https://dspace.kpfu.ru/xmlui/handle/net/6048 2026-09-06T11:33:47Z 2026-09-06T11:33:47Z Felix Lugo Jose Guillermo Tirado Kota Aleksis Varfolomeev Mikhail Alekseevich Al-Muntaser Ameen Ahmed Suwaid Muneer Yuan Chengdong Ancheyta Juarez Jorge https://dspace.kpfu.ru/xmlui/handle/net/186124 2026-09-04T07:19:32Z 2023-01-01T00:00:00Z

Chemical and structural changes of resins during the catalytic and non-catalytic aquathermolysis of heavy crude oils Felix Lugo Jose Guillermo; Tirado Kota Aleksis; Varfolomeev Mikhail Alekseevich; Al-Muntaser Ameen Ahmed; Suwaid Muneer; Yuan Chengdong; Ancheyta Juarez Jorge Resins are important molecules for colloidal system (maintaining asphaltenes dispersed) of heavy oils and are responsible of their high viscosity (together with asphaltenes). The results of characterization of resins before and after aquathermolysis by molecular weight, elemental analysis, Fourier transform infrared, nuclear magnetic resonance, and ultraviolet fluorescence were collected and analyzed to highlight the changes in chemical and structural properties. The discussion is based on the transformations that resin molecules undergo via hydrogenation, deoxygenation, desulfurization, cracking, ring opening, dealkylation and pyrolysis reactions at steam injection conditions. Some correlations were developed between properties of resins. It was found that the type of ligand plays an important role for catalytic aquathermolysis besides the type of active metal since a synergic effect of these factors produces diverse results in the properties of resins. The molecular weight of resins is greater improved using oil-soluble catalysts compared with water-soluble catalysts and non-catalytic aquathermolysis. Mo-based catalysts usually exhibit higher hydrogenation capability and sulfur removal than other active metals, while Fe-based catalysts commonly improves dealkylation and pyrolysis of side chain reactions of resins.

2023-01-01T00:00:00Z Tirado Kota Aleksis Felix Lugo Jose Guillermo Al-Muntaser Ameen Ahmed Chemam Mokhamed Said Varfolomeev Mikhail Alekseevich Yuan Chengdong Ancheyta Juarez Jorge https://dspace.kpfu.ru/xmlui/handle/net/186123 2026-09-04T07:09:42Z 2023-01-01T00:00:00Z

Molecular Asphaltene Transformations during Aquathermolysis of Heavy Crude Oil: Analysis of the Literature Data Tirado Kota Aleksis; Felix Lugo Jose Guillermo; Al-Muntaser Ameen Ahmed; Chemam Mokhamed Said; Varfolomeev Mikhail Alekseevich; Yuan Chengdong; Ancheyta Juarez Jorge Despite the remarkable effort performed to understand the reaction mechanism of asphaltenes during aquathermolysis reaction, the knowledge level about their molecular structures and reaction pathways is still limited. This work thoroughly reviews and discusses experimental results reported from different samples of asphaltenes during the aquathermolysis reaction to obtain information about the elemental composition, functional groups, and average structural parameters using analytical characterization techniques, including elemental analysis, Fourier transform infrared spectroscopy, synchronous fluorescence spectroscopy, X-ray diffraction analysis, electron paramagnetic resonance spectroscopy, and nuclear magnetic resonance spectroscopy. By studying the structural changes of asphaltenes, theoretical support is provided for future research on the aquathermolysis of heavy crude oils in the presence and absence of various catalysts such as water-soluble, ionic liquids-based, mineral, and heterogeneous. Characterization analyses show that the changes in asphaltenes are strongly influenced by the operating conditions, catalyst type, and asphaltene structure. Certain catalysts and hydrogen donors provide a higher effect on asphaltenes and their functional groups that have been observed through changes in the molecular weight, aromaticity, and condensation as well as representative parameters of the aggregation state of asphaltene molecules.

2023-01-01T00:00:00Z Felix Lugo Jose Guillermo Tirado Kota Aleksis Quitian Alexander Sámano Vicente Varfolomeev Mikhail Alekseevich Yuan Chengdong Ancheyta Juarez Jorge https://dspace.kpfu.ru/xmlui/handle/net/186122 2026-09-04T07:01:46Z 2023-01-01T00:00:00Z

Changes in structural parameters of SARA fractions during heavy oil hydrocracking using dispersed catalysts Felix Lugo Jose Guillermo; Tirado Kota Aleksis; Quitian Alexander; Sámano Vicente; Varfolomeev Mikhail Alekseevich; Yuan Chengdong; Ancheyta Juarez Jorge Most of the characterization of SARA fractions of heavy crude oils during hydrocracking reactions is focused only on asphaltenes, and scarce works are devoted to analyze the differences in the structural parameters of all SARA fractions. In this work, a heavy crude oil is upgraded by non-catalytic and catalytic hydrocracking in a batch reactor at low severity conditions (3.9 MPa H2 pressure, 380 ?C temperature, 800 rpm stirring rate, and 4 h reaction time). Three ore catalysts (hematite, magnetite and molybdenite) and one analytical grade catalyst (iron oxide) are employed. After reaction, the upgraded oils are first distilled and then separated into SARA fractions by the ASTM D86-16a and ASTM D2007-11 methods, respectively. NMR (1H and 13C), FTIR and GPC analyses are used to characterize SARA fractions before and after hydrocracking. The hydrocracking products exhibited a reduction in the average molecular weight of all SARA fractions as function of the hydrogenation capacity of each catalyst in the following order: Fe2O3 (analytical grade) ) Molybdenite ) Hematite ) Magnetite. The structural parameters of saturates fraction remains unchanged except for the production of small length aliphatic chains from heavier fractions. For aromatics, resins and asphaltenes fractions, the number of aliphatic carbons is reduced due to dealkylation reactions increasing their aromaticity. For resins and asphaltenes fractions, hydrogenation and ring opening reactions are also carried out. Mo-based catalyst is mainly aimed at the conversion of asphaltenes, while the Fe-based catalysts focused on the conversion of resins.

2023-01-01T00:00:00Z Felix Lugo Jose Guillermo Tirado Kota Aleksis Varfolomeev Mikhail Alekseevich Yuan Chengdong Ancheyta Juarez Jorge https://dspace.kpfu.ru/xmlui/handle/net/186120 2026-09-04T06:51:23Z 2023-01-01T00:00:00Z

Characteristic curves correlations to predict SARA composition and gas yields during heavy crude oil non-catalytic aquathermolysis Felix Lugo Jose Guillermo; Tirado Kota Aleksis; Varfolomeev Mikhail Alekseevich; Yuan Chengdong; Ancheyta Juarez Jorge Characteristic curve equations are used to calculate the products distribution during the non-catalytic aquathermolysis of Ashal'cha heavy crude oil at different reaction times (12, 24, 48, and 72 h) and temperatures (250 and 300 ?C) with a 3:7 water-to-oil weight ratio. The developed equations accurately estimate the experimental information at different time of reaction and temperature with average absolute error lower than 5%. Unstable primary and secondary (UPS) products equations predicted the experimental results for aromatics and saturate fractions better than stable primary and secondary (SPS) products equations. On the contrary, the gas fraction was well calculated with the SPS products correlation.

2023-01-01T00:00:00Z