Ppm Acetic Acid Research Articles

Effect of Alkyl Chain Length of Quaternary Ammonium Surfactant Corrosion Inhibitor on Fe (110) in Acetic Acid Media via Computer Simulation

Density functional theory (DFT) and molecular dynamics (MD) simulations were employed to investigate the inhibition mechanism of cationic quaternary ammonium surfactant corrosion inhibitors (CIs) with varying chain lengths in 1.0 M HCl and 500 ppm acetic acid on Fe (110) surfaces. DFT calculations demonstrated that all surfactant CI molecules possess favorable inhibition properties, with the cationic quaternary ammonium groups (N+) and alpha carbon serving as electron-donating reactive centers, characterized by a low band-gap energy of 1.26 eV. MD simulations highlighted C12, with a 12-alkyl chain length, as the most promising CI molecule, exhibiting high adsorption and binding energies, a low diffusion coefficient, and a random distribution at low concentrations, thereby facilitating optimal adsorption onto the Fe (110) metal surface. The insights gained from computational modeling regarding the influence of alkyl chain length on inhibition efficiency, coupled with the comprehensive theoretical understanding of cationic quaternary ammonium surfactant CI molecules in acidic corrosion systems, can serve as a foundation for the future development of innovative surfactant CI molecules incorporating ammonium-based functional groups.

Bottom of Line Corrosion Mechanism in Marginal Sour Environment Wet Gas Pipelines

Internal pipeline corrosion is a well-recognized issue in the oil and gas industry, especially in multiphase flow systems, such as wet gas transportation pipelines that contain mixed phases. Internal corrosion typically manifests as either top-of-the-line corrosion (TLC) or bottom-of-the-line corrosion (BLC). While corrosion mechanisms in sweet environments (dominated by CO₂) are relatively well-understood, those in sour environments (dominated by H₂S) remain less thoroughly examined. In sour environments, the primary corrosion product is iron sulfide (FeS), while in sweet environments, iron carbonate (FeCO₃) tends to form. In marginally sour conditions, FeS layers are often non-uniform, promoting localized corrosion and pitting because low concentration of H2S. It is hypothesizes that higher concentrations of H₂S reduce both the pitting rate and depth.The objective of this research is to investigate the corrosion rate, surface profile, and morphology in a marginal sour environment, using profilometry analysis (ASTM G46) to assess pitting. The experiments were conducted in a glass cell setup simulating pipeline conditions with 3 wt% brine solution and 1000 ppm acetic acid. Corrosion behavior was assessed at H₂S concentrations of 0 ppm, 30 ppm, and 80 ppm using weight loss analysis, surface morphology, and profilometry measurements. Results indicate that increasing H₂S concentration decreases the pitting rate, supporting the study’s hypothesis.

Highly responsive and stable room temperature acetic acid gas sensor based on nano-composite of MXene Ti3C2TX-NiCo2O4-MnO2

Designing novel acetic acid gas sensors is highly imperative for human health. Two-dimensional (2D) layered MXene Ti3C2Tx is becoming an emerging and promising material in gas sensing. In this manuscript, the hydrothermal method was used to synthesize MXenes Ti3C2Tx/Nb2CTx supported NiCo2O4-MnO2 composites and pure materials. The structure, chemical composition and morphology of the samples were studied by SEM, EDS, TEM, HRTEM, XRD, BET, FTIR, UV–visible, XPS and Raman, justifying the successful synthesis of products. The layered structure of Ti3C2Tx enhanced the BET surface area and provided sufficient sites, which assisted the gas sensing improvement. The gas sensors were fabricated from synthesized products and were tested for different kinds of VOCs deeply. The results exposed that the gas sensor of Ti3C2Tx-NiCo2O4-MnO2 (5 % of Ti3C2Tx = NCO-Mn-Ti-5) was highly sensitive to 20 ppm acetic acid and very less responsive to all other VOCs (acetone, TMA, ethanol, methanol, formaldehyde, acetaldehyde, acetylene and xylene) at room temperature. The response (Rg/Ra) to 20 ppm acetic acid was 12.5 and the lowest detection limit was 0.05 ppm. Additionally, the sensor of NCO-Mn-Ti-5 revealed great stability/reproducibility, short response/recovery times and linearity between acetic acid concentration and response. The idea of the novel sensor (NCO-Mn-Ti-5) could be potentially useful in the field of sensors.

Electrochemical, microstructural and theoretical validation of 2-(2-Bromophenyl)-1H-benzimidazole as inhibitor for C1018 steel during very aggressive CO2 corrosion

This work is motivated by the lack of research papers reporting benzimidazole derivatives in very aggressive CO2-corrosion systems. We appraise the inhibitive performance of 2-(2-bromophenyl)-1 H Benzimidazole (BPHB) in CO2-saturated 3.5 % sodium chloride (NaCl) + 50 ppm acetic acid (HAc) without and with 1 M hydrochloric acid (HCl) using electrochemical impedance spectroscopy (EIS), potentiodynamic polarization (PDP), scanning electron microscopy (SEM) and x-ray diffraction (XRD). We augment results from these techniques with molecular dynamics simulations and density functional theory, as computational modelling techniques. In the absence of HCl, the inhibitor adsorbs firmly on the steel surface, displays a strong cathodic influence on corrosion potential (Ecorr) and current density (icorr), and minimizes both general and pitting corrosion with ∼ 80 % efficiency. The presence of HCl furnishes abundant H+ ions that significantly diminish the cathodic influence of BPHB, blocks its firm adsorption and, although it reduces the extent of general and pitting corrosion, lowers its efficiency to ∼ 70 %. Computational modelling techniques confirm electrochemical and surface probe results. The nitrogen atoms and CC bonds in the imidazole ring are the centers that facilitate BPHB adsorption. The inhibitor adsorbs in such a way as to maximize surface coverage. However, adsorption is more energetically favored in the absence of HCl, based on Eads calculations.

A novelty strategy for AMD prevention by biogas slurry: Acetate acid inhibition effect on chalcopyrite biooxidation and leachate

With the widespread application of anaerobic digestion technology, biogas slurry become the main source of organic amendments in practice. Comprehensive studies into the inhibitory effects of low molecular weight (LMW) organic acids, essential components in biogas slurry, on the sulfide minerals biooxidation and its bioleaching (AMD) have been lacking. In this study, acetic acid (AA) served as a representative of LMW organic acids in biogas slurry to investigate its impact on the inhibition of chalcopyrite biooxidation by Acidithiobacillus ferrooxidans (A. ferrooxidans). It was shown that AA could slow down the chalcopyrite biooxidation and inhibit the jarosite formation on the mineral surface. Compared with the control group (0 ppm AA), the sulfate increment in the leachate of the 50 ppm, 100 ppm, and 200 ppm AA-treated groups decreased by 36.4%, 66.8%, and 69.0%, respectively. AA treatment (≥50 ppm) could reduce the oxidation of ferrous ions in the leachate by one order of magnitude. At the same time, the bacterial concentration of the leachate in the 50 ppm, 100 ppm, and 200 ppm AA-treated groups decreased by 70%, 93%, and 94%, respectively. These findings provide a scientific basis for new strategies to utilize biogas slurry for mine remediation and contribute to an enhanced comprehension of organic amendments to prevent AMD in situ in mining soil remediation.

Comparative study on hydrogen losses via microbial byproduct in the presence of methane and nitrogen cushion gas

This study comprehensively investigates H2 loss resulting from injecting two gas mixtures: I (60% H2 + 30% CH4 + 5% N2 + 5% CO2) and II (60% H2 + 30% N2 + 5% CH4 + 5% CO2) into an aqueous solution containing 20,000 ppm sodium chloride and 100 ppm acetic acid (a microbial by-product of acetogenesis) within Bandera clay-rich sandstone reservoirs. Conducted at 42 °C and 1350 psi, various analytical techniques, including X-ray diffraction (XRD), Scanning Electron Microscopy with Energy Dispersive X-ray (SEM-EDX) spectroscopy, Fourier Transform Infrared (FTIR) spectroscopy, porosity and permeability assessments, pH and ion analysis, and gas chromatography, were utilized to assess the relevant properties of rocks, formation water, and gas content before and after 50 days treatment. The results indicate minimal sample reactivity, with dissolution primarily affecting dolomite and albite minerals. On average, porosity increased by 19% in formulation I and 15% in formulation II, while permeability decreased by 4.7% in formulation I and 5.3% in formulation II. In formulation I, H2 fraction decreased by 2.79%, CH4 increased by 7.15%, and CO2 decreased by 9.36%, with N2 remaining constant, whereas in formulation II, H2 only decreased by 1.3%, CH4 increased by 19.22%, and CO2 decreased by 3.58%, with N2 remaining consistent. Overall, the N2 cushion gas condition (i.e., formulation II) slightly outperformed CH4 in minimizing H2 losses. This study thus provides significant insights into potential H2 loss within a microbial-by-product-rich environment for underground hydrogen storage.

Highly responsive double-shell ZnO hollow microspheres based gas sensor for acetic acid detection in vinegar

Acetic acid sensing materials for environmental and related food quality control requiring high sensitivity and selectivity, and ppb-level detection limit, remain challenging. Double-shell ZnO hollow microspheres were prepared by a surfactant assisted template method, and the resultant gas sensor showed excellent acetic acid sensing performance. The sensor response reached 116 to 100 ppm acetic acid at 270°C with a short response time of 3.2 s. The relationship between acetic acid concentration and the response was established, and the detection limit reached 100 ppb. DFT theory computational results demonstrated the highest adsorption energy of the ZnO gas sensor to acetic acid among all tested gases, proving its high selectivity to acetic acid. Besides, the unique double-shell hollow structure with abundant oxygen vacancy and large surface area might be the other factors that gave rise to its excellent acetic acid gas sensing performance. Based on the gas sensor, a method for fast quantitative detection of acetic acid content in vinegar was developed. The linear relationship between sensor response and acetic acid gas concentration of vaporized white vinegar was established, and the acetic acid content in the vinegar can be quickly determined. The result proved our acetic acid sensor to be a promising candidate for practical applications.

The room temperature ethanol gas sensors based on MoS2-CuGaO2 composite prepared by hydrothermal method

In this paper, MoS2-CuGaO2 composites were successfully synthesized by hydrothermal method. The composites were characterized by X-ray diffraction (XRD), Scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared (FTIR), X-ray photoelectron spectroscopy (XPS), respectively. The specific surface area and pore size distribution were obtained by N2 adsorption-desorption isotherms. The gas sensing property measurements were conducted. The sensitivity of pure CuGaO2 based gas sensor to 100 ppm acetic acid and benzene vapor was 1.4 at 25oC. The sensitivity of MoS2-CuGaO2 composite (M − 5) was 6.0 towards 100 ppm ethanol vapor at 25oC. And the detection limit of MoS2-CuGaO2 (M − 5) based sensor was 0.1 ppm. The results demonstrated that MoS2 had effect on the selectivity and sensitivity of the MoS2-CuGaO2 composites. M − 5 composite is considered to be promising for ethanol sensing application in room temperature.

High response ZnO gas sensor derived from Tb@Zn-MOFs to acetic acid under UV excitation

As an n-type metal oxide semiconductor with a wide band gap (3.37 eV), ZnO has been widely used as gas sensors, but pure ZnO gas sensors suffer from low sensitivity. In this work, Zn-metal organic frameworks (Zn-MOFs) were synthesized by introducing H3BTC and H2ABDC as organic ligands, and then the Zn-MOFs were combined with Tb and calcined at 530 ℃ to obtain the derived oxides named as Tb@ZnO-1 and Tb@ZnO-2, respectively, in order to improve the gas sensitivity. Meanwhile, the microstructures and gas sensing properties of the two MOFs and their derivatives were characterized. Interestingly, the Zn-ABDC MOFs were observed as plush spherical microspheres assembled from nanowires, more possibly favorable for gas adsorption. In fact, prominent oxygen defects and chemisorbed oxygen content were found in the derivative Tb@ZnO-2. As a result, it exhibited good gas-sensitive properties and selectivity towards acetic acid, with a high response value of 47.30 at 240 ℃ for 100 ppm acetic acid gas and a very short response time (1 s), and the response value increased to 77.80 under UV excitation. The gas-sensitive mechanism and UV excitation mechanism are discussed.

DFT Calculation and MD Simulation Studies on Gemini Surfactant Corrosion Inhibitor in Acetic Acid Media.

Gemini surfactant corrosion inhibitor (CI) is one type of CI mainly used in mitigating corrosion in the complex system of oil/gas production industries. Computer modeling methods such as density functional theory (DFT) calculation and molecular dynamic (MD) simulation are required to develop new CI molecules focusing on their application condition as a prediction or screening process before the physical empirical assessment. In this work, the adsorption inhibition efficiencies of two monomer surfactants (2B and H) and their respective Gemini structures with the addition of different spacers (alkyl, benzene, ester, ether, and ketone) are investigated using DFT calculation and MD simulation method in 3% sodium chloride (NaCl), and 1500 ppm acetic acid solutions. In DFT calculation, 2B-benzene molecules are assumed to have the most promising inhibition efficiency based on their high reactivity and electron-donating ability at their electron-rich benzene ring region based on the lowest bandgap energy (0.765 eV) and highest HOMO energy value (-2.879 eV), respectively. DFT calculation results correlate with the adsorption energy calculated from MD simulation, where 2B-benzene is also assumed to work better as a CI molecule with the most adsorption strength towards Fe (110) metal with the highest negative adsorption energy value (-1837.33 kJ/mol at temperature 323 K). Further, diffusion coefficient and molecular aggregation analysis in different CI concentrations through MD simulation reveals that only a small amount of Gemini surfactant CI is needed in the inhibition application compared to its respective monomer. Computer simulation methods successfully predict and screen the Gemini surfactant CI molecules that can work better as a corrosion inhibitor in acetic acid media. The amount of Gemini surfactant CI that needs to be used is also predicted. The future planning or way forward from this study will be the development of the most promising Gemini surfactant CI based on the results from DFT calculation and MD simulations.

Enhanced acetic acid detection for Tb2O3 @MOF-derived ZnO at room temperature

As an n-type metallic oxide semiconductor with a wide bandgap of 3.37 eV, ZnO suffers from low sensitivity for gas sensor application. In order to improve the gas sensitivity, Zn- metal-organic frameworks (MOFs) were synthesized by introducing organic ligands of H2BDC/H2NDC via DMF-C2H6O2 binary solvothermal method, and then the MOFs were integrated with Tb3+. After calcination at 450 ℃, Tb@Zn-BDC/Tb@Zn-NDC derivate, labeled as Tb2O3 @ZnO-1/Tb2O3 @ZnO-2, were obtained. The MOFs or derivates were characterized by various techniques. Interestingly, Zn-NDC MOFs were observed to be assembled by loose bundles with a rough surface and Tb@Zn-NDC MOF maintained the morphology of loose bundles with dispersed Tb2O3 nanoparticles. The Tb2O3 @ZnO-2 were composed of granular Tb2O3 and ZnO nanorods, where p-n heterojunction is formed at the contact interfaces， exhibiting the best sensitivity of 13.26–100 ppm acetic acid at 20 ℃. In particular, the sensitivity increased up to 41.57 and the lowest detection limit was only 500 ppb under UV light excitation. The enhanced sensing performance to acetic acid is attributed to the mesoporous structure of MOF derivatives, formation of p-n heterostructures and UV light irradiation.

Experimental Study on Top-of-the-Line Corrosion Using Thin-Film Electrical Resistance Sensors: Study the Effects of Organic Acids and Volatile Corrosion Inhibitors

Thin-film electrical resistance (ER) sensors have been developed to monitor top-of-the-line corrosion (TLC). The objective is to address the ER measurement sensitivity and to investigate the TLC mechanism in the presence of acetic acid, monoethylene glycol (MEG), decanethiol, and diethylamine (DEA). The results showed that 1,000 ppm acetic acid increased TLC by 49%. 80 wt% MEG reduced TLC by 41%. 10 ppm decanethiol achieved TLC inhibition efficiency of 97% while 400 ppm DEA exhibited poor TLC inhibition efficiency (<15%). The ER sensors were able to record an average TLC rate of 0.03 mm/y in less than 24 h.

Ultrathin δ-MnO2 nanoribbons for highly efficient removal of a human-related low threshold odorant - acetic acid

Efficient removal of human-emitted gaseous pollutants in indoor air may greatly reduce ventilation-related energy consumption, however few efforts have been made. Here we reported the room and low-temperature catalytic removal of a human-emitted odorant - acetic acid with odor threshold of 5.6 ppb. Ultrathin δ-MnO2 nanoribbons (δ-MnO2 UTNRs) with the thickness of 1–1.5 nm and aspect ratio of 200–600 was synthesized, which produced abundant active oxygen species such as hydroxyl radicals and superoxide at room temperature without light irradiation. Accordingly, as-prepared δ-MnO2 UTNRs could transform acetic acid into CO2 even at room temperature. The 100% one-through removal capacity for ~1 ppm acetic acid was about 20 mg/g, and it could be completely regenerated at 140 °C. This study opens a new research direction and demonstrates that it is possible to catalytically remove human-emitted gaseous pollutant at low and even at room temperature.

Survival of Salmonella Typhimurium and Escherichia coliO157:H7 on blueberries and impacts on berry quality during 12 weeks of frozen storage after washing with combinations of sodium dodecyl sulfate and organic acids or hydrogen peroxide

AbstractSalmonella spp. and Escherichia coli are well tolerant of freezing. This study was to investigate survival of the foodborne pathogens during storage at −18 ± 2°C for 12 weeks on blueberries after washing with: 500 ppm acetic acid plus 5,000 ppm sodium dodecyl sulfate (SDS) (AA/SDS), 20 ppm peroxyacetic acid plus 5,000 ppm SDS (PPA/SDS), or 200 ppm hydrogen peroxide plus 5,000 ppm SDS (H2O2/SDS), when compared with findings from no wash, or wash with water, 80 ppm PPA or 200 ppm chlorinated water. Following a 60 s contact with one of the three new solutions, the treatments showed 3.3–3.9 log10 CFU/g reductions in Salmonella Typhimurium and E. coli O157:H7 counts. After 2 weeks of frozen storage, 3.9–4.2 log10 CFU/g reductions of Salmonella and E. coli were observed. After 12 weeks of frozen storage, Salmonella and E. coli survivors were below detection limits (0.39 log10 CFU/g) in berries washed with new solutions. The frozen storage had a significant impact (p < .05) on microbial counts of both treated and nontreated blueberries. Although none of these washings decreased the total phenolic and anthocyanins contents and apparent quality at time 0, frozen storage caused significant damage on the texture of both treated and nontreated blueberries. Interestingly, no significant decrease in the total phenolic, anthocyanins content, and apparent quality was observed during the 12‐week frozen storage. The counts of total bacteria, yeasts, and molds decreased throughout storage for treated and untreated berries. This demonstrates that the three wash solutions enhance the safety of frozen berries.

Y-Doped ZnO for Acetic Acid Sensing Down to ppb at High Humidity

Introduction Acetic acid is a key tracer in chocolate and coffee processing defining their final taste. Additionally, it is a promising breath marker for cystic fibrosis and gastro-oesophageal reflux disease as breath concentrations are significantly increased with 170 ppb [1] and 85 ppb [2], respectively, compared to healthy humans (48 ppb). However, current sensors lack ppb to ppm level sensitivity with high selectivity to detect relevant acetic acid concentrations accurately in gas mixtures at high humidity (90%). Here, we present an acetic acid selective gas sensor able to detect lowest ppb-level concentrations. It consists of Y-doped ZnO nanoparticles whereas doping level, particle & crystal size as well as film morphology were subsequently optimized in a flame spray pyrolysis (FSP) reactor. Method ZnO nanoparticles with different (0 - 10 mol%) Y-doping contents were produced by flame spray pyrolysis (FSP) and directly deposited [3] onto water-cooled Al2O3 sensor substrates forming a highly porous sensing network. The mechanical stability of the nanoparticles on the Al2O3 was fortified by in-situ annealing [4] with a particle-free xylene flame followed by annealing at 500 °C for 5 h in an oven. The sensors were mounted onto Macor holders, placed in a sensing chamber and installed in an evaluation setup described elsewhere [5]. The sensors were heated to 250 - 450 °C and tested on 1 ppm acetic acid, acetone, ethanol and ammonia at relative humidity ranging from 10 to 90%. Results and Conclusions Figure 1a shows a top view SEM of the sensing film for ZnO doped with 1 mol% Y. The doping thermally stabilizes the particles during high temperature treatment and preserves the highly porous nanostructured sensing network typical for FSP. In specific, it consists of aggregates and agglomerates of individual nanoparticles with particle sizes ~35 nm (Figure 1a, inset), as determined by nitrogen adsorption from filter-collected powders and ideal for gas sensing due to the high available surface area.Figure 1b shows the sensor response to 1 ppm acetic acid, ethanol, acetone and H2 as a function of the doping content. Additionally, the doping with 1 mol% Y increases the sensor response to acetic acid and selectivity to ethanol and acetone compared to pure ZnO (Figure 1b). That way, even concentrations down to 50 ppb were detectable at 50% relative humidity (RH), unprecedented by other acetic acid sensors. Note that at higher doping contents, the responses to all analytes decrease again, most likely due to the isolating character of segregated Y2O3. As a result, an inexpensive acetic acid detector has been developed that could be easily incorporated into a portable breath analyzer, used for food processing monitoring or incorporated into orthogonal arrays [6].

Electrochemical and Computational Insights on the Application of Expired Metformin Drug as a Novel Inhibitor for the Sweet Corrosion of C1018 Steel.

An expired metformin drug (MET) was used as a corrosion inhibitor for C1018 carbon steel in a CO2-saturated 3.5 wt % NaCl + 340 ppm acetic acid solution under static conditions. The inhibitor was evaluated using electrochemical methods complemented with surface analytical measurements and computational modeling. The drug displayed a high inhibition efficiency of ∼90% at 200 ppm. Impedance analyses revealed a rise in the charge transfer resistance at the steel–solution interface upon the addition of the inhibitor. Polarization measurements suggested that MET acted more like a cathodic-type corrosion inhibitor and significantly reduced the corrosion current density. The adsorption of MET on the steel substrate followed the Langmuir isotherm, showing a mixed type of physical and chemical modes of adsorption. The thermodynamic parameters revealed strong and spontaneous adsorption on the steel surface. The surface analysis using SEM supported the inhibitor adsorption on the steel substrate. Based on the DFT simulation, inhibition by MET is mainly achieved by its protonated form, which leads to the formation of a thin film on the steel surface rather than the modification of the work function of the steel surface. The experimental and theoretical estimations of pKa complemented the DFT results, both agreeing that the monoprotonated form of MET is the dominant form in which the inhibitor adsorbs on the steel surface to form a thin film rather than modify the work function of the steel surface.

Growth kinetic study of electrochemically active bacterium Shewanella putrefaciens MTCC 8104 on acidic effluent of jute stick pyrolysis

ABSTRACT Production of bioelectricity from waste streams using electrochemically active bacteria (EAB) has a great prospect. This article focuses on the assessment of the assimilation of acid-rich pyroliquid (APL), appearing from the waste stream of pyrolysis unit of jute stick, by one of EAB, Shewanella putrefaciens MTCC 8104. At the optimum temperature ( = 37°C) and pH ( = 4), the strain can assimilate up to 230 ppm of acetic acid per hour. Microscopic analysis indicates the presence of nanowires in the bacteria. Diauxic growth pattern is exhibited when both APL and whey are used as carbon sources. The minimum inhibitory concentration of acetic acid against S. putrefaciens has been determined to be 8000 ppm. Growth kinetics of the strain has been determined by using APL having acetic acid concentration between 100 and 7500 ppm, as carbon source. While the Monod model can explain the growth in the uninhibited zone, Wayman model has been proved to be the fittest by statistical analysis using the Akaike Information Criterion. The kinetic parameters μmax, Ks and Ki are 0.11 h−1, 13.17 and 75930.1 mg/L, respectively, with R 2 value of 0.977.

The acetic acid vapor sensing properties of BaSnO3 microtubes prepared by electrospinning method

In this paper, BaSnO3 microtubes were prepared via electrospinning method using Ba(NO3)2 and SnCl4·5H2O as raw materials. The as-prepared samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS), respectively; the gas sensing properties of the as-prepared sample were also investigated. The results revealed that BaSnO3 microtubes could be obtained by calcining the precursor at 700 °C for 6 h. It was revealed that the sensor device based on BaSnO3 microtubes (700 °C, 6 h) exhibited excellent selectivity and high response toward acetic acid vapor at the operating temperature of 245 °C, the ratio of S1000 ppm acetic acid to S1000 ppm ethanol was about 14.4; especially, when the concentration of acetic acid was as low as 0.3 ppm, the response was still able to reach 1.4.

Corrosion Rate Analysis of API 5L Gr B Steel Pipe in Acetic Acid Contained Crude Oil Treatment System by Using Amine Base Organik Corrosion Inhibitor

Corrosion is the main problem in the processing of crude oil containing soap emulsion by using acetic acid based demulsifier. This study aims to analyze corrosion of API 5L Gr B steel pipe in the solution of 90% brine and 10% crude oil with addition of 2000 ppm of acetic acid based demulsifier at various concentration of amine based organic inhibitor. Corrosion testing was conducted using weight loss coupon. SEM and EDS analysis were performed to investigate corroded specimen. The weight loss results indicate that amine based organic inhibitor made the steel resistant to corrosion with an inhibitor effectiveness of up to 96.67% at a concentration of 40 ppm. SEM observation following with EDS analysis identifying the presence of inhibitor and corrosion product protection layer.

Doped ZnO for Selective Acetic Acid Sensing

Introduction Acetic acid is a key tracer in chocolate and coffee processing defining their final taste. Additionally, it is a promising breath marker for cystic fibrosis and gastro-oesophageal reflux disease as breath concentrations are significantly increased with 170 ppb [1] and 85 ppb [2], respectively, compared to healthy humans (48 ppb). However, current sensors lack ppb to ppm level sensitivity with high selectivity to detect relevant acetic acid concentrations accurately in gas mixtures at high humidity (90%). Here, we present an acetic acid selective gas sensor able to detect lowest ppb-level concentrations. It consists of doped ZnO nanoparticles whereas doping level, particle & crystal size as well as film morphology were subsequently optimized in a flame spray pyrolysis (FSP) reactor. Method ZnO nanoparticles with different (0 - 10 mol%) doping contents were produced by flame spray pyrolysis (FSP) and directly deposited [3] onto water-cooled Al2O3 sensor substrates forming a highly porous sensing network. The mechanical stability of the nanoparticles on the Al2O3 was fortified by in-situ annealing [4] with a particle-free xylene flame followed by annealing at 500 °C for 5 h in an oven. The sensors were mounted onto Macor holders, placed in a sensing chamber and installed in an evaluation setup described elsewhere [5]. The sensors were heated to 250 - 450 °C and tested on 1 ppm acetic acid, acetone, ethanol and ammonia at relative humidity ranging from 10 to 90%. Results and Conclusions Figure 1a shows a top view SEM of the sensing film for ZnO doped with 1 mol% transition metals. The doping thermally stabilizes the particles during high temperature treatment and preserves the highly porous nanostructured sensing network typical for FSP. In specific, it consists of aggregates and agglomerates of individual nanoparticles with particle sizes ~35 nm (Figure 1a, inset), as determined by nitrogen adsorption from filter-collected powders and ideal for gas sensing due to the high available surface area.Figure 1b shows the sensor response to 1 ppm acetic acid, ethanol, acetone and H2 as a function of the doping content. Additionally, the doping with 1 mol% increases the sensor response to acetic acid and selectivity to ethanol and acetone compared to pure ZnO (Figure 1b). That way, even concentrations down to 50 ppb were detectable at 50% relative humidity (RH), unprecedented by other acetic acid sensors. Note that at higher doping contents, the responses to all analytes decrease again, most likely due to the isolating character of segregated transition metal phases. As a result, an inexpensive acetic acid detector has been developed that could be easily incorporated into a portable breath analyzer, used for food processing monitoring or incorporated into orthogonal arrays [6].