In-situ catalytic upgrading of heavy oil using oil-soluble transition metal-based catalysts
Authors: Suwaid, Muneer A.; Varfolomeev, Mikhail A.; Al-muntaser, Ameen A.; Yuan, Chengdong; Starshinova, Valentina L.; Zinnatullin, Almaz; Vagizov, Farit G.; Rakhmatullin, Ilfat Z.; Emelianov, Dmitrii A.; Chemodanov, Artem E.
In this study, oil-soluble transition metal-based catalysts (Fe, Co, Ni) are proposed for catalyzing aquathermolysis reactions in steam injection process for heavy oil production to achieve in-situ upgrading of heavy oil. Their catalytic performance and possible mechanism were investigated by autoclave experiments together with a comprehensive analysis of the change in physical and chemical properties of the upgraded oil using SARA analysis, viscosity measurement, GC, GC-MS, FTIR, and 13C NMR, etc. Simultaneously, the in-situ transformation of these catalysts was also analyzed by TG-FTIR, XRD, and Mossbauer spectra, etc. to better under the possible catalytic mechanism. The results showed that the in-situ transformation of these oil soluble catalysts occurred during the thermal treatment process at 250 degrees C and 300 degrees C, and their metal-based complexes, oxide, sulfide, and sometime pure metal were in-situ generated and played a catalytic role for aquathermolysis reactions. These catalysts showed a good catalytic performance at 300 degrees C for heavy oil upgrading in reducing viscosity, increasing saturates content (especially low molecule weight alkanes), decreasing resins and asphaltenes content, removing sulfur and nitrogen, and decreasing polyaromatics content, etc. by inhibiting the condensation and recombination reactions and promoting thermal decomposition reactions of heavy components (resin, asphaltene, and polycyclic aromatics, long chain alkanes, etc.) and hydrogenation reaction. Nickle gives the best catalytic performance. The low cost and easy access together with its high catalytic activity make its wide application a great potential in catalyzing aquathermolysis reaction in steam injection process for in-situ upgrading and heavy oil recovery.
Histological diversity and molecular characteristics in gastric cancer: relation of cancer stem cell-related molecules and receptor tyrosine kinase molecules to mixed histological type and more histological patterns
Authors: Sentani, Kazuhiro; Imai, Takeharu; Kobayashi, Go; Hayashi, Tetsutaro; Sasaki, Naomi; Oue, Naohide; Yasui, Wataru
Background Gastric cancers (GCs) are still one of the leading causes of cancer-related mortality. The histological and molecular features of GC may differ widely from area to area within the same tumor. Intratumoral heterogeneity has been considered a major obstacle to an efficient diagnosis and successful molecular treatment. Methods We selected and reevaluated 842 GC cases and analyzed the relationship between numbers or composites of histological patterns within tumors, and clinicopathological parameters in mucosal and invasive areas. In addition, we searched for the GC-associated molecules or molecular subtypes marking histological diversities. Results GC cases with more histological numbers or mixed types in invasive areas showed significantly higher T grade and staging, whereas those in mucosal areas did not show any significant associations. GCs with histological diversities showed poorer prognosis and characteristically expressed cancer stem cell-related molecules (CD44, CD133 or ALDH1) and receptor tyrosine kinase molecules (HER2, EGFR or c-MET) as well as Helicobacter pylori infection. Expressions of CD44, HER2, c-MET, laminin 5 center dot 2 or retained E-cadherin in mucosal areas were predictive of more histological numbers and mixed types in invasive areas. In addition, the chromosomal instability subtype of GC showed significant associations with more histological numbers and mixed histological type, whereas the genomic stability subtype of GC showed a significant relationship with pure type. Conclusions We displayed the relationship between histological diversity and molecular features in GC, and we hope that the present data can contribute to the early diagnosis and prevention, and effective treatment of GC.