Effect of ethyl acetate addition on phase stability,octane number and volatility criteria of ethanol-gasoline blends

Blending ethanol in gasoline causes problems related to volatility and phase stability of the fuel blends. Ethanol is completely miscible with water so it has high affinity to water that may be present in storage tanks or that formed due to humidity. Drop in ambient temperature influences the stability of ethanol-gasoline blends and causes phase separation to the blend. This phase separation cause disadvantages like: poor quality fuel, loss in cost, and damage to storage tanks and engine parts due to corrosion. In this work, Ethanol-blended gasolines E5, E10, E15, E20 and ethanol-free gasoline (E0) were formulated to study the effects of ethyl acetate addition on these fuels. The obtained results revealed that the addition of ethyl acetate to ethanol-gasoline blends has many advantages such as enhancing the stability of the fuel blends and improving octane number with no adverse impacts on the volatility criteria of the investigated fuel blends.     

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

ABSTRACT

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.     

乙醇柴油对不同添加剂感受性的研究

研究了醇类助溶剂和表面活性剂对乙醇柴油容水量和相分离温度的影响，考察了加入助溶剂和表面活性剂以及其它柴油添加剂后乙醇柴油的氧化安定性、润滑性和低温流动性的变化。结果表明，醇类助溶剂中正癸醇对乙醇柴油的助溶效果最好，亲水亲油平衡值为5～10的表面活性剂对于改善乙醇柴油的容水稳定性效果较好。乙醇柴油无需加入抗氧化稳定剂，加有表面活性剂的乙醇柴油无需加入润滑性添加剂，但可加入流动改进剂和十六烷值改进剂。     

STABILITY STUDIES OF A JET FUEL CONTAINING NO ORGANO- SULFUR COMPOUNDS

Instability, incompatibility, phase separation, or sludge-sediment formation are all terms that denote fuel degradation. Middle distillate fuels continue to have significant instability problems. Specific chemical reaction pathways that initiate the reactions that in turn lead to fuel instability and incompatibility are difficult to isolate. Results from our laboratory indicated that the sedimentation process can be modeled by considering various organo-sulfur oxidation products. These reactions are initiated by a hydroperoxide induced oxidation process. The present research is directed toward a stability study of a jet fuel that has been processed to contain zero weight percent sulfur.     

Influence of ethyl acetate addition on volatility,octane rating,and phase stability of methanol–gasoline blends

The effect of adding ethyl acetate (EA) on the phase stability of methanol–gasoline blends was investigated by measuring their water tolerance (WT) at three different temperatures (30°C, 15°C, and 0°C). The influence of EA addition on volatility was also studied to evaluate EA as a stabilizer for methanol–gasoline fuels. It was found that EA elevates the WT and octane number of the fuels without causing any adverse impact on the volatility of the blends.     

The Instability of Storage of Middle Distillate Fuels: A Review

Abstract

The author reviews the research studies that have been so far carried out and reported in the literature on the stability of middle distillate fuels. The emphasis is mainly given to understand the stability of diesel fuels. It has been divided into five principle sections: (a) Introduction, (b) Methods for Determination of Fuel Stability, (c) Mechanism of Degradation, (d) Composition of Total Gum, and (e) Current Status of Methods to Improve Fuel Stability. The introduction provides information of in-stabilization of distillate fuel that depends on the various blending streams of middle distillates in the introduction part. In the second section the author elaborate the methods so far used to determine the instability of middle distillate fuels. The third section serves the elaborated mechanism of degradation, the role of chemical composition of distillate fuels, and the responsible components in distillate fuels that impart in degradation of distillate fuels. The fourth section comprises the composition of material formed during degradation and the fifth section of reveals the current status of methods used to improve the stability. In combination, these five sections would provide a ready reference source of data available in the literature on diesel fuel stability.     

Physicochemical Properties and Performance Characteristics of Naphthenoaromatic Jet and Diesel Fuels Obtained by Hydrotreating of Highly Aromatic Fractions

The composition and physicochemical and chemmotological properties of jet and diesel fuels obtained by hydrogen treatment of highly aromatic fractions—light cycle oil, pyrolysis tar, and coal tar—are considered in comparison with fuels obtained by hydrotreating of straight-run petroleum fractions. The influence of the hydrocarbon composition on the density, calorific value, viscosity, pour point, smoke point, cetane number, compatibility with elastomers, sooting tendency, combustion stability, and CO and NO _x emissions of fuels are also considered. The interrelation of the composition of hydrocarbons and heteroatomic compounds of naphthenic jet fuels with thermo-oxidative and thermal stability has been analyzed in detail, and differences between the fuels in stability depending on the feedstock and hydrogenation depth have been shown. The usefulness of naphthenoaromatic distillates as additives that enhance both the thermal and thermo-oxidative stability of petroleum jet fuels is pointed out. Promising fields of research have been defined, including selective hydrogenation to produce certain stereoisomers; a targeted approach to feedstock compounding; and optimization of fuel composition to obtain desired characteristics using modern analytical techniques, such as GC × GC, HPLC, GC–MS, GC/TOF-MS, and ESI-MS.     

THE IMPACT OF RED DYE ON THE STABILITY OF MARINE DIESEL FUELS

The use of red dye formulations to identify high sulfur diesel fuels were mandated before their effects on fuel stability had been thoroughly investigated. The effects of the red dye on stability were studied in a group of ten low- and high-sulfur diesel fuels. The red dye was not found to significantly degrade storage stability and thermal oxidation stability of these fuels, beyond normal variations. There were some effects noticed on blending compatibility, but, in general, these were within the range of effects due to fuel composition.     

柴油的储存安定性研究

用2，5—二甲基吡咯、四氢咔唑代表非碱性氮化合物，2—甲基吡啶、2—甲基喹啉代表碱性氮化合物，苯乙烯代表不饱和烃，苯甲酸、环烷酸、l—萘酚、对甲苯磺酸、邻甲苯硫酚代表酸性化合物和含硫化合物。将这些化合物单独和以各种组合形式加入直馏柴油中，观察它们对柴油安定性的影响。结果表明，除2，5—二甲基吡咯外，其它化合物在没有非碱性氮化合物的催化作用下，对柴油安定性的影响很小。2，5—二甲基吡咯与酸性化合物共同作用，对柴油的安定性影响最大，特别是它与对甲苯磺酸、l—萘酚共同作用时，对柴油安定性的影响要远大于与烷基和环烷基酸性化合物共同作用的影响。传统的由酚类和胺类抗氧剂为主的安定性添加剂，对含有较多类似2，5—二甲基吡咯类的非碱性化合物引起的柴油的不安定是无效的。新研制的柴油安定性添加剂对抑制由非碱性化合物引起的催化裂化柴油的颜色变深和沉渣生成有较好的效果。     

ANALYSIS OF INSTABILITY DEPOSITS TO THERMAL IN AVIATION JET FUELS

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.     

MECHANISMS OF SYNFUEL DEGRADATION. 3. INTERACTIVE EFFECTS IN NITROGEN COMPOUND INDUCED STORAGE INSTABILITY IN SHALE DERIVED DIESEL FUEL

Deterioration in fuel quality upon storage has been a continuing problem in the utilization of middle distillate fuels. For diesel fuels. Instability is usually defined by the formation of insoluble sediments and gums and by the accumulation of hydroperoxides. Gravimetric accelerated storage stability tests conducted with model compounds as dopants in otherwise stable distillate fuels have demonstrated that oxidative condensation reactions of polar heterocylces are deleterious to stability. In particular, nitrogen containing aromatics (pyrroles, pyridinea, indoles, etc.) appear to be very harmful. Correlation of model dopant studies with results obtained with actual unstable fuels has indicated that autoxidation processes are usually not isolated reactions but are sensitive to the presence of other fuel constituents. In an effort to learn more about potential interactive effects, we have examined the autoxidation of two model compounds, 2, 5-dimethylpyrrole and 3-methylindole, in a shale diesel fuel in the presence of a second model dopant (a hydroperoxide, organic acid or base). The results presented support the notion that such interactive effects may be of critical importance in defining the stability of actual middle distillate fuels.     

溶剂精制提高催化裂化柴油的安定性

找到了一种用于催化裂化柴油精制的溶剂，使精制油的催速储存安定性沉渣和颜色均达到了优级轻柴油的标准（沉渣＜20mg／100mL，色号不大于3．5）。剂油体积比在1：10－1：500范围内，精制油收率达到99％以上。溶剂在精制油中的含量低，经水洗即可除去，溶剂与抽出物分离后可以循环利用。     

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.     

SURFACE ACTIVE PROPERTIES OF CLAY TREATED JET FUELS

The effect of water contamination in jet fuels on the adsorbent capacity of Attapulgite clay to adsorb and retain N compounds was studied. The effluent jet fuel showed the presence of N molecules indicating that the clay, contaminated with water, does not retain N compounds. The GC/MS analysis of spent clay indicated that only quinolines were adsorbed and retained on the clay. The interfacial tension (IFT) values measured at the jet fuel/water interface were found to increase with a decrease in basic N content of clay treated jet fuels. Quinolines and pyridines present in jet fuel are surface active and adsorb on the Attapulgite clay, however, in the presence of water some N molecules adsorb at the jet fuel/water interface. Since pyridines were not found on the spent clay, the results indicate that the pyridines adsorb at the jet fuel/water interface. The tendency of pyridines to adsorb at the jet fuel/water interface will lead to their poor retention on the clay. The presence of N compounds and water contamination in jet fuel might lead to inefficient operation of clay treaters. The jet fuels having the IFT value below 40 mN/m were found to contain basic N molecules and have poor stability. The clay treated jet fuels having the IFT values in the range of 42.6-46.2 mN/m were found to have a good stability. The use of IFT measurements at the jet fuel/water interface provides an opportunity to better monitor the efficiency of clay treatment and the quality of jet fuels.     

SURFACE ACTIVE PROPERTIES OF CLAY TREATED JET FUELS

The effect of water contamination in jet fuels on the adsorbent capacity of Attapulgite clay to adsorb and retain N compounds was studied. The effluent jet fuel showed the presence of N molecules indicating that the clay, contaminated with water, does not retain N compounds. The GC/MS analysis of spent clay indicated that only quinolines were adsorbed and retained on the clay. The interfacial tension (IFT) values measured at the jet fuel/water interface were found to increase with a decrease in basic N content of clay treated jet fuels. Quinolines and pyridines present in jet fuel are surface active and adsorb on the Attapulgite clay, however, in the presence of water some N molecules adsorb at the jet fuel/water interface. Since pyridines were not found on the spent clay, the results indicate that the pyridines adsorb at the jet fuel/water interface. The tendency of pyridines to adsorb at the jet fuel/water interface will lead to their poor retention on the clay. The presence of N compounds and water contamination in jet fuel might lead to inefficient operation of clay treaters. The jet fuels having the IFT value below 40 mN/m were found to contain basic N molecules and have poor stability. The clay treated jet fuels having the IFT values in the range of 42.6–46.2 mN/m were found to have a good stability. The use of IFT measurements at the jet fuel/water interface provides an opportunity to better monitor the efficiency of clay treatment and the quality of jet fuels.     

乙醇与柴油的相溶性研究

1. Introduction As an alternative fuel, ethanol is used possibly asblending stocks for gasoline when petroleum runs short.Gasohol programs were started in Henan Province andJilin Province in 2001 and, more recently, also inseveral other provinces. Conside…     

液相加氢喷气燃料的贮存安定性能

按照3号喷气燃料国家标准对中国石化长岭分公司液相加氢喷气燃料(LPHJT)进行全分析,考察了LPHJT的贮存安定性;并对其吸附洗脱出来的不安定性组分进行了元素分析和红外光谱测定,考察了其对喷气燃料热安定性的影响.结果表明:在所考察的1.5 a贮存时间内,与加氢前的喷气燃料原料(LPHJF)相比,未加添加剂的液相加氢喷气...     

喷气燃料中金属离子对热安定性的影响

采用过渡金属环烷酸盐作为携带剂,配制不同含量的喷气燃料溶液,考察了铜、铁、锌3种金属离子对喷气燃料氧化安定性的影响。结果表明,铜、铁、锌3种过渡金属离子的存在对动态热氧化安定性有明显的影响。3种过渡金属影响动态热氧化安定性的顺序为：铜＞铁＞锌。该结论对防止喷气燃料生产运输过程中受到金属离子污染有很好的指导意义。     

相平衡方法研究柴油中石蜡结晶行为

 应用冷滤点测定仪分离在冷滤点温度下的模拟柴油、加剂模拟柴油、基础柴油及加剂柴油的液相和固相，用气相色谱法测定液、固两相中正构烷烃的组成，并通过分配因子Z计算得到在冷滤点温度下石蜡结晶量、石蜡的正构烷烃含量。实验结果表明，用该分离方法以及计算方法来研究柴油在冷滤点温度下液-固平衡态的结晶行为是可行的。