Showing papers on "Gasoline published in 1997"

The Atmospheric Aerosol-Forming Potential of Whole Gasoline Vapor

Abstract: A series of sunlight-irradiated, smog-chamber experiments confirmed that the atmospheric organic aerosol formation potential of whole gasoline vapor can be accounted for solely in terms of the aromatic fraction of the fuel The total amount of secondary organic aerosol produced from the atmospheric oxidation of whole gasoline vapor can be represented as the sum of the contributions of the individual aromatic molecular constituents of the fuel The urban atmospheric, anthropogenic hydrocarbon profile is approximated well by evaporated whole gasoline, and thus these results suggest that it is possible to model atmospheric secondary organic aerosol formation

Aromatics, Reformulated Gasoline, and Atmospheric Organic Aerosol Formation

Abstract: Secondary organic aerosol (SOA) yield curves have been obtained for 17 individual aromatic species from an extensive series of sunlight-irradiated smog chamber experiments. These yield curves, interpreted within the framework of a gas/aerosol absorption model, are used to quantitatively account for the SOA that is formed in a series of smog chamber experiments performed with the whole vapor of 12 different reformulated gasolines. The total amount of secondary organic aerosol produced from the atmospheric oxidation of whole gasoline vapor can be represented as the sum of the contributions of the individual aromatic molecular constituents of the fuel.

Air quality model evaluation data for organics. 4. c2-c36 non-aromatic hydrocarbons

Abstract: The concentrations of 143 non-aromatic hydrocarbons are quantified in 36 samples (32 urban and 4 background) collected during a severe Los Angeles area photochemical smog episode. Gas phase, semivolatile, and particle phase organic compounds are viewed simultaneously across the carbon number range from C_2 to C_(36). Compound classes studied include the n-alkanes, branched alkanes, n-alkenes, branched alkenes, diolefins, alkynes, saturated cyclic hydrocarbons, unsaturated cyclic hydrocarbons, biogenic hydrocarbons, petroleum biomarkers, and the unresolved complex mixture contained within the semivolatile and particle phase organics samples. The abundance of the n-alkanes falls almost exponentially with increasing n-alkane carbon number, and the distribution of the n-alkanes between the gas and particle phases follows vapor/particle partitioning theory. The concentrations of individual low molecular weight alkenes decline during transport across the urban area in about the order expected given their initial rates of reaction with the hydroxyl radical. Petroleum biomarker concentrations that act as tracers for particulate organics emitted from vehicle exhaust have declined substantially between 1982 and 1993, reflecting the increased penetration of catalyst-equipped cars into the vehicle fleet. The most pronounced change in vapor phase non-aromatic hydrocarbons concentrations between 1987 and 1993 is a reduction in the concentration of the lightest blending components of gasoline (e.g., butanes), reflecting new regulations that limit the Reid vapor pressure of gasoline.

Theoretical study of C-C bond formation in the methanol to gasoline process

Abstract: Density functional theory is used to study one of the most successful routes to the production of synthetic fuels, the conversion of methanol to gasoline (MTG process) with an acidic zeolite. With ...

Reducing NOx emissions from an engine by selective catalytic reduction utilizing solid reagents

Abstract: Urea or other solid NO x -reducing reagent is employed in a selective catalytic reduction process on emissions from diesel and lean-burn gasoline engines. The solid reagent is fed to a gas generator that produces a reactant gas by heating. In one embodiment the reactant gas is maintained at elevated temperatures to prevent condensation products from forming. The reactant gas contains ammonia and is fed to the exhaust on an as-needed basis.

Fluid catalytic cracking

Abstract: Fluid catalytic cracking, or FCC, was the first application of fine-powder fluidization. Interestingly, the first commercial FCC unit (Esso’s Model I in 1942) had both the reactor and regenerator in the form of entrained circulating fluid beds. Over 50 years later, FCC is still the major application of fluidization with over 350 FFC units operating worldwide, and with new ones coming on stream every year. FCC units convert heavy fuel oil and petroleum residue to lighter products. Major FCC products are gasoline, diesel fuel, heating oil, heavy cycle oils, which are used as bunker fuels or converted to carbon black, and light gases such as propene and butenes, which are converted to alkylate gasoline, methyl-tertiary-butyl ether, and are used for the production of petrochemicals.

ETBE Synthesis via Reactive Distillation. 1. Steady-State Simulation and Design Aspects

Abstract: Ethyl tert-butyl ether (ETBE) is an alternative gasoline oxygenate that combines the blending properties of methyl tert-butyl ether (MTBE) and the renewability of ethanol. Technologically, the best means of synthesis utilizes reactive (or catalytic) distillation to maximize hydrocarbon conversion and energy efficiency while simultaneously producing a high-purity ether product. Mathematical models of reactive distillation are based on the conventional distillation process with supplementary equations added to model the reactions present. Ether−alkene−alcohol systems are highly nonideal in the liquid phase so that careful selection of physical property routines is required to ensure satisfactory simulation results. Column simulations performed here using both Pro/II and SpeedUp show excellent agreement with previously published experimental data for a MTBE system and also agree well with each other for both MTBE and ETBE systems. A homotopy analysis was performed on the tuned simulation models to determine ...

Liquid Fuels by Low-Severity Hydrotreating of Biocrude

Abstract: Bio crude (fast pyrolysis oil from wood) was hydrotreated to minimize the negative aspects of this fuel. The instability of the oil was reduced by reaction of the most unstable functional groups. Concurrently, the oxygenated component of the oil was also reduced, resulting in an improved energy density. Changes in the physical handling properties were also modified. All of this change was accomplished at less severe processing conditions (lower temperature, shorter residence time) than that required for the earlier processing for gasoline production. Improved conversion was achieved by the use of a downflow reactor system. The experiments reported include those performed with clean (filtered hot vapor) biocrude just recently available from processing systems in the U.S.

Potential Air Quality Effects of Using Ethanol−Gasoline Fuel Blends: A Field Study in Albuquerque, New Mexico

Abstract: The use of alternate fuels has been proposed as a method of improving urban air quality by reducing combustion- related pollution. One such program mandates the use of oxygenates in the wintertime to reduce CO emissions in cities such as Albuquerque, NM. A field study was conducted in Albuquerque to determine the atmospheric impacts of the use of ethanol fuels. Atmospheric concentrations of ozone, oxides of nitrogen, CO, peroxyacetyl nitrate (PAN), aldehydes, and organic acids were measured in the summer of 1993, before the use of ethanol fuels, and in the winters of 1994 and 1995, during the use of 10% ethanol fuel (>99%). Data showed increased levels of peroxyacetyl nitrate (PAN) and aldehydes in winter. The formaldehyde/ acetaldehyde ratio was 1.4, indicating an anthropogenic source, and PAN and acetaldehyde levels were anti-correlated over short time periods, indicating primary acetaldehyde emissions. A comparison of data taken at rural sites south of the city indicates that although there is a significant anthropogenic component to the aldehyde concentrations during the winter, there are also contributions from the photochemical oxidation of natural hydrocarbons.

ETBE Synthesis via Reactive Distillation : 2. Dynamic Simulation and Control Aspects

Abstract: Ethyl tert-butyl ether (ETBE) is growing in importance as a gasoline oxygenate and octane enhancer. Its gasoline blending properties are superior to methyl tert-butyl ether (MTBE), and its semirenewability is attracting subsidies from many governments. Synthesis of ETBE via reactive distillation offers advantages of higher conversion, improved energy efficiency, and lower capital costs. A dynamic simulation, based on the MESH equations with supplementary equations to model the main chemical reaction, was developed using SpeedUp. The simulations were then utilized for the study of transient open-loop responses and for control system design. The control of a reactive distillation column presents several difficulties not normally associated with distillation, and dynamic simulation proved to be the ideal tool for the study and resolution of these problems. Some general recommendations for the control of reactive ETBE columns are made, including the need to address control issues early in the design process t...

Butanol—a single cylinder engine study: engine performance

Abstract: The effect of methanol and butanol addition to gasoline on brake specific fuel consumption (b.s.f.c.), exhaust gas temperature, and thermal efficiency has been experimentally investigated. A Hydra single cylinder, spark ignition, fuel injection engine was used over a wide range of fuel/air equivalence ratio (ϕ=0⋅8 to 1⋅3) for 30% volume alcohol–gasoline blends. The goal of this work is to study the engine performance when methanol and butanol–gasoline blends are used. The performance measurements show that there is an increase in b.s.f.c. when using alcohol–gasoline blends, and b.s.f.c. of a butanol–gasoline blend is less than for a methanol–gasoline blend. The experimental results show that the engine thermal efficiency was decreased when fueled with alcohol–gasoline blends. It was found that there was about a 4.5% reduction in engine thermal efficiency at ϕ=1⋅0 when 30% butanol was blended with gasoline compared to pure gasoline. The exhaust gas temperature measurements show that there is an increase in temperature in the case of using gasoline as compared to alcohol–gasoline blends, and that the temperature reaches a maximum at ϕ≈1⋅1 when using gasoline and alcohol–gasoline blends. © 1997 by John Wiley & Sons, Ltd.

Effect of Ambient Temperature and E-10 Fuel on Primary Exhaust Particulate Matter Emissions from Light-Duty Vehicles

Abstract: During the winter of 1994-1995, the State of Alaska Department of Environmental Conservation conducted a multi-faceted program designed to evaluate the impact of switching from regular gasoline to an E-10 fuel (gasoline with 10% ethanol) in Fairbanks. As part of that program, 10 in-use vehicles were tested on a chassis dynamometer at temperatures of 20, 0, and -20 degrees F using both fuels. Three of these vehicles were retested in the EPA facilities at Research Triangle Park, North Carolina, under the same conditions. Vehicles were driven over the Urban Dynamometer Driving Schedule of the Federal Test Procedure during testing. PM-10 exhaust emission samples were collected at Fairbanks, and total particulate samples were obtained at the EPA. Results from both parts of this study indicate that particulate matter (PM) emission rates increased with decreasing temperature for both fuels. The increase occurred primarily during cold starting and is assumed to be due to enrichment. Particulate matter emission rates during operation on the E-10 fuel were lower relative to rates obtained during operation on the base gasoline. Exhaust hydrocarbon and PM emissions were well correlated, suggesting that fully phased-in Federal Tier 1 vehicle emission standards will reduce PM emissions from new vehicles and that rich-operating, high emitters can be expected to have high PM emissions. (A)

Toluene Solubility in Water and Organic Partitioning from Gasoline and Diesel Fuel into Water at Elevated Temperatures and Pressures

Abstract: A simple and reliable system for determining the solubility and partitioning behavior of liquid fuel components in liquid water up to 250 °C has been developed. The system shows good agreement with literature values at ambient temperature for the solubility of toluene and for fuel/water partitioning coefficients (Kfw). Toluene solubility increased ∼23-fold by raising the temperature from ambient to 200 °C but was not affected at ambient temperature by changing the pressure from 1 to 50 bar. The increases in partitioning of benzene, toluene, ethylbenzene, xylenes, and naphthalene from gasoline into liquid water with increasing temperature ranged from 10-fold for benzene to 60-fold for naphthalene when the temperature was raised from ambient to 200 °C. Similarly, the increases in partitioning of polycyclic aromatic hydrocarbons from diesel fuel into liquid water ranged from ∼130-fold for naphthalene to 470-fold for methylnaphthalene when the temperature was raised from ambient to 250 °C. The effect of tempe...

Bromine emissions from leaded gasoline

Abstract: Gasoline lead additives contain brominated compounds. When leaded gasoline is combusted, some of the bromine can be emitted as methyl bromide which can contribute to stratospheric ozone depletion. Based on world use of lead in gasoline and on gasoline scavenger formulations, we estimate that worldwide use of bromine in gasoline peaked in the early 1970s at 170±20 kT/yr and that by 1995 this had decreased to 23±2.5 kT/yr. The fraction of bromine in leaded gasoline that is emitted as methyl bromide ranges over two orders of magnitude. At the upper end of this range, the decrease in methyl bromide emissions from the 1970s to the 1990s could have equaled the increase in emissions from use of methyl bromide as a fumigant in the same period.

Results of Long‐term Experimental Carcinogenicity Studies of the Effects of Gasoline, Correlated Fuels, and Major Gasoline Aromatics on Rats

Abstract: Unleaded gasoline, with high aromatic content, leaded gasoline, gasoil (diesel), kerosene, toluene, xylenes, ethylbenzene, and 1,2,4-trimethyl-benzene were submitted to long-term experimental carcinogenicity bioassays. The mixtures and the compounds were administered by stomach tube, in olive oil, once daily, 4 days weekly, for 104 weeks, to male and female Sprague-Dawley rats. The animals were kept under control until the end of the experiments. With varying degrees of evidence, all the tested materials were found to increase the total number of malignant tumors and of some site-specific tumors. They must therefore be considered carcinogenic. On the basis of our results the rank of carcinogenic potency of the tested aromatic hydrocarbons increases in the following order: 1,2,4-trimethylbenzene, ethylbenzene, xylenes, toluene (benzene).

Process for generating pure benzene from reformed gasoline

Abstract: A process is disclosed for generating pure aromatic compounds from a reformed gasoline which contains aromatic compounds, olefins, diolefin, and triolefins, which comprises the steps of: (a) selectively hydrogenating the olefins, diolefins and triolefins in the reformed gasoline to obtain a mixture of hydrogenated, non-aromatic compounds and aromatic compounds; and (b) separating the aromatic compounds from the hydrogenated, non-aromatic compounds in the mixture formed during step (a) by either extractive distillation, liquid--liquid extraction or both to obtain the pure aromatic compounds.

Method of determining the composition of fuel in a flexible fueled vehicle

Abstract: The present invention provides a flexible fuel compensation system for controlling operating parameters of an internal combustion engine based on a learned value of the percent alcohol content of the fuel using an oxygen feedback system. The methodology determines a fuel composition multiplier based on the percent alcohol content and implements gasoline operating parameters for the internal combustion engine if the fuel composition multiplier is less than a first threshold value, mixed gasoline/alcohol operating parameters if the fuel composition multiplier is greater than the first threshold value, and high concentration alcohol operating parameters if the fuel composition multiplier is greater than a second threshold value for a number of comparison checks. After a predetermined period, the fuel composition multiplier is updated and re-compared to the first and second thresholds and the appropriate one of the aforementioned operating parameters is implemented. A third update of the fuel composition multiplier is made if the determined fuel composition multiplier is less than the actual percent alcohol content of the fuel by more than a given amount.

Production of benzene, toluene, and xylene (BTX) from FCC naphtha

Abstract: Cracked naphtha feeds such as FCC naphtha and coker naphtha are upgraded to produce chemical grade BTX (benzene, toluene, xylene with ethylbenzene) while co-producing a low sulfur gasoline of relatively high octane number. The cracked, sulfur-containing naphtha is processed by hydrodesulfurization followed by treatment over an acidic catalyst, preferably a zeolite such as ZSM-5 or zeolite beta with a hydrogenation component, preferably molybdenum. The treatment over the acidic catalyst in the second step restores the octane loss which takes place as a result of the hydrogenative treatment and results in a low sulfur gasoline product to permit a low sulfur gasoline of blending quality to be obtained with the BTX. The BTX can be extracted from the second stage effluent, preferably from a C 6 -C 8 fraction of this effluent.

Recent Decrease in the Lead Concentration of Antarctic Snow

Abstract: Differential Pulse Anodic Stripping Voltammetry (DPASV) was applied to determine the lead concentration in recent snow at two sites in the Victoria Land region, East Antarctica. Snow samples were collected during the 6th Italian Scientific Expedition to Antarctica (austral Summer 1990-91) along the wall of 2.5 m-deep hand-dug pits and by coring to a depth of about 1 m. The measurements revealed that lead content in Antarctic snow increased continuously from 1965 (about 3 pg/ g) to the early 1980s (maximum about 8 pg/g), after which a marked, rapid decrease took place during the second half of 1980s, down to 2-4 pg/g in 1991. Estimates of the lead contributions from rocks and soils, volcanoes and the marine environment, together with analysis of statistical data on non-ferrous metal production and gasoline consumption, and the corresponding lead emissions into the atmosphere of the Southern Hemisphere, show that a net anthropogenic component is present and support the hypothesis that the trend observed in Antarctic snow may be related to lead consumption in gasoline, which firstly was on the rise, then declined owing to the increased use of unleaded gasoline.

Pressure swing adsorption for VOC recovery at gasoline loading terminals

Abstract: Volatile organic compound (VOC) emissions from gaso-line storage and distribution facilities are coming under increased scrutiny in both the United States and Europe. The recently passed European Community stage 1 directive for gasoline emissions has established an emissions limit of 35 grams total organic compounds (TOC) per cubic meter gasoline loaded (35 g TOC/m 3 ) Similarly, the United States Environmental Protection Agency Standard 40 CFR Part 63 has established an emission limit of 10 mg TOC per liter of gasoline loaded (l0g TOC/m 3 ). The German TA-Luft standard, the most stringent known gasoline emission regulation, has set an emissions limit of 150 mg TOC (excluding methane) per cubic meter of loaded product (0,15 g TOC/m 3 ). The Dow Chemical Company has successfully applied the SORBATHENE Solvent Vapor Recovery Unit technology, a pressure swing adsorption process, to meet these increasingly stringent gasoline and light hydro carbon vapor emission standards. Working through technology licensees (Radian International LLC, Austin, Texas and McTay Engineering, Bromborough, United Kingdom), a field trial demonstrating 99 + % recovery efficiencies has been conducted at a major U.S. gaso-line storage and distribution terminal, and the first commercial SORBATHENE gasoline vapor recovery unit has been installed at a major storage and distribution terminal in Leeds, United Kingdom.

Vapor recovery system and method

Abstract: A system and method for recovering a gasoline vapor/air mixture from a vehicle tank during the dispensing of gasoline from a storage tank into the vehicle tank in which the mixture flows from the vehicle tank to the storage tank during the dispensing of the gasoline. A sensor is provided which detects a property of the mixture which corresponds to the vapor content of the mixture. The flow of the mixture is controlled in response to the vapor content of the mixture.

Additive concentrate for fuel compositions

Abstract: An additive concentrate for use in fuels, especially in gasoline for internal combustion engines, comprising (a) 0.2 to 10 wt. % ashless friction modifier which is liquid at room temperature and pressure selected from (i) n-butylamine oleate or derivatives thereof, (ii) a substance comprising tall oil fatty acid or derivatives thereof, and (iii) mixtures of (i) and (ii); (b) 10 to 80 wt. % deposit inhibitor, and (c) carrier fluid. The particular selection of friction modifier (a) enables a stable additive concentrate to be formulated without the need for additional solubilising agent for the friction modifier, while containing sufficient friction modifier to achieve a significant benefit in fri loss, when incorporated in gasoline used to fuel an internal combustion engine, and hence an improvement in fuel economy.

Exposure to regular gasoline and ethanol oxyfuel during refueling in Alaska.

Abstract: Although most people are thought to receive their highest acute exposures to gasoline while refueling, relatively little is actually known about personal, nonoccupational exposures to gasoline during refueling activities. This study was designed to measure exposures associated with the use of an oxygenated fuel under cold conditions in Fairbanks, Alaska. We compared concentrations of gasoline components in the blood and in the personal breathing zone (PBZ) of people who pumped regular unleaded gasoline (referred to as regular gasoline) with concentrations in the blood of those who pumped an oxygenated fuel that was 10% ethanol (E-10). A subset of participants in a wintertime engine performance study provided blood samples before and after pumping gasoline (30 using regular gasoline and 30 using E-10). The biological and environmental samples were analyzed for selected aromatic volatile organic compounds (VOCs) found in gasoline (benzene, ethylbenzene, toluene, m-/p-xylene, and o-xylene); the biological samples were also analyzed for three chemicals not found in gasoline (1,4-dichlorobenzene, chloroform, and styrene). People in our study had significantly higher levels of gasoline components in their blood after pumping gasoline than they had before pumping gasoline. The changes in VOC levels in blood were similar whether the individuals pumped regular gasoline or the E-10 blend. The analysis of PBZ samples indicated that there were also measurable levels of gasoline components in the air during refueling. The VOC levels in PBZ air were similar for the two groups. In this study, we demonstrate that people are briefly exposed to low (ppm and sub-ppm) levels of known carcinogens and other potentially toxic compounds while pumping gasoline, regardless of the type of gasoline used.

Internal combustion engine provided with means of suppressing oil dilution

Abstract: PROBLEM TO BE SOLVED: To provide a means of reliably suppressing engine oil dilution by fuel for use in a cylinder-direct fuel injection type internal combustion engine. SOLUTION: A dilution detector means detects the dilution of engine oil by fuel including gasoline on the basis of the concentration of hydrocarbon in blowby gas, the pressure, sonic velocity and infrared ray absorptance in the crankcase, and the viscosity, pH value, electric resistance and capacitance of engine oil-among others. If the detection value exceeds predetermined allowable dilution, a dilution suppressor means is started up to temporarily vary the fuel injection timing, injection pressure, cooling water temperature, oil temperature, ignition timing, and intake valve closing timing among others and thus to lower the dilution. That control prevents the sliding parts of the engine from seizing up. COPYRIGHT: (C)1998,JPO

Meeting the challenge of MTBE biodegradation

Abstract: Oxygenated and reformulated gasolines have been developed in response to air pollution control regulations targeted at reducing carbon monoxide emissions and photochemical air pollution. The 1990 Clean Air Act Amendments required the addition of fuel oxygenates to gasoline in areas where the level of carbon monoxide exceeded national ambient air quality standards. In the South Coast Air Basin gasoline containing oxygenated compounds has been in use since the late 1980`s. One oxygenated fuel additive most often selected by producers to meet the requirements is methyl tert-butyl ether (MTBE). However, large production numbers associated with MTBE production, combined with the compound`s high water solubility, chemical stability, and toxicity, make it a potentially important groundwater pollutant. The County Sanitation District of Los Angeles, Joint Water Pollution Control Plant in Carson, California is one of the few wastewater treatment plants in the nation that receives refinery wastewater discharge. It has operated several pilot-scale compost-based biofilters for control of various volatile organic contaminants throughout the plant since a 1991 joint study with the University of California, Davis. After one year of operation, one of the biofilters spontaneously developed the ability to degrade MTBE. The paper describes the collaborative efforts to determine the feasibility ofmore » transferring the degrading microbial population from the solid to liquid phase, without loss of activity, and to determine some of the environmental requirements necessary for survival of the microbial culture.« less