Showing papers on "Fuel oil published in 1989"

Four-lump kinetic model for fluid catalytic cracking process

Abstract: In the fluid catalytic cracking reactor heavy gas oil is cracked into more valuable lighter hydrocarbon products. The reactor input is a mixture of hydrocarbons which makes the reaction kinetics very complicated due to the involved reactions. In this paper, a four-lump model is proposed to describe the process. This model is different from others mainly in that the deposition rate of coke on catalyst can be predicted from gas oil conversion and isolated from the C1–C4 gas yield. This is important since coke supplies heat required for endothermic reactions occurring in the reactor. By this model we can also conclude that the C1–C4 gas yield increases with increasing reactor temperature, while production of gasoline and coke decreases.

Comparison of autochthonous bacteria and commercially available cultures with respect to their effectiveness in fuel oil degradation

Abstract: This study examined the microbial degradation of fuel oil by nine highly adapted different commercially available mixed bacterial cultures (DBC-plus™, Flow Laboratories, Meckenheim, F.R.G.) and a bacterial community from a domestic sewage sludge sample. All mixed cultures were cultivated under aerobic batch conditions shaking (110 rpm) at 20°C in a mineral base medium containing 1 or 5% (v/v) fuel oil as the sole carbon source. Percent degradation of fuel oil and the n-alkane fraction was recorded for the nine DBC-plus cultures and the mixed population of the activated sludge sample. The increase in colony counts, protein, and optical density was studied during a 31-day incubation period for DBC-plus culture A, DBC-plus culture A2 and the activated sludge sample. The activated sludge mixed culture was most effective in degrading fuel oil, but various isolated bacterial strains from this bacterial community were not able to grow on fuel oil as the sole carbon source. In contrast, the n-alkane degradation rates of the DBC-cultures were lower, but single strains from the commercially available mixed cultures were able to mineralize fuel oil hydrocarbons. Strains ofPseudomonas aeruginosa were isolated most frequently and these organisms were able to grow very rapidly on fuel oil as a complex sole carbon source. The results indicate that fuel oil degradation in domestic sewage sludge is performed by mixed populations of naturally occurring bacteria and does not depend on the application of highly adapted commercially available cultures.

Purification of hydrocarbonaceous fractions

Abstract: A process for recovering diamondoid compounds from hydrocarbonaceous minerals and/or from deposits left by such minerals in equipment or otherwise, which comprises dissolving diamondoid compounds in an aromatic distillate fuel oil; extracting aromatics from the solution; and separating diamondoid compounds from the raffinate of the extraction.

W/O emulsion realizes low smoke and efficient operation of DI engines without high pressure injection

Abstract: This paper describes an experiment in which water-in-gas oil emulsified fuel is used without high pressure or high injection rate to improve engine performance parameters such as smoke, NO/sub chi/, and BSFC in a DI diesel engine. The results are compared with high pressure and high injection rate operation using gas oil.

Modeling of thermal steam cracking of an atmospheric gas oil

Abstract: Gas oil cracking experiments in the presence of steam were performed in a loboratory-scale tubular quartz or Inconel reactor. The effects of temperature, inlet steam to gas oil ratio, and residence time on the major effluent products were investigated. The temperature, steam to gas oil weight ratio, and residence time were varied in the ranges 628-800 {degrees}C, 1-2 kg/kg, and 0.4-1.0's, respectively. The best yield of ethylene, 27% by weight, was obtained in the quartz reactor at 770 {degrees}C, residence time of 0.6 s, and mass ratio of steam to gas oil equal to 1. Experiments combined with a simulation model allows the authors to predict the effluent products distribution as a function of temperature and residence time. Several kinetic models were attempted. The best one was a mechanistic radical and molecular model. Gas oil feedstock composition was simplified, taking into account radical and molecular model. Gas oil feedstock composition was simplified, taking into account one compound as representative of the principle hydrocarbon families. For this study, the model proposed consisted of 138 reactions, 18 species, and 24 radicals.

A method for improving cold flow of hydrocarbon fuel oils

Abstract: A method is disclosed for improving low temperature cold flow of fuel oils by using a cross-­linked ester compound consisting essentially of a nitrogen-containing compound having hydroxyl group, a straight chain fatty acid, and a cross-linking agent.

Assessing distillate fuel storage stability by oxygen overpressure at higher temperatures

Abstract: A new oxygen overpressure method has been used to purposely accelerate the reactions leading to insoluble sediments formation by forcing oxygen into solution in the fuel at a pressure of 100 psig and then stressing the fuel under conditions of accelerated storage at various temperatures from 43 to 100˚C. The method makes use of gravimetric determination of the total insolubles formed. In order to test the reliability of this higher temperature method, a mini-round robin was conducted using five middle-distillate fuels tested at four different laboratories at the same 90˚C/16 hr/100 psig conditions. Also, stability data for 26 marine gasoil and for 22 F-76 fuels from a world-wide fuel survey were obtained. The results are compared to results obtained from other standard tests. All results are tabulated in gravimetric form in mg of total insoluble sediment per 100 ml of fuel

Oil recovery process and apparatus for oil refinery waste

Abstract: A process and apparatus for the recovery of oil from aqueous oil refinery waste involves mixing the waste with a fluidizing oil and evaporating the water from the mixture in a plurality of stages. The dewatered mixture is fed to a delayed coking system in which a conventional coker feedstock is being used. The heavy hydrocarbon portion of the dewatered mixture changes to coke and light hydrocarbon material, the inert solids become trapped in the coke, and the fluidizing oil vaporizes. A stream of heavy coker gas oil is fed from a fractionator in the delayed coking system to a fluidizing tank where it is mixed with the sludge to define the fluidizing oil. Another hot stream of hydrocarbon material from the coker fractionator is sent to the evaporator section to provide the heat for evaporation.

Aqueous combustion catalysts and fuels

Abstract: The invention relates to an aqueous catalyst solution for the improved combustion of materials containing carbon and/or hydrocarbon, such as fuel oils, fuel gases and solid fuels, and/or for the removal of deposits of soot or tar on surfaces of the combustion chamber, and it is characterised above all in that the aqueous catalyst solution has a pH of at least 7 and contains, in a catalytically active quantity, tetravalent cerium (Ce ) and alkali metal, alkali earth metal and/or magnesium compounds which, after combustion or thermal decomposition, show an alkaline reaction, and complexing agents for this Ce The invention also relates to a liquid or solid fuel, in particular fuel oil or coal, which is characterised in that it contains the aqueous catalyst solution in such a quantity that the cerium content is between 1 and 100 ppm, preferably about 35 ppm, relative to the fuel quantity

Ultra Low NOx Emissions for Gas and Liquid Fuels Using Radial Swirlers

Abstract: Curved blade radial swirlers using all the primary air were investigated with applications to lean burning gas turbine combustor primary zones with low NOx emissions. Two modes of fuel injection were compared, central and radial swirler passage injection for gaseous and liquid fuels. Both fuel systems produced low NOx emissions but the upstream mixing in the swirler passages resulted in ultra low NOx emissions. A 140mm diameter atmospheric pressure combustor was used with 43% of the combustor air flow into the primary zone through the radial swirler. Radial gas composition measurements at various axial distances were made and these showed that the flame stability and NOx emissions were controlled by differences in local mixing at the base of the swirling shear layer downstream of the swirler outlet. For radial passage fuel injection it was found that a very high combustion efficiency was obtained for both propane and liquid fuels at 400K and 600K inlet temperatures. The flame stability, although worse than for central fuel injection was considerably better than for a premixed system. The NOx emissions at one bar pressure and 600K inlet temperature, compatible with a high combustion efficiency, for propane and kerosene were 3 and 6 ppm at 15% oxygen. For Gas Oil the NOx emissions were higher, but were still very low at 12ppm. Assuming a square root dependence of NOx on pressure these results indicate that NOx emissions of 48ppm for Gas Oil and less than 12ppm for gaseous fuels could be achieved at 16 bar pressure, which is typical of recent industrial gas turbines. High air flow radial swirlers with passage fuel injection have the potential for a dry solution to the NOx emissions regulations.Copyright © 1989 by ASME

Correlation of pour point of gas oil and vacuum gas oil fractions with compositional parameters

Abstract: We have carried out a detailed investigation of the pour points (PPt) of gas oil (GO) (250-375 °C boiling range) and vacuum gas oil (VGO) (375-500 °C) fractions obtained from Bombay High crude oil. The aim of the study was to obtain an insight into the dependence of the pour point on compositional parameters such as the n-paraffin concentration (PC) and the influence of the length of the n-paraffinic chain (CL). The experimental work consisted of (i) detailed characterization of both narrow 25°C cuts along with the two broad cuts (250-375 and 375-500 °C) and (ii) a study of the effect of progressive addition of n-paraffin concentrates (urea-adductable portions) of the narrow cuts on the cold-flow behavior of the broad cuts from which the urea adductables have been removed. A simple correlation has been put forward that allows the prediction of the pour point from a knowledge of PC and CL. The study should provide a rational basis for a fundamental predictive method for the cold-flow behavior of GO and VGO fractions.

The effect of bacteria and bioturbation by Clymenella torquata on oil removal from sediment

Abstract: Clymenella torquata, a representative of conveyor-belt feeding tube worms, was studied in laboratory microcosms for its effect on the removal of No. 2 fuel oil from sediment. Possible enhancement of microbial degradation of the oil was considered as well. Concentrations of the aromatic fraction of the oil were measured by synchronous fluorescence spectroscopy. Clymenella reduced the oil concentration of the surrounding sediment by 20 to 50% (p<0.05) in 10 days. Concentrations of oil in the worm tubes were 25 to 32% (p<0.001) less than the surrounding sediment. Sediment bacteria cultured in oil supplemented artificial sea water could use the oil as their sole C source, but did not significantly degrade the aromatic fraction.

Organically modified clays

Abstract: Organically modified clays are prepared by replacing the exchangeable inorganic cations present in the natural clays. Organic cations used in this replacement process are then able to adsorb other organic compounds. Thus, an organically modified clay can adsorb organic constituents that are otherwise unaffected or possibly adversely affected by unmodified clays. Organically modified clays may be mixed with additional stabilization agents (such as cement, cement kiln dust, or fly ash) to solidify contaminated soils or organic wastes into a stable mass. The stabilized mass has improved bearing properties and a reduced potential for leaching hazardous constituents into the environment. Because organically modified clays swell in the presence of organic fluids, such as gasoline or fuel oil, they may also be used as sorbents in spill control or in liners for fuel oil tank containment areas. The sorption capabilities of a number of both unmodified and organically modified clays are compared. Data are also presented on the use of organically modified clays for organic sludge stabilization. The findings indicate the feasibility of stabilization technology for remediation of organically contaminated sites as compared with the excavate-and-remove option. The adsorption of organics by organically modified clays is critical to this process.

Fuel composition and fuel additive

Abstract: Disclosed herein are a fuel composition comprising a fuel oil added with at least two kinds of soaps selected from cerium, neodymium and lanthanum soaps and a fuel additive comprising an organic solution that contains at least two kinds of soaps selected from cerium, neodymium and lanthanum soaps.

Reprocessing of contaminated oils

Abstract: A process is disclosed for reprocessing contaminated oils, such as used crankcase oil from automobile engines, by thermal treatment, such as visbreaking, in the presence of other hydrocarbon feedstocks, followed by fractional distillation for the recovery of a gasoline fraction, a carboxylic acid fraction, a gas oil fraction containing chlorinated hydrocarbons and a high boiling bottoms fraction The gas oil fraction is subjected to catalytic hydrocracking with the simultaneous destruction of chlorinated hydrocarbons The resulting hydrocracked oils, after separation of hydrogen chloride, are free from chlorine compounds and other contaminants

Upgrading lower olefins

Abstract: An improved olefin upgrading technique has been developed for increasing production of premium heavy hydrocarbons, such as distillate fuel, from lower olefin feedstocks. The feedstock is converted over a shape-selective medium pore oligomerization acid zeolite catalyst into heavier hydrocarbons in MOGD reactors. The effluent is separated in phase separation zone; the first portion of the liquid product is recycled as recycle stream to fresh feedstock. The second portion of the liquid product is fractionated in a fractionation zone to obtain heavy hydrocarbons rich in C10+ hydrocarbons, light gas, LPG, gasoline as well as an overflash fractionation stream rich in intermediate C5 to C9 hydrocarbons, which is recycled, along with the recycle stream, to the fresh feedstock, thereby providing a more efficient and lower cost recovery process.

Determination of aldehydes and ketones in natural gas combustion in the ppb range by high-performance liquid chromatography

Abstract: The reported identification and determination of trace compounds in flue products of natural gas burning equipment is based on DNPH precolumn derivatization and followed by HPLC separation. The optimized HPLC analysis has been applied to the determination of trace amounts of aldehydes and ketones in polluted air such as lab and ambient air as well as natural gas and oil combustion products in a hospital. The results obtained in a hospital show that the oil fuel combustion process emits a considerable amount of toxic acrolein, whereas the emission of acetone is predominant in natural gas combustion.

Commercial Experience In The Operation of Atmospheric Residue Desulfurization Units In Kuwait National Petroleum Company at Mina Al-Ahmadi Refinery

Abstract: Residue desulfurization is being practiced at KNPC Mina Al-Ahmadi Refinery by the operation of four trains of Atmospheric Residue Desulfurization (ARD) Units, a UNOCAL HDS/Unicracking licensed process, as part of refinery modernization and further upgrading projects. By hydrotreating of atmospheric residue of Kuwait Export crude, KNPC has enhanced its ability to produce low sulfur fuel oil (LSFO) for local and export markets. In addition, these process units constitute an integral part of an upgrading scheme through the removal of contaminants from the atmospheric residue, allowing a maximization of production of vacuum gas oil as a feed stock for downstream conversion processing. This paper presents and discusses the ARD process at KNPC's Mina Al-Ahmadi site and the role of these units in the refinery scheme. It compares and highlights the experiences gained from operating these units using two different catalyst systems, namely total hydrodesulfurization and a combination of hydrodemetallation and hydrodesulfurization catalysts. The performance of these two catalyst systems is compared in the context of achieving the required processing objectives (such as LSFO yield, sulfur and metal content, higher value cracked product yields and properties), catalyst run length, hydrogen consumption, run profiles and particular operational features and problems relevant to each catalyst system. These are evaluated within the constraints of actual feedstock properties and equipment limitations. Operational data are also addressed with a focus on feed properties, severity levels, reactor temperature profiles, reactor pressure drops, catalyst handling during unloading and the effects of unit throughput and other factors on catalyst deactivation rate. The two catalyst systems are also compared in terms of general physical properties. As a conclusion, and based on the present experience at Mina Al-Ahmadi Refinery, the paper highlights the most appropriate catalyst systems for these ARD units to meet KNPC's present and future processing objectives and requirements, with respect to hydrotreating severity, conversion level, processing a more severe feedstock and catalyst regenerability.

Testing the Regulatory Threat Hypothesis: Media Coverage of the Energy Crisis and Petroleum Pricing in the Late 1970s

Abstract: We argue that during the 1979 oil crisis major domestic oil companies held down price increases of politically sensitive oil products relative to their foreign counterparts to reduce the probability of adverse government action. To test this "regulatory threat" hypothesis, we compare the reaction of unregulated fuel oil prices to political pressure. We measure political pressure with the level of U.S. television coverage of energy issues. We find that media coverage influenced U.S. home heating oil prices charged by domestic oil companies, but not foreign oil companies. In contrast, for the less politically sensitive residual fuel oil, media coverage did not influence prices of either domestic or foreign oil companies.

Arc furnace equipped with fuel oil/oxygen burners and fuel oil/oxygen burner

Abstract: The invention relates to arc furnaces. An arc furnace is equipped with burners of the fuel oil/oxygen type incorporating an axial pipe 4 with ejector for ejecting liquid fuel, in the withdrawn position L into an external nozzle defining, with the pipe 4, an annular passage 26 for oxidising oxygen; the nozzle has a double wall 12-28 with an annular wall 17 forming passages for the supply 27 and return 28 of coolant water. The inner and end-of-nozzle wall 12-13 is made from thicker copper (minimum 12 mm) than that of the outer wall 14-19. Thus satisfactory protection as regards metal splashes coming from the furnace is afforded.

Production of carbon black

Abstract: PURPOSE: To obtain a carbon black having high specific surface area and primary structure by generating combusting gas flow with burning fuel oil in a primary combusting process and a specific secondary combusting process and performing the injection of atomized raw material oil. CONSTITUTION: Primary fuel oil and air for combustion are introduced into a combustion region having large diameter through a primary fuel oil nozzle 5 to generate combusting gas flow. Next, said combusting gas flow is flowed into a throat-like combusting region 7 having narrow diameter at ≥100m/sec line velocity to perform the burning of secondary fuel oil introduced from axial direction of furnace and/or perpendicular direction to the furnace axis. Further, resultant combusting gas flow is introduced into a reacting region 9 having narrow diameter and raw material oil atomized by an oxidizing gas is injected from periphery of the reacting region to generate carbon black-containing gas flow. Then, the carbon black-containing gas flow is introduced into rear reacting region 11, thus quenched by a quenching tool 12 to afford the objective carbon black. COPYRIGHT: (C)1991,JPO&Japio