ABSTRACT
The present study examined the adsorption and corrosive inhibitive properties of neem root on mild steel in alkaline and acidic media. The objectives of the study were to extract liquid from Azadirachta indica (neem) root; inhibit the corrosive mild steel in H2SO4 and NaOH solutions and examine the effects of inhibitor and corrodent concentration on inhibitor efficiency. The neem root was obtained from the neem trees in Michael Okpara University of Agriculture, Umudike. The stock solution of the extract obtained was used in preparing 0.5N, 1.0N H2SO4 and NaOH for mass loss method and 3N, 4N, and 5N H2SO4 and NaOH for thermometric analysis, respectively. The weight loss experiment was carried out at 30 and 600C. The result showed that the corrosion rate was found to increase with increase in the corrodent concentration and also with increase in temperature. The extract from the neem root was found to be an inhibitor for mild steel in 0.5 M H2SO4 and NaOH. However, the metal was found to corrode faster in NaOH than in H2SO4 solution. Inhibition efficiency increased with increase in inhibitor concentration. It was therefore recommended that natural plant extracts such as neem root extract can be utilized as a corrosion agent against corrosion in both acidic and alkaline environment.
TABLE OF
CONTENTS
Cover
page
Declaration
i
Certification
ii
Dedication
iii
Acknowledgment
iv
Table
of contents v
List
of tables vii
List
of figures viii
Abstract
ix
CHAPTER
ONE
INTRODUCTION
1.1
Background of Study 1
1.2 Statement of problem 3
1.3 Aim and Objectives of Study 4
1.4 Justification of Study 4
1.5 Scope of the Study
CHAPTER
TWO
LITERATURE
REVIEW
2.1 Corrosion
6
2.2 Corrosion Inhibitors 6
2.3 Plant based corrosion inhibitors 8
2.3.1 Solvent effect
10
2.3.2 Temperature and Immersion time effect 11 2.3.3 Adsorption mechanism
12
2.4 Extraction 12
2.4.1
Inhibitors Extraction
16
CHAPTER
THREE
MATERIALS
AND METHODS
3.1 Materials 19
3.2 Extraction 19
3.3 Gasometric
method
19
3.4 Thermometric
method 20
3.5 Gravimetric
method (weight loss experiment) 21
CHAPTER
FOUR
RESULTS
AND DISCUSSION
4.1. Effect
of corrodent concentration
22
4.2. Effects of inhibitor concentration on
inhibition efficiency 24
4.3. Products composition of Pyrolytic oil 33
4.4. Higher Heating value of Char
33
CHAPTER
FIVE
CONCLUSION
AND RECOMMENDATION
5.1
Conclusion 29
5.2 Recommendation 29
REFERENCES
LIST OF TABLES
Table 4.1: Values of corrosion rate (mpy), inhibition efficiency (I %)
and degree
of surface coverage (θ) for mild steel
corrosion for neem root in 0.5 M
H2SO4 at 30 oC
and 60oC 25
Table 4.2: Values of corrosion rate (mpy),
inhibition efficiency (I %) and degree
of surface coverage (θ) for mild steel
corrosion for neem root in 0.5 M
NaOH at 30 and 60oC 26
LIST OF FIGURES
Figure 2.1. Basic
parts of a plant and their common active compounds 10
Figure
2.2 Diagrams of common extraction
methods 14
Figure
3.1a: Mild steel coupons before
adsorption 21
Figure
3.1b: Mild steel coupons after
adsorption 21
Figure 4.1a: Plot of corrosion rate against corrodent
concentration for mild steel
corrosion in H2SO4
at 300C and 600C 23
Figure 4.1b: Plot of corrosion rate against corrodent
concentration for mild steel 23
corrosion in NaOH at 300C and 600C
Figure 4.2a: Plot of weight loss against time for mild
steel corrosion in 0.5 M H2SO4 24
in
the absence and presence of extract at 300C
Figure 4.2b: Plot of weight loss against time for mild
steel corrosion in 0.5 M H2SO4 25
in the absence and presence of extract
at 600C
Figure 4.3a: Plot of inhibition efficiency (% I) against
extract concentration for mild 27
steel in H2SO4 at 300C
and 600C
Figure 4.3b: Plot of inhibition efficiency (% I) against
extract concentration for mild 27
steel in H2SO4 at 300C and 600C
DICK, D (2023). Adsorption And Corrosive Inhibitive Properties Of Some Naturally Occurring Substance (A Case Study Of Extracts Of Roots And Fruits Peels In Alkaline And Acidic Media). Mouau.afribary.org: Retrieved Dec 22, 2024, from https://repository.mouau.edu.ng/work/view/adsorption-and-corrosive-inhibitive-properties-of-some-naturally-occurring-substance-a-case-study-of-extracts-of-roots-and-fruits-peels-in-alkaline-and-acidic-media-7-2
DICK, DICK. "Adsorption And Corrosive Inhibitive Properties Of Some Naturally Occurring Substance (A Case Study Of Extracts Of Roots And Fruits Peels In Alkaline And Acidic Media)" Mouau.afribary.org. Mouau.afribary.org, 15 Aug. 2023, https://repository.mouau.edu.ng/work/view/adsorption-and-corrosive-inhibitive-properties-of-some-naturally-occurring-substance-a-case-study-of-extracts-of-roots-and-fruits-peels-in-alkaline-and-acidic-media-7-2. Accessed 22 Dec. 2024.
DICK, DICK. "Adsorption And Corrosive Inhibitive Properties Of Some Naturally Occurring Substance (A Case Study Of Extracts Of Roots And Fruits Peels In Alkaline And Acidic Media)". Mouau.afribary.org, Mouau.afribary.org, 15 Aug. 2023. Web. 22 Dec. 2024. < https://repository.mouau.edu.ng/work/view/adsorption-and-corrosive-inhibitive-properties-of-some-naturally-occurring-substance-a-case-study-of-extracts-of-roots-and-fruits-peels-in-alkaline-and-acidic-media-7-2 >.
DICK, DICK. "Adsorption And Corrosive Inhibitive Properties Of Some Naturally Occurring Substance (A Case Study Of Extracts Of Roots And Fruits Peels In Alkaline And Acidic Media)" Mouau.afribary.org (2023). Accessed 22 Dec. 2024. https://repository.mouau.edu.ng/work/view/adsorption-and-corrosive-inhibitive-properties-of-some-naturally-occurring-substance-a-case-study-of-extracts-of-roots-and-fruits-peels-in-alkaline-and-acidic-media-7-2