Refinery Samples Research Articles

A Study of The Radionuclides of The Petroleum Waste In Dora and Bijie Refineries Using (Hpge) Detector

The aim of this study is to detect the radioactivity of radionuclides and measure the specific activities and the uranium concentration in (19) samples of crude oil and oil waste were brought from two oil locations Dora refinery, Bijie refinery.
 The measurements in this study were done by using two techniques:
 1- Gamma rays spectroscopy system was used to measure the specific activity for radionuclides. This system is consist of high purity of germanium detector (HPGe) with personal computer as multi channel analyzer (MCA) that computerized to plot the radioactive spectrum and compute the specific activities of the radionuclides. There are seven radionuclides are detected:
 (Bi-214, Ra-226, TI-208, Bi-212, Pb-212, K-40, and Cs-137), these radionuclides included; two
 
 radionuclides (Bi-214,Ra-226) belong to the U-238 series, three radionuclides (TI-208, Bi-212, Pb-212) belong to Th-232series, one natural radionuclide (K-40), and one artificial radionuclide (Cs-137).
 For Dora refinery samples, the averages of specific activities of (Bi-214, Ra-226) were (7.79, 16.08) Bq/kg respectively, the averages of specific activities of (TI-208, Bi-212, Pb-212) were (7.95,4.05,5.75) Bq/kg , the average of specific activities of (Cs-137) was (0.64) Bq/kg , the average of specific activities of (K-40) was (99.3) Bq/kg.
 For Bijie refinery samples, the average of specific activities of (Bi-214) was (0.39) Bq/kg, the averages specific activities of (Bi-212, Pb-212) were (0.02,0.01) Bq/kg, the average of specific activities of (K-40) was (2.28) Bq/kg , and three radionuclides (Ra-226, TI-208, and Cs-137) were not appeared in Bijie samples.
 2- solid state nuclear track detectors technique (SSNTDs), the uranium concentration determined by using CR-39 track detector and fission fragment track technique, the nuclear reaction used as source of uranium fission fragment is U-235 (n-f) obtained by the bombardment of U-235with thermal neutrons emitted from (Am-Be) neutron source with flux (5000 n/cm2.s) for seven days, the concentration were calculated by
 comparison with the standard samples. The uranium concentration in Dora refinery samples were ranged between (0.95-3.34) ppm with average (2.03) ppm for solid samples and (1.25) ppm for liquid samples. The uranium concentration in Bijie refinery samples were ranged from (0.42-1.46) ppm with average (0.55) ppm in the solid samples and (1.24) ppm in the liquid samples, these results are agreement with the permissible limit from IAEA, the permissible limit is (1mSv/y) for the public.

Determination of fifteen phenols in wastewater from petroleum refinery samples using a dispersive liquid—liquid microextraction and liquid chromatography with a photodiode array detector

This work proposes for the first time a dispersive liquid-liquid microextraction (DLLME) method for the simultaneous extraction of 15 phenols (including isomers) from refinery wastewater with identification by liquid chromatography coupled to photodiode array detection (LC-PDA). The compounds studied were phenol, cresols, nitrophenols and chlorophenols including the isomers: 2–nitrophenol and 4-nitrophenol; o-cresol, m-cresol and p-cresol; 2,4-dichlorophenol and 2,6-dichlorophenol; 2,4,6-trichlorophenol and 2,4,5-trichlorophenol. Because of the presence of isomers and similar compounds, different mobile phases, comprising several combinations of methanol, acetonitrile and purified water, and different flow rates were tested to provide separation. Also, retention factors, selectivity and resolution were evaluated. For DLLME, volumes of extraction (1-octanol) and disperser (acetone) solvents were optimized by a 22 full factorial design. The optimum conditions involved using the use of 250 μL 1-octanol and 1000 μL of acetone. The limits of quantification were between 2.5 and 10 μg L−1. Analytical recoveries ranged from 69 to 129%, with relative standard deviations (RSD) below 20%. The proposed analytical method was successfully applied to the determination of these compounds in refinery wastewaters. Phenol, o-cresol p + m-cresol and 2,4-dimethylphenol were detected in a concentration range from 15 to 78 μg L−1 and 300–2120 μg L−1 in the treated and raw wastewaters, respectively.

Fate and effect of naphthenic acids on oil refinery activated sludge wastewater treatment systems

Naphthenic acids (NAs) are a complex group of alkyl-substituted acyclic, monocyclic and polycyclic carboxylic acids present in oil sands process waters, crude oil, refinery wastewater and petroleum products. Crude oil, desalter brine, influent, activated sludge mixed liquor and effluent refinery samples were received from six United States refineries. The total acid number (TAN) of the six crudes tested ranged from 0.12 to 1.5 mg KOH/g crude oil and correlated to the total NA concentration in the crudes. The total NA concentration in the desalter brine, influent, activated sludge mixed liquor and effluent samples ranged from 4.2 to 40.4, 4.5 to 16.6, 9.6 to 140.3 and 2.8 to 11.6 mg NA/L, respectively. The NAs in all wastewater streams accounted for less than 16% of the total COD, indicating that many other organic compounds are present and that NAs are a minor component in refinery wastewaters. Susceptibility tests showed that none of the activated sludge heterotrophic microcosms was completely inhibited by NAs up to 400 mg/L. Growth inhibition ranging from 10 to 59% was observed in all microcosms at and above 100 mg NA/L. NAs chronically-sorbed to activated sludge mixed liquor biomass and powdered activated carbon (PAC) were recalcitrant and persistent. More than 80% of the total NAs remained in the solid phase at the end of the 10-day desorption period (five successive desorption steps). Throughout a 90-day incubation period, the total NA concentration decreased by 33 and 51% in PAC-free and PAC-containing mixed liquor microcosms, respectively. The lower molecular weight fraction of NAs was preferentially degraded in both mixed liquors. The persistence of the residual, higher molecular weight NAs is likely a combination of molecular recalcitrance and decreased bioavailability when chronically-sorbed to the biomass and/or PAC.

The Bioremediation of Refinery Wastewater Using Inorganic Fertilizer

This study investigated the treatment of refinery wastewater using inorganic fertilizer. The biological method of treatment using the process of bioremediation was used. Inorganic fertilizer (NPK 15:15:15) was used to biostimulate the microorganisms present in the wastewater. Five samples of the refinery wastewater with equal pollution load were treated with different amounts of fertilizer (5, 10, 20, 30, and 40 g/l). Biochemical oxygen demand (BOD), pH, dissolved oxygen (DO) and total hydrocarbon content (THC) of the wastewater were monitored for a period of 35 days. From the results obtained, the BOD was observed to have dropped from 68.71 to 30.23 m/l; 68.71 to 23.92 mg/l; 68.71 to 22.11 mg/l and then 68.71 to 21.86 mg/l for the 5, 10, 20, 30, and 40 g/l of the refinery samples, respectively. Similar decreases were also observed for the other physiochemical parameters, except for the pH and DO, which increased with time. It was observed that the 40 g/l sample was more effective in the 35 days of the study and these results met the Federal Environmental Protection Agency (FEPA) standard for BOD, which is within the range of 30–35 mg/l. Hence, the method of bioremediation using fertilizer in the treatment of refinery wastewater can be applied on a large scale treatment.

Simultaneous speciation of arsenic (As(III), MMA, DMA, and As(V)) and selenium (Se(IV), Se(VI), and SeCN−) in petroleum refinery aqueous streams

High-performance liquid chromatography (HPLC) coupled to an ICP-MS with an octapole reaction system (ORS) has been used to carry out quantitative speciation of selenium (Se) and arsenic (As) in the stream waters of a refining process. The argon dimers interfering with the (78)Se and (80)Se isotopes were suppressed by pressurizing the octapole chamber with 3.1 mL min(-1) H(2) and 0.5 mL min(-1) He. Four arsenic species arsenite--As(III), arsenate (As(V)), monomethylarsonic acid (MMA), and dimethylarsinic acid (DMA)--and three inorganic Se species--selenite Se(IV), selenate Se(VI), and selenocyanate (SeCN(-))--were separated in a single run by ion chromatography (IC) using gradient elution with 100 mmol L(-1) NH(4)NO(3), pH 8.5, adjusted by addition of NH(3), as eluent. Repeatabilities of peak position and of peak area evaluation were better than 1% and about 3%, respectively. Detection limits (as 3sigma of the baseline noise) were 81, 56, and 75 ng L(-1) for Se(IV), Se(VI), and SeCN(-), respectively, and 22, 19, 25, and 16 ng L(-1) for As(III), As(V), MMA, and DMA, respectively. Calibration curve R (2) values ranged between 0.996 and 0.999 for the arsenic and selenium species. Column recovery for ion chromatography was calculated to be 97 +/- 6% for combined arsenic species and 98 +/- 3% for combined selenium species. Because certified reference materials for As and Se speciation studies are still not commercially available, in order to check accuracy and precision the method was applied to certified reference materials, BCR 714, BCR 1714, and BCR 715 and to two different refinery samples--inlet and outlet wastewater. The method was successfully used to study the quantitative speciation of selenium and arsenic in petroleum refinery wastewaters.

Occupational exposure to benzene at the ExxonMobil refinery in Beaumont, TX (1976–2007)

Because crude oil and refined petroleum products can contain benzene and benzene is considered a known carcinogen by numerous independent and governmental agencies, including the International Agency for Cancer Research, the petroleum industry has implemented exposure control programs for decades. As part of the benzene control programs, significant exposure assessments have been performed; both qualitatively and through quantitative measurements. In this study, we evaluated the airborne concentrations of benzene and their variability over time at the ExxonMobil refinery in Beaumont, TX between 1976 and 2007. The results of 5854 personal air samples are included in this analysis; 3761 were considered non-task (> or =180 min) personal samples, and 2093 were considered task-related (<180 min) personal samples. Dock and loading rack samples were analyzed separately from the refinery samples because in addition to refinery products, employees at the dock and loading rack also handled chemical plant products. In general, the non-task personal refinery air samples indicated that exposures of the past 30 years were generally below the occupational exposure limit of 1 ppm (mean=0.30 ppm, SD=3.1), were higher during routine (mean=0.32 ppm, SD=3.3) than turnaround operations (mean=0.16 ppm, SD=0.87), and decreased slightly over time. The job sampled most frequently during routine operations was that of process technician, and, as broken down by area, resulted in the following mean benzene air concentrations: coker (n=146, mean=0.014 ppm, SD=0.036), lube extraction unit (n=31, mean<0.070 ppm), pipestills (n=136, mean=0.12, SD=0.47), waste treatment (n=107, mean=0.20, SD=0.28), and all other areas (n=1115, mean=0.059 ppm, SD=0.36). Task-based samples indicated that the highest exposures resulted from the tank cleaning tasks, although the overall task mean benzene air concentration was 1.4 ppm during routine operations. The most frequently sampled task during routine operations was blinding and breaking, and the mean benzene air concentrations associated with this task were statistically higher in the reformer area of the refinery (n=311, mean=3.2 ppm, SD=7.9) than in all other areas (n=200, mean=0.92 ppm, SD=3.1). However, task-related exposures were found to be statistically similar across job categories for a given task. This study thus provides a task-focused analysis for occupational exposure to benzene during refinery operations, and will be useful for understanding exposures at this refinery.

Compositional Study of Polar Species in Untreated and Hydrotreated Gas Oil Samples by Electrospray Ionization Fourier Transform Ion Cyclotron Resonance Mass Spectrometry (ESI FTICR−MS)

Two gas oil samples, untreated feed and hydrotreated product oil, were analyzed. Both basic and acidic polar species were detected by electrospray ionization (ESI) Fourier transform ion cyclotron resonance mass spectrometry, and the detected species were characterized on the basis of their elemental compositions. Samples were real refinery samples, with one sample being a certain distillation fraction of crude oil (feed) and the other sample being a hydrotreated feed oil (product). Comparison of the compositions of untreated and hydrotreated oil provides insight into (1) compounds that are resistant to processing, (2) compounds that are removed/degraded by processing, and (3) new compounds that are produced during processing. N1 class compounds were found to be the most abundant basic species in both oil samples. In addition, the proportion of N1 class compounds was clearly greater in the product oil than in the feed oil, which indicates that these basic species must be resistant to removal by hydrotreatment. All basic NxOy-, NxSz-, and NxOySz-containing compounds that were detected in the feed oil were completely removed by hydrotreatment. However, some of the OySz compounds remained in the oil after hydrotreatment. Negative-ion ESI revealed that the majority of the acidic polar species in the product sample were N1 compounds, which was also the predominant class in the feed sample. The second most abundant species were the Oy-containing compounds. All of the O1 compounds that were detected in the feed oil were degraded during the hydrotreatment process, as were the O2 compounds with double-bond equivalent (DBE) values >4. Acidic NxOy-, NxSz-, OySz-, and NxOySz-containing compounds were not completely removed by the processing, but the relative abundances of these species were no longer significant in the product oil.

PREDICTION OF PHYSICOCHEMICAL PROPERTIES OF FCC FEEDSTOCK BY CHEMOMETRIC ANALYSIS OF THEIR ULTRAVIOLET SPECTRUM

Chemometric analysis by Partial Least Squares (PLS) has been applied in this work to correlate the ultraviolet spectrum of combined Fluid Catalytic Cracking (FCC) feedstocks with their physicochemical properties. The prediction errors obtained in the validation process using refinery samples demonstrate the accuracy of the predicted properties. This new analytical methodology allows obtaining in one analysis detailed information about the most important physicochemical properties of FCC feedstocks and could be used as a valuable tool for operational analysis.

Comparison of soybean peroxidase with laccase in the removal of phenol from synthetic and refinery wastewater samples

AbstractBACKGROUND: Several studies have demonstrated the feasibility of treating aqueous phenols and aromatic amines with oxidoreductases in synthetic wastewater samples. However, little work has been done on the effectiveness of enzymatic treatment on real wastewater. Here a comparison was made of the oxidative coupling of phenol catalyzed by laccase or soybean peroxidase (SBP) using synthetic and refinery wastewaters.RESULTS: Optimization of pH, enzyme concentration, effect of polyethylene glycol (PEG) addition, and reducing anions were examined for a 3 h reaction time. Laccase had an optimum pH of 5.6–6.0, while SBP had a broad optimum from 6.0 to 8.0. In synthetic samples in tap water to achieve ≥ 95% removal of 1.0 mmol L−1 phenol in 3 h required 0.12 and 1.5 U mL−1 of catalytic activity of laccase and SBP, respectively. In refinery samples comparable removals required 1.2‐ to 1.8‐fold more enzyme than in synthetic tap water samples. Added PEG allowed for a small reduction in the SBP concentration for synthetic wastewater but was ineffective with either enzyme in treating refinery samples. Reducing ions increased the demand for oxidant but, with the exception of cyanide, phenol removal still occurred.CONCLUSION: Both laccase and SBP were effective in removing phenol from aqueous refinery samples, albeit at slightly higher concentrations than required for the corresponding synthetic samples. Copyright © 2008 Society of Chemical Industry

Doehlert matrix for optimisation of procedure for determination of nickel in saline oil-refinery effluents by use of flame atomic absorption spectrometry after preconcentration by cloud-point extraction.

This paper proposes a preconcentration procedure for determination of nickel in saline aqueous waste samples by flame atomic absorption spectrometry (FAAS). It is based on cloud-point extraction of nickel(II) ions as 2-(5-bromo-2-pyridylazo)-5-diethilaminophenol (Br-PADAP) complexes using octylphenoxypolyethoxyethanol (Triton X-114) as surfactant. The optimisation step was performed using a four-variable Doehlert design, involving the factors centrifugation time (CT) of system after addition of surfactant, solution pH, methanol volume (MV) added at micellar phase, and buffer concentration (BC). The analytical response used was absorbance, after volume correction. Using the established experimental conditions in the optimisation step the procedure enables nickel determination with a detection limit (3 delta/ S) of 0.2 microg L(-1), quantification limit (10 delta/ S) of 0.7 microg L(-1), and precision, calculated as relative standard deviation ( RSD) of 4.7 ( n=8) and 3.5% ( n=8) for nickel concentration of 1 and 5 microg L(-1), respectively. The preconcentration factor, determined from the ratio of the slopes of the analytical curves with and without preconcentration, is 74. The recovery achieved for nickel determination in the presence of several cations demonstrated that this procedure could be applied for analysis of water samples. The robustness was checked by using saturated fractional factorial designs, centred on the established experimental conditions in the optimisation step. The results of these tests demonstrated that the variables centrifugation time and buffer concentration are robust for modification by 10% and that solution pH and methanol volume are robust for 5%. Accuracy was evaluated by using the certified material reference SLEW-3 estuarine water for trace metals. The procedure was used for determination of nickel in saline effluents from oil refinery samples. Recovery results (95-104%) indicate that the procedure has satisfactory accuracy for nickel determination in these samples.

Quantitative determination of oxalate in Bayer liquor by capillary zone electrophoresis A validative study

The applicability of capillary zone electrophoresis (CZE) for the routine determination of oxalate in Bayer liquors was investigated. The effects of electrolyte composition, capillary conditioning, temperature and applied voltage were studied, with the use of temperature control, isomigration mode and an appropriate capillary conditioning regime proving critical in minimising variations in peak migration time. The CZE method, which utilised a chromate-based electrolyte (containing an osmotic flow modifier) and indirect photometry, demonstrated excellent within-batch precision, giving a migration time precision of less than 0.30% R.S.D. and an analysis precision of less than 1.2% R.S.D. The method also demonstrated excellent between-batch precision, with the overall analysis precision, obtained for five alumina refinery samples run over five days, being 2.3, 1.1, 1.7, 1.5 and 1.3% R.S.D., respectively. The between-batch migration time precision for the oxalate peak was 0.89% R.S.D., while the absolute oxalate peak area precision was 2.5% R.S.D. The method within- and between-batch precision values were comparable to those expected from other instrumental separation techniques, demonstrating that CZE can be an appropriate technique for routine analysis, even for complicated sample matrices, such as Bayer liquors.

ChemInform Abstract: Nickel and Vanadium on Equilibrium Cracking Catalysts by Imaging Secondary Ion Mass Spectrometry.

AbstractSIMS data from refinery samples of several types of fluidized catalytic cracking catalysts show the metals in catalytic cracking feedstocks to initially deposit near the external surface of catalyst particles.

Nickel and vanadium on equilibrium cracking catalysts by imaging secondary ion mass spectrometry

The distribution of nickel and vanadium has been determined on refinery samples of several types of fluidized catalytic cracking catalyst. Data from imaging secondary ion mass spectrometry show that metals in catalytic cracking feedstocks initially deposit near the external surface of catalyst particles. Nickel remains in the area where it was deposited, while vanadium shows both intraparticle and interparticle mobility. Vanadium accumulates throughout catalyst particles, but shows a preference for both rare earth exchanged Y-zeolite and alumina phases in composite catalyst. By contrast, nickel shows no preference for catalyst phases and accumulates monotonically with time. The lack of mobility in deposited nickel makes it a good measure to determine the age of individual particles.

Study of Osmophilic Yeasts producing Invertase

Oxygen is taken up by the cells of purple sulphur bacterium Thiocapsa roseopersicina BBS grown in the light under anaerobic conditions and in the darkness under aerobic conditions. Respiration is stimulated by sulphide and thiosulphate but not by organic substrates which increase the yield of the cultures. Azide and cyanide inhibit oxygen uptake by the cells in the presence of sulphide and thiosulphate, and also utilization of these compounds. Amytal, atebrin, and rotenone inhibit oxygen uptake by the cells in the presence of sulphide but have no effect on their respiration in the presence of thiosulphate. Light produces reversible inhibiting action on respiration of the cells. Therefore, Thiocapsa roseopersicina can grow in the darkness by oxidizing sulphur compounds with the participation of oxygen.