Abstract:This work aims to investigate the effect of active catalytic nanoparticles on the improvement of the efficiency in recovery of a continuous steam injection process. Catalytic nanoparticles were selected through batch-adsorption experiments and the subsequent evaluation of the temperature for catalytic steam gasification in a thermogravimetric analyzer. A nanoparticulated SiO2 support was functionalized with 1.0 wt % of NiO and PdO nanocrystals, respectively, to improve the catalytic activity of the nanoparticles. Oil recovery was evaluated using a sand pack in steam injection scenarios in the absence and presence of a 500 mg/L SiNi1Pd1 nanoparticles-based nanofluid. The displacement test was carried out by constructing the base curves with water injection followed by steam injection in the absence and presence of the prepared treatment. The oil recovery increased 56% after steam injection with nanoparticles in comparison with the steam injection in the absence of the catalysts. The API gravity increases from 7.2 to 12.1. Changes in the asphaltenes fraction corroborated the catalytic effect of the nanoparticles by reducing the asphaltenes content and the 620 C+ residue 40% and 47%, respectively. Also, rheological measurements showed that the viscosity decreased by up to 85% (one order of magnitude) after the nanofluid treatment during the steam injection process.Keywords: enhanced oil recovery; extra-heavy oil; nanofluid; nanoparticle; steam injection; oil upgrading
Heavy And Extra-heavy Oil Upgrading Technologies Pdf Free
The author presents an in-depth account and a critical review of the progress of industry and academia in underground or In-Situ upgrading of heavy, extra-heavy oils and bitumen, as reported in the patent and open literature. This work is aimed to be a standalone monograph, so three chapters are dedicated to the composition of petroleum and fundamentals of crude oil production and refining.
"As is obvious from the contents in the Chapters and topics that have been covered in this book, Cesar has vast knowledge in all aspects of petroleum industry. Although the focus of the book is on insitu upgrading, the author covers topics from the molecular structure and characterization to transportation and different upgrading technologies. It is timely that Cesar completed this book as the Subsurface upgrading for Heavy oils and bitumen is gaining momentum in Canada. It is expected that this book will be used extensively by process engineers, academics, research labs and should be owned by libraries to be used as a reference book for teaching and learning all aspects of heavy oil and bitumen production and processing."
Thermal hydrocracking and catalytic hydrocracking of heavy oil and model reactant have been carried out to investigate the effect of dispersed Mo catalyst on slurry-phase hydrocracking. The XRD and XPS patterns suggested that the major existence form of dispersed Mo catalyst in slurry-phase hydrocracking was MoS2. Experimental data revealed that the conversion of feedstock oils and model reactant increased with the presence of catalyst, while the yields of light products (gas, naphtha) and heavy products (vacuum residue, coke) decreased, the yields of diesel and vacuum gas oil increased in the meantime. Besides, the yields of aromatic hydrocarbon and naphthenic hydrocarbon in naphtha fraction decreased. Effect parameters R G (the ratio of i-C4H10 yield to n-C4H10 yield) and isoparaffin/n-paraffin ratio were proposed to study the reaction mechanism of slurry-phase hydrocracking, the smaller effect parameters showed that there was no carbonium ion mechanism in slurry-phase hydrocracking, which still followed the free radical mechanism, and that the isomerization ratio of products decreased with the presence of Mo catalyst.
Figure 3 shows that the presence of molybdenum naphthenate led to low yields of gas, naphtha, VR and coke. Under the hydrocracking conditions, the edge and corner sulfur ions in MoS2 can be readily removed, then the coordinatively unsaturated sites (CUS) and sulfur ion vacancies are formed. H2 molecule splits to hydrogen free radical through homolytic and heterolytic ways on the CUS [35]. The hydrogen free radical that subsequently transfers into feedstock oils mainly involves in the following reactions: hydrogen abstraction reaction with alkane; addition reaction with olefin and aromatic hydrocarbon; and combining with another free radical to form a stable molecule. The hydrocarbon free radical is mainly produced though the thermal cracking of hydrocarbon. Thus, the degree of larger molecule cracking at thermal hydrocracking and catalytic hydrocracking would be the same under the same reaction temperature and time. With the presence of molybdenum naphthenate, the higher hydrogen free radical concentration promoted the combination of hydrogen free radical and hydrocarbon free radical. Therefore, the conversions of feedstock oils are increased with the presence of dispersed Mo catalyst. Meanwhile, the serious cracking and condensation of hydrocarbon free radical were suppressed, which reduced the yields of light products (gas, naphtha) and heavy products (VR, coke), respectively. Taken the KLVR experiments as example, the unreactive KLVR yield of catalytic hydrocracking was decreased from 23.67 wt% of thermal hydrocracking to 21.73 wt%, which means that the conversion of KLVR was increased from 76.33 to 78.27 wt%. Meanwhile, the coke yield was decreased from 6.53 to 5.23 wt%. Therefore, the dispersed catalyst obviously increased the conversion of feedstock oils, meanwhile, the serious cracking and coke formation were inhibited.
The gaseous product distributions of model reactant after thermal hydrocracking and catalytic hydrocracking are shown in Table 6. Methane and ethane were the major components of gaseous product, while the olefin yield of catalytic hydrocracking gaseous product was decreased from 6.866 vol % of thermal hydrocracking gaseous product to 5.984 vol %. R G values of model reactant that followed thermal hydrocracking and catalytic hydrocracking pathway were 0.724 and 0.510, respectively. Compared to the R G value of model reactant reacted without MoS2 catalyst, R G value decreased by 29.6 % when the reaction followed catalytic hydrocracking pathway. However, the R G value decreased less than 10 % when the reactant was feedstock oils. The bigger decrease of R G value in model reactant experiments was caused by the sustainable activity of MoS2 catalyst. Nitrogen compounds and coke [37, 38], which could contribute to the catalyst deactivation during the heavy oil hydrocracking process, does not exist in the model reactant system. Therefore, hydrogen free radical was provided during the whole reaction process and the formation of isomerization products was suppressed sharply.
The results of this study indicate that the product composition of thermal hydrocracking and catalytic hydrocracking are the same; therefore, there is no carbonium ion mechanism in slurry-phase hydrocracking, which still follows the free radical mechanism. The conversion of feedstock oils and model reactant increased with the presence of Mo catalyst. The slurry-phase hydrocracking of heavy oil can suppress the unsatisfactory products (gas, VR, coke). R G value, BI and PIONA results indicate that the higher concentration of hydrogen free radical created on the dispersed catalyst promotes the cracking of aromatic hydrocarbon and naphthenic hydrocarbon, however, the formation of isomerization products is suppressed.
Heavy oils refer to a type of petroleum that is difficult to recover from the reservoir due to their relatively higher viscosity and density (Al-Jawad and Hassan 2012; Speight 2013a, 2016). Usually, they are deficient in hydrogen but are rich in metals, sulphur, and carbon (Speight 2013b). However, the value of heavy oils would need to be increased by the use of several upgrading technologies (Gray 2015). In addition to the reduction in viscosity, the use of these upgrading technologies would also be expected to mitigate the possible environmental risks associated with the exploitation and exploration of these heavy oils.
Many studies have reported the use of pyrolysis as a processing technology for oil sands and oil shale (Shun et al. 2017; Jia et al. 2018; Nie et al. 2018; Tian et al. 2018; Chen et al. 2020; Kang et al. 2020). Many of these recent theoretical, field, and experimental studies were carried out under different reaction conditions, with a view to generating oils and gases. To the best of our knowledge, there is paucity of recent critical and comprehensive reviews on the pyrolysis of heavy oils despite an abundance of studies on the subject matter. This review aims to bridge information gaps on the fundamentals of pyrolysis as upgrading technology for heavy oils. First, the pyrolysis systems and reactors are described. Then, the reaction mechanisms of pyrolysis are illustrated. The effects of process conditions such as temperature and residence time on the composition and quality of pyrolytic oils and gases were also discussed.
This review is a clear indication that the choice of pyrolysis system and/or reactor influences the composition and quality of product yields. The economic cost might then be a suitable criterion to be considered in the selection of operating parameters and pyrolysis systems. Further research should be explored in removing the oxygen present in the gas phase of the pyrolytic products. The development of suitable catalysts for the upgrading of heavy oils is also recommended so as to reduce the residence time of the feedstock in the reactors. Highly efficient cost-effective reactors should also be developed in the future. Generally, the liquid products obtained from the pyrolysis of oil shale are unstable. They also contain significant amounts of nitrogen, sulphur, and oxygen-containing compounds, which makes it difficult for them to be used directly as liquid fuels. The quality of pyrolytic oils should be improved to meet specifications for use in the petroleum and petrochemical industry. Additional purification units for gases should be incorporated into pyrolysis reactors to make them useful as fuels. Although substantial evidence exists that the use of pyrolysis technology offers a reduction in the emissions of greenhouse gases, further assessment of environmental sustainability should be carried out to ensure compliance with environmental policies and guidelines. 2ff7e9595c