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Showing papers by "ExxonMobil published in 1981"


Journal ArticleDOI
13 Mar 1981-Science
TL;DR: Spectroscopic measurements indicate that an electron is transferred from the cation (such as Ti(3+) or Nb(4+)) to the metal particle, which leads to profound changes in the catalytic and chemisorption properties and the morphology of the metal particles.
Abstract: Many commercially important catalysts consist of small metal particles dispersed on inorganic oxide surfaces. Although in most cases there is no significant interaction between the metal and the support, strong bonding can be demonstrated in a recently discovered class of supported-metal catalysts. These cases typically involve group VIII metals dispersed on transition metal oxides whose surfaces can be reduced to form cations with lower valences. Spectroscopic measurements indicate that an electron is transferred from the cation (such as Ti3+ or Nb4+) to the metal particle. This, in turn, leads to profound changes in the catalytic and chemisorption properties and the morphology of the metal particles.

1,036 citations


Journal ArticleDOI
George Dewey Cody1, Thomas Tiedje1, B. Abeles1, B.G. Brooks1, Y. Goldstein1 
TL;DR: The effect of thermal and structural disorder on the electronic structure of hydrogenated amorphous silicon is investigated by measurement of the shape of the optical absorption edge as a function of temperature and thermal evolution of hydrogen as discussed by the authors.
Abstract: The effect of thermal and structural disorder on the electronic structure of hydrogenated amorphous silicon is investigated by measurement of the shape of the optical absorption edge as a function of temperature and thermal evolution of hydrogen. The data are consistent with the idea that the thermal and structural disorder are additive, and suggest that the disorder, rather than the hydrogen content, is the fundamental determining factor in the optical band gap.

974 citations


Journal ArticleDOI
TL;DR: The primary effect in the hydrodesulfurization of dibenzothiophene by transition metal sulfides is related to the position the metal occupies in the periodic table.

722 citations


Journal ArticleDOI
TL;DR: In this article, the kinetics of the water gas shift (WGS) reaction as catalyzed by alumina-supported Group VIIB, VIII, and IB metals are examined.

488 citations


Patent
Bertram T Willman1
06 Apr 1981
TL;DR: In this paper, a method for treating a field containing viscous oil or bitumen for subsequent production is described, and the steps central to the process are drilling a horizontal well within the oil-bearing stratum, and heating the oil in the vicinity of the horizontal well to produce a hot liquid corridor.
Abstract: A method for treating a field containing viscous oil or bitumen for subsequent production is described. The steps central to the process are drilling a horizontal well within the oil-bearing stratum, and heating the oil in the vicinity of the horizontal well to produce a hot liquid corridor. The open borehole is filled and the oil in the heated corridor is displaced from one end to the other. The corridors may be connected in various configurations to effectively displace a high percentage of oil in a particular field.

362 citations


Journal ArticleDOI
Rathin Datta1
TL;DR: In this article, a mixed culture of anaerobic microorganisms was used to ferment corn stover to form simple (C2-C6), volatile organic acids, and the yield of acid with respect to material fermented was 84%.
Abstract: Corn stover was fermented with a mixed culture of anaerobic microorganisms to form simple (C2-C6), volatile organic acids. Alkaline pretreatment allowed a greater fermentation of the pectin and hemicellulose than of the cellulose and lignin, but all components were utilized. The percent fermentation of the soluble fraction, hemicellulose, cellulose, and lignin was 79.6, 74.1, 36.9, and 20.9%, respively. The yield of acid (as acetate) with respect to material fermented was 84%.

202 citations


Patent
17 Dec 1981
TL;DR: A natural wax-containing ink jet ink for use in an ink jet apparatus which features good print quality is described in this paper, where the ink is discharged from the ink jet printer at elevated temperatures above ambient.
Abstract: A natural wax-containing ink jet ink for use in an ink jet apparatus which features good print quality. The ink jet ink is discharged from the ink jet ink apparatus at elevated temperatures above ambient.

201 citations


Patent
10 Aug 1981
TL;DR: In this paper, a method for reducing the permeability of underground formations penetrated by a wellbore by placing the composition of the present invention down the well-bore was proposed.
Abstract: The present invention relates generally to the composition and method for reducing the permeability of subterranean formations penetrated by a wellbore. The composition of the present invention comprises a wellbore fluid having dispersed therein a fluid loss control agent comprising a polyester polymer which is substantially insoluble in the wellbore fluid. The polymer degrades in the presence of water at an elevated temperature to form small molecules which are soluble in a fluid in the subterranean formation. The method of the present invention comprises reducing the permeability of subterranean formations penetrated by a wellbore by placing the composition of the present invention down the wellbore.

195 citations


Patent
16 Mar 1981
TL;DR: In this article, the authors present a process and apparatus for measuring total fixed gaseous nitrogen species, including NH3, NO, NO2, HCN and organic amines, in a non-catalytic quartz preheater.
Abstract: Process and apparatus for measuring total fixed gaseous nitrogen species, including NH3, NO, NO2, HCN and organic amines in gaseous mixtures. The process involves catalytic conversion at elevated temperature of all fixed nitrogen species to nitric oxide, NO, followed by chemiluminescent measurement of the resulting NO concentration. The improvement features of the process are the use of a reduced pressure gaseous sample flow to prevent N2 poisoning of the heated platinum catalyst and a preheat step of the reduced pressure gaseous mixture in an inert, non-catalytic quartz preheater prior to catalytic conversion to prevent loss of some species, such as NH3, through premature catalyzed reaction with NO and subsequent loss from the system as N2.

149 citations


Journal ArticleDOI
C.H. Chang1, Shirley S. Chan1
TL;DR: In this article, a comparison of the Raman spectrum of amorphous MoS 3 and poorly crystalline MoS 2 has been performed using infrared and Raman spectroscopies.

141 citations


Journal ArticleDOI
TL;DR: In this article, a general, physico-chemical analysis of mass transfer rate promotion in the system CO2-potassium carbonate-water-promoter is presented, showing that differences between inorganic and organic promoters are predominently quantitative, not qualitative.

Journal ArticleDOI
TL;DR: In this paper, a kinetic analysis of the hydrodesulfurization of dibenzothiophene (DBT), a representative model of the condensed sulfur heterocyclics found in heavy petroleum feeds, has been carried out.

Journal ArticleDOI
H.Chang Chin1
01 Jan 1981-Carbon
TL;DR: Carbon-sulfur surface compounds (C χ S ), in which sulfur is chemically bound, have been prepared with a sulfur content greater than 30 wt%. X-Ray diffractometry and electron microscopy show that the structure of the material is similar to that of disordered carbons.

Journal ArticleDOI
Rostam J. Madon1, W.F. Taylor1
TL;DR: The Fischer-Tropsch synthesis was carried out at various experimental conditions on an unpoisoned and sulfur-poisoning precipitated, alkali-promoted iron-copper catalyst as discussed by the authors.

Journal ArticleDOI
01 Jun 1981-Fuel
TL;DR: In this paper, coal combustion experiments were carried out over the temperature range 25-900 °C using air at atmospheric pressure in a derivative thermogravimetric analysis system. But the results showed that combustion rates increased progressively with increasing temperature, passed through maxima and then declined.

Patent
27 Aug 1981
TL;DR: In this article, the authors present a method for separating the treated gas into a methane-rich gas stream and a gas stream containing primarily carbon monoxide and hydrogen, which is then passed from the steam reforming furnace into the gasifier.
Abstract: Methanol is produced by gasifying a carbonaceous feed material with steam in the presence of a carbon-alkali metal catalyst and added hydrogen and carbon monoxide at a temperature between about 1000° F. and about 1500° F. and at a pressure in excess of about 100 psia to produce a raw product gas comprising methane, steam, carbon dioxide, carbon monoxide, hydrogen and hydrogen sulfide; withdrawing the raw product gas from the gasifier and treating it for the removal of steam, particulates, hydrogen sulfide and carbon dioxide to produce a treated gas containing primarily carbon monoxide, hydrogen and methane; separating the treated gas into a methane-rich gas stream and a gas stream containing primarily carbon monoxide and hydrogen; passing the methane-rich gas stream to a steam reforming furnace wherein a portion of the methane is reacted with steam to produce hydrogen and carbon monoxide which is then passed from the steam reforming furnace into the gasifier; passing the gas stream containing primarily carbon monoxide and hydrogen to a methanol synthesis reactor where the carbon monoxide is reacted with the hydrogen in the presence of a methanol synthesis catalyst to form methanol; recovering methanol product from the effluent exiting the methanol synthesis reactor thereby leaving a gas comprised of carbon monoxide, hydrogen, methane and carbon dioxide; and recycling at least a portion of this gas to the separation step of the process.

Journal ArticleDOI
Rathin Datta1
TL;DR: The data show that acidogenic fermentation can produce useful volatile fatty acids in high yields from a complex lignocellulosic feedstock and could be useful in converting biomass to chemical feedstocks and fuel.
Abstract: Corn stover was fermentd by anaerobic acidogenic bacteria to produce volatile (C2-C6) organic acids Mild pretreatment with dilute alkali solutions produced a two-fold increase in fermentability A mixture of lime and sodium carbonate was found to be a better pretreatment agent than sodium hydroxide Methane generation was inhibited by low temperature less than or equal to 25 degrees Celcius and high solids greater than or equal to 25% (w/v) fermentation Volatile acid yields of 05-055 g acetic acid equivalent/g dry ash-free (DAF) stover could be obtained in batch fermentations Several extractants and extraction solvents for organic acids were found to be nontoxic to acidogenic fermentation The data show that acidogenic fermentation can produce useful volatile fatty acids in high yields from a complex lignocellulosic feedstock These fermentation are nonsterile, need no stirring, and are easy to run Moreover, cellulose, pentosans, and other carbohydrates are directly utilized by acidogenic bacteria Hence, acidogenic fermentation could be useful in converting biomass to chemical feedstocks and fuel

Patent
Jr. Paul E. Eberly1
02 Jan 1981
TL;DR: In this article, a process wherein a particulate sorbent mass of zeolite which has been ion-exchanged with zinc or cadmium to provide pore size openings of about 5A, and particularly zinc, is contacted with a moist hydrocarbon process stream which contains sulfur, sulfur compounds, and other contaminants, these being adsorbed onto said particulate sorb mass, and the process stream thereby denuded of said sulfur, sulphur compounds, or other contaminants.
Abstract: A process wherein a particulate sorbent mass of zeolite which has been ion-exchanged with zinc or cadmium to provide pore size openings of about 5A, and greater, particularly zinc, is contacted with a moist hydrocarbon process stream which contains sulfur, sulfur compounds, and other contaminants, these being adsorbed onto said particulate sorbent mass, and the process stream thereby denuded of said sulfur, sulfur compounds, and other contaminants Thereafter, the sulfur, sulfur compounds, and other contaminants, are readily desorbed, or removed from said particulate sorbent mass by contacting, and purging same with a gas stream, suitably hydrogen, or a hydrogen-containing gas, at elevated temperature

Journal ArticleDOI
TL;DR: In this paper, the temperature dependence of the magnetic susceptibility of single crystals of PrB 4, GdB 4, TbB 4, HoB 4 and TmB 4 was reported.

Journal ArticleDOI
TL;DR: In this paper, generalized valence-bond calculations suggest that atomic oxygen chemisorbed on Ni(100) leads to two distinct low-lying states: (1) the radical state with ${R}_{\ensuremath{\perp}}=0.88$ \AA{} and (2) the surface oxide state with
Abstract: Generalized valence-bond calculations suggest that atomic oxygen chemisorbed on Ni(100) leads to two distinct low-lying states: (1) the radical state with ${R}_{\ensuremath{\perp}}=0.88$ \AA{} and ${\ensuremath{\omega}}_{\ensuremath{\perp}}=55$ meV and (2) the surface oxide state with ${R}_{\ensuremath{\perp}}=0.26$ \AA{} and ${\ensuremath{\omega}}_{\ensuremath{\perp}}=38$ meV. We suggest that the radical state dominates for $p(2\ifmmode\times\else\texttimes\fi{}2)$ and that the oxide state dominates for $c(2\ifmmode\times\else\texttimes\fi{}2)$. We find that atomic H, Cl, and S lead to only one low-lying state.

Journal ArticleDOI
R.T.K. Baker1, R.D. Sherwood1
TL;DR: In this paper, controlled-atmosphere electron microscopy studies of the nickel/graphite system have revealed that in a strong oxidizing environment carbon gasification occurred mainly by the uncatalyzed route.

Journal ArticleDOI
01 Jan 1981-Carbon
TL;DR: The behavior of chromium is quite unique, not fitting into the well established patterns, i.e. pitting or channeling as mentioned in this paper, and particles remain motionless throughout the oxidation sequence and the action is seen as an acceleration of edge recession.

Journal ArticleDOI
TL;DR: In this article, the authors report the observation of strongly nonlinear conductivity with a sharp threshold field and a giant dielectric constant in the charge-density-wave state of Ta${\mathrm{S}}_{3}.
Abstract: We report the observation of strongly nonlinear conductivity with a sharp threshold field and a giant dielectric constant in the charge-density-wave state of Ta${\mathrm{S}}_{3}$. We argue that these properties reflect the dynamical behavior of the charge-density-wave condensate, and compare the observed behavior with the properties of Nb${\mathrm{Se}}_{3}$.

Patent
Jr Arthur W Langer1
14 Dec 1981
TL;DR: In this paper, a process for preparing linear olefins which comprises polymerizing an ethylene containing gas in the presence of a catalyst comprising the reaction product of a transition metal halide and an aluminum alkyl compound was described.
Abstract: In a process for preparing linear olefins which comprises polymerizing an ethylene containing gas in the presence of a catalyst comprising the reaction product of a transition metal halide and an aluminum alkyl compound in the presence of a diluent and maintaining the mole ratio of ethylene to olefin reaction product at a relatively high level so as to produce a product comprising at least 90 mole % linear olefins, the process is improved and the product purity is maintained by killing the activity of the catalyst prior to the occurrence of deleterious side reactions which tend to reduce the product purity.

Patent
Evans John L1
28 Sep 1981
TL;DR: In this article, a method for controlling the flow of drilling fluid through a subaqueous wellbore is disclosed, which comprises the steps of continuously measuring the output flow rate (A) of the drilling fluid from the well-bore, the input flow rate of the fluid to the vessel, and at least a component of the pitch and roll (P/R) signal and the roughness of the sea.
Abstract: A method for controlling the flow of drilling fluid through a subaqueous wellbore is disclosed. The method comprises the steps of continuously measuring the output flow rate (A) of the drilling fluid from the wellbore, the input flow rate (B) of the drilling fluid to the wellbore, and at least a component of the pitch and roll (P/R) of the vessel, computating a floating alarm limit (C) dependent upon the pitch and roll (P/R) signal and the roughness of the sea, filtering the periodic fluctuation of the output flow rate (A) due to the motion of the vessel, and computating the delta flow signal (D) by subtracting the input flow rate (B) from the filtered output flow rate (A). The method further comprises the step of generating a signal whenever the absolute value of the delta flow rate (D) exceeds the floating alarm limit (C) to provide a visible warning that the flow of drilling fluid is out of control and to either close off the wellbore in case of a kick or to stop the flow of fluid and stop drilling in case of lost returns. Apparatus for controlling the flow of drilling fluid through a subaqueous wellbore is disclosed while drilling from a floating vessel. The wellbore is connected to the lower end of the drill string and the lower end of an annulus by a valve through which the drilling fluid flows. The upper end of the annulus is connected to a conduit from which the drilling flows to the suction side of a pump which circulates the drilling fluid therefrom into the upper end of the drill string, through the wellbore, and back up the annulus into the conduit. The apparation comprises an output flow meter connected to the exit of the conduit, an input flow meter connected between the pump and the upper end of the drill string, means mounted on the vessel for sensing the pitch and roll of the vessel, and computer means for receiving the output flow rate (A) signal from the output flow meter, the input flow rate (B) from the input flow meter, and the pitch and roll (P/R) signal from the pitch and roll sensing means. The computer means calculates an alarm limit (C) based on the pitch and roll (P/R) signal and the roughness of the sea continuously filters the periodic fluctuation of the output flow rate (A) due to the motion of the vessel, computes the delta flow signal (D) by subtracting the input flow rate (B) from the filtered output flow rate (A), and generates a signal whenever the delta flow rate (D) exceeds the floating alarm limit (C) to provide a warning of a possible blowout or lost circulation condition and to either close off the wellbore in case of a kick or to stop the flow of fluid and stop drilling in case of lost returns.

Patent
26 Jun 1981
TL;DR: In this paper, a fairing for elongated elements is proposed for mounting on a marine drilling riser having flotation modules, which is made as a stream-lined shaped body that has a nose portion in which the elongated element is accommodated and a tail portion.
Abstract: A fairing for elongated elements is disclosed for reducing current-induced stresses on the elongated element. The fairing is made as a stream-lined shaped body that has a nose portion in which the elongated element is accommodated and a tail portion. The body has a bearing connected to it to provide bearing engagement with the elongated element. A biasing device interconnected with the the bearing accommodates variations in the outer surface of the elongated element to maintain the fairing's longitudinal axis substantially parallel to the longitudinal axis of the elongated element as the fairing rotates around the elongated element. The fairing is particularly adapted for mounting on a marine drilling riser having flotation modules.

Journal ArticleDOI
TL;DR: A series of mixed metal oxides with pyrochlore structure has been discovered and can be described by the general formula A2[B2−xAx]O7−y where A = Pb or Bi, B = Ru or Ir, 0 < x ≲ 1 and 0 ≤ y ≤ 0.5 as mentioned in this paper.

Journal ArticleDOI
TL;DR: The authors' modeling indicates that the power dissipation in the dye coating is enhanced compared with the dissipation of dye deposited on a nonresonant structure, helping elucidate the excitation mechanisms of Raman and fluorescent emission of adsorbates at rough silver interfaces.
Abstract: We have used Mie theory to account for the features of the transmission spectra of dye-coated silver-island films. The unusual behavior of the spectra arises from the effect of the dispersion and damping of the optical response of the absorbing coating on the structural resonances of the silver islands. Our modeling indicates that the power dissipation in the dye coating is enhanced compared with the dissipation of dye deposited on a nonresonant structure. These results help elucidate the excitation mechanisms of Raman and fluorescent emission of adsorbates at rough silver interfaces.

Patent
Clarke Christopher T1
11 Aug 1981
TL;DR: In this paper, the authors used a mixture of more than 50 wt % of a Group IIa metal over-based detergent and up to 50 t % of an antioxidant, provided the weight ratio of the mixture to antioxidant lies between 75:1 and 50:1, all parts by weight referring to total active matter of the additive.
Abstract: Lubricating oil compositions suitable for use in marine diesel engines comprise 60 to 85 parts by weight of lubricating oil, 15 to 30 parts by weight of a mixture of more than 50 wt % of a Group IIa metal overbased detergent and up to 50 wt % of a Group Ia metal overbased detergent and 02 to 5 parts by weight of an antioxidant, provided the weight ratio of the overbased detergent mixture to antioxidant lies between 75:1 and 50:1, all parts by weight referring to total active matter of the additive When used in loop-scavenged crosshead marine diesel engines fouling of air ports with deposits is considerably reduced and there is a satisfactory anti-wear performance