Effect of the heteroatom presence in different positions of the model asphaltene structure on the self-aggregation: MD and DFT study

Effect of the Pyrrolic Nitrogen Functional Group in the Selective Adsorption of CO2: GCMC, MD, and DFT Studies

“…Furthermore, to fully understand the adsorption process, DFT calculations were used to study the interaction between gases and adsorbents. All calculations were carried out via Gaussian 09 software. , The DFT b3lyp/6-311++g­(d,p) method was used to optimize the model coal-derived asphaltene molecule structure. Subsequently, analyses such as theoretical reactivity descriptors and electrostatic potential (ESP) maps were prepared based on this optimized structure and DFT method.…”

“…Our previous study investigated the importance of the heteroatom in the self-aggregation of the model asphaltene, indicating that asphaltene heteroatoms can change the asphaltene inclination to self-aggregation and change the electronic structure and solubility parameters . Moreover, in this study, the effect of the NH group is investigated on the CO 2 adsorption on the model coal-derived asphaltene.…”

“…19 Our previous study investigated the importance of the heteroatom in the self-aggregation of the model asphaltene, indicating that asphaltene heteroatoms can change the asphaltene inclination to self-aggregation and change the electronic structure and solubility parameters. 20 Moreover, in this study, the effect of the NH group is investigated on the CO 2 adsorption on the model coal-derived asphaltene. Among the influence studies of surface alteration on selective CO 2 adsorption, there is a controversy between researchers about the effect of the NH functional group (pyrrole) on the adsorption of CO 2 , 21 and in this study, three powerful tools, including GCMC, MD, and DFT, in the microscopic simulation were used to thoroughly investigate the effect of the NH functional group in the selective adsorption of CO 2 among other gases.…”

Review on Application of Nanotechnology for Asphaltene Adsorption, Crude Oil Demulsification, and Produced Water Treatment

“…N (0.6%−3.3%) may be present as pyrrolic, pyridine, and quinoline types of functional groups, and O (0.3%−4.9%) can be present as hydroxyl, carbonyl, and carboxyl groups. 24 It is important to mention that O-and N-containing groups impart positive and negative charges, respectively. Typically, pyridine is identified as the major contributor to the basicity of asphaltenes, whereas carboxylic acid groups are the main contributors toward acidity of asphaltenes.…”

“…Generally, the S atoms (0.3%–10.3%) are present in heterocycles, sulfide, or thiophene groups. N (0.6%–3.3%) may be present as pyrrolic, pyridine, and quinoline types of functional groups, and O (0.3%–4.9%) can be present as hydroxyl, carbonyl, and carboxyl groups . It is important to mention that O- and N-containing groups impart positive and negative charges, respectively.…”