ExxonMobil

About: ExxonMobil is a company organization based out in Irving, Texas, United States. It is known for research contribution in the topics: Catalysis & Polymer. The organization has 16969 authors who have published 23758 publications receiving 535713 citations. The organization is also known as: Exxon Mobil Corporation & Exxon Mobil Corp..

Observation of nonclassical optical diffusion.

Abstract: The optical diffusion coefficient D and photon absorption time ${\mathrm{\ensuremath{\tau}}}_{\mathrm{a}}$ in a sample of titania spheres in air are determined from measurements of picosecond pulse transmission over the wavelength range 514--650 nm. At 514 nm, D=1.45\ifmmode\times\else\texttimes\fi{}${10}^{4}$ ${\mathrm{cm}}^{2}$/s. This corresponds to an anomalously small value of the effective mean free path l\ifmmode \tilde{}\else \~{}\fi{}==3D/v=250 A\r{}, where v is the velocity of light in the medium. Throughout the wavelength range measured, l\ifmmode \tilde{}\else \~{}\fi{}\ensuremath{\le}0.15\ensuremath{\lambda}. Assuming that D is reduced by coherent backscattering and that the optical mobility edge is given by the Ioffe-Regel criterion, the renormalization factor at 514.5 nm is 2.8.

Two decades of ocean CO2 sink and variability

Abstract: Atmospheric CO 2 has increased at a nearly identical average rate of 3.3 and 3.2 Pg C yr −1 for the decades of the 1980s and the 1990s, in spite of a large increase in fossil fuel emissions from 5.4 to 6.3 Pg C yr −1 . Thus, the sum of the ocean and land CO 2 sinks was 1 Pg C yr −1 larger in the 1990s than in to the 1980s. Here we quantify the ocean and land sinks for these two decades using recent atmospheric inversions and ocean models. The ocean and land sinks are estimated to be, respectively, 0.3 (0.1 to 0.6) and 0.7 (0.4 to 0.9) Pg C yr −1 larger in the 1990s than in the 1980s. When variability less than 5 yr is removed, all estimates show a global oceanic sink more or less steadily increasing with time, and a large anomaly in the land sink during 1990–1994. For year-to-year variability, all estimates show 1/3 to 1/2 less variability in the ocean than on land, but the amplitude and phase of the oceanic variability remain poorly determined. A mean oceanic sink of 1.9 Pg C yr −1 for the 1990s based on O 2 observations corrected for ocean outgassing is supported by these estimates, but an uncertainty on the mean value of the order of ±0.7 Pg C yr −1 remains. The difference between the two decades appears to be more robust than the absolute value of either of the two decades. DOI: 10.1034/j.1600-0889.2003.00043.x

Pressure swing reforming

Abstract: Synthesis gas is produced though a cyclic method where the first step of the cycle includes reforming a hydrocarbon feed over a catalyst to synthesis gas in a first zone of a bed and the second step reheats this first zone. A hydrocarbon feed is introduced to a bed along with CO2 and optionally steam where it is reformed into synthesis gas. The synthesis gas is collected at a second zone of the bed and an oxygen-containing gas is then introduced to this second zone of the bed and combusted with a fuel, thereby reheating the first zone to sufficient reforming temperatures. Additionally, a non-combusting gas can also be introduced to the second zone to move heat from the second zone to the first zone.

In-situ retorting of oil shale

Abstract: Fluid, such as liquid water, is injected into the rock surrounding an in situ oil shale retort at sufficient pressure and flow rate so that the injected fluid flows toward the retort to block the path of hot liquid and gaseous kerogen decomposition products escaping from the retort and to return heat to the retort. The successful conduct of an oil shale retorting operation usually requires that the retort temperature be maintained at a temperature sufficient to decompose efficiently the kerogen contained in the oil shale. By reducing the heat loss from an active retort, the amount of energy required to maintain a desired temperature therein is reduced. The fluid injection method also maintains pressure in an in-situ oil shale retort, allowing in-situ oil shale retorting to be efficiently conducted at a desired pressure. The method also reduces the danger to mineworkers who may be engaged in adjacent mining operations due to the escape of hazardous gases from an active retort. The method allows a series of sequential in-situ oil shale retorts in an oil shale formation to be placed more closely together than previously practical by reducing hot fluid leakage from each active retort to one or more abandoned retorts adjacent thereto, thus improving the recovery factor from the formation. The method also minimizes contamination of the formation surrounding an active in-situ retort due to hazardous chemicals which may be contained in the kerogen decomposition products leaking from the retort.