Description:DESCRIPTION:
Field of the invention:
[0001] The present disclosure generally relates to the technical field of a green corrosion inhibitor, and in specific relates to a method for preparing a composition of allium sativm and allium cepa skins extract as the green corrosion inhibitor for iron metal in a sulphuric acid environment, thereby reducing environmental impact and offering cost-effective protection for iron assets.
Background of the invention:
[0002] Iron is one of the most abundant and readily accessible metals, making it a popular choice for construction, machinery, tools, and various other applications. Its tensile strength, ductility, and low cost contribute to its extensive use. Despite its strength, iron rapidly reacts with oxygen and moisture in the environment, leading to rust, a type of iron oxide. Corrosion is a called process that degrades that structure of the metal, affecting the performance and lifespan. While corrosion happen naturally, environments containing strong acids like sulphuric acid significantly accelerate the process.

[0003] Sulphuric acid is widely employed in a variety of industrial processes, battery production, and cleaning agents. Exposure to such environments iron components to deteriorate quickly, leading to material damage, and economic losses. Susceptibility of iron to corrosion, especially in acidic environments, is crucial for industries and individuals relying on this versatile metal. By employing corrosion prevention strategies like protective coatings, inhibitors, and material selection, the lifespan and safety of iron-based structures and equipment can be significantly extended.

[0004] Diminish the difficulties, corrosion inhibitors are employed. These chemicals work by interfering with the corrosion process, and decreasing pace of material degradation. Traditionally, effective corrosion inhibitors were frequently manufactured with chemicals like chromates, phosphates, and nitrates that can pose significant environmental and health risks. Some conventional inhibitors can be acutely or chronically toxic to humans and other organisms. Exposure can cause skin irritation, respiratory problems, or even organ damage. These chemicals can also accumulate in the environment, disrupting ecosystems and posing risks to wildlife. They have the potential to pollute water bodies and contaminate soil, leading to long-term environmental damage.

[0005] Bio-based corrosion inhibitors are derived from renewable sources like plant extracts, agricultural waste, or microbial products. These provide a sustainable and environmentally friendly alternative to traditional chemicals. The bio-based inhibitors frequently possess desirable properties like biodegradability, low toxicity, and readily available raw materials. Furthermore, they can be modified for specific applications and potentially offer good performance in various environments.

[0006] In existing technology, a plant extract-based food additive is known. The plant extract-based food additive is belongs to the technical field of food additives. The food additive comprises onion extract, garlic extract, green tea extract, ginkgo leaf extract, momordica grosvenori, mulberry anthocyanian extract, dark plum extract and remaining of water. The food additive has effects of relieving fatigue, killing bacteria, removing toxic substance, and enhancing immunity. However, the plant extract-based food additive that may have the potential to corrode the material. Moreover, the plant extract-based food additive that damage the environment include polluting water bodies and contaminating soil, and being difficult to handle.

[0007] Therefore, there is a need for a method for preparing a bio-based corrosion inhibitor composition that utilises a mixture of allium sativum and allium cepa skin to create of green corrosion inhibitors. There is also a need for a method for preparing a bio-based corrosion inhibitor composition that provides green inhibitors for corrosion industry through safety, biodegradability, ecological acceptability, and renewability. Further, there is also a need for a method for preparing a bio-based corrosion inhibitor composition that is effective corrosion protection and reduces the need for frequent repairs and replacements of iron equipment, lowering overall maintenance costs.
Objectives of the invention:
[0008] The primary objective of the invention is to a method for preparing a bio-based corrosion inhibitor composition that provides green inhibitors for corrosion industry through safety, biodegradability, ecological acceptability, and renewability.

[0009] Another objective of the invention is to a method for preparing a bio-based corrosion inhibitor composition that reduces environmental impact and offering cost-effective protection for iron assets.

[0010] The other objective of the invention is to a method for preparing a bio-based corrosion inhibitor composition that utilises the availability of bio-waste to promote resource recovery and sustainability.

[0011] The other objective of the invention is to a method for preparing a bio-based corrosion inhibitor composition that reduces the need for frequent repairs and replacements of iron equipment, lowering overall maintenance costs.

[0012] Yet another objective of the invention is to a method for preparing a bio-based corrosion inhibitor composition that provides a cost-effective and eco-friendly alternative to synthetic corrosion inhibitors.

[0013] Further objective of the invention is to a method for preparing a bio-based corrosion inhibitor composition that eliminates the need for potential harmful synthetic chemicals, and provides a safer alternative for both humans and the environment.
Summary of the invention:
[0014] The present disclosure proposes a method for preparing a bio-based corrosion inhibitor composition for iron metal substrate. The following presents a simplified summary in order to provide a basic understanding of some aspects of the claimed subject matter. This summary is not an extensive overview. It is not intended to identify key/critical elements or to delineate the scope of the claimed subject matter. Its sole purpose is to present some concepts in a simplified form as a prelude to the more detailed description that is presented later.

[0015] In order to overcome the above deficiencies of the prior art, the present disclosure is to solve the technical problem to provide a method for preparing a composition of allium sativm and allium cepa skins extract as the green corrosion inhibitor for iron metal in a sulphuric acid environment, thereby reducing environmental impact and offering cost-effective protection for iron assets.

[0016] According to an aspect, the invention provides a method for a novel bio-based corrosion inhibitor composition for iron metal substrate. At one step, collects plurality of allium sativum and allium cepa skins and thoroughly rinse with de-ionised water to remove dirt and debris. At another step, the plurality of allium sativum and allium cepa skins is dried with paper towels in a well-ventilated area for at least 4 weeks at room temperature. At another step, the plurality of allium sativum and allium cepa skins is grinds into a fine powder using a grinder or blender. At another step, extracts a weight of 20 gr each of allium sativum and allium cepa skins powder, mixing with 500 ml of the de-ionized water for at least 3 hr to obtain mixture through a soxhlet extraction process.

[0017] At another step, filter the mixture in a centrifuge tube for at least 20min to remove residual debris, thereby extracting a solution in a flask. At another step, 54.4 ml of sulfuric acid (H2SO4) is diluting with 1lit of de-ionised water to obtain a stock solution of 1 M H2SO4. At another step, the stock solution is mixes with the mixture at different volume concentrations through parts per million (PPM), thereby attaining an inhibitor solution. Further, at another step, at least one metal substrate is immerse in a specific concentrations for at least 24hr at room temperature, thereby determining a corrosion rate and a surface deterioration analysis of the at least one metal substrate.

[0018] In one embodiment herein, the 1 M H2SO4 is a solution containing one mole of sulfuric acid with 98 gr dissolved in the de-ionised water to make one lit of the inhibitor stock solution. In one embodiment herein, the inhibitor solution is derived for mixing the stock solution with the mixture at different volume concentration of 0, 300, 600, and 900 PPM, thereby performing the corrosion rate and the surface deterioration analysis.

[0019] In one embodiment herein, the each metal substrate is made up of an iron material. In one embodiment herein, the each metal substrate is measured by a sensitive analytical balance for calculating weight loss and corrosion rate at before and after immersion test in the each concentration solution. In another embodiment herein, the corrosion rate and the surface deterioration analysis of the at least one metal substrate are calculated by scanning electron microscopy (SEM), and atomic force microscopy (AFM).

[0020] Further, objects and advantages of the present invention will be apparent from a study of the following portion of the specification, the claims, and the attached drawings.
Detailed description of drawings:
[0021] The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate an embodiment of the invention, and, together with the description, explain the principles of the invention.

[0022] FIG. 1 illustrates a flowchart of a method for a method for preparing a bio-based corrosion inhibitor composition for iron metal, in accordance to an exemplary embodiment of the invention.

[0023] FIG. 2A illustrates a pictorial representation of a process for preparing the bio-based corrosion inhibitor composition for iron metal, in accordance to an exemplary embodiment of the invention.

[0024] FIG. 2B illustrates a schematic view of a metal substrate, in accordance to an exemplary embodiment of the invention.

[0025] FIG. 3A illustrates a pictorial representation of the at least one metal substrate without inhibitor solution of a SEM test, in accordance to an exemplary embodiment of the invention.

[0026] FIG. 3B illustrates a pictorial representation of the at least one metal substrate with inhibitor solution of the SEM test, in accordance to an exemplary embodiment of the invention.

[0027] FIGs. 4A-4B illustrate pictorial representations of the at least one metal substrate with and without an inhibitor solution of an AFM test, in accordance to an exemplary embodiment of the invention.

[0028] FIGs. 5A-5D illustrate graphical representations of the weight loss against different inhibitor solution concentrations in 1 M H2SO4 after 24 hr immersion of the at least one metal substrate at different temperatures, in accordance to an exemplary embodiment of the invention.

[0029] FIG. 6 illustrates a graphical representation of a corrosion rate and an inhibitor efficiency of the at least one metal substrate immersed in the stock solution of 1 M H2SO4, in accordance to an exemplary embodiment of the invention.

[0030] FIG. 7A illustrates a graphical representation of a Langmuir isotherm of the metal substrate in 1 M H2SO4, in accordance to an exemplary embodiment of the invention.

[0031] FIG. 7B illustrates a graphical representation of an Arrhenius plot of log CR versus 1000/T, in accordance to an exemplary embodiment of the invention.
Detailed invention disclosure:
[0032] Various embodiments of the present invention will be described in reference to the accompanying drawings. Wherever possible, same or similar reference numerals are used in the drawings and the description to refer to the same or like parts or steps.

[0033] The present disclosure has been made with a view towards solving the problem with the prior art described above, and it is an object of the present invention to provide a method for preparing a composition of allium sativm and allium cepa skins extract as the green corrosion inhibitor for iron metal in a sulphuric acid environment, thereby reducing environmental impact and offering cost-effective protection for iron assets.

[0034] According to an exemplary embodiment of the invention, FIG. 1 refers to a flowchart 100 of a method for preparing a bio-based corrosion inhibitor composition for iron metal. At step 102, collects plurality of allium sativum and allium cepa skins and thoroughly rinse with de-ionised water to remove dirt and debris. At step 104, the plurality of allium sativum and allium cepa skins is dried with paper towels in a well-ventilated area for at least 4 weeks at room temperature. At step 106, the plurality of allium sativum and allium cepa skins is grinds into a fine powder using a grinder or blender. At step 108, extracting a weight of 20 gr each of allium sativum and allium cepa skins powder and mixing with 500 ml of the de-ionized water for at least 3 hr to obtain mixture through a soxhlet extraction process.

[0035] At step 110, filter the mixture in a centrifuge tube for at least 20 min to remove residual debris, thereby extracting a solution in a flask. At step 112, 54.4 ml of sulfuric acid (H2SO4) is diluting with 1lit of de-ionised water to obtain a stock solution of 1 M H2SO4. At step 114, the stock solution is mixes with the mixture at different volume concentrations through parts per million (PPM), thereby attaining an inhibitor solution. Further, at step 116, at least one metal substrate 202 (as shown in FIG. 2B) is immerse in a specific concentrations for at least 24 hr at room temperature, thereby determining a corrosion rate and a surface deterioration analysis of the at least one metal substrate 202.

[0036] In one embodiment herein, the allium cepa is an onion skin. Onion is one of the important crops among all horticultural commodities. The onion is processed mainly for flakes, powder, oil, and pickle via various unit operations, such as peeling, cutting, slicing, and dicing. At the industrial level, processing of onion generates huge amount of onion waste in the form of skin, stalk, and root. In general, onion waste can be categorized into industrial waste, domestic waste, and post-harvest or supply chain waste. In one embodiment herein, the allium sativm is a garlic skin, which is derived from the agriculture aspect. The environmental waste of garlic peel is about 16-20 percent of seed stock weight. Approximately 2.3-2.9 million tons of garlic peels were generated as waste worldwide. The peels are composed of 41-50 percent of cellulose, 16-26 percent of hemi cellulose and 26-30 percent of lignin.

[0037] According to another exemplary embodiment of the invention, FIG. 2A refers to a pictorial representation of a process for preparing the bio-based corrosion inhibitor composition for iron metal. In one embodiment herein, the plurality of allium cepa and sativm skins are washed and dried at room temperature for four weeks, and then grinds into the fine powder. Later, 20 gr each of powdered plurality of allium cepa and sativm skins are mixed with 500 ml of deionized water to obtain the mixture through the soxhlet extraction process at 90 degrees for at least 3 hr. The soxhlet extraction process is a special apparatus to continuously extract the desired components from the solid mixture using a refluxing solvent. The extract is then filtered using a centrifuge to remove any solid particles.

[0038] Later, the preparation of the stock solution of 1 M sulfuric acid is prepared by diluting 54.4 ml of 98% sulfuric acid in 1 lit of distilled water. Three immersion 1 M sulfuric acid is prepared by diluting 54.4 ml of 98 percent of sulfuric acid in 1 lit of distilled water. Later, the preparation of plurality of metal substrate 202 through cut into identical square coupons of two sizes 30x30 mm and 20x20 mm. The surface of the at least one metal substrate 202 are polished with abrasive papers to remove any protective layer and expose the bare metal for corrosion analysis. The polished of at least one metal substrate 202 cleaned with ethanol, rinsed with deionized water, and dried.

[0039] Later, analysis corrosion test of the at least one metal substrate 202. The weight of the at least one metal substrate 202 is accurately measured before immersion test. The at least one metal substrate 202 are then immersed in the different inhibitor solutions (including the control solution without inhibitor) for at least 24 hr at 308 K (35°C) through the American society of tool and material testing (ASTM G31-72 standard).

[0040] In one example embodiment herein, the corrosion testing is very nature precludes complete standardization. The ASTM G31-72 standard, rather than a standardized procedure, is presented as a guide so that some of the pitfalls of such testing may be avoided. Experience has shown that all metals and alloys do not respond alike to the many factors that affect corrosion and that “accelerated” corrosion tests give indicative results only, or may even be entirely misleading. It is impractical to propose an inflexible standard laboratory corrosion testing procedure for general use, except for material qualification tests where standardization is obviously required.

[0041] Later immersion the at least one metal substrate 202 are re-weighed, and the weight loss is calculated. The corrosion rate for each metal substrate 202 is determined based on the weight loss data by the following expression
(1)
Where, CR - Corrosion rate (mmpy), W - Weight loss of metal substrates (gm), ? - Density (gm/cm3), t - Immersion time (h), A – Surface area (cm2).

[0042] From the above calculated corrosion rate values (CR) the inhibition efficiencies for the Iron, specimens in 1 M H2SO4 solutions containing different concentrations of inhibitor solutions at various temperatures were calculated by the following equation.
(2)
Where = corrosion rate absence of inhibitor, = corrosion rate in presence of inhibitor.

[0043] Later, the preparation of surface analysis is calculated by the scanning electron microscopy (SEM) and atomic force microscopy (AFM) are used to analyse the surface of the coupons before and after immersion in the inhibitor solutions and the control solution. SEM images reveal the extent of cracking and other surface damage caused by corrosion. AFM analysis provides quantitative data on the surface roughness of the coupons. In one embodiment herein, the plurality of metal substrate is made up of an iron material.

[0044] According to another exemplary embodiment of the invention, FIG. 3A refers to a pictorial representation 302 of the at least one metal substrate 202 without inhibitor solution of the SEM test. In one embodiment herein, the SEM image typically provides high magnification views of surfaces, often in the range of thousands to tens of thousands of times. The SEM image show the topography of the iron metal substrate, including any cracks, or other irregularities. The presence and severity of these features can be indicative of the extent of corrosion. The grain structure of the metal substrate 202 is crystal lattice. Depending on the preparation of the at least one metal substrate 202 show any contaminants present on the surface, such as dust particles or corrosion products.

[0045] According to another exemplary embodiment of the invention, FIG. 3B refers to a pictorial representation 304 of the at least one metal substrate 202 with an inhibitor solution of the SEM test. In one embodiment herein, the SEM image of iron metal with an inhibitor solution can vary greatly depending on several factors, including type of inhibitor, inhibitor concentration, and exposure time. The inhibitor solution is effective at protecting the iron from corrosion, the surface will appear smoother than untreated iron, which is typically rough and uneven due to the formation of the corrosion product. The at least one metal substrate 202 is typically rough and uneven due of formation of corrosion product. In some cases, might be able to see the inhibitor molecules themselves on the iron metal surface. The inhibitor solution may affect the grain structure of the iron, which can be seen in the SEM image as changes in the brightness or contrast of different areas of the surface.

[0046] According to another exemplary embodiment of the invention, FIGs. 4A-4B refer to pictorial representations (402, 404) of the at least one metal substrate 202 with and without the inhibitor solution of the AFM test. In one embodiment herein, the surface of the at least one metal substrate 202 is much smoother and more even than the surface without inhibitor solution. This is because the inhibitor has formed a protective film on the surface of the metal, which prevents it from corroding. The AFM test is conducted on a surface of the metal substrate 202 with pits and cracks, after immersing the metal substrate 202 into the inhibitor solution. Later, immersing of the at least one metal substrate 202, which is formed a protective film, thereby preventing from corroding.

[0047] According to another exemplary embodiment of the invention, FIGs. 5A-5D refer to graphical representations (502, 504, 506, 508) of the weight loss against different inhibitor solution concentrations in 1 M H2SO4 after 24 hr immersion of the at least one metal substrate 202 at different temperatures. The temperatures (303K, 308K, 313K, and 318K) with varying concentrations of the inhibitor solution (0 ppm, 5 ppm, 300 ppm, 600 ppm, and 900 ppm).

[0048] In one embodiment herein, the increasing inhibitor solutions concentration generally leads to decreased weight loss. The inhibitor molecules adsorb onto the at least one metal substrate 202 surface, thereby forming a protective layer that hinders the dissolution of at least one metal substrate 202 into the acid. In another embodiment herein, the increasing the temperature leads to increased weight load. The higher temperatures increase the kinetic energy of the reacting molecules, making the corrosion reaction proceed faster.

[0049] Table. 1
Temperature (K) Concentration (ppm) Weight loss (g) Rate of corrosion (mmpy) Inhibitor efficiency (%)
303 0 0.202 10.40414 0
300 0.075 3.862924 62.87129
600 0.037 1.905709 81.68317
900 0.01 0.515057 95.0495
308 0 0.33 16.99687 0
300 0.131 6.747241 60.30303
600 0.068 3.502385 79.39394
900 0.025 1.287641 92.42424
313 0 0.32 16.48181 0
300 0.133 6.850253 58.4375
600 0.097 4.996049 69.6875
900 0.037 1.905709 88.4375
318 0 0.44 22.66249 0
300 0.233 12.00082 47.04545
600 0.1956 10.07451 55.54545
900 0.1 5.150566 77.27273

[0050] In another embodiment herein, the temperature of 303K is the lowest temperature of the at least one metal substrate 202. The lowest inhibitor concentration (5 ppm) define a significant reduction in weight loss compared to the uninhibited case (0 ppm), thereby indicating the inhibitor solution is very effective at this temperature. In another embodiment herein, the temperature of 308K is effective temperature, but the higher concentrations (600 ppm and 900 ppm) are needed to achieve the same level of protection as seen at 303K. In another embodiment herein, the temperature of 313K and 318K is the highest temperature. The inhibitor solution is less effective react with the at least one metal substrate 202. The highest concentration (900 ppm) does not fully prevent weight loss, thereby involving the inhibitor film is not stable enough at these temperatures.

[0051] According to another exemplary embodiment of the invention, FIG. 6 refers to a graphical representation 602 of corrosion rate and inhibitor efficiency of the at least one metal substrate 202 immersed in the stock solution of 1 M H2SO4. In one embodiment herein, the corrosion rate of the at least one metal substrate 202 in stock solution of 1 M H2SO4 at different temperature (303 K, 308 K, 313 K, and 318 K) with varying inhibitor concentrations (0 ppm, 200 ppm, 400 ppm, 800 ppm, and 1000 ppm). The inhibitor efficiency of the same inhibitor at the same temperatures and the inhibitor concentrations.

[0052] In another embodiment herein, the different temperatures of the at least one metal substrate 202 increasing the inhibitor concentration is generally leads to the decreased corrosion rate and the increased inhibitor efficiency. The inhibitor molecules absorb onto the at least one metal substrate 202, thereby forming the protective layer that hinders the dissolution of at least one metal substrate 202 into the acid. In another embodiment herein, the different inhibitor concentrations are increase the temperature of the at least one metal substrate 202 is generally leads to the increased corrosion rate and the decreased inhibitor efficiency due to the higher temperatures increase the kinetic energy of the reacting molecules, thereby creating the corrosion reaction proceed faster and the inhibitor film less stable.

[0053] In one embodiment herein, the lowest temperature (303K), the inhibitor concentration of 200 ppm has considerable reduction in corrosion rate and the high inhibitor efficiency at least 80 percent due to the inhibitor is very effective at this temperature. In another embodiment herein, the temperature (308K and 313K), the inhibitor is still effective but higher concentration of (800 ppm and 1000 ppm) are needed to achieve the same level of protection as seen at 303K. The inhibitor efficiency is also lower at these temperatures, at least 60-70 percent. In another embodiment herein, the highest temperature (318K), the inhibitor is least effective. Even the highest concentration of the 1000 ppm only reduces the corrosion rate by at least 50 percent, and the inhibitor efficiency is at least of 40 percent due to the inhibitor protective film is not stable enough at this temperature.

[0054] In another embodiment herein, the different inhibitor solution have different action modes, and might be less or more effective depending on the specific concentration. The surface morphology of the at least one metal substrate is also effect the absorption of the inhibitor and effectiveness. The immersion of the at least one metal substrate 202 is also affect the corrosion rate and the effectiveness of the inhibitor.

[0055] According to another exemplary embodiment of the invention, FIG. 7A refers to a graphical representation 702 of a Langmuir isotherm of the metal substrate 202 in 1 M H2SO4. In one embodiment herein, the process of adsorption is mainly affected by the charge, metal surface nature, electronic characteristic of the metal surface, the temperature of the reaction, and the presence of electron with drawing or electron-donating groups in the derivatives, the electrochemical potential at the solution interface, solvent adsorption, and others ionic species. Many reported works and reviews proved that the corrosion inhibition of metals is mainly due to the adsorption of inhibitor molecules on the metal surface and the adsorption behaviour obeys many adsorption isotherm models. The gravimetric data was used to find out the values of surface coverage (?) at various drug concentrations to explain the best-fit isotherm for the adsorption process.

[0056] The results are best fitted by the Langmuir adsorption isotherm, according to the following equation
+ C (3)
Where, Kads and C are the equilibrium constant of the adsorption process and the inhibitor concentration, respectively.
(4)
Where, Kads is the absorption equilibrium adsorption constant, ?- surface coverage area, C - concentration of inhibitor. It is generally accepted that the expired drug compounds studied inhibit the corrosion process by adsorbing its constituent molecules at the metal/solution interface. Also, it is believed that the formation of a solid organic molecule complex with the metal atom has received considerable attention.

[0057] According to another exemplary embodiment of the invention, FIG. 7B refers to a graphical representation 704 of Arrhenius plot of log CR versus 1000/T. In one embodiment herein, the activation parameters of the inhibition process for mild steel in 1 M H2SO4 solution, weight loss measurements were performed at a temperature range 308–338 K in the absence and presence of the metal substrate 202. A plot of the logarithm of the corrosion rate (mg cm-2 h-1) of the metal substrate versus 1000/T gave a straight line (as shown in FIG. 7B). According to the Arrhenius equation is analyse the activation energy calculation:
(5)
where, EA is the apparent activation energy for the corrosion of the metal substrate, R is the gas constant, and T is the absolute temperature based on the weight loss measurement at 900 ppm of the at least one metal substrate 202. The straight lines were obtained according to the transition state equation obtained from slopes of the plot logCR verses 1000/T is 116.92 kJ/mol for at least one metal substrate 202.

[0058] Numerous advantages of the present disclosure may be apparent from the discussion above. In accordance with the present disclosure, the method for preparing a bio-based corrosion inhibitor composition that provides green inhibitors for corrosion industry through safety, biodegradability, ecological acceptability, and renewability. The proposed a method for preparing a bio-based corrosion inhibitor composition that reduces environmental impact and offering cost-effective protection for iron assets. The proposed a method for preparing a bio-based corrosion inhibitor composition that utilises the availability of bio-waste to promote resource recovery and sustainability.

[0059] The proposed a method for preparing a bio-based corrosion inhibitor composition that reduces the need for frequent repairs and replacements of iron equipment, lowering overall maintenance costs. The proposed a method for preparing a bio-based corrosion inhibitor composition that provides a cost-effective and eco-friendly alternative to synthetic corrosion inhibitors. The proposed a method for preparing a bio-based corrosion inhibitor composition that eliminates the need for potential harmful synthetic chemicals, and provides a safer alternative for both humans and the environment.

[0060] It will readily be apparent that numerous modifications and alterations can be made to the processes described in the foregoing examples without departing from the principles underlying the invention, and all such modifications and alterations are intended to be embraced by this application.
, Claims:CLAIMS:
I / We Claim:
1. A method for preparing a bio-based corrosion inhibitor composition for iron metal, comprising:
rinsing and collecting plurality of allium sativum and allium cepa skins thoroughly with de-ionised water to remove dirt and debris;
drying the plurality of allium sativum and allium cepa skins with paper towels in a well-ventilated area for at least 4 weeks at a room temperature;
grinding the plurality of allium sativum and allium cepa skins into a fine powder separately using a grinder;
extracting a weight of at least 20 gr each of allium sativum and allium cepa skins powder, mixing with 500 ml of the de-ionized water for at least 3 hr to obtain a mixture through a soxhlet extraction process;
filtering the mixture in a centrifuge tube for at least 20 min to remove residual debris, thereby extracting a solution in a flask;
diluting 54.4 ml of sulfuric acid (H2SO4) with 1 lit of de-ionised water to obtain a stock solution of 1 M H2SO4;
mixing the stock solution with the mixture at different volume concentrations through parts per million (PPM), thereby attaining an inhibitor solution; and
immersing at least one metal substrate (202) in a specific concentrations for at least 24 hr at a room temperature, thereby determining a corrosion rate and a surface deterioration analysis of the at least one metal substrate (202).
2. The method for preparing the bio-based corrosion inhibitor composition for iron metal as claimed in claim 1, wherein the 1 M H2SO4 is a solution containing one mole of sulfuric acid with 98 gr dissolved in the de-ionised water to make one lit of the inhibitor stock solution.
3. The method for preparing the bio-based corrosion inhibitor composition for iron metal as claimed in claim 1, wherein the inhibitor solution is derived for mixing the stock solution with the mixture at different volume concentration of 0, 300, 600, and 900 PPM, thereby performing the corrosion rate and the surface deterioration analysis.
4. The method for preparing the bio-based corrosion inhibitor composition for iron metal as claimed in claim 1, wherein at one metal substrate is made up of an iron material.
5. The method for preparing the bio-based corrosion inhibitor composition for iron metal as claimed in claim 1, wherein the each metal substrate is measured by a sensitive analytical balance for calculating a weight loss and a corrosion rate at before and after immersion test in the each concentration solution.
6. The method for preparing the bio-based corrosion inhibitor composition for iron metal as claimed in claim 1, wherein the corrosion rate and the surface deterioration analysis of the at least one metal substrate are calculated by scanning electron microscopy (SEM), and atomic force microscopy (AFM).