The Distribution of Ni and V in Resin and Asphaltene Subfractions and Its Variation During Thermal Processes

<div><p>Ni and V deactivate catalysts and promote coking during heavy oil upgrading. Distribution of metals and metalloporphyrins, and its variation in thermal process, would benefit the more efficient upgrading. Majority of metals concentrate in resins and asphaltenes. To thoroughly study the metals distribution in these fractions, both were subdivided. It is indicated that the interactions between metalloporphyrins and asphaltenes play a significant role in metals distribution. Variation of metals distribution showed that the trend metals concentrated into heavier subfractions and was enhanced by thermal treatment and inhibited by hydrogen sources. Synergism was observed between hydrogen and hydrogen donor for the inhibition.</p></div

Compatibility of Heavy Blends Evaluated by Fouling and Its Relationship With Colloidal Stability

<div><p>To predict oil compatibility is crucial because incompatibility could cause severe deposition and fouling problems. Therefore, compatibility of heavy oils and blends in different ratios were evaluated by fouling at heat transfer conditions. Thermal resistance and fouling rates were obtained on a fouling loop. Effect of colloidal stability based on asphaltene precipitation and SARA composition on fouling was also discussed. Results showed that different variations of fouling rate versus blending ratio were observed for these blending systems. For oils whose viscosities approach at heat conditions, the lower colloidal stability of blends is the higher fouling rate is. However, for oils with greatly different viscosities, inconsistency was observed between compatibility by the two indicators, which is attributed to remarkable change of flow condition. This indicates that both colloidal stability and flow condition play key roles in fouling. Oil compatibility at heat transfer condition is favored being predicted by fouling instead of correlating with the colloidal stability.</p></div

Mineralogical characteristics of continental shale: a case study in Yan-Chang Formation, Ordos Basin

<p>The Chang 7 Member of the Yan-Chang Formation (Yan-Chang #7 Member), which is located in the central south of the Ordos Basin (China), is assessed for its potential as a shale gas resource. The characteristics and spatial variability of mineral components in this continental shale formation play a crucial role in evaluating and characterising the shale reservoirs. We collected 64 shale core samples from 30 representative sampling sites located in the central south of the Ordos Basin using X-ray diffraction and field emission scanning electron microscopy to study the mineral compositions, vertical/planar variations of minerals, and the major controlling factors that result in such variations. Based on the relative fractions of the dominant minerals, the shale rocks can be classified into four categories: quartz-rich (type #1), illite/chlorite-rich (type #2), illite–smectite mixed-layer-rich (type #3) and feldspar-rich (type #4). In general, type #1 is mainly located in the northwest of the study area, type #4 is mainly located in the south of the study area, and types #2 and #3 are sandwiched between types #1 and #4. In the centre of the basin, the illite content increases with burial depth and the conversion from smectite to illite, which is experimentally confirmed in this study, enhances the surface porosity of shale. The major factors influencing the properties and spatial variability of the mineral components include sedimentary environment, provenance and diagenesis. Compared with marine shales in China <i>(e.g.</i> Longmaxi marine shales), the Yan-Chang #7 Member continental shale has a higher clay content, but lower calcite, dolomite and pyrite contents. The brittleness indexes of type #1 shale in Wuqi and its surrounding areas are marginally higher than that of Longmaxi marine shales, which makes the type #1 shale in the Wuqi and its surrounding areas slightly easier to fracture than the Longmaxi marine shales.</p

Spark Plasma Sintered bismuth telluride-based thermoelectric materials incorporating dispersed boron carbide

The mechanical properties of bismuth telluride based thermoelectric materials have received much less attention in the literature than their thermoelectric properties. Polycrystalline p-type Bi0.5Sb1.5Te3 materials were produced from powder using spark plasma sintering (SPS). The effects of nano-B4C addition on the thermoelectric performance, Vickers hardness and fracture toughness were measured. Addition of 0.2 vol% B4C was found to have little effect on zT but increased hardness by approximately 27% when compared to polycrystalline material without B4C. The KIC fracture toughness of these compositions was measured as 0.80 MPa m1/2 by Single-Edge V-Notched Beam (SEVNB). The machinability of polycrystalline materials produced by SPS was significantly better than commercially available directionally solidified materials because the latter is limited by cleavage along the crystallographic plane parallel to the direction of solidification