LIQUID PHASE CO-OXIDATION OF THIOPHENOL AND STYRENE BY OXYGEN AND t-BUTYL HYDROPEROXIDE

Instability problems in both shale and petroleum derived middle distillate jet fuels have been correlated with the presence of peroxidic species. Although a good body of knowledge exists concerning the formation of peroxides in the liquid phase, relatively little is known about the reaction/ decomposition pathways available when other functional groups are present, since sulfur is the most abundant heteroatam present in jet fuels, the reaction of t-butyl hydroperoxide (tBKP) and/or oxygen with thiophenol in the presence of the active olefin, styrene, was examined in deaerated benzene at 120°C. The complex product mixture was analyzed by combined capillary column GC/MS. Major products included acetone, t-butanol and isdbutylene from the tBHP. Thiophenol and styrene combined to form addition products. Phenyl disulfide was observed from the thiophenol. The results indicated that although the product slate was complex, it was possible to explain the product mix in terms of a few competing reactions.     

LIQUID PHASE OXIDATION OF THIOPHENOL AND INDENE BY t-BUTYL HYDROPEROXIDE AND OXYGEN

The tert-butyl hydroperoxide (tBHP) or oxygen initiated oxidation of thiophenol in the presence of the active olefin indene was examined in benzene at 120C. The reaction is kinetically complex, but it was possible to relate the product distribution to a few competing reactions. The product mix was determined for several reaction time periods. The product slate was similar for all time periods, but yields of the individual components varied significantly with increasing reaction time. Gaseous products included isobutylene and a trace of methane. The major product from tBHP was t-butanol. The major product observed from thiophenol was phenyl disulfide. Addition products included the major product 2-phenylthiyl indan. Oxidation products included: indanols, indanones, and the sulfoxide and sulfone of the major product 2-phenylthiyl indan. Solvent participtation was noted by trace amounts of toluene.     

REACTIONS OF BENZYL PHENYL SULFIDE NEAT AND IN DENSE POLAR SOLVENTS

ABSTRACT

The reactions of benzylphenylsulfide (BPS) neat, in tetralin, in dense water, and in supercritical methanol were studied. A free-radical mechanism described the neat pyrolysis of BPS to the major products toluene, thiophenol, diphenyldisulfide, and diphenylsulfide. An analytical rate expression deduced from this mechanism was consistent with results from both neat pyrolysis and copyrolysis with added thiophenol. Reaction in dense water yielded benzaldehyde, whereas reaction in super critical methanol yielded methylphenylsulfide and benzaldehyde, as additional primary products. Thus reaction in water and methanol was by parallel pyrolysis and solvolysis pathways.     

THE INTERACTIONS OF THIOLS WITH OLEFINS AND THEIR EFFECTS ON AUTOXIDATION DURING JFTOT TESTING

ABSTRACT

Previous research has shown that low concentrations of thiols will act as radical traps to inhibit autoxidation. When added to a fuel, thiols accelerated the rate of oxygen reaction without a commensurate increase in peroxidation. Evidence for the oxidative addition of thiols to olefins has been found to occur by studying the addition of thiophenol to indene in a model fuel during stressing in the JFTOT apparatus. Two different thiol-indene adducts were found in the effluent, with the product distribution being temperature dependent. This process could account, in part, for the differences in thiol influences on autoxidation observed in model systems and in fuels.     

Oxidative Degradation of Petroleum Products Via A Non-Peroxyl Radical Chain Pathway. Electron Transfer Initiated Oxidation (ETIO) Revisited.

ABSTRACT

The oxidative deterioration of petroleum products (change in physical/chemical properties upon prolonged storage under “ambient” conditions) is a complex, yet fascinating problem. For gasoline and jet fuel, a peroxyl radical chain oxidation mechanism is most likely operative during oxidative deterioration. For oxidatively reactive diesel fuel and asphalt, the available experimental evidence suggests that oxidative degradation is not a classical peroxyl radical chain. It is proposed that ETIO is consistent with the available experimental data for oxidatively reactive diesel fuels and asphalt. This paper will critically review pertinent literature dealing with the oxidative degradation of fuel products with focus upon evidence that illustrates the distinction between ETIO and peroxyl radical chain mechanism of oxidative deterioration.     

ANALYSIS OF INSTABILITY DEPOSITS TO THERMAL IN AVIATION JET FUELS

ABSTRACT

Gas chromatographic systems using nitrogen phosphorus and flame ionization detectors were utilized to analyze JP-5 fuels for reactants that lead to thermal instability products. High and low stability fuels defined by Naval Research Laboratory Gravimetric Jet Fuel Thermal oxidation Test (GRAV JFTOT) were chosen to make gross and detailed comparisons of the reactants present in each fuel. Whole fuel samples were analyzed and compared. An acid extract, HeOH extract, and MeOH saturated with MDA extract were also analyzed for each fuel sample using GC analysis. This study demonstrates the usefulness of extraction of bases and polars in defining thermal instability reactants in jet fuels. Data indicates the MDA does not appear to be useful as an extraction modifier for polars.     

CHARACTERIZATION OF HEAVY OIL FRACTIONS OBTAINED FROM THERMAL TREATMENT IN PRESENCE OF SULFIDES AND H-DONOR ADDITIVES

ABSTRACT

Analytical studies have been performed on effluents issued from thermal conversion of Safaniya Vacuum residue (Arab Heavy) in presence of tetralin, thiophenol and methyldisulfide. In contrast to thermal behavior of the heavy oil alone, low coke amount was produced at high conversion level (up to 50%) beside good product qualities as demonstrated from analysis of the remained 500°C⁺ fractions. H-donor diluent and sulfide additives help effectively in lowering the carbon residue values and maintaining the H/C ratios at the highest values compatible with the conversion. Microstructural parameters of the liquid effluents and their asphaltenic parts are obtained ¹H and ¹³C NMR spectroscopy and average molecular weight determination. Even at high conversion level results allow to assess a rapid dealkylation process at the first stage of the thermal treatments associated with a good control in the evolution of the size of polyaromatic units. Optical Microscopy and X-ray analysis outline the specific effect of tetralin as a. delayed coking additive.     

5TH INTERNATIONAL CONFERENCE ON STABILITY AND HANDLING OF LIQUID FUELS

Abstract

The 5th International Conference on Stability and Handling of Liquid Fuels was held in Rotterdam, the Netherlands October 3-7,1994. A number of petroleum companies, national petroleum stockpiling agencies, academe, government, research institutes, and additive manufacturers were represented by more than 200 attendees from 28 nations worldwide. The conference was chaired by Harry N. Giles of the U.S. Department of Energy. Fifty-five papers were presented in 12 technical sessions with an additional ten posters included in a separate session. Topics included jet and other middle distillate fuels, microbiology, long-term and strategic storage, expert systems, gasoline, test methods, and environmentally-friendly fuels.     

HYDROZEN TRANSFER HYDROCRAKING OF C.PROCERA UNDER AMBIENT PRESSURE CONDITIONS TO GET VALUE ADDED CHEMICALS AND FUELS

ABSTRACT

Biomass is renewable source of energy while the reserves of petroleum arc being depleted. The latex of a potential petrocrop, Colotropis procera, a lalicifcr, arid-plant which is rich in hydrocarbon type triterpene compounds etc. was found lo be a better feed slock for thermal hydrocracking as compared to whole plant biomass inlcrms of liquid product yield. Studies of chemical reaction dynamics of the thermal cracking of latex at 200-400°C showed that the process should be termed as hydrogen-tranfer (H-T) hydrocracking of latex under ambient pressure conditions. The hydrogen rich cracked trilcrpenoids act as the H-donors in this process, where nascent hydrogen atoms and free radicals chemically plug the cracked moities to stabilise these. Latex was also coagulated and the H-T hydrocracking of the feedstock coagulum gave a higher yield of cracked oil in comparision lo that from the dried latex. A model triterpene compound, ursolic acid has been subjected to H-T hydrocracking to understand the process of hydrocracking of latex under similar conditions and it was found that triterpencs on H-T hydrocracking produced only liquid and gaseous products and no solid char. The temperature for hydrocracking of latex has been optimized to 350°C and molecular sieve was round to catalyse the H-T Hytrocraking process to yield more liquid product The distillation range of cracked latex on(CLO)Obtained from H.T Hytrocracking of C procera Latex indicated that it can be used as fuel. Moreover CLO resembled diesel fuels and was predominantly paraffinic in nature as characterised by NMR and FTIR spectral analysis. A process has been recommended for gelling value added fuels and chemicals from C. procera latex.     

喷气燃料储存中生成的胶质化合物的研究

用中性氧化铝吸附和无水乙酸脱附的方法制备了几种喷气燃料的吸附胶质(Adsorptive gum)。通过模拟加速储存试验考察了喷气燃料中生成的吸附胶质。采用色一质联用分析法(GC-MS)和红外光谱分析法(FT-IR)分析了吸附胶质的组成，并探讨了喷气燃料在储存过程中吸附胶质的变化规律。结果表明，变色喷气燃料中的颜色物质全部集中在吸附胶质中，吸附胶质的组成以烷基苯酚类(及其二聚物)和芳香酯类化合物为主。吸附胶质能有效地反映喷气燃料在储存过程中的变质情况，储存中吸附胶质和颜色增加显著，新生成的吸附胶质与储存前燃料中的吸附胶质无显著差别。吸附胶质的产生与喷气燃料在一定条件下的氧化和缩聚反应有关。吸附胶质可能是储存中所产生的不溶物的母体化合物。     

A Novel Kinetic Model of Complex Reaction Systems in Molecular Level: Part 2. Simulation of Deep Catalytic Cracking

Abstract

A kinetic model of complex reaction systems such as DCC-I in molecular level was built by the method that combined Monte Carlo simulation and structural-oriented lumping. Seventy-five reaction rules, including the reactions of paraffins, olefins, naphthenics, and aromatics, were made to build the reaction networks of complex reaction system DCC-I. The results showed that the relationship of product yields with reaction extent was reasonable, the yields and properties of major products, propylene and gasoline, in optimized reaction extent gave a good agreement with the plant data, and the reaction rules and the reaction network could very well reflect the characters of DCC-I. Simulations of two sets of molecules produced by the same regular plant data were parallel, and the kinetic model had good repeatability, convergence, robustness, and sensitivity.     

低压喷气燃料加氢脱硫反应动力学模型研究

在固定床小试装置上,采用新一代喷气燃料加氢专用催化剂RSS-2,测定不同性质的喷气燃料在不同反应条件下的产品硫含量,在此基础上对喷气燃料加氢脱硫反应进行动力学计算,建立相应的加氢脱硫反应动力学模型。结果表明：喷气燃料加氢脱硫反应接近于活塞流反应模型,表观脱硫反应级数为1.1级;在考察的反应条件下,反应压力和氢油比对脱硫反应的影响较小,反应级数分别为0.273和0.375;反应温度对脱硫反应的影响可以用阿累尼乌斯方程定量表示,脱硫反应活化能为114.5 kJ/mol;所建立的低压喷气燃料加氢脱硫反应动力学模型在一定的范围内能较好地预测喷气燃料产品硫含量,为企业调整工艺参数提供参考依据。     

COMPARATIVE REACTION STUDY OF METHYLCYCLOHEXANE AND 3-METHYLHEXANE IN H2 AND N2 ON Pt/Al2O3 CATALYST

ABSTRACT

The reaction of methylcyclohexane and 3-methylhexane were studied in a pulse microcatalytic reactor using H₂ and N₂ carriers on Pt/Al₂O₃ catalyst at temperatures from 350 to 500°C, contact times (W/F) of 1.25 × 10^?3–3.75 × 10^?3 g min/ml and a total pressure of 4.0 kg/cm². In N₂, there was complete conversion of methylcyclohexane to methane, benzene and toluene while similar products were produced for 3-methylhexane, albeit with diminished conversion level. In H₂, methane was produced from 3-methylhexane conversion while aromatization without demethylation was obtained in addition to some cracking for methylcyclohexane at the low temperature range (350–400°C); a higher temperature range (460–500°C) resulted in complete fragmentation for methylcyclohexane. In H₂–N₂ mixtures, the presence of N₂ of not less than 50% in the carrier gas stream yielded an aromatic catalyst at conditions where only cracking activity was previously evident. The differences in product distribution and/or product types for the two reactants in H₂ and N₂ suggest a different reaction mechanism for both reactants.     

ACETALDEHYDE FROM CARBON MONOXIDE AND CHLOROMETHANE

ABSTRACT

Acetaldehyde (CH₃CHO) is the major oxygenated product of the thermal reaction of carbon monoxide and chloromethane under reaction conditions, i.e., between 600 °C and 700 °C, and between 0.1 MPa and 1 MPa. The reaction conditions have a significant effect on the formation of the products.     

MICROBIAL. TRANSFORMATION AND BIODEGRADATION OF CALOTROPIS PROCERA LATEX TOWARDS OBTAINING VALUE ADDED CHEMICALS,PHARMACEUTICALS AND FUELS

ABSTRACT

The latex of Calotropia arocera (Ait.) R.Br., (a potential petrocrop) may be exploited to obtain fuels and chemicals. This latex has been subjected to microbial action with Sphaerotilus aeruginosa, Sphaerotilus natans, Streptococcus sp.. Escherichia coli. Penicllllum expanaum and Mucor Sp. with an aim to find out a biochemical route way to obtain fuels and chemicals. The treated latex was extracted with hexane, chloroform and methanol separately. The extracts obtained were analysed using 13CNMR and ¹HNMR spectral techniques to understand the chemical dynamics of biotransformation of latex components. Microbial action was found to degrade, biotransform, oxidise, dehydrogenate and dearomatize the chemical components of the latex. S. aeruginosa and streptococcus sp were found to be the potential candidates for the microbial degradation of latex. Latex mainly contains triterterpenoid, steroid etc. compounds. These acyclic and naphthenic type of compounds are stabler and relatively less reactive compounds. Hydrotreatment of such compounds by thermal degradation would require drastic conditions. The complex degradation reactions at high temperature (under pressure) would be slower. Microbial treatment renders the latex (;and compounds present therein) as reactive substrates or feedstocks close for hydrotreatment for obtaining value added and premium products. These products may include value added chemicals, fuels and pharmaceuticals etc. in the long run. Microbial treatments may reduce the heat panalty of the hydrogen treatment etc. process. This may also make the rates of the hydrotreatment etc. reactions faster to afford the continuous processes in the long run     

REACTIONS OF BENZYL PHENYL SULFIDE NEAT AND IN DENSE POLAR SOLVENTS

The reactions of benzylphenylsulfide (BPS) neat, in tetralin, in dense water, and in supercritical methanol were studied. A free-radical mechanism described the neat pyrolysis of BPS to the major products toluene, thiophenol, diphenyldisulfide, and diphenylsulfide. An analytical rate expression deduced from this mechanism was consistent with results from both neat pyrolysis and copyrolysis with added thiophenol. Reaction in dense water yielded benzaldehyde, whereas reaction in super critical methanol yielded methylphenylsulfide and benzaldehyde, as additional primary products. Thus reaction in water and methanol was by parallel pyrolysis and solvolysis pathways.     

Oxidative Instability of Fuels: Nickel Catalyzed Reactions

Abstract

The reactions that lead to long-term storage instability of fuels are not fully understood. Various reports in the literature link particular fuels with specific reactions, usually oxidation or free radical processes. Trace quantities of metals are present in all processed fuels. The metal source can be naturally occurring or present from fuel handling. The usual case is to look at the reaction of the metal or metal ion with molecular oxygen or other active oxygen species such as hydroperoxides. This article reports on the reaction of a nitrogen heterocycle, indole. We propose a mechanism that shows that catalytic amounts of nickel can produce compounds of higher molecular weight and increased polarity.     

HYDROPROCESSING OF DISTILLATES DERIVED FROM OIL SANDS AND COAL: SUMMARY OF CANMET FINDINGS

ABSTRACT

The development of technologies for refining commercially available synthetic crudes from Alberta oil sands is of increasing economic importance in view of projected expansions in their utilization. Similar developmental concerns will arise in upgrading refinery residual oils and possible use of coal-derived liquids. Extensive information is now available on the effectiveness of hydroprocessing technology in upgrading middle distillates from oil sands and light and middle distillates from coal. Although standard refinery processes are inadequate for production of specification diesel and jet fuels from these unconventional sources, it appears that major improvement is attainable when different catalytic systems are applied. Experimental findings which address relevant phenomena are reviewed and new directions in technology development are identified.     

Hydropyrolysis of Light Hydrocarbons in H2/Ar Plasma Jet

Abstract

The hydropyrolysis of light hydrocarbons were carried out in H₂/Ar plasma jet at atmosphere pressure and average temperature between 1500K and 3000K. The raw material was Liquefied Petroleum Gas. The experimental results show that among all the pyrolysis products, major product is acetylene. Carbon black is the byproduct. The yield and selectivity of acetylene can reach 74%, 80%, respectively. Carbon black is characterized with XRD, TEM, and adsorption-and-desorption of liquid nitrogen, respectively.     

PYROLYSIS REACTIONS OF LONG CHAIN ALKYL PYRIDINES

ABSTRACT

The presence of n-alkanes in jet fuel can be explained if large n-alkanes are present in the crude oil source. Quantities of large n-alkanes present in crudes made from shale are insufficient, however, to explain the amounts found (up to 37%) in jet fuel made from these crudes. Although possible precursors to small n-alkanes are branched alkanes or substituted cyclic compounds, this paper shows that attack in the side chain of model pyridine compounds, similar to those found in shale crudes, affords a path to significant yields of n-alkanes. This study shows free radical attack at the alpha and gamma positions in the side chain to be favored. The major initial product distribution can be explained on the basis of Fabuss-Smith-Satterfield theory.