The recovery of glycerine from spent soap lye has been done using soap lye samples obtained from the hot process of soap production using palm kernel oil (P.K.O).

The main advantage of hot process is that exact concentration of the lye solution is not known, but to perform this with adequate success, the lye and fat are boiled together at 80 – 1000C at times above 1000C until saponification occurs. The overall weight of glycerine recovered per 100g of oil used was 9.0g. The quantity of spent soap lye obtained was 250ml, Acid value was 555.39, percentage free acid value was 5.6%, total fatty acid = 7.131, percentage free caustic acid = 0.14%, percentage free  fatty acid obtained was 0.07131%, the specific gravity was 1.059, purity of glycerine was 92%. These parameters obtained were measured relatively to international standards with negligible error due to the type of equipment used. From the result, it is evident that the amount of glycerine recovered depends largely on the quantity of spent soap lye. Other processes the spend soap lye and the glycerine undergo as may be seen in other chapters includes, salting out, filtration, splitting and others. 


Title page

Letter of Transmittal

Approval page/certification

Approval page




Table of Contents

List of Figures/Tables

Definition of Terms/Nomenclature

Chapter One

1.0      Introduction

1.1 background of the study

1.2 statement of the problem

1.3 scope and limitation of the study

1.4 Purpose/aim/objectives of the study

1.5 Method of Research

1.6 Significance of the study

Chapter Two

2.0      Literature Review

2.01 Recovery of glycerine from spent soap lye

2.02 Twitchel Process

2.03 Autoclave Saponification

2.04 Lime Saponification

2.05 Acid Saponification

2.06 Aqueous saponification

2.07 Splitting Fats with Ferments

2.08 Kretbitz Process

2.09 Distillation of Fatty Acids

2.10 History of Glycerine

2.11 Lye Clarification

2.12 Glycerol Detection and Estimation

2.13 Glycerine as a by-product of soap manufacture

2.14 Process Description of Soap Production

2.15 Process Summary

2.16 Ion Exchange

2.17 Soap Removal

2.18 Composition of Glycerine production

2.19 Physical properties of Glycerine

2.20 Chemical Properties of Glycerine

2.21 Sources and Types of Lipids

2.22 Distinction between Fats and Oils

2.23 Uses of Glycerine

2.24 Major Types of saponification

2.25 Separation of Glycerine and Free Fatty Acid

2.26 Quantifying the Phosphoric Acid to be used

2.27 Metabolism

2.28 Application of Glycerine in Food

2.29 Application of Glycerine in Urethane Polymers

2.30 Application o Glycerine in Drug and Cosmetics

2.31 Application of Glycerine in Lubricants

2.32 application of Glycerine in Snuffs

2.33 Other Uses of Glycerine

2.34 Hyper Osmotic Effects

2.35 Basic raw material for Glycerine Production

  Chapter Three

3.0      Experimental Procedure

3.01 The Saponification Process

3.02 Splitting Method

3.03 Determination of the viscosity of Glycerine

3.04 Titration

3.05 Percentage Free Alkaline (FCA)

3.06 Bleaching of Crude Glycerine

       Chapter Four

4.0      Experimental Result and Analysis

5.0      Discussion

5.1 Conclusion

5.2 Recommendation

5.3 References

5.4 Appendix      


Table 2.0

Properties of glycerine

Table 2.1

Physical properties of glycerine

Table 4A

Glycerine producer association standard for Glycerine recovery

Table 4B

Estimation consumption of glycerol in various industries

Table 4C

Order of increment of the amount of % glycerine in all the samples.

Table 4D

Standard deviation table for percentage (%) salt and percentage glycerine


%     =      Percentage

N/4  =      Quarter normal

Lbs  =      Pounds

C.C  =      Cubic centimeter

PZ    =      Paterson Zochonis

IEA  =      International Equitable Association

KSI  =      Kitchen Soap Industries

SSL  =      Laboratory Stimulated sample

V      =      Volume of Acid

FFA=      Free fatty Acid

AV   =      Acid Value

SD   =      Standard Deviation

FCA=      Free Caustic Alkali

CA   =      Percentage Concentration of Glycerol

Vs    =      Volume of NaOH added to the sample

Vb    =      Volume of NaOH

 Added to the bank

Ws   =      Weight of Sample

% FAV = Percentage free Acid Value




Glycerine, (otherwise known as propan 1, 2, 3 triol) is found dissolved in the soap lye and also as an impurity in the crude soap during the saponification of fats and oils with caustic soda. Customarily, the process of soap manufacture, from fats and oil yields glycerol to about 10% of the value of the soap formed and due to its varied uses, its recovery is pertinent to the manufacturing cost analysis for any soap making business. Glycerol being an important bye product of soap manufacture, many small scale and medium scale soap manufacturers normally discards the lye as an unwanted product.

Glycerol occurs in nature combined in the form of triglycerides (fats and oil) and is obtained during the saponification of these triglycerides. This process was the only means of producing glycerol commercially, until 1949 when synthetic glycerol was produced as the compound recovered as by-product from the soap manufacture was sufficient for the world consumption. Alternatively, glycerol is synthesized from propene by the alternate chlorination and hydroxylation process. It is also obtained from the fermentation of various sugars. Glycerine is also produced by various routes from propylene. The epichlorohydrin process is the most important; it involves the chlorination of propylene to give ally chloride which is oxidized with a strong base to give epichlorohydrin. This epichlorohydrin is then oxidized to give glycerine.

In biodiesel, glycerine is a waste, as a result, the market for glycerol is depressed and the old epichlorohydrin process for glycerol synthesis is no more economically viable.

Fats and oils are esters of glycerine with long-chain fatty acid such as stearic acid (C17H35COOH) Palmitic acid (C15H31COOH) and oleic acid (C17H33COOH). Since glycerine contains three –OH groups, it can form three series of esters thus;

Mono-ester              di-ester            and tri-esters

CH2.OH                   CH2.OH           CH2.O.OC.R

CH.OH                     CH.O.OC.R      CH.O.OC.R

CH2.O.OC.R            CH2.O.OC.R    CH2.O.OC.R

Mono=-ester            di-ester            tri-ester

Some of the major industrial applications of glycerol include the manufacture of alkyd resins and flexible polyurethane for the plastic industry. It is also an important ingredient in cosmetics and adhesive manufacture. Many pharmaceutical preparations such as glycerol phenol mixture which serves as tranquilizers utilize glycerol.

Glycerol residue has been reported to contain 20.2% glycerol, 6.6% fatty acids (as soap) and 64.3% salt. Thus 91.1% of it is potentially useful. It is obviously advantageous, both environmentally and economically, to recover the glycerol in the waste material from soap industries as a potential alternative for the production of glycerol using chemical methods.


The method of analyzing glycerine is greatly varied due to the fact that glycerine contained impurities which acted so much like glycerine as to introduce serious errors in the determination of crude glycerine. This however led to the appointment of committees in the United States and Europe to investigate the method of glycerine analysis. It was concluded in the meeting of the International Committee set for this purpose, that acetin method should control the buying and selling of glycerine, but the more convenient bichromate method in a standardized form might be used in factory control and other technical purposes.

The quantity of recovered residual salt is dependent on the point of recovery and nature of lye treatment. Neutralizes of the acid and alkaline content of the soap lye helps to reduce the amount of salt originally combined with soap by precipitation, coagulation and flocculation. This is done through their pH adjustments.

The whole process becomes entirely cumbersome as absolute care is taken to ensure that glycerine passes through all the stages required to obtain pure glycerine devoid of impurities.

Purchase Detail

Hello, we’re glad you stopped by, you can download the complete project materials to this project with Abstract, Chapters 1 – 5, References and Appendix (Questionaire, Charts, etc) for N5000 ($15) only,
Please call 08111770269 or +2348059541956 to place an order or use the whatsapp button below to chat us up.
Bank details are stated below.

Bank: UBA
Account No: 1021412898
Account Name: Starnet Innovations Limited

The Blazingprojects Mobile App

Download and install the Blazingprojects Mobile App from Google Play to enjoy over 50,000 project topics and materials from 73 departments, completely offline (no internet needed) with the project topics updated Monthly, click here to install.

0/5 (0 Reviews)
Read Previous


Read Next


Translate »