Kamal N. Jha

Chemical composition of gases in Athabasca bitumen and in low-temperature thermolysis of oil sand, asphaltene and maltene

Abstract Athabasca oil sand on degassing in vacuo releases gases volatile at −78 °C which are composed of neopentane, methane, acetaldehyde, propane and propylene. At elevated temperature, 70–210 °C, additional quantities of these materials are produced by thermolysis along with other C2C5 hydrocarbons, CO2, CO, H2S, COS, CS2 and SO2. The activation energies of product formations were determined: they all have unusually low values, pointing to a catalytic effect of the mineral matter present. These results clearly suggest a thermal rather than a microbial origin for the volatile materials present in the oil-sand formations. The separated asphaltene and maltene yield similar products but with considerably higher activation energies. If the values obtained are representative of the entire formation then the amounts (on bitumen reserves of 1012 bbl) of neopentane and methane produced are 2.1 × 106 and 1.05 × 104 tpa, respectively.

I. Kinetics of Reactions of Electrons during Radiolysis of Liquid Methanol. II. Reaction of Electrons with Liquid Alcohols and with Water

The gamma radiolysis of liquid methanol has been studied over the temperature range from its melting point ( − 98°) to its critical temperature (240°). The value of G(H2) varies from 4.95 at −98° to 5.45 at 25° and 8.0 at 240°. Sulfuric acid and nitrous oxide were added as electron scavengers at −97°, 25°, and 150°. The nitrogen and hydrogen yields were calculated as functions of the nitrous oxide concentration at each of the three temperatures. The calculations were based on a proposed mechanism. Homogeneous kinetics were used for the reactions of the free ions and nonhomogeneous kinetics were used for the reactions in spurs. At −97°, G(total ionization) = 4.6 and the value is assumed to be independent of temperature. The yield of free ions is G(esolv−)fi = 2.0 ± 0.2, independent of temperature from −97° − 150°. The reaction esolv−→CH3Osolv−) + H has a rate constant of 4.6 × 105 sec− 1 at 25° and an activation energy equal to that of dielectric relaxation (3.7 kcal/mole); the entropy of activation of the...

Pressure Shifts in Properties of Solvated Electrons in Alcohols and Water

Pressure shifts of the optical absorption maxima of solvated electrons are, respectively, in electron volts per kilobar and nanometers per kilobar: in water 0.053 and −19; in ethanol 0.062 and −20; in methanol ∼ 0.05 and −15. The half‐width of the absorption spectrum of esolv− in water is increased from 0.9 eV at 1 bar to 1.2 eV at 3.8 kbar. In both ethanol and methanol the half‐lives are reduced by pressure. In ethanol Δ V‡ (esolv− → ROsolv− + H) = − 16 cm3 mol−1. In water Δ V‡ (esolv− + S → S−) ≈ −1 cm3 mol−1.

The isotopic composition of carbon in the Alberta oil sand

Abstract The carbon isotopic ratios obtained from Athabasca bitumen, asphaltene and maltene have the same value δ 13 C = −29.6 per ml . The corresponding values in the Cold Lake deposits are −30.6, −30.0 and −31.6 per ml. The ratios determined for methane collected from the oil sand and its fractions are about 15 per ml lower than the above values. It appears that the Athabasca and Cold Lake Reservoirs have similar histories.

Effect of Temperature on the Reactions of Electrons during the γ Radiolysis of Liquid n‐Propanol

Purified n‐propanol was irradiated at temperatures from − 120° to + 264° and G(H2) increased from 4.1 to 5.9 over this range. Solutions of electron scavengers (acid and nitrous oxide) were irradiated at − 120°, + 25°, and 140°. The values of G(H2) for absolutely pure n‐propanol were estimated to be 4.3 at − 120°, 4.9 at 25°, and 6.0 at 140°. The value of G(total ionization) ≈ 4.3 estimated at − 120° was assumed to be independent of temperature. The free‐ion yield was G(esolv−)fi = 1.1 at − 120°, 1.2 at + 25°, and 0.8 at 140°. A reaction mechanism was proposed and the measured hydrogen and nitrogen yields were subjected to kinetic analysis; homogeneous kinetics were used for the reactions of the free ions and nonhomogeneous kinetics were used for the reactions in spurs. The activation energy of dielectric relaxation (6.1 kcal/mole) is greater than that of diffusion (∼ 4.5 kcal/mole); it was necessary to use a time‐averaged value of the dielectric constant for the smaller ion–electron separation distances a...

Effect of Pressure on the Rates of Reaction of Solvated Electrons in Liquid Ethanol

At a γ radiolysis dose of 1× 1018 eV/g in ethanol at 296°K the hydrogen yields in neutral ethanol were G(H2)=5.0 at 1 bar and 5.5 at 5.3 kbar; in 1 mM and 1 M sulfuric acid G(H2)=5.7, independent of pressure. The electron scavengers nitrobenzene, acetone, and naphthalene reduce the hydrogen yields in neutral and acidic ethanol at 1 bar and 5.3 kbar; increasing the pressure greatly reduces the ease of scavenging the free ions but has only a small effect on scavenging efficiency in the spurs. Using as a standard the reaction esolv−→ C2H5Osolv−+H with k=1.2× 105 sec−1 at 1 bar and Δ V‡ =−14.4 cm2/mole averaged between 0 and 5.3 kbar, one obtains the following values for k(M−1· sec−1) and Δ V‡ (cm3/mole): esolv−+Hsolv+, 2.8× 1010 at zero ionic strength, +4.5; esolv−+C6H5NO2, 1.5× 1010, +7.5; esolv−+naphthalene, 5.0× 109, +5.6; esolv−+CH3COCH3, 4.2× 109, +5.1. The diffusion coefficient of solvated electrons in ethanol appears to correlate with the liquid viscosity; this is different from the behavior of electr...

Application of the Refined Model of Nonhomogeneous Kinetics to the Reactions of Electrons during the γ Radiolysis of Ethanol and 2‐Propanol. Energies and Entropies of Activation of the Reactions of Solvated Electrons with Alcohols and with Water

The yields of nitrogen and hydrogen from the radiolysis of solutions of nitrous oxide in ethanol and in 2‐propanol at temperatures from about − 100° to + 140° have been calculated by the refined model of the nonhomogeneous kinetics of ionic reactions in irradiated alcohols. The calculated yields agree satisfactorily with those measured experimentally. The value G(total ionization)= 4.3 was assumed for both liquids. In “absolutely pure” ethanol the values of G(H2) and G(esolv−)fi were estimated to be, respectively, 5.3 and 1.7 at − 112°, 5.3 and 1.5 at + 25°, 6.3 and 1.4 at 90°, and 6.9 and 1.2 at 145°. For the decomposition of the solvated electron esolv−→ROsolv− + H [Eq. (8)] in ethanol at 25°, k8 = 1 × 105sec−1 E8∼4.6 kcal/mole, and ΔS8†∼−21 cal/deg·mole. In “absolutely pure” 2‐propanol the values of G(H2) and G(esolv−)fi were estimated to be, respectively, 4.1 and 1.2 at −85°, 4.9 and 1.3 at + 25°, and 5.4 and 1.0 at 140°. For the decomposition of the solvated electron in 2‐propanol at 25°, k8 = 3 × 10...