Magnitude and Risk Factors of Promiscuous Sexual Behavior among Students in Addis Ababa ...

88 Pages·2016·0.42 MB·English

ADDDIS ABAABA UNIVVERSITTY
SCHOOOL OF GRRADUAATE STUDIES
ADDIIS ABABBA INSTIITUTE OOF TECHHNOLOGGY
DEPAARTMENNT OF CHHEMICAAL ENGGINEERIING

Evaluaation annd optimmization of proocess coonditionss for LLime
sacchaarate claarification in thee manuffacture oof planttation white
sugar:The casee of Metaahara suggar Factoory
By
Abaynneh Bazezzew
A Theesis Submmitted too the Scchool of Graduaate Studiies of Adddis
Ababaa Universsity in Paartial Fulfillmentt of the RRequiremments for the
Degreee of Mastter of Sciience in CChemical Engineeriing
(Food Engineering)

Advisoor Eng. GGachew SShiferaw
Juune, 2011
AAddis Abbaba
ADDIS ABABA UNIVERSITY
SCHOOL OF GRADUATE STUDIES

Addis Ababa Institute of Technology
Department of Chemical Engineering

Evaluation and optimization of process conditions for Lime
saccharate clarification in the manufacture of plantation white
sugar:The case of Metahara sugar Factory
By
Abayneh Bazezew

Approved by the Examining Board:
_____________________ ___________________
Chairman, Department’s Graduate Committee
___________________ ___________________
Advisor
________________________ __________________
External Examiner
________________________ __________________
Internal Examiner
i
Acknowledgement
Above all, I praise the LORD Jesus Christ and next, I want to express my sincere gratitude to my
advisor Eng. Gizachew Shiferaw for excellent scientific guidance and support in fruitful ideas. I
also appreciate all staff of the Chemical Engineering Department for their unreserved assistance,
sharing of knowledge and for extensive scientific discussions. All colleagues and friends of the
members of food engineering, environmental and process engineering streams are greatly
thanked for the enthusiastic studying atmosphere during the entire stay throughout the
programme duration. It is my greatest pleasure to thank Dr.Eng.shimelis Admassu, and
Prof.W.Sokol, in the Department of chemical Engineering and Ato Lemma Gurmu, project and
productivity manager of Metahara Sugar Factory for excellent assistance. Last but not least, my
heartfelt gratitude goes to my wife, W/ro Mesafint Teshome, for her understanding love, patience
and shouldering all the responsibilities. It is her greatest encouragement and sacrifices that
brought this work to a successful end.

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Table of contents
Chapter title page
Title page i
Acknowledgement ii
Table of contents iii
List of tables vii
List of figures Viii
List of acronyms ix
List of appendices x
Abstract xi
1 INTRODUCTION                                                                                                                                                1 
  1.1 Background 1
1.2 Statement of the problem 2
1.3 Objectives                                                                                                                                                2 
   1.3.1 General objective 2
1.3.2 Specific objectives                                                                                                                                  3 
   1.4 Significance of the project 3
2 LITERATURE REVIEW 4
2.1 Production and processing of sugar cane in Ethiopia 4
2.2 Sugar economy in Ethiopia 4
2.3 General overview of Metehara Sugar Factory 6
2.4 Metehara Sugar Factory clarification process steps and their description 7
2.4.1 Objective of juice clarification 9
2.4.2 Methods of clarification                                                                                                                   9 
      iii
2.4.3Reaction of clarification 12
2.4.4 Lime and its behavior in clarification 12
2.4.5 Role of phosphate in juice clarification 14
2.4.6 Summary of lime action on juice clarification 15
2.4.7 Action of SO gas on juice clarification 16
2
2.4.8 Juice sulphitation 17
2.4.8.1 Sulphitation tank 18
2.4.9 SO gas generation 20
2
2.4.9.1 Air compressor 22
2.4.9.2 Sulphure oven 22
2.4.9.3 Air dryer 22
2.4.9.4 Scrubber 22
2.4.10 Milk of lime preparation 23
2.4.11 Lime and its quality 25
2.4.11.1 Solubility of CaO 26
2.4.12Modification of liming system with lime saccharate 28
2.4.13 pH control in a sugar factory 31
2.4.14 Flash tank 31
2.4.15 Flocculants 32
2.4.16 Juice settling 34
2.4.16.1 Juice clarifier 36
2.4.16.2 The Dorr clarifier 37
2.4.16.3 SRI clarifier 38
2.4.17 Recovery of sugar from mud 38
iv
2.4.17.1 Importance of mud filtration 39
2.4.17.2 Mud conditioning for filtration 39
2.4.17.3 Types of filters 39 
3 MATERIALS AND METHODS 42 
 3.1 Materials 42
3.2 Methods 43
3.2.1 Description of experimental setup and sampling technique 43
3.2.2 Brix determination 43
3.2.3 Pol determination 43
3.2.4 Determination of the purity of juice 44
3.2.5 Determination of soluble phosphate 44
3.2.6 Determination of reducing sugars in juice 45
3.2.7 Determination of colour in juice 45
3.2.8 Determination of Calcium and Magnesium 46
3.2.9 pH measurement of juice samples 47
3.2.10 Determination of settling rate 47 
 3.3 Data analysis procedure 48 
4 RESULTS AND DISCUSSION 49 
  4.1 Characterization of mixed juice quality for different combination of cane varieties 49
4.2 Comparisons of clarification performance parameters using milk of lime and lime
saccharate 50
4.3 optimization of clarification parameters using lime saccharate clarification 55
      4.3.1 Optimization results 55
4.3.2 Graphical plot 58 
v
4.4 Effect of lime saccharate clarification on the factory’s performance 61
  4.4.1 Chemical consumption 61 
5 CONCLUSION AND RECOMMENDATION 62
   5.1 Conclusion 62
5.2 Recommendation 62 
REFERENCES 63
APPENDICES 65

Vi
List of tables

Table title page
2.1 Sugar demand projection (2001/02-2012) 5
2.2 Density and concentration of milk of lime 25
2.3 Solubility of lime at different temperature and sucrose content 27
2.4 Mixed juice quality of different cane varieties 49
2.5 Milk of lime treatment case1 50
2.6 Milk of lime treatment case2 51
2.7 Milk of lime treatment case3 51
2.8 Milk of lime saccharate treatment case1 52
2.9 Milk of lime saccharate treatment case 2 52
2.10 Milk of lime saccharate treatment case3 53
2.11 Comparative lime consumption data 61
D.1 5 years’ boiling house perforormance of Metahara Sugar Factory 85
E.1 Lime test 86
E.2 Lime saccharate test 88
E.3 Mixed juice parameters characterization 90
E.4 Optimization data 91

vii
List of figures
Figure title page
2.1 Juice clarification process for the production of plantation white sugar 7
2.2 The raw juice particle 13
2.3 Calcium phosphate bridging 15
2.4 Milk of lime preparation plant of Metehara Sugar Factory 23
2.5 Flow diagram of lime saccharate clarification plant 30
2.6 Settling zones in the clarifier 37
2.7 Quality parameters of cane varieties 49
2.8 Overlay plot of purity 58
2.9 Overlay plot of settling rate 58
2.10 Overlay plot of CaO 59
2.11 Overlay plot of reducing sugars 59
2.12 Overlay plot of mud volume 60

viii
List of Acronyms
Acronym Nomenclature
B’e beaume
Bx Brix
EBA Everything but Arms
EDTA Ethylene di -amine -tetra acetic acid
ESISC Ethiopian sugar industry support center
EU Europian Union
HVA Handlers Vereeniging Amsterdam
ICUMSA International commission for uniform methods of sugar analysis
Lts/day litres per day
MW mega watt
NRNS non removable non sugars
NS non sugars
NSE non sugar removal efficiency
Pol polarization
Ppm parts per million
Qts quintals
RNS removable non sugars
RS Reducing sugars
TCD tonnes of cane per day
TU transfer units

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