizing its
conditions to maximize its extraction. Describes methods of modeling LEM systems and
highlights some applications with industrial potential. The optimum operating conditions for the
extraction of alcohol and organic acids are evaluated experimentally.

3. TABLE OF CONTENTS
Page
ACKNOWLEDGEMENTS …………………………………………………….. I
SYNOPSIS ……………………………………………………………….………. III
TABLE OF CONTENTS………………………………………………………… IV
LIST OF TABLES ………………………………………………………….......... VIII
LIST OF FIGURES …………………………………………………………….... IX
CHAPTER 1: INTRODUCTION
1.1: General introduction............................................................................................ 1
1.2: Economic importance of downstream operations................................................ 1
1.2.1: Stages in downstream processing.………………………………………... 2
1.2.2: Conventional downstream operations……………………………………. 3
1.2.3: Limitations of existing membrane separation techniques……………........ 3
1.3: Liquid Emulsion Membranes - Recent development in downstream operation... 4
1.3.1: Why Liquid Emulsion Membrane Technology?…………………………. 5
1.4: Aim of the present work…………...…………………………………................ 7
CHAPTER 2: REVIEW OF LITERATURE & THEORETICAL ASPECTS
2.1: In Food processing……………………………………………………………… 8
2.2: Other areas……………………………………………………………………… 12
2.3: National status………………………………………………………………….. 13

4. 2.4: Properties of Emulsion and its components……………………………………. 15
2.4.1: Lecithin as surfactant……………………………………………………... 15
2.4.2: Liquid light paraffin oil as membrane phase..……………………………. 16
2.4.3: Dispersed phase as Distill water ….……………………………………… 16
2.4.4: Kerosene as organic phase……………………………………………….. 16
2.4.5: Aliquat 336 as carrier…………………….………………………………. 17
2.4.6: Span 80 as surfactant…..…………………………………………………. 17
2.4.7: Sodium carbonate as stripping phase...…………………………………… 18
2.5: Principle behind Extraction of Organic acids using LEMs...…………………… 18
2.6: Factors affecting LEM performance……………………………………………. 20
2.6.1: Membrane Rupture……………………………………............................... 20
2.6.2: Membrane Swelling……………………………………………………….. 20
2.6.3: Selectivity…………………………………………………………………. 21
2.6.4: Enzyme Inactivation by the Membrane…………………………………… 21
2.7: Mathematical modeling…………………………………………………………. 22
2.8: Quality control tests for Emulsions…………………………………………. …. 25
2.8.1: Stability testing……………………………………………………………. 25
2.8.2: Determination of particle size and particle count…………………………. 26
2.8.3: Determination of viscosity………………………………………………… 26
2.8.4: Determination of phase separation………………………………………… 26
2.8.5: Determination of Electrophoretic properties………………………………. 26
2.8.6: Rheological studies………………………………………………………... 27
2.9: Preservation of Emulsions……………………………………………………….. 27

5. 2.9.1: Preservation from microorganisms………………………………………… 27
2.9.2: Preservation from oxidation……………………………………………….. 27
CHAPTER 3: RESEARCH METHODOLOGY & EXPERIMENTAL SET UP
3.1: De-alcoholization. …………………………………………………………......... 28
3.1.1: Materials…………………………………………………………………… 28
3.1.2: Methods…………………………………………………………………… 28
3.1.2.1: Emulsion preparation……………………………………………………. 28
3.1.2.2: Extraction ………………………………………………………………. 29
3.1.2.3: Alcohol estimation………………………………………………………. 29
3.1.2.4: Measurement of membrane swelling…………………………………..... 31
3.2: Extraction of organic acids……………………………………………………… 31
3.2.1: Materials ………………………………………………………………….. 31
3.2.2: Methods …………………………………………………………………... 31
3.2.2.1: Preparation of Emulsion…………………………………………………. 31
3.2.2.2: Extraction……………………………………………………………….. 31
3.2.2.3: De-emulsification……………………………………………………...... 32
3.2.2.4: Estimation………………………………………………………………. 32
CHAPTER 4: RESULTS AND DISCUSSIONS
4.1: Effect of various parameters on the De-alcoholization rate…………………..... 34
4.1.1: Effect of surfactant (lecithin) concentration and reaction time on
percentage alcohol extraction………………...…………………………… 34
4.1.2: Effect of stirring time on extraction rate.……...……………………………… 38

6. 4.1.3: Effect of stirring speed on extraction rate…………………………….….. 40
4.1.4: Effect of exterior phase (Feed) concentration ……………………………. 42
4.1.5: Effect of exterior phase (Feed) volume ………………………………….. 44
4.1.6: Effect of internal aqueous (Dispersed) phase…………………………….. 46
4.1.7: Multiple stage extraction ………………………………………………….......... 48
4.1.8: De-alcoholization of Anyhocyanin extract solution……………………… 50
4.1.9: De-alcoholization of simulated pineapple wine………………………….. 52
4.2: Effect of various parameters on the extraction of organic acids……………….. 54
4.2.1: Effect of the Surfactant concentration……………………………………… 54
4.2.2: Effect of stirring time.……………………………………………………. 56
4.2.3: Effect of stirring speed…………………………………………………… 58
4.2.4: Effect of External phase (Feed) concentration...…………………………. 60
4.2.5: Effect of External phase (Feed) volume ……...…………………………... 62
4.2.6: Effect of stripping reagent volume ……………………………………….. 64
4.2.7: Effect of stripping reagent concentration ………………………………… 66
4.2.8: De-Emulsification …………………………………………........................ 68
4.3: Extraction of other organic acids…...……………………………………….. 70
CONCLUDING REMARKS……… …………………………………………....... 75
CONTRIBUTIONS OF THE WORK……………………………………………. 77
SCOPE FOR FUTURE WORK………………………………………………….. 78
BIBLIOGRAPHY………………………………………………………………….. 79
LIST OF TABLES:

7. Table Title Page
1.1: cost of downstream process………………………............................................. 2
4.1.1: Efect of surfactant concentration on De-alcoholization rate………………… 36
4.1.2: Effect of stirring time on the de-alcoholization rate.…………………. …….. 38
4.1.3: Effect of stirring speed on the de-alcoholization rate…………………........... 40
4.1.4: Effect of feed concentration on the de-alcoholization rate…………………... 42
4.1.5: Effect of feed volume on the de-alcoholization rate…..……………………... 44
4.1.6: Effect of dispersed phase volume on the de-alcoholization rate……………... 46
4.1.7: Effect of multiple stage extraction on the de-alcoholization rate..…………… 48
4.1.8: De-alcoholization of Anthocyanin extract solution…………………………... 50
4.1.9: De-alcoholization of simulated pineapple wine……………………………... 52
4.2.1: Effect of surfactant concentration on rate of citric acid extraction…………. 54
4.2.2: Effect of stirring time on rate of citric acid extraction………………………. 56
4.2.3: Effect of stirring speed on rate of citric acid extraction…………...………… 58
4.2.4: Effect of Feed concentration on rate of citric acid extraction……..………… 60
4.2.5: Effect of Feed volume on rate of citric acid extraction…..………………….. 62
4.2.6: Effect of stripping volume on rate of citric acid extraction………………….. 64
4.2.7: Effect of stripping concentration on rate of citric acid extraction…………… 66
4.2.8: Effect of sonication on de-emulsification…………………….. …………….. 68
4.3.1: Percentage Acetic acid extracted and percentage feed recovered…………… 70
4.3.2: Percentage Ascorbic acid extracted and percentage feed recovered….……… 71
4.3.3: Percentage Formic acid extracted and percentage feed recovered….……….. 71
4.3.4: percentage Lactic acid extracted and percentage feed recovered..…………… 71
LIST OF FIGURES:
Figures Title Page

8. 1.1: Thin Sheet supported Liquid membrane…..……………………………………. 4
1.2: Emulsion Liquid Membrane……………………………………………………. 5
2.1: Structure of Lecithin...…………….. …..……………………………………… 15
2.2: Structure of Aliquat 336………………………………………………………... 17
2.3: Structure of Span 80………………………………………………..…………... 17
2.4: Transport mechanism in LEMs ………………..……………………………….. 19
2.5: Lumped two-phase model of a LEM globule…….…………………………….. 22
2.6: The advancing front model…….……………………………………………...... 24
2.7: The reaction zone model………………………………………….…………….. 25
3.1: Steps in the preparation of liquid emulsion……………...……………………… 28
3.2: Standard graph to find concentration of alcohol.……………………………… 30
4.1.1: Effect of surfactant concentration at different stirring speed………….……. 37
4.1.2: At varying stirring time……..………………………..………………..…….. 39
4.1.3: At varying stirring speed ………………………...………………….………. 41
4.1.4: Varying concentration of alcohol in the Exterior (Feed) phase.…………….. 43
4.1.5: Varying volumes of feed solution……………..………………………..…… 45
4.1.6: At varying ratios of oil: dispersed phase………..…………………………… 47
4.1.7: Subjecting feed to repeated extraction…………………….………………… 49
4.1.8: De-alcoholizing Anthocyanin extract solution …………………….....…....... 51
4.1.9: De-alcoholizing simulated pineapple wine………………………...………… 53
4.2.1: Effect of surfactant concentration on extraction of citric acid.………………. 55
4.2.2: Effect of stirring time on extraction of citric acid……….………………….. 57
4.2.3: Effect of stirring speed on extraction of citric acid…………………………. 59
4.2.4: Effect of feed concentration on the extraction of citric acid ……………….. 61
4.2.5: Effect of feed volume on the extraction of citric acid……………………… 63

9. 4.2.6: Effect of stripping volume on extraction of citric acid….…………….…….. 65
4.2.7: Effect of stripping concentration on extraction of citric acid……….……… 67
4.2.8: Effect of sonication time on De-Emulsification. ………….………………… 69
4.3.1: Extraction of different organic acids at varying contact periods……………. 72
4.3.2: percentage feed recovery, after extraction at different contact periods.….…. 72