Development of Environmental Friendly Corrosion Inhibitor From the Extract of Areca Flower for Mild Steel in Acidic Media

One of the industries that play a role in supporting the development of the country is the oil and gas industry. In addition, this industry has an influence on the country's economy, so it must be operated as efficiently as possible so as not to produce substantial costs and not have a significant impact on the country's economy. The oil and gas industry is equipped with good supporting equipment that plays an important role in the success of the production process. The most important equipment for the continuity of production is the pipe. Generally, this pipe is made of mild steel and the material commonly used for pipes in the oil and gas industry is API 5L. Corrosion is one of the challenges found in pipes in the oil and gas industry. This is due to aggressive ions such as Cl– and also the fluid contained in the pipe. The aggressive ions that exist can cause corrosion in the form of pitting corrosion. Corrosion that occurs in pipes in the oil and gas industry must be addressed as efficiently as possible with effective results. Inhibitors are one solution that can provide effective results in reducing corrosion rates. Corrosion rate can be reduced by 99 % or more if the concentration of the inhibitor is appropriately added. Generally, inhibitors that are often used are inorganic inhibitors, where these inhibitors contain chemical compounds that are harmful to the environment and health. So, currently there are many developed environmentally friendly inhibitors, namely inhibitors produced from plants and fruits. Environmentally friendly inhibitors do not have an impact on environmental pollution because the material from these inhibitors has organic properties. Until now, there have been many studies on environmentally friendly inhibitors carried out on API 5L steel. However, there have been no studies on inhibitors obtained from Areca Flower extract as environmentally friendly inhibitors. Thus, this study was conducted in order to determine the effect of adding environmentally friendly inhibitors on the corrosion behavior of API 5L steel pipes in aggressive environments, namely HCl media. Areca flower extract has been investigated as a green corrosion inhibitor on API 5L Grade B in 1 M HCl acidic solution using Linear polarization and Electrochemical Impedance Spectroscopy (EIS). Additions of 4 ml, 8 ml, 12 ml, 16 ml, and 20 ml of corrosion inhibitors increase the efficiency of the inhibitors. Optimum inhibition efficiency occurs with the addition at a concentration of 20 ml is 96.6 % on Electrochemical Impedance Spectroscopy (EIS) testing. Polyphenolic and flavonoid compounds contained in the areca flower inhibit corrosion by physical adsorption, to form a monolayer which can inhibit corrosion. Adsorption occurs spontaneously in accordance with Langmuir isothermal adsorption. The polarization showed that the areca flower extract acts through mixed-type inhibition. The value of the free energy of –7.026 kJ/mol of adsorption indicated that the adsorption of inhibitor molecules was typical of physical adsorptio

Studi Pendahuluan Pengendapan Cerium, Lanthanum, dan Neodymium dari Larutan Klorida Menggunakan Sodium Karbonat pada Pengolahan Monasit Bangka

Mineral monasit sebagai mineral ikutan penambangan timah di Kepulauan Bangka Belitung mengandung unsur tanah jarang ringan, diantaranya Cerium (Ce), Lanthanum (La), dan Neodymium (Nd). Tujuan penelitian ini adalah untuk memperoleh konsentrat unsur tanah jarang karbonat melalui proses pengendapan dengan sodium karbonat (Na2CO3), serta menentukan pengaruh konsentrasi dan volume Na2CO3 terhadap recovery pengendapan Ce, La, dan Nd. Persiapan umpan dilakukan dengan mengikuti rute proses pengolahan monasit menggunakan metode basa meliputi tahapan dekomposisi, pelarutan, dan pengendapan unsur radioaktif. Recovery pengendapan tertinggi untuk Ce, La, dan Nd yaitu sebesar 10,84%, 7,81%, dan 2,68% pada penggunaan Na2CO3 dengankonsentrasi 30% wt dan volume 55 mL

Decomposition of Ferronickel Slag Through Alkali Fusion in the Roasting Process

Ferronickel slag is a by-product of the nickel smelting process. Recycling of ferronickel slag is required since it contains valuable elements besides its potency to pollute the environment. In order to take advantage of the valuable materials and reducing the potential hazard, beneficiation of ferronickel slag is essential. Alkali fusion of ferronickel slag using Na2CO3 in the roasting process was carried out. This study aims to determine the decomposition of the mixture of ferronickel slag-Na2CO3 in the roasting process. Roasting temperature and time were 800–1,000 °C and 60‒240 minutes, respectively. Characterizations of the ferronickel slag were conducted by XRF, ICP-OES, XRD and SEM-EDS. Meanwhile, roasted products were characterized using ICP-OES, XRD and SEM-EDS. Characterization of the ferronickel slag indicates that Mg and Si are the main elements followed by Fe, Al and Cr. Moreover, olivine is detected as the main phase. The roasting process caused percent weight loss of the roasted products, which indicates decomposition occurred and affected the elements content, phases and morphology. The roasting process at about 900 °C for 60 minutes is a preferable decomposition base on the process conditions applied and the change of elements content. Aluminum (Al) and chromium (Cr) content in the roasted products upgraded significantly compared to iron (Fe) and magnesium (Mg) content. Olivine phase transforms to some phases, which were bounded with the sodium compound such as Na2MgSiO4, Na4SiO4 and Na2CrO4. The rough layer is observed on the surface of the roasted product as a result of the decomposition process. It indicates that liquid-solid mass transfer is initiated from the surfac

Development of Cobalt-free Oxide (Sm0.5Sr0.5Fe0.8Cr0.2O3-δ) Cathode for Intermediate-temperature Solid Oxide Fuel Cells (IT-SOFCs)

A cobalt-free perovskite oxide Sm0.5Sr0.5Fe0.8Cr0.2O3-δ (SSFC) has been exploited as a novel cathode for intermediate-temperature solid oxide fuel cells (IT-SOFCs). The cathode model was synthesized with the addition of the chromium element in the B side of the composite metallic oxide system, which was then formed by the solid-state reaction method. The model system was further characterized in detail for getting the properties behavior. The solid-state reaction of the SSFC system was observed through thermal gravimetric analysis. Meanwhile, the structural properties were investigated by x-ray diffraction, and the weight loss was examined by the thermal gravimetric analysis as well. Furthermore, the thermal expansion coefficient was determined by the thermal-mechanical analysis, and the conductivity properties were tested by the thermal conductivity analysis. The result showed that the SSFC cathode demonstrated the crystalline structure based on the design with a perovskite phase. The oxygen content created on the model structure was obtained to be 2.98 after the calcination process. The average thermal expansion coefficient was achieved up to 5.0×10-6 K-1 as the heating given up to 800 °С. Moreover, the conductivity value reached from 2 S∙cm-1 at 400 °С and it increased to be a maximum of 7.5 S∙cm-1 at 700 °С. In addition, the presence of Cr6+ cation valence coordinated with the oxygen anion could lead to generating a large concentration of oxygen vacancies on the cathode surface, facilitating the transport of the O2− anion in the cathode system. Based on these results, the SSFC cathode has good properties as a composite system promising for IT-SOFCs application in the futur

A Study of Cerium Extraction From Bangka Tin Slag Using Hydrochloric Acid

Bangka Tin Slag (BTS) was a tin-smelting waste containing high silica and other elements that have high economic value, including cerium, which is a rare earth element. Silica and Ce2O3 contents in BTS were 32.86 % and 1.35 % respectively. Other elements that have high concentrations in BTS include 15.46 % of CaO, 10.88 % of Al2O3, and 9.20% of Fe2O3. The objective of this study was to determine the optimum conditions for cerium extraction using HCl, which includes HCl concentration, temperature, particle size, stirring speed, and dissolution time. In addition, the effect of these parameters on Ce extraction was also studied. The one-factor-at-time method was used to determine the optimum conditions. Pretreatment of BTS with the alkaline fusion method and water leaching was done to reduce both the silica content and increasing its porosity. Alkaline fusion carried out at 700 ℃ using NaOH converts the silica into water-soluble sodium silicate. Characterization of the slag structure before and after the pretreatment process was completely carried out by using X-ray diffraction (XRD), X-ray fluorescence (XRF), Scanning electron microscope (SEM), and optical microscope. Furthermore, measurement of Ce content in the filtrate of the dissolution process was performed with inductively coupled plasma – optical emission spectrometry (ICP-OES). The results showed that the optimum of 75.16 % Ce was extracted by using some parameter conditions, namely by 2.5 M of HCl concentration, at the temperature of 40 ℃, with the particle size of –325 mesh, stirring speed of 150 rpm, and dissolution time of 180 minutes. Each parameter gives a significant effect on Ce extraction, wherein the initial stage, the increase in the value of each parameter gives an increase in Ce extraction and begins to decrease when equilibrium occur

Development of White Tea Extract as Green Corrosion Inhibitor in Mild Steel Under 1 M Hydrochloric Acid Solution

This work covers the effectiveness of the White tea extract as a green corrosion inhibitor and is correlated to the strength and stability bonding between the phenolic molecule and the Fe atoms in mild steel and how this interaction can be studied by altering the concentration and temperature. White tea has received considerable attention due to its capability as a corrosion inhibitor and has been extensively studied using electrochemical techniques. However, accurate and systematic functional group identification and surface modification have been missing. Our study sought to demonstrate the quantitative measurement of electrochemical impedance spectroscopy (EIS) complemented by the FTIR (Fourier transform infrared spectroscopy), Total Phenolic Test, and Raman Spectroscopy. The SEM (Scanning Electronic Microscope)/EDX (Energy-Dispersive X-Ray Spectroscopy), and AFM (Atomic Force Microscope) were used to study the surface modification. The EIS results show that the optimum inhibition efficiency was 96 % in a solution of 80 ppm at 60 °C. Acetone 70 % was used to extract White tea and gives 14.17±0.25 % phenolic compound. Spectroscopic studies show -OH, Aromatic C=C, C=O and C-O-C become major contributors in the adsorption process and are found on the surface of metals as corrosion protection. Meanwhile, the thermodynamic calculation shows the White tea was adsorbed chemically. The nearness of R2 to 1 shows the adsorption agrees with the Langmuir adsorption isotherm. Eventually, the surface modification revealed that phenol molecules are responsible to reduce the corrosion rate at 16.38×10-3 mpy. Our results are expected to provide a guideline for future research in White tea as a green corrosion inhibito