Preparation of Efficient Carbon-Based Adsorption Material Using Asphaltenes from Asphalt Rocks

Abstract

In this work, the asphaltenes from natural Indonesia asphalt rocks were taken as raw materials for the preparation of micromesoporous enriched carbon material through pyrolysis (<500 °C) and KOH activation (<900 °C) processes. It is found that, during the pyrolysis process, the asphaltenes could be converted to noncondensable gas (36.02%), pyrolytic tar (26.57%), and residual char (37.44%). When the char was mixed together with KOH for heating, more carbons would be released due to the activation reaction, forming a carbon network. The optimal activation conditions were obtained at KOH/char ratio of 3:1 and 800 °C for 30 min. Results also show that almost all of the nitrogen atoms stay in the solid carbon during heating with little releasing to the gas or liquid products. The final obtained porous carbon materials are determined to possess a specific surface area of 1735 m2/g with rich micropores (∼2.0 nm). Instrumental characterizations show that there are abundant heteroatomic groups, including SO, OH, and N, on the activated carbon surface. Further tests by adsorption indicate that the adsorption of methylene blue on the porous carbon material is monolayer adsorption. The maximal adsorption capacity is determined to be at 556.00 mg/g, much higher than that of some commercial activated carbons. It is also indicated that the adsorption kinetics follows the pseudo-second-order kinetic model. These findings suggest that the asphaltene derived carbon material would be promising efficient adsorbents. It also sheds lights on the resourcilization of asphaltenes.

Optimization of Methylene Blue Dye Removal Adsorbed on Olive Pomace Derived Activated Charcoal: Isotherm, Kinetic and Thermodynamic Studies

“…The positive enthalpy (ΔH°) is in favor of an endothermic process. The heat of adsorption (ΔH° < 40 kJ/mol) indicate the MB adsorption is a physical process [32]. These results are similar to Hameed's et al (2007) nding which shows that the adsorption of methylene blue on bamboobased activated charcoal is spontaneous and physical in nature.…”

“…5a). on the other hand, the separation factor (R L ) was used to evaluate the adsorption process in the studied system: Unfavorable (R L > 1), linear (R L = 1), favorable (0 < R L < 1), or irreversible (R L = 0) [12], [30], [32] this parameter is de ned by:…”

Petroleum Asphaltene-Based Activated Nanoporous Carbon for CO2 Capture and H2 Storage

“…In 2015 and 2017, IBM Zurich confirmed the island architecture by obtaining atomic force microscopy (nc-AFM) images of asphaltene molecules. , Asphaltenes are soluble in toluene and chloroform and insoluble in linear alkanes, including n -heptane and n -hexane. , The richness in sp 2 -hybridization of carbon species and polycyclic aromatic hydrocarbons found in the chemical structures of asphaltenes ease the cross-linking of these molecules. , The development of porous carbon nanosheets with a certain level of graphitization obtained from asphaltenes, a cheap and abundant by-product, for mass production might have significance for both the environment and crude oil industry . Several reports have explained the synthesis of nanoporous carbonized asphaltenes. ,, The results obtained by using asphaltenes were either low-surface-area carbon such as 1590 and 1717 m 2 /g, or a costly modification procedure tested in the synthetic steps to augment the surface area of the carbonized material. − In carbonizing asphaltenes, an important aspect, as revealed by AFM imaging, is that, depending on the origin, the asphaltene structure presents a different number of fused aromatic rings and different types of pentagonal rings …”

Pyrolysis of Asphaltenes Derived from Residual Oils and Their Thermally Treated Pitch

“…The mid-temperature region (400–455 °C) in Figure 8 shows that asphaltenes derived from AR and VR have considerably high activation energies compared to other samples, indicating easier structural changes due to the cleavage of weak chemical bonds, such as C-heteroatoms and C–C bond (alkyl side chains). 39 …”

“…The mid-temperature region (400−455 °C) in Figure 8 shows that asphaltenes derived from AR and VR have considerably high activation energies compared to other samples, indicating easier structural changes due to the cleavage of weak chemical bonds, such as C-heteroatoms and C−C bond (alkyl side chains). 39 Figure 9 illustrates that the estimated molecular activation energies for the thermal treatment of asphaltene samples increase with increasing severity. The wide variations in activation energies are attributed to the complex decomposition mechanism of the asphaltene molecule.…”