• Applied Chemistry for Engineering
• /
• v.9 no.5
• /
• pp.781-785
• /
• 1998

Material and electrochemical characteristics of petroleum coke of the nongraphitic carbon prepated with attrition milling for 6~48 hours and heat-treatment at $700^{\circ}C$ for 1 hour was investigated. The milling condition affects the particle size distribution, BET specific surface area and interlayer distance of petroleum cokes. Carbon electrode with petroleum cokes prepared at the milling time of 12~24 hours and having average particle size of $6{\sim}8{\mu}m$ showed best electrochemical characteristics form the investigation of cyclic voltammogram and charge-discharge characteristics.

• Analytical Science and Technology
• /
• v.8 no.2
• /
• pp.131-138
• /
• 1995

We have discussed on the structural transition and its effect on the electrical property of Li-GFDICs and Li-PCDICs occuring during the deintercalation process of Li-Graphite Fiber Intercalation Compounds(Li-GFICs) and Li-Petroleum Cokes Intercalation Compounds(Li-PCDICs) synthesized under pressure and temperature by spontaneous oxidation by air circulation. The analytical results were obtained by X-ray diffraction and electrical specific resistivity measurements. According to X-ray analysis, we have found that the major stage of Li-GFICs was stage 2 and those of Li-PCICs were stage 1 and stage 2, respectively. And from this results of the deintercalation process, we have found that the deintercalation process did not occur any more after 5th week of Li-GFDICs and after 3rd week of Li-PCDICs. According to the results of the electrical specific resistivity measurements, Li-GFDICs showed little variation to 3rd week and rising in the steady curve after 4th week, while Li-PCDICs showed a rising in the steady curve to 3rd week and a declining curve after 3rd week. Therefore from these results, we can consider that graphite fiber and petroleum cokes as a substrate can be also used as an anode material of battery because they have good intercalation-deintercalation reactivity with lithium.

• Clean Technology
• /
• v.28 no.1
• /
• pp.1-8
• /
• 2022

To confirm the applicability of the water gas shift reaction for the production of high purity hydrogen for petroleum cokes, an unutilized low grade resource, Cu/ZnO/MgO/Al₂O₃ (CZMA), catalyst was prepared using the co-precipitation method. The prepared catalyst was analyzed using BET and H₂-TPR. Catalyst reactivity tests were compared and analyzed in two cases: a single LTS reaction from syngas containing a high concentration of CO, and an LTS reaction immediately after the syngas passed through a HTS reaction without condensation of steam. Reaction characteristics in accordance with steam/CO ratio, flow rate, and temperature were confirmed under both conditions. When the converted low concentration of CO and steam were immediately injected into the LTS, the CO conversion was rather low in most conditions despite the presence of large amounts of steam. In addition, because the influence of the steam/CO ratio, temperature, and flow rate was significant, additional analysis was required to determine the optimal operating conditions. Meanwhile, carbon deposition or activity degradation of the catalyst did not appear under high CO concentration, and high CO conversion was exhibited in most cases. In conclusion, it was confirmed that when the Cu/ZnO/MgO/Al₂O₃ catalyst and the appropriate operating conditions were applied to the syngas composition containing a high concentration of CO, the high concentration of CO could be converted in sufficient amounts into CO₂ by applying a single LTS reaction.

• Applied Chemistry for Engineering
• /
• v.21 no.1
• /
• pp.11-17
• /
• 2010

Modifying surface of activated carbon for the electrode of EDLC with an organic electrolyte was investigated to improve the electrochemical performance of EDLC by the microwave radiation. Three kinds of activated carbons, prepared activated carbon from petroleum cokes and pitch cokes and commercial activated carbon BP-25, were used for this study. For all investigated activated carbons, hydrophilic functional groups-containing oxygen disappeared from the surface of activated carbon as microwave radiation. And as microwave radiation time was increased, the specific surface area and total pore volume of activated carbons were reduced and average pore diameter were increased. From theses effects, interfacial resistance of EDLC with the modified activated carbon electrode was drastically decreased, and discharge capacitance was increased although the specific surface area of activated carbon was reduced by this microwave radiation.

• Korean Chemical Engineering Research
• /
• v.54 no.4
• /
• pp.501-509
• /
• 2016

The economic feasibility of a commercial indirect liquefaction process with the co-gasification process of petroleum coke which has been recognized as hazardous waste because of high sulfur content and bituminous coal and sub-bituminous coal mixtures was assessed. The 2,000 ton/day scale indirect liquefaction process including co-gasification, clean up, Fischer-Tropsch conversion and so on was assumed and used to analyze economical efficiencies with various conditions. Financial data from previous studies were modified and used and economical sensitivities with various mixture ratios were evaluated in this study. As a result, economic values of petroleum coke were superior than those of coals because of increasing sulfur sale. Also, mixtures with petroleum coke and bituminous coal was more favorable that those with petroleum coke and sub-bituminous coal due to lower moisture content. In case of sub-bituminous coal, the mixture ratio with petroleum coke had to be over 40wt% for the IRR of mixture to surpass 10%.

• Applied Chemistry for Engineering
• /
• v.9 no.7
• /
• pp.1065-1069
• /
• 1998

This study was investigated to improve peformance of carbon negative electrode for lithium ion secondary battery. The carbon electrode was prepared by mixing with graphitic carbon material, natural graphite, and nongraphitic carbon material, petroleum cokes, which was heat-treated at $700^{\circ}C$ for l hour. Its electrochemical and charge-discharge characteristics were tested according to mixing ratio of different two types of carbon material. The carbon electrode prepared with various mixing ratio showed both charateristcs of two different types of carbon materials and the best characteristics as carbon electrode was demonstrated at mixing ratio of 1:1.

• Carbon letters
• /
• v.10 no.4
• /
• pp.293-299
• /
• 2009

Potassium hydroxide activated carbons were prepared from Egyptian petroleum cokes with different KOH/coke ratios and at different activation temperatures and times. The textural properties were determined by adsorption of nitrogen at $-196^{\circ}C$. The adsorption of iodine and methylene blue was also investigated at $30^{\circ}C$. The surface area and the non-micropore volume increased whereas the micropore volume decreased with the increase of the ratio KOH/coke. Also the surface area and porosity increased with the rise of activation temperature from 500 to $800^{\circ}C$. Textural parameter considerably increased with the increase of activation time from 1 to 3 h. Further increasing of activation time from 3 to 4 h was associated with a less pronounced increase in textural parameters. The adsorption of iodine shows the same trend of surface area and porosity change exhibited by nitrogen adsorption, with KOH/coke ratio and temperature of activation. Adsorption of methylene blue follows pseudo-first-order kinetics and its equilibrium adsorption follows Langmuir and D-R models.

• Applied Chemistry for Engineering
• /
• v.28 no.4
• /
• pp.432-436
• /
• 2017

Carbon blocks were prepared by compression molding process using the mixture of isotropic cokes and binder pitches, which were reformed with different ${\beta}$-resin contents from pyrolysis fuel oil. Physical and chemical properties and also thermal behavior of binder pitches were investigated through elemental analysis, FT-IR and thermogravimetric analysis, respectively. The adhesion of binder pitches to isotropic coke particles was evaluated from SEM images of the fracture surface of carbon blocks. From these results, it is shown that the adhesion between the cokes and binder was enhanced by increasing the ${\beta}$-resin content of binder pitches. The density of the carbon block after carbonization also increased from 1.325 to $1.383g/cm^3$ by increasing the ${\beta}$-resin content of binder pitches from 1.4 to 20.1%.

• Bulletin of the Korean Chemical Society
• /
• v.35 no.8
• /
• pp.2357-2360
• /
• 2014

Phosphorus-doped soft carbons were successfully prepared by carbonizing petroleum cokes treated with phosphorus acids, such as $H_3PO_2$, $H_3PO_3$, and $H_3PO_4$. The effect of the type of phosphorus acids used on the composition, structure, and electrochemical performance of the soft carbons was extensively investigated. The soft carbons modified with $H_3PO_3$ and $H_3PO_4$ exhibited dramatically improved reversible capacities and outstanding rate capabilities.

• Carbon letters
• /
• v.15 no.4
• /
• pp.277-281
• /
• 2014

A series of high capacity soft carbons with different phosphorus contents were successfully prepared by carbonizing petroleum cokes treated with hypophosphorous acid at $900^{\circ}C$. The effect of phosphorus content on the electrochemical performance of the soft carbons was extensively investigated. The P-doped soft carbons exhibited greatly enhanced discharge capacities and outstanding rate capabilities with increasing phosphorus content. In addition, the influence of temperature on the electrochemical behaviors of the soft carbons was investigated in a wide temperature range of $25^{\circ}C$ to $50^{\circ}C$. Surprisingly, the electrochemical properties of the pristine and P-doped soft carbons were highly sensitive to the operating temperature, unlike conventional graphite. The pristine and P-doped soft carbons exhibited significantly high discharge capacities of 470 and 522 mAh/g, respectively, at a high temperature of $50^{\circ}C$.