• Applied Chemistry for Engineering
• /
• v.31 no.6
• /
• pp.688-696
• /
• 2020

Petroleum coke (petcoke) is widely used, next to coal, as a gasification feedstock. In gasification processes, the viscosity of the ash and the formation of crystalline phases must be understood to ensure the continuous removal of slag. This study investigates the effect of CaO and V2O3 on petcoke slag viscosity. The viscosity of the molten slag was measured in the temperature range of 1100~1600 ℃ while varying the concentration of each component. The crystalline phases formed in a cooled slag were examined. The most slag samples tested in this study exhibited crystalline slag behavior. The increased CaO concentration resulted in a lower viscosity and a lower Tcv. The viscosity behavior changed from the glassy to crystalline slag and also showed a higher Tcv as the concentration of V2O3 increases. Most slag samples showed different crystalline phases from top to bottom. Anorthites and Ca-V phases were observed in the top and middle section, while the bottom section mainly showed V2O3 and anorthite. The vanadium in the ash forms Ca-V and V-Fe phases and also remains in molten slag. A low melting Ca-V phase can contribute to lowering the viscosity.

• 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.

• Proceedings of the Korean Institute of Surface Engineering Conference
• /
• 2014.11a
• /
• pp.91-91
• /
• 2014

주석함유 2차 공정 부산물인 양극 슬라임내의 금속을 회수하기 위하여 탄소환원반응을 통해 금속 회수에 미치는 공정변수의 영향을 조사하였다. 열역학 모델링과 금속환원 실험결과, 환원 온도와 고체 환원제인 코크스(cokes)에 공정 변수에 따라 금속으로 환원이 될 수 있음을 확인하였다.

• Proceedings of the Korea Society for Simulation Conference
• /
• 1998.03a
• /
• pp.70-73
• /
• 1998

본 연구에서는 광양제철소에서 철광석과 코크스를 이용하여 용선을 생산하는 고로공장과 이러한 용선을 용강으로 변화시키는 제강공장지역을 운행하는 기관차 및 TLC (Torpedo Ladle Car)의 용선 수성작업을 분석하여 기관차 및 TLC의 적정댓수를 산정하고, 운행 패턴의 변화에 따른 대안들을 검토하였다. 시뮬레이션은 AUTOMOD II를 이용하여 수행하였으며, 시뮬레이션에 이용되는 관련 기준 및 운행 패턴을 수집하여 확정하고, 실적치의 분포를 추정하였다. 시뮬레이션의 결과는 현장 전문가들의 이해를 높이기 위아여 Animation을 통하여 가시화하였다.

• 한국기계연구소 소보
• /
• s.20
• /
• pp.105-114
• /
• 1990

The relationship between the properties of two kinds of calcined cokes and graphitized forming bodies were examined. The microstructures of the forming bodies are already determined to some degree at the stage of baking. Calcined cokes as well as baked forming bodies using the same coke as filler were heat treated at various temperatures and their structural and properties changes with heat treated temperature were studied. The transition in properties changes with heat treatment in forming bodies were observed around $2000^{\circ}C$. The characteristics of the finial graphite bodies are strongly dependent on the properties of the raw material cokes.

• Journal of Korean Society of Occupational and Environmental Hygiene
• /
• v.10 no.2
• /
• pp.53-67
• /
• 2000

Coke-oven workers are regularly exposed to coke oven emissions (COE), which consist primarily of polynuclear aromatic hydrocarbons (PAH) and volatile organic components. This study assessed the exposure of coke-oven workers to COE and PAH. The results of this study are as follows. 1. Among the 136 samples on coke-oven workers 33.1% exceeded the occupational exposure limit to the Coal Tar Pitch Volatiles ($0.2mg/m^3$) established by the Korean Ministry of Labor and American Conference of Governmental Industrial Hygienists(ACGIH). 2. The coke-oven workers were classified into twelve job categories and there was statistically significant difference among the airborne concentrations of COE and PAH in twelve job categories(p<0.001). 3. There was no significant difference of the airborne concentrations of COE between NIOSH method and OSHA method applied. 4. There was a significant correlation between the airborne concentrations of total PAH and COE(r=0.733, p<0.01). 5. The percentage of naphthalene in total PAH was 55.9% and the highest among those of 16 PAHs. There was a significant correlation between the airborne concentrations of naphthalene and total PAH(r=0.90, p<0.01) and this study recommends naphthalene as the index component of PAH.

• 한국신재생에너지학회:학술대회논문집
• /
• 2008.10a
• /
• pp.230-233
• /
• 2008

The vanadium rich ash of petroleum coke can give a slagging problem during because of the high melting point of $V_2O_3$. For continuous removal of the slag, petroleum coke is often mixed with coal, and the viscosity of the mixed slag is an important property, determining the gasification temperature. The viscosities of the mixed slag from various mixing ratios of petroleum coke and a bituminous coal were investigated. When mixed with a crystalline coal slag, $T_{cv}$ was increased at a higher the coke content in the mixed feed. When the $V_2O_3$ concentration was greater than 4.5%, it was difficult to get accurate measurements of $T_{cv}$. The SEM/EDX analyses of the cooled slag revealed that the major crystalline phase was anorthite, and $T_{cv}$ should be related to the formation temperature of anorthite. The SEM/EDX analyses also showed that, at low concentrations of vanadium, part vanadium formed a crystalline phase with Al-Si-Ca-Fe, and the rest remained in the glassy phase, suggesting that vanadium existed as a slag component at the low viscosity region. At a high concentration, vanadium forms a phase with Ca, and the Ca-V phase was separated from the slag phase, and formed a layer above the slag. FeO in petroleum coke also played an important role determining viscosity: at high temperatures, increased FeO lowered the viscosity, but as it formed a spinel phase, the depletion of FeO in the slag resulted in a higher viscosity.

• Resources Recycling
• /
• v.30 no.1
• /
• pp.77-82
• /
• 2021

Reduction of CO2 emissions is an important issue in the steel industry, and the research on carbon materials that can partially replace cokes is necessary to reduce CO2 emissions. Meanwhile, the biomass fuel contains some fixed carbon, and the carbon content in the biomass can be increased by torrefaction. As one of the biomass fuels, coffee grounds contains about 55 mass% of carbon, and its about 270,000 tons are landfilled and incinerated annually in Korea. In addition, research on the recycling process due to the increase in annual coffee consumption is required. In this study, the effect of temperature on the concentration of fixed carbon in coffee grounds was investigated during torrefaction. Moreover, the effects of mixing ratio of torrefied coffee grounds with cokes on the carbon concentration and dissolution efficiency in the metal sample were investigated.

• 한국연소학회:학술대회논문집
• /
• 2004.11a
• /
• pp.33-40
• /
• 2004

Combustion of coke/anthracite in an iron ore sintering bed is characterized quantitatively by introducing newly defined parameters related to propagation and thickness of combustion zone and maximum temperature. The parameters are obtained by sintering pot experiment and I-D, unsteady numerical model which treats solid material as multiple solid phases. Experiments and calculations are performed for various major operating parameters: air inlet velocity, different type of fuels which have different reactivity and diameter of the solid fuel. Effects of the operating parameters on the productivity and quality of the sintering process are investigated and evaluated quantitatively and the results show that optimized air supply rate and diameter of anthracite for replacement of coke can be obtained. This approach can be applied to other kinds of combustors for characterization of the combustion in the solid fuel beds.

• 한국연소학회:학술대회논문집
• /
• 2014.11a
• /
• pp.297-299
• /
• 2014

Petroleum coke has high heating value and low price. Due to the steadily increasing demand for heavy oil processing, the production volume of petroleum coke tends to be expanded. The high availability and low price of petroleum coke have been strongly considered as candidate fuel for power generation facilities. However the high carbon content, high sulfur content and nitrogen content of petroleum fuel are known to produce relatively large quantity of CO2, high NOx and SO2 emission. In this work, a series of numerical simulations have been carried out in order to investigate the effects of swirl flow intensity on combustion furnace, which is most important operating condition. Results show that the temperature distribution was spatially uniform at about 1600K but high temperature region are located quite differently depending on swirl number. In addition, numerical temperature data was compared with experimental temperature data and its temperature difference shows less than 10%. On the other hand, discrepancy between numerical and experimental emission data were slightly large with necessities of improved emission model.