The description methods of combustion front are required to be fast and accurate for in-situ combustion (fire flooding), and the current methods can't fully conform that requirement. However, the ...description method based on conventional data monitoring is a way to solve this problem. The experimental results of dry combustion indicates that the position of combustion front has a nearly linear correlation with the total acid numbers (TAN) of oil produced for in-situ combustion (ISC). Meanwhile, the tendency of pressure variation between neighboring air injection wells can determine the state and the time of combustion chamber connected in linear ISC process. Therefore, based on the relationship between TAN, injection pressure and combustion front, the acid numbers-pressure(ANP) method is established，which is suitable for dry linear fire flooding. Further, this method is applied to the calculation of the position of the combustion front in HQ1 ISC pilot area in Xinjiang over the years. Compared with other methods, the ANP method can rapidly calculate the position of combustion front and confirm the connectivity of combustion chamber. In addition, the combination of the ANP and other method is a good solution to confirm the position of combustion front for dry linear ISC process.
High acid crude oils contain large amount of naphthenic acids which cause serious corrosion problem in petroleum industry. Therefore, the removal of naphthenic acids becomes a great concern and ...challenge for oil refineries. In this study, the naphthenic acids in high TAN crude oils were removed by esterification with low consumption of methanol using a solid acid catalyst consisting of 12-tungstophosphoric acid (TPA) supported on γ-Al2O3 (TPA/γ-Al2O3) in a fixed-bed up-flow reactor. The catalyst was prepared by conventional wet impregnation method, and it possessed 25 wt% TPA with high dispersion, and large pore structure. TPA leaching problem from catalyst support was not observed during the reaction. The effect of various reaction parameters such as temperature and liquid hour space velocity (LHSV), and methanol to the crude oil ratio on TAN reduction were investigated in detail to maximize TAN reduction. The results revealed that the TPA/γ-Al2O3 catalyst effectively removed the naphthenic acids via esterification in high TAN crude oils. The TAN decreased with increase in methanol/oil mass ratio, reaction temperature, but it increased with increase in LHSV. In a long-term experiments (up to 100 h) running at a reaction temperature of 250 °C and LHSV of 3 h−1 using 2 wt% methanol in acidic crude oil, the TANs of acidic crude oil reduced from 2.0 mg KOH/g to a value below 0.5 mg KOH/g which is an acceptable TAN value of crude oil to process in the refineries without material upgrades.
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•CaCl2, MgCl2, and SrCl2 in crude oil impact TAN obtained using the ASTM D664 method.•100 mg of CaCl2, MgCl2 and SrCl2 in crude oil is sufficient to alter the TAN.•Alcoholic KOH and ...CaCl2, MgCl2, or SrCl2 react to form hydroxides and increase TAN.•Salt effect may differ according to crude oil sample (light or heavy).
The most widely used method for determining the total acid number (TAN) in crude oils is American Society for Testing and Materials (ASTM) D664, which is subject to interference from hydrolyzable salts. This study investigated and determined at which salt concentration NaCl, CaCl2, MgCl2, and SrCl2 significantly interfere with the determination of the TAN in crude oil using the ASTM D664 method. To evaluate the influence of salts on the titration solvent of ASTM D664 and crude oil, pure chloride salts, and two mixtures of these salts, were added to the titration solvents (at 1500–8000 mg kg−1) and water-in-oil emulsions (alpha and gamma). Precipitation was observed during the titrations of these solvents. Analysis of the precipitates via gravimetric analysis, X-ray diffraction, and attenuated total reflection Fourier transform infrared spectroscopy demonstrated that they were composed of Ca(OH)2, Mg(OH)2, and Sr(OH)2. The alpha oil exhibited an increase in acidity from 0.28 up to 2.47 mg KOH g−1 with the chloride salt mixtures, whereas gamma oil exhibited an increase in acidity from 2.26 up to 4.17 mg KOH g−1 with the chloride salt mixtures. One hundred milligrams of CaCl2, MgCl2, or SrCl2 remaining in the oil was sufficient to interfere with the in TAN determination using the ASTM D664 method.
The Athabasca Oil Sands industry produces large volumes of oil sands process-affected water (OSPW) as a result of bitumen extraction and upgrading processes. Constituents of OSPW include chloride, ...naphthenic acids (NAs), aromatic hydrocarbons, and trace heavy metals, among other inorganic and organic compounds. To address the environmental issues associated with the recycling and/or safe return of OSPW into the environment, water treatment technologies are required. This study examined, for the first time, the impacts of pretreatment steps, including filtration and petroleum-coke adsorption, on ozonation requirements and performance. The effect of the initial OSPW pH on treatment performance, and the evolution of ozonation and its impact on OSPW toxicity and biodegradability were also examined. The degradation of more than 76% of total acid-extractable organics was achieved using a semi-batch ozonation system at a utilized ozone dose of 150
mg/L. With a utilized ozone dose of 100
mg/L, the treated OSPW became more biodegradable and showed no toxicity towards
Vibrio fischeri. Changes in the NA profiles in terms of carbon number and number of rings were observed after ozonation. The filtration of the OSPW did not improve the ozonation performance. Petroleum-coke adsorption was found to be effective in reducing total acid-extractable organics by a 91%, NA content by an 84%, and OSPW toxicity from 4.3 to 1.1 toxicity units. The results of this study indicate that the combination of petroleum-coke adsorption and ozonation is a promising treatment approach to treat OSPW.
► Filtration and petroleum-coke adsorption were used as ozonation pretreatments steps. ► The filtration of the OSPW did not improve the ozonation performance. ► Carbon number and number of rings in the NA structure influenced the levels of NA oxidation. ► OSPW becomes more biodegradable and showed no acute toxicity after ozonation. ► Adsorption followed by ozonation was found to be a promising method to treat OSPW.
This paper presents the experimental results carried out to evaluate the oxidation and storage stabilities of various biodiesel fuels. The biodiesel fuels are palm methyl ester (PME), jatropha methyl ...ester (JME), coconut oil methyl ester (COME), 20% blends of PME with diesel fuel and 20% blends of JME with diesel fuel. The ordinary diesel fuel was used for comparison purposes. Various ASTM standard methods were used to evaluate all the samples at the interval of 180 h over a 2160 h (three months) duration. Oxidation stability of the samples was measured by induction period (IP) using a Rancimat instrument. Other properties such as density, viscosity, flash point, total acid number (TAN), and total base number (TBN) were measured. The results show that almost all fuel samples met the standard specifications regarding IP. The trends for density, viscosity and TAN increased, while the TBN decreased due to oxidation. For the flash point, the trend also decreased, but the rate was very low. In overall consideration, among the biodiesels, COME was found to be better in respect to oxidation and storage stabilities. The results of this investigation will be used to sustainable development of biodiesel fuel from various stock resources.
► Induction period of Diesel, PME, JME, PME 20, JME 20 and COME are studied. ► Tested biodiesels showed promising result in terms of induction period and almost all of them met the standard specifications. ► During storage period, adverse effect of oxidation is observed regarding the density kinematic viscosity, TBN and flash point. ► TAN is the most concerning one for all biodiesel samples since none of them meet the standard specified value.
Transformers are indispensable components in any power network, facilitating the delivery of generated electricity to consumers at the most secure voltage level. The insulation system of oil-filled ...transformers is critical for the safe operation of power transformers, although it undergoes consistent degradation over time. Similar to blood in a human body, the insulating fluid serves as a condition monitoring medium. Most traditional oil aging detection methodologies operate offline; thus, they are most suitable for planned maintenance activities. These methods, however, have their drawbacks, including potential safety risks, contamination of samples, loss of productive hours, and the potential risk of overlooking early signs of aging that could occur beyond the maintenance cycle window. The Myers oil quality index (OQIN) number, derived from the quotient of interfacial tension (IFT) and total acid number (TAN) values, provides a tool for classifying transformer oil into seven distinct categories, expanding the potential for both offline and online oil applications. In this work, eighteen 750 mL samples of natural ester oil (NEO) are procured, aged, and analyzed using offline TAN and IFT techniques, and their respective values (IFT, TAN, and OQIN) are recorded. These experimental datasets are employed to verify and validate (V&V) an OQIN machine learning model. The model is further validated using existing mineral oil (MIN) datasets. The high-performance metrics, demonstrated in terms of accuracy, precision, sensitivity, specificity, and F-Score, confirm the effectiveness of the model for online transformer oil aging detection and classification. The bagged tree ensemble model shows the best performance for OQIN, NEO, and MIN, respectively, in terms of accuracy (100%, 83.30%, 100%), precision (100%, 90%, 100%), sensitivity (100%, 88%, 100%), specificity (100%, 96%, 100%), and F-Score (100%, 84.76%, 100%). This development proposes the potential for a shift from traditional offline scheduled maintenance aging detection methods to an online/Internet of Things (IoT)-based prescriptive aging detection, thereby enhancing the reliability of transformer performance in situ.
As the demand for critical and valuable metals increases due to industrial developments, especially in electronics and high-technology industries, the search for novel and sustainable sources grows ...in significance. Incinerated municipal solid waste (MSW) is a potential source of valuable metals, since a lot of waste from electrical and electronic equipment (WEEE) is not recycled properly and are is managed together with the refuse fraction of MSW, which is often landfilled or incinerated. Bottom Ash (BA) is the main by-product of incinerated MSW, which has been characterized to assess the potential recovery of valuable metals. The determination of the total amount of valuable metals (Ag, Al, Au, Be, Co, Cu, Ga, Ge, In, Ir, Li, Ni, Pd, Pt, Sb, Ta, and W) in seasonal samples of weather bottom ash (WBA) was performed by a total acid digestion followed by a chemical analysis. Besides, a sequential extraction procedure (SEP) is conducted to define their partition. The characterisation has shown that the content of valuable metals in the incineration WBA, which was highest in the 0–2 mm fraction was much lower than in concentrated ores commonly used as primary sources. Moreover, the SEP showed little potential for the valorisation of most of the metals, as they are embedded in or bound to a silicic matrix or sintered metal oxides, and so their extraction requires strong-acid digestion or a highly oxidizing environment. This work contributes to the use of residual sources as secondary resources and to the correct management of the end-of-life electrical and electronic equipment.
•WEEE are not recycled properly and are managed with the refuse fraction of MSW.•MSWI bottom ash is a potential source of valuable metals coming from WEEE.•MSWI bottom ash has been characterized to evaluate the recovery of valuable metals.•Valuable metals are mainly in fine fractions with lower contents than mineral sources.•Valuable metals are embedded in Si-matrix and require severe condition for extraction.
Total acid number (TAN) has been considered an important indicator of the oil quality of used oils. TAN is determined by potentiometric titration, which is time-consuming and requires solvent. A more ...convenient approach to determine TAN is based on infrared (IR) spectral data and multivariate regression models. Predictive models for the determination of TAN using the IR data measured from ashless dispersant oils developed for aviation piston engines (SAE 50) have been developed. Different techniques, including Projection Pursuit Regression (PPR), Partial Least Square, Support Vector Machines, Linear Models and Random Forest (RF), have been used. The used methodology involved a five folder cross validation to derive the best model. Then a full error measure over the whole dataset was taken. A backward variable selection was used and 25 highly relevant variables were extracted. RF provided an acceptable modelling technology with grouped dataset predictions that allowed transformations to be performed that fitted the measured values. A hybrid method considering group of bands as features was used for modelling. An innovative mechanism for wider features selection based on genetic algorithm has been implemented. This method showed better performance than the results obtained using the other methodologies. RMSE and MAE values obtained in the validation were 0.759 and 0.359 for PPR model respectively.
•Predictive models are useful to determine TAN using IR from ashless dispersant oils for aviation.•For dimension reduction, PCA and Independent component analysis (ICA) have been applied.•A model based on non-linear regression by Support Vector Machines (SVM) with Gaussian kernel was implemented.•A hybrid method considering group of bands as features was used for modelling which showed better performance.
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