Coke Generation Research Articles

Simulation of edge water invasion mitigation of the SAGD chamber by low temperature oxidation (LTO) coking air injection and optimization of operating parameters

During the long-term use of steam assisted gravity drainage (SAGD) in oil fields, the continuous expansion of the steam chamber often leads to edge water invasion, which significantly reduces thermal efficiency and oil production rate. To address this challenge, we hypothesize that a low temperature oxidation (LTO) coke formation air injection method may alleviate edge water invasion. To test our hypothesis, we developed a numerical SAGD model tailored to a typical SAGD field, the Guantao Du84 block in the Liaohe Oilfield, China. The model incorporates a four-step coke generation kinetics and considers the complexity of coke distribution. Our results reveal that coke generation (1) shifts the direction of edge water flow from the steam chamber to a vertical downward direction, (2) causes pore clogging, resulting in reduced flow velocity, (3) leads to reduced porosity and water cut, significantly improving oil recovery as compared to nitrogen injection (e.g., by 18.2% in the Guantao Du84 block), and (4) allows for proactive establishment of coke zones before the water cut reaches 85%. Through this numerical study, we investigate the feasibility of implementing the method of LTO coking air injection in SAGD fields and provide insights into its optimization.

An experimental study of the endothermic catalytic cracking of hydrocarbon aviation fuels under extreme conditions

Methylcyclohexane (MCH) is a suitable surrogate endothermic fuel that can operate under extreme conditions and it can be utilized to better understand the mechanisms of endothermic catalytic cracking and coke generation in jet engines. Zn-impregnated desilicated Zeolite Socony Mobil–5 (ZSM-5) zeolite catalysts have been successfully prepared and studied for aviation fuel cracking under high temperature and pressure conditions (550 °C; 50 bar). First, micropore ZSM-5 was desilicated by the alkali treatment method with NaOH to increase the mesopore distributions. In the second step, Zn-doped mesopore ZSM-5 zeolites were prepared by the incipient wetness impregnation method with an aqueous solution of zinc nitrate. After the endothermic pyrolysis of MCH fuel over the modified zeolite catalysts, the condensed liquid product fraction (%) was analyzed. It can be deduced that a reasonable combination of these advanced synthesis strategies can increase catalytic cracking performance. This study showed that, in the context of endothermic catalytic cracking of hydrocarbon aviation fuels at supercritical jet conditions, Zn-doped desilicated zeolites exhibited a decreased quantity of coke deposition.

Catalytic Esterification of Pentaerythritol over a Mesoporous Composite SnCl2@HZSM‐5 Catalyst

AbstractThe mesoporous HZSM‐5 and SnCl2@HZSM‐5 mesoporous composite were prepared by two‐step crystallization and wet impregnation method, respectively. The catalytic esterification performances of SnCl2, HZSM‐5 and SnCl2@HZSM‐5 were compared. SnCl2@HZSM‐5 had the most amount of total and weak acidity, and the weakest acid strength. More total acid content was beneficial to increase pentaerythritol conversion, and the weak acid could improve the selectivity of PETS, and weak acid strength was beneficial to inhibit the formation of carbon deposits. Brönsted and Lewis acid sites were present simultaneously on the SnCl2@HZSM‐5 catalyst. Moreover, some extra Brönsted acid sites were created on the SnCl2@HZSM‐5 catalyst, because the interaction of SnCl2 with HZSM‐5 may result in the exchange of Sn2+ with protons. Both acid sites could catalyze the esterification reaction, and the Brönsted acid site was more beneficial to increasing PETS selectivity. Therefore, SnCl2@HZSM‐5 showed the highest pentaerythritol conversion, PETS selectivity and catalytic stability. The generation of coke and the leaching of Sn were the main cause of catalyst deactivation. Under the optimized process conditions: 105 °C, 4.7 molar ratio of stearic acid and pentaerythritol, 1.2 wt % catalyst amount and 2.5 wt % SnCl2 loading, after 3 h reaction time, the pentaerythritol conversion, PETS selectivity and yield was 99.3 %, 97.2 % and 96.5 %, respectively.

High performance of direct ethanol-fueled protonic ceramic fuel cells via ethanol steam reforming using non-noble metal catalysts

To prevent anode degradation due to coke from the ethanol fuel in protonic ceramic fuel cells, a reforming layer containing CeO2 and non-noble metal catalysts such as Cu, Ni, and Co is attached to the anode. Ethanol fuel with steam is supplied directly to the anode side. The fuel cell performance with ethanol fuel and the long-term stability of the cell are measured at a low temperature of 500 °C. Coking in the reforming layer and anode of the protonic ceramic fuel cells are also investigated. The reforming layer with Cu/CeO2 is ineffective for preventing coke generation in the Ni-cermet anode because of the poor catalytic activity of the Cu catalyst for ethanol reformation. This results in extensive degradation of the fuel cell performance over time. In the reforming layer containing Ni/CeO2 or Co/CeO2, coke is generated near the surface of the layer, but is absent below the middle. Therefore, placing a reforming layer with a Co/CeO2 or Ni/CeO2 catalyst on top of the Ni-cermet anode prevents coke generation. The Co catalyst exhibits more stable performance over time in ethanol fuel than the Ni catalyst because of the higher catalytic activity of the former for ethanol reformation.

Preparation of hierarchical EU-1 zeolite via NH4F etching and the catalytic activity in cracking of n-hexane

One-dimensional microporous zeolite, EU-1, has tighter restriction for bulky intermediates, exhibiting more favorable selectivity of propylene than ZSM-5 in catalytic cracking. However, the diffusion limitation accelerates coke generation, passivates acid sites and deactivates the zeolite. In this study, a strategy was proposed to etch amorphous species between EU-1 nanocrystals using NH4F solution to improve the diffusion property. It was found that the etching process occurred on the crystal surface and mesopores were introduced. Catalytic performance evaluation in n-hexane cracking demonstrated that the maximum propylene selectivity over parent EU-1 was 33.6 wt% (vs. 5.7 wt% for ZSM-5). The n-hexane conversion was increased by 24 wt% over EU-1 etched in 20 wt% NH4F solution. Moreover, the introduction of mesopores provides accommodation space for coke. This study developed hierarchical EU-1 zeolite with favorable diffusion ability and reported a feasible strategy to improve the catalytic performance of EU-1 for propylene production.

Influence mechanism of K on cellulose pyrolysis by stepwise isothermal method in-situ DRIFTS method

The influence mechanism of alkali metal potassium (K) on cellulose pyrolysis is a vague and fundamental key topic in the field of biomass thermal conversion. In this study, the pyrolysis of cellulose and K-impregnated cellulose was compared by in-situ DRIFTS (Diffused Reflectance Infrared Fourier Transform Spectroscopy) and TG (Thermal Gravimetric)–MS (Mass Spectrum) experiment, and quantum chemical calculations were used to verify the peak position and pyrolysis mechanism of infrared (IR) spectroscopy. Stepwise isothermal in-situ DRIFTS was designed to study the reaction path at high temperatures. It was found that in the early stage of pyrolysis, K accelerated the activation of cellulose by attacking the hydrogen bond (H-bond) in the crystal structure of cellulose, increased the dehydration rate between molecules, and promoted the decomposition of cellulose. Simultaneously, it weakened the epoxy–ether bond, inhibited the formation of dehydrated sugar, and promoted the formation of furan. Subsequently, K combined with carbonyl groups to form C–O–K structures, which improved the thermal stability of certain oxygen-containing functional groups such as carbonyls/aldehydes, so that these structures were retained until higher temperature. K promoted the conversion of dehydrated sugars to straight-chain ketones/aldehydes, which led to an increase in carbon conversion. During the coke generation stage, K promoted the formation of disordered carbon and residues, thereby inhibiting coke aromatization. The isothermal in-situ DRIFTS method proposed in this study was demonstrated to better inhibit the high temperature drift of IR spectrum during pyrolysis. It clarified the conversion between functional groups at high temperatures, which is expected to promote the development of other high-temperature pyrolysis mechanism.

Investigation of different configurations of alumina packed bed reactor for coke free conversion of benzene

Conversion of producer gas tar without coke generation is a great challenge. This study investigates conversion of tar model benzene using different configurations of highly non-porous ɣ-Al2O3 packed bed reactor at 1000–1100 0C. The configurations comprised of different positions (relative to top (P1), center (P2) and bottom (P3) of reactor furnace), heights (5, 13 and 25 cm) and particles sizes (0.5, 3 and 5 mm) of alumina packed bed. Steam and CO2 were used as reforming media for tested benzene concentrations (0.4–1.8 vol%). The results showed benzene conversions of 48–91% with negligible steady thin coke generation using a packed bed (height: 25 cm, particles size: 3 mm) at P1. Whereas, relative high benzene conversions of 63–93 and 68–95% at P2 and P3 respectively with unsteady thick coke generation at benzene concentrations greater than 0.4 vol% increased differential upstream pressures (DUPs) of beds. Similar unsteady coke generation at benzene concentrations greater than 0.8 vol% and temperature of 1100 0C was observed with packed beds of heights of 5 and 13 cm, and particles size of 0.5 mm at P1. Generation of unsteady coke with condensed structure as evidenced by its characterization was attributable to increased benzene polymerization and reduced bed surface gasification reactions due to improperly installed packed bed. Developed kinetic model predicted well the generated coke. As conclusion, properly installed alumina packed bed pertaining to tar concentration and other experimental conditions may inhibit coke generation during tar conversion.

Mesoporous Beta zeolites with controlled distribution of Brønsted acid sites for alkylation of benzene with cyclohexene

The distribution of Brønsted acid sites in three-dimensional 12-membered pore channels of Beta zeolite was a decisive factor in the alkylation of benzene with cyclohexene. Here, the Brønsted acid site distribution in Beta zeolitic channels was precisely regulated by tuning the content of Na+ in crystallization system combined with tetraethylammonium cation, the Beta-55 with Brønsted acid sites exclusively located in straight channels (along a- and b-axis directions) was successfully synthesized by utilizing tetraethylammonium as the structure-directing agents without Na+ species, and the fraction of Brønsted acid sites in sinusoidal/straight channels of Beta zeolites can be accurately controlled by tailoring the content of Na+ in synthesis gel. Catalytic properties in the liquid alkylation between benzene and cyclohexene exhibited that Beta-55 zeolites with the Brønsted acid sites solely located in a-axis and b-axis channels showed the highest cyclohexene conversion, cyclohexylbenzene selectivity and longest lifetime in this reaction. In addition, the resultant Beta zeolites also exhibited low coke generation rate and robust regeneration performance in the alkylation reaction.

Study on thermochemical conversion of triglyceride biomass catalyzed by biochar catalyst

This study investigates the fast catalytic pyrolysis of rubber seed oil over a CO2-activated biochar catalyst in the temperature range of 600–800 °C, producing high-value products. The effect of activation time on the catalytic performance and the possibility of using the deactivated catalyst as fuel are also examined. The results indicate that extending the activation time can increase the specific surface area and oxygen active sites of biochar catalyst, thereby improving the catalytic performance. At optimum temperature (800 °C), the biochar catalysts increase the syngas yield from 507.90 mL/g to 634.51 mL/g while facilitating the conversion of polycyclic aromatic hydrocarbons to monocyclic aromatic hydrocarbons. Consequently, the yield of monocyclic aromatic hydrocarbons is increased from 3.72 wt% to 55.77 wt%. Out of the monocyclic aromatic hydrocarbons, benzene and its derivatives are important chemicals, with a yield of 46.80 wt%. Besides, microporous channels in biochar catalysts inhibit the generation of coke, reducing the coke yield from 13.57 to 5.59 wt%; the coke deposit on biochar catalyst is pyrolytic coke. The high heating value of the deactivated biochar catalyst reach 28.605 MJ/kg, and it can be used as a solid fuel. Finally, a mechanism for converting polycyclic aromatic hydrocarbons to monocyclic aromatic hydrocarbons during the fast catalytic pyrolysis of the rubber seed oil is proposed.

Inherently separated syngas production from plastic waste fast pyrolysis integrated with volatile chemical looping conversion with CO2 splitting

To convert plastic waste into high-value products coupled with CO2 utilization, this study proposed a new concept to produce inherently separated syngas through fast pyrolysis integrated with volatile chemical looping CO2 splitting. Three conversion modes, i.e., redox, cracking and redox-cracking mixed modes, were evaluated using different catalyst, and found that cracking mode with Ni/Al2O3 or Ni/MgAl2O4 exhibited better fuel conversion and syngas separation performance than redox and mixed modes (using Ca2Fe2O5 and Ni/Ca2Fe2O5, respectively), achieving nearly full CO-H2 separation from the syngas product. Focusing on the cracking mode, higher temperature facilitated the fuel and coke conversion, due to the endothermic nature of both reaction stages. The syngas separation efficiency increased during 5 cycles and stabilized ∼95% while using Ni/MgAl2O4 catalyst. The redox between Ni0 and Ni2+ was inevitable for both cracking catalysts during multiple cycles due to the Ni-support interaction, limiting the full separation of syngas. The accumulation of low-reactive coke during multiple cycles was another important consideration. Ni/MgAl2O4 possessed weaker Ni-support interaction and less coke accumulation than Ni/Al2O3, thus performed better syngas separation efficiency. Therefore, it is crucial to minimize Ni-support interaction and the generation of high-graphitic coke for optimization.

Hydrogen production from oilfield wastewater by gasification in supercritical water with a continuous system

Multi-component supercritical thermal fluid (MCSCTF) generated based on supercritical water gasification (SCWG) technology can significantly enhance heavy oil recovery. In this paper, the performance of oilfield wastewater SCWG was systematically investigated with a continuous system. Thermodynamic analysis showed that total gasification of oilfield wastewater in supercritical water (SCW) was feasible due to the inhibition of coke generation. The addition of Na2CO3 or K2CO3 can facilitate steam reforming and water–gas shift reactions to achieve high H2 yields and carbon gasification efficiency (CE). The generation of the abundant gas was attributed to the rapid decomposition of the liquid products by free radical reactions at high temperatures. As the feedstock concentration increased, the oil–water emulsion structure may favor the intense pyrolysis reaction over the steam reforming reaction resulting in lower CE. The suitable ratio of emulsion to preheat water flow (1:5) can increase the heating rate of the feedstock and ensure the decomposition time of the intermediate products to obtain high CE (96%). The trends in the change of gas products at different operating parameters were supported by thermodynamic calculations. This work can provide the basis for the subsequent coupled hydrogen oxidation technology to generate MCSCTF.

Lignin and spent bleaching clay into mono-aromatic hydrocarbons by a cascade dual catalytic pyrolysis system: Critical role of spent bleaching clay

In the present study, a cascade dual catalytic system was used for the co-pyrolysis of lignin with spent bleaching clay (SBC) to efficiently produce mono-aromatic hydrocarbon (MAHs). The cascade dual catalytic system is composed of calcined SBC (CSBC) and HZSM-5. In this system, SBC not only acts as a hydrogen donor and catalyst in the co-pyrolysis process, but is also used as a primary catalyst in the cascade dual catalytic system after recycling the pyrolysis residues. The effects of different influencing factors (i.e., temperature, CSBC-to-HZSM-5 ratio, and raw materials-to-catalyst ratio) on the system were explored. It was observed that, when the temperature was 550 °C, the CSBC-to-HZSM-5 ratio was 1:1, and when the raw materials-to-catalyst ratio was 1:2, the highest bio-oil yield was 21.35 wt%. The relative MAHs content in bio-oil was 73.34 %, whereas the relative polycyclic aromatic hydrocarbons (PAHs) content was 23.01 %. Meanwhile, the introduction of CSBC inhibited the generation of graphite-like coke as indicated by HZSM-5. This study realizes the full resource utilization of spent bleaching clay and reveals the environmental hazards caused by spent bleaching clay and lignin waste.

Catalysts for gaseous organic sulfur removal.

Organic sulfur gases (COS, CS2 and CH3SH) are widely present in reducing industrial off-gases, and these substances pose difficulties for the recovery of carbon monoxide and other gases. The reaction pathways and reaction mechanisms of organic sulfur on different catalyst surfaces have yet to be fully summarized. The literature shows that many factors, such as catalyst synthesis method, loaded metal composition, number of surface hydroxyl groups, number of acid-base sites and methods of surface modification, have important effects on the catalytic performance of metal catalysts. Therefore, this paper presents a comprehensive review of the research on the application of catalysts such as zeolites, metal oxides, carbon-based materials, and hydrotalcite-like derivatives in the field of organic sulfur removal. Future research prospects are summarized, more in situ characterization experiments and theoretical calculations are needed for the catalytic decomposition of methanethiol to analyze the coke generation pathways at the microscopic level, while the simultaneous removal of multiple organic sulfur gases needs to be focused on. Based on previous catalyst research, we propose possible innovations in catalyst design, desulfurization technology and organic sulfur resource utilization technology.

Regulating surface acid-base balance on NaZSM-5 by Fe modification towards enhanced methanol dehydration to dimethyl ether

Mostly, adjusting or modifying the surface acidity by embedding other elements on HZSM-5 is carried out to promote catalytic performance for methanol dehydration. However, the modified HZSM-5 allows to conduct the dehydration reaction at high temperatures (≥ 220 °C), and with lower catalytic activity. In this work, the modification of NaZSM-5 by simple impregnation in Fe3+ solution to adjust its surface acidity-basicity was attempted. The obtained composite was systematically characterized by XRD, SEM, TEM, XPS, UV–vis, 29Si and 27Al MAS NMR, and N2 adsorption-desorption measures, respectively, and it presented high efficiency for dehydration of methanol to dimethyl ether at lower reaction temperature due to the uniform distribution of the active sites and acid-base balance on the surface, achieving >90% conversion with ca. 100% selectivity at 180 °C. The acidic and basic sites as the active ones on the catalyst surface were measured by NH3- or CO2-TPD. The methanol adsorption behavior was explored by in situ IR technique, realizing the associative catalytic role of acidic-basic balance. Moreover, as it continuously runs over 500 h, the catalytic activity and selectivity hold constant without coke generation, indicating its super high stability.

Synthesis of needle coke by co-carbonization of coal liquefaction pitch and refined soft pitch

ABSTRACT Needle coke was a type of engineering material and function artificial carbon material that was extensively utilized as a raw material for the synthesis of ultra-high power electrodes and nuclear graphite. The characteristics of the pitch have a considerable influence on the generation of needle coke of high quality. To study the potential of coal liquefaction pitch (CLP) for the synthesis of high-quality needle coke, refined soft pitch was utilized as an additive to generate needle coke via the co-carbonization method. The optical microscope (OM), scanning electron microscopy (SEM), X-ray diffraction, Raman spectrum, and curve-fitted method were used to analyze the microstructure, true density, carbon crystalline distribution, and micro-strength of the generated needle coke, respectively. Factually, the blending of CLP and refined soft pitch was an essential method to adjust the thermal stability of the pitch mixtures. In addition, co-carbonization of CLP and refined soft pitch was an effective technique for preparing needle coke of high quality with a true density of 2.206 g/cm−3 and a fibrous structure and leaflet structure content of 94.44%.

The Effects of SiO2/Al2O3 and H2O/Al2O3 Molar Ratios on SAPO-34 Catalyst in the Methanol to Olefin Process

Informed through synthesis and characterization of NH 3 TPD, BET techniques, the current study investigated the right contribution of silicon and water content on a 9 sample SAPO-34 catalyst with different molar ratios. The final prepared SAPO-34 catalytic performed reaction for the Methanol to olefin process was processed and reported at 410 0 C a reactor of fixed-bed. It was shown that catalysts with different SiO2 /Al2O3 and H2O/Al 2 O 3 ratios demonstrated high ethylene and propylene selectivity, due to their intensified crystallinity and size of crystals (1.3 to 1.7 μm). The highest degrees of ethylene and propylene selectivity for 3 samples were 50.25, 21.20, and 48.44, 19.16 respectively. Samples with ratios of different that possess high density and acute acidic sites to deactivate rapidly. The high density of acute acidic sites promoted the ultimate response to saturated hydrocarbons and aromatics based on olefins’ hydrogen transfer to and resulted in the coke generation on the top layer of the catalyst.

System-level analysis for continuous BTX production from shale gas over Mo/HZSM-5 catalyst: Promotion effects of CO2 co-feeding on process economics and environment

Benzene, toluene, and xylene (BTX) production from shale-derived CH4, C2H6, and C3H8 is considered an energy-efficient technology substituting their naphtha-cracking counterparts. However, the economics of BTX production from shale gas remains questionable because of the rapid deactivation of the catalyst, originating from the coke generation. Herein, we present a BTX production strategy with CO2 co-feeding for catalyst stability enhancement and additional H2 production. Our process prevents coke deposition on the active sites of Mo and zeolite, and improves the operation time of reactors compared to that of shale gas without CO2 co-feeding. Concurrently, H2 and CO are produced with BTX owing to the dry reforming reaction of hydrocarbons over the Mo/HZSM-5 catalyst. Most importantly, the economics of BTX production with CO2 co-feeding is evaluated using individual system components integrated with two different CH4 conversion processes (steam-reforming-based H2 and methanol production). The BTX production with CO2 co-feeding lowers the methanol production cost by additionally producing methanol generated by CO from the BTX reactor, while the H2 production cost increases. Moreover, the life cycle assessment proves that the CO2 emission during the methanol production process is significantly reduced by recycling the CO2 produced in the subsequent process.

A Data-Driven Semi-Supervised Soft-Sensor Method: Application on an Industrial Cracking Furnace

The cracking furnace is the key equipment of the ethylene unit. Coking in furnace tubes results from the generation of coke during cracking, which will compromise the heat transfer efficiency and lead to shape change of tubes. In order to keep the cracking furnace operating economically and safely, the engineers need to decoke according to the surface temperature of the furnace tube. However, the surface temperature of the furnace tube is difficult to obtain in practice. Due to redundant instrumentation and the high level of process control in cracking furnaces, a large number of operation data have been collected, which makes it possible to predict the surface temperature of furnace tubes based on autocorrelation and cross correlation within and among variables. Traditional prediction methods rely on labeled data samples for training, ignoring the process information contained in a vast amount of unlabeled data. In this work, a data-driven semi-supervised soft-sensor method is proposed. Considering the nonlinear and dynamic relationship among variables, long short-term memory network (LSTM) autoencoder (AE), a deep neural network suitable for the feature extraction of long-term nonlinear series, is used for pre-training to extract process data features from unlabeled and labeled data. Then, principal component analysis (PCA) and mutual information (MI) are applied to remove feature correlation and select features related to target variables, respectively. Finally, the selected data features are utilized to establish a soft-sensor model based on artificial neural network (ANN). Data from an industrial cracking furnace of an ethylene unit is considered to validate the performance of the proposed method. The results show that the prediction error of furnace tube surface temperature is about 1% and successfully aid engineers in determining the optimal time for decoking.

Valorization of furniture industry-processed residue via catalytic pyrolysis with methane

An increase in furniture industry processed residue and its release to the environment can cause serious environmental and health problems. In this study, the catalytic pyrolysis of furniture industry processed residue, as an emerging solution for its treatment, was performed over different zeolite catalysts, such as HZSM-5(silica/alumina = 30), HZSM-5(80), HY(30), and HBeta(38) using a lab-scale reactor. The effects of the nitrogen, methane, and methane decomposition environments were also evaluated. Non-catalytic pyrolysis under a methane decomposition gas (a simulated hydropyrolysis condition) resulted in a more than two-fold higher yield of benzene, toluene, ethylbenzene, and xylene than under the nitrogen and methane environments. For catalytic pyrolysis in methane, HZSM-5(30) showed the maximum affinity towards the production of benzene, toluene, ethylbenzene, and xylene compared to other zeolites owing to its higher acidity, lower coke generation, and enhanced shape selectivity. HBeta and HY showed lower yield of benzene, toluene, ethylbenzene, and xylene than HZSM-5(30) because of their large pore size, causing more coke formation. The methane-decomposition environment promoted dehydroaromatization, co-aromatization, direct coupling, and Diels-Alder reactions, further increasing the yield of benzene, toluene, ethylbenzene, and xylene over HZSM-5(30). It is suggested that catalytic pyrolysis of furniture industry processed residue over HZSM-5 under methane decomposition gas would be an eco-friendly and sustainable strategy that not only tackles its disposal challenges but also produces valuable aromatics for fuel applications.

An experimental investigation in the formation damage mechanism of deposited coke in in-situ combustion process using nuclear magnetic resonance

The success of an in situ combustion process is dependent on the stability and movement of the combustion front. During an in situ combustion process, coke is an important product for maintaining the stability of the combustion front. However, before being consumed by the combustion reaction, coke is deposited in the porous media; thus, it may cause the blockage of the pore throat and affect the subsequent air injection. In this study, the low-field nuclear magnetic resonance technique was applied to examine the influence of oxidized coke and pyrolyzed coke on the porous media. The results revealed that the coke deposition phenomenon was considerable in porous media and affected porosity. The formation damage was considerably severe in oxidized coke because of the drastic low-temperature oxidation. In case of the pyrolyzed core, the influence of coke on porosity is limited because of the low amount of coke generation. The average reduction in porosity was 21.90%, while that of the pyrolyzed coke is only 9.09%. Montmorillonite had the greatest catalytic effect on coke deposition for both oxidation and pyrolysis processes. Illite, kaolinite, and chlorite have an impact on coke deposition; however, because the change in porosity is attribute to a combination of multiple factors, the result is a lack of regularity. Heat causes the pore to reform and the fracture to form. The change in porous media can reduce the impact of coke deposition phenomenon on total porosity. Because of the high-temperature environment, this influence is more pronounced in the pyrolyzed core.