Coke Blend Research Articles

Evaluation of Biochar and Coke Blends for Slag Foaming Applications in Electric Arc Furnace Steelmaking

Evaluation of Biochar and Coke Blends for Slag Foaming Applications in Electric Arc Furnace Steelmaking

Modern Use of Biochar in Various Technologies and Industries. A Review

The article analyzes the use of biochar in various industries and the national economy (as a sorbent, fuel, reducing agent in the metallurgical industry, a component of coal coke blends, biocomposites, modification of explosives, fertilizers, etc.) It is noted that the direction of use depends on the quality and characteristics of biochar (size, physical properties, chemical composition), which are determined by the nature of the raw material, its chemical composition and carbonization temperature.

Equilibrium Modelling and Optimization of the Co-gasification of E-waste and Petcoke

Addressing the critical issues of Electronic waste (E-waste) with its low recycling and environmental impacts, this study highlights the necessity for efficient waste management and energy recovery. Leveraging petroleum coke's rich carbon content, co-gasification presents a viable method to transform E-waste into syngas. Using response surface methodology (RSM), the research analyzes various E-waste and petroleum coke blends, focusing on how gasification temperatures and pressures affect cold gas efficiency (CGE). Results highlight that the 25% printed circuit board (PCB) socket blend achieves an optimal CGE of 66.03% at 1,171.27°C and 1.95 bar via RSM and attains 64.10% CGE at 1,150°C and 1 bar as per the equilibrium model, in contrast to the 75% blend's CGE of 49.96% at 1,256°C and 1.57 bar, and 47% at 1,250°C and 1 bar. These findings reveal significant optimization opportunities in co-gasification processes, providing key insights for efficient E-waste handling and syngas generation.

Experimental Investigation of Expansion during Formation Process of Formed Coke Blending with Torrefied Biomass

Experimental Investigation of Expansion during Formation Process of Formed Coke Blending with Torrefied Biomass

Co-pyrolysis of petroleum coke and wood pellet blend: Kinetic and Thermodynamic Evaluation using Thermogravimetric Analysis

The increasing demand for sustainable energy attracted researchers to explore the co-pyrolysis of several wastes. The present study evaluated the kinetic and thermodynamic parameters for the co-pyrolysis of wood pellets and petroleum coke (1:1 by mass) blends using thermogravimetric analysis. The TGA data were analyzed through iso-conversional Ozawa-Flynn-Wall (OFW), Kissinger-Akahira-Sunose (KAS) models, along with the Coats-Redfern method. The results reflect that the order of reaction increases with an increased heating rate. An average value of activation energy calculated was 119.6 kJ mol−1 (OFW) and 126.2 kJ mol−1 (KAS). The values calculated for ΔH, ΔG and ΔS were in line with the past relevant studies on blends. The value ΔG was observed to fall around 182 kJ mol−1. The Coats-Redfern reaction mechanism indicates that D5 (based on diffusion) and F3 (based on chemical reaction) are best apt to the thermal process of degradation. DTA data specifies that degradation involves exothermic and endothermic reactions for the temperature range under study. The study not only provide the basic characteristics of one of the most dominant waste from refinery, but provides a platform for its futuristic potential usage with reliable kinetic and thermodynamic parameters for scale up, optimization, utilization and limitation for efficient system design.

A Study on Bio-Coke Production—The Influence of Bio-Components Addition on Coke-Making Blend Properties

Due to global warming, technologies reducing CO2 emissions in the metallurgical industry are being sought. One possibility is to use bio-coke as a substitute for classic coke made of 100% fossil coal. Bio-coke can be produced on the basis of coal with the addition of substances of biomass origin. Blends for the production of bio-coke should have appropriate coke-making properties to ensure the appropriate quality of bio-coke. The article presents the results of the research on the influence of the addition (up to 20%) of bio-components of different origins to the coke blend on its coke-making properties, i.e., Gieseler Fluidity, Arnu—Audibert Dilatation and Roga Index. The bio-components used in the research were raw and thermally processed waste biomass of different origins (forestry: beech and alder woodchips; sawmill: pine sawdust; and the food industry: hazelnut shells and olive kernels) and commercial charcoal. Studies have shown that both the amount of additive and the type of additive affect the obtained coking properties. There was a decrease in fluidity, dilatation and Roga Index values, with more favorable results obtained for the addition of carbonized biomass and for additives with a higher apparent density. A regressive mathematical model on the influence of the share of the additive and its properties (oxygen content and apparent density) on the percentage decrease in fluidity was also developed.

Effects of Mustard Husk, Wheat Straw, and Flaxseed Residue Blending on Combustion Behavior of High Ash Coal and Petroleum Coke Blends

Abstract This present work reports the combustion studies of coal, petroleum coke (PC) and biomass blends to assess the effects of the mustard husk (MH), wheat straw (WS), and flaxseed residue (FR) blending toward improvement of coal combustion characteristics. Ignition temperature (TS), maximum temperature (TP), burnout temperature (TC), activation energy (AE), and thermodynamic parameters (ΔH, ΔG, and ΔS) were analyzed to evaluate the impact of biomass and PC blending on coal combustion. Experimental results indicate that coal and PC have inferior combustion characteristics compared to MH, WS, and FR. With the increase in WS content in blends from 10 to 30%, TS reduced from 371 to 258 °C and TP decreased from 487 to 481 °C, inferring substantial enhancements in combustion properties. Kinetic analysis inferred that blended fuel combustion could be explained mostly using reaction models, followed by diffusion-controlled and contracting sphere models. Overall, with the increase in FR mass in blends from 10 to 30%, AE decreased from 108.97 kJ/mol to 70.15 kJ/mol signifying ease of combustion. Analysis of synergistic effects infers that higher biomass addition improves coal and PC blends’ combustion behavior through catalytic effects of alkali mineral matters present in biomass. Calculation of thermodynamic parameters signified that combustion of coal and PC is challenging than biomasses; however, blending of biomass makes the combustion process easier.

Stamp-Charged Coke-Making Technology—The Effect of Charge Density and the Addition of Semi-Soft Coals on the Structural, Textural and Quality Parameters of Coke

Coke is an integral component of the blast furnace charge; therefore, it plays an important role in the integrated steelmaking process. Achieving the required coke quality parameters by producers requires the use of a high proportion of the highest quality coking coals (hard coking coals) in the coking blends, which significantly increases the unit production costs. Approximately 75% of these costs are constituted by the cost of the coal blend’s preparation. There is a deficit in the best quality coking coals on the world market and their supply are characterized by large fluctuations in quality parameters. Therefore, from the point of view of the economics of coke production, it is advantageous to produce high-quality coke from a coke blend with the highest possible content of cheaper coals. The paper presents the results of the influence of coal charge bulk density and semi-soft coking coal content in the coking blend on the textural and structural parameters of coke, which determine its quality. Research has shown that the application of increased density influences the parameters of the texture and structure of the coke, which shape its quality parameters. The use of stamp-charging technology contributes to the improvement of the coke quality or enables the production of coke of a predetermined quality from blends containing cheaper semi-soft coals.

Evaluation of chemical stabilisation methods of coal-petcoke fly ash to reduce the mobility of Mo and Ni against environmental concerns

Reducing the potential leaching of Mo and Ni from the fly ash (FA) of petroleum coke is an increasingly important issue as Asia and Europe’s demand is expected to drastically intensify as continuing urbanisation and technological innovation demands ever more electricity. In the present study, we investigated coal combustion products (CCP) from a large coal-fired power station fed with a 56:44 coal/petroleum coke blend. Results revealed that leachable concentrations of Mo and Ni from FA were in the upper non-hazardous limit and in the inert limit, respectively (2003/33/EC). Whilst common prevention measures for Mo and Ni based on the adsorption capacity of boiler slag (BS), a mixture of BS: goethite, and jarosite, were considered insufficient to reduce the potential leaching of Mo into FA leachates, a novel chemical stabilisation method based on an aggregate product of portlandite and FA immobilised both Mo and Ni such that the resulting concentrations were below the limits established in the abovementioned 2003 EC Decision. Precipitation may be responsible for the fixation of Mo and Ni in the FA: portlandite aggregates as Ca(MoO4) and NiMoO4, respectively. The findings of this novel study support the use of this aggregate to reduce FA pollutants, which will be of particular interest to nations that remain largely coal/petroleum coke-dependant.

Encapsulites, and the suppression of internal gas pressure in industrial metallurgical coke blends

Isolated, encapsulated coke microstructures in industrial coke blends, (referred to here as encapsulites), contain textural evidence of growth in high pressure conditions revealed by collapsed, stretched, and pulled-apart thin pore walls, with crushed porosity. This texture is not rare in blends, but is more commonly seen in single-source test oven cokes that have generated very high internal gas pressures. In addition, reflectances of encapsulite microstructures are quite different from the enveloping coke, leading to identification of two varieties, (1): isotropic, low-bireflectance coke derived from soft coking coal, surrounded by a low anisotropy coke envelope, and, (2): highly-anisotropic fused-inertinite or fused-vitrinite, contained within an envelope of a lower rank coke.Time, temperature and fluidity play critical roles in the order and magnitude of development of encapsulites, where entrapment by a fluid plastic layer of earliest melting vitrinites isolates not-yet-melted coal particles. Subsequently, with rising plastic layer temperatures, the encapsulated material also melts, but it is now enclosed within an impermeable, gas-proof semicoke that acts as a pressure suppressor. The encapsulite may develop a thickened outer wall, but internal thin-cell-wall porosity implodes, causing localized structural collapse. The development of encapsulites is a/the mechanism that suppresses and dampens the internal gas pressure exerted by strongly expanding coals used as components in some industrial blends. Encapsulite volumes of 2.23–22.4% are described.Encapsulites contribute to mechanical strength. Thick walls of isotropic material protect against CO2 reactivity attack, adding strength to coke. On fused inertinite kernels of highly anisotropic encapsulites, measured anisotropy quotients (AQ’s) of >8.3, are of similar magnitude to pyrolytic carbon, which too increase CSR quality.

Utilization of Waste HDPE for Sustainable EAF Steelmaking: Carbon Dissolution into Liquid Steel

Carbon dissolution from blends of metallurgical coke with high-density polyethylene (HDPE) into liquid steel at 1823 K is investigated in-depth. HDPE is blended with metallurgical coke into three different ratios (blends H1, H2, and H3) and used as a carburizer. Compared to coke, a significant improvement in carbon dissolution is observed in the case of blend H3 with the carbon picked up by liquid steel after 60 min of reaction and the dissolution rate (K) is 4.5 wt% and 15.2 × 10−3 s−1, respectively. For coke alone, the melt carbon content is 0.8 wt% and the dissolution rate of 0.3 × 10−3 s−1. SEM micrographs and corresponding off-gas analysis reveal that the gasification of HDPE/coke blends slow down the coverage of ash oxides at the Fe–C interface and modify morphology of the ash layer. The associated reactions of volatiles generated during the thermal degradation of the polymer can aid the carburization of liquid steel to some extent. However, the amount of gas generated must be high enough to overcome the effect of ash oxides at the Fe–C interface. This study has strong implications in enhancing the potential of recycling waste polymers for sustainable steelmaking.

Bench Mark Prebaked Anode Production with Russian Raw Materials

800x600 Expansion of the Russian aluminium smelting is foreseen by using high amperage Rusal prebaked pot technology. For a high productivity of such modern smelters - thanks high amperage but also high current efficiency, but also for low energy consumption - the performance of the prebaked anodes is decisive. Bench mark anode quality is therefore critical for low metal production cost. The intrinsic quality of anodes depends on the raw materials, mainly on the coke properties, and on the production equipment and their operating parameter conditions. Based on a review of the domestic available green cokes, a prediction of the corresponding calcined coke blend and of the prebaked anode properties has been performed. Provided that a state of the art carbon plant installation is available, including the rodding shop for the butts quality, the bench mark quality of the prebaked anodes made with a representative coke blend has been defined. This forecast of the best achievable anode quality will be the basis for technical assessments of the performance of existing and future Russian carbon plants. Normal 0 false false false RU X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:Обычная таблица; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-parent:; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:Times New Roman,serif;}

Existence of Synergistic Effects During Co-pyrolysis of Petroleum Coke and Wood Pellet

Abstract This study attempts to comprehend the thermal degradation behaviour of different blends of petroleum coke (denoted as PC) and wood pellets (denoted as WP) (1:0, 3:1, 1:1. 1:3 and 0:1) using thermogravimetric (denoted as TG) analysis under N2 atmosphere with constant particle size range of 500–850 µm and at constant heating rate of 5 °C/min. TG experiments indicated that it is difficult to predict the pyrolysis characteristics of their blends accurately based on individual components and blending ratios. The non-additive behaviour of TG curves of the blends indicates presence of synergistic effects which could further promote the volatile yields during the co-pyrolysis process. The mixed model including homogeneous reaction model (denoted as HRM) and shrinking core model (denoted as SCM) models were used to predict the variation in kinetic parameters (activation energy and pre-exponential factor) with different blend ratios. The most obvious synergistic effects were observed when the blending ratio was 25 % on account of maximum mass loss rate from the differential thermogravimetry (denoted as DTG), maximum deviation based on root mean square (denoted as RMS) value as well as divergence in the differential thermogravimetric analysis (denoted as DTA) curve.

Grinding characteristics of coal and petroleum coke/coal blends on utilization for combustion

ABSTRACTPetroleum coke (PC) blend with coal is an attractive feedstock for combustion process. The present work investigates the grinding characteristics of PC blend with coal in a laboratory ball mill to meet an industrial tube mill conditions. Tests were carried out using a laboratory batch ball mill for optimal production of −200 mesh size product. The ground products at different combinations were subjected to sink-float tests. Experimental results suggested that the petcoke with coal at 5.0% blend ratio was optimum for generation of −200 mesh size product. It was also observed that increasing coal/petcoke blend ratio beyond 5.0% leads to a decrease in −200 mesh size generation. The better performance could be achieved at the blending ratio of 5%, perhaps resulting from the synergistic effect of the blends. With the aforementioned blend ratio, the optimal condition of the milling time was found to be 3 h. The percentage of coal to the total charge and percentage of petcoke to the total charge of the ball mill product at various blends were also calculated for all the blends and at all grinding time intervals. The results obtained could provide a useful insight to predict the industrial mill performance.

Characterization of Cokes from Delayed Co-Coking of Decant Oil, Coal, Resid, and Cracking Catalyst

The following focuses on the quality of coke produced from delayed coking blends of decant oil, coal, and resid, and it also examines the effect of adding a cracking catalyst to each blend. We also examine the role of coal, resid, and catalyst addition on the formation of green coke, calcined coke, and graphitized cokes. The overall goal was to see if use of lower quality feedstocks could produce marketable coke. The coal sample was cleaned using the best available technology to as low a level of ash yield (as determined by proximate analysis) as possible. Conversion and yield results from the delayed coking of DO, DO/coal, and DO/resid/coal as well as each reaction using catalyst are discussed. Gas products obtained from the delayed coking experiments were characterized, and results are discussed. Green cokes obtained from different delayed coking processes were evaluated using optical microscopy; the cokes were calcined and graphitized. X-ray diffraction, temperature-programmed oxidation, and proximate/ultimate analyses were used to characterize green coke, calcined coke, and graphitized coke. In general, the green coke generated from the various reaction conditions (DO and DO plus coal) produced a coke that is adequate as an anode grade coke and is suitable as a graphite filler, but because of either the sulfur and/or ash content is not suitable for nuclear graphite production or metallurgical coke. In general, adding catalyst increased the liquid yields, while decreasing the coke/gas yield, and improved the carbon quality, but added to the ash composition. For reactions of DO/coal/resid, the carbon is not suitable for anode grade coke, graphite, nuclear graphite, or metallurgical coke, and addition of catalyst actually decreased the quality of the coke.

Reduction of FeO in EAF steelmaking slag by blends of metallurgical coke and end-of-life polyethylene terephthalate

The reduction of FeO containing slag by blends of metallurgical coke and end-of-life polyethylene terephthalate (PET) has been investigated through experiments conducted in a laboratory scale horizontal tube furnace. Composite pellets of EAF slag (47·1%FeO) with coke, PET and blends of coke/PET (in four different proportions) were rapidly heated at 1550°C under high purity argon gas and the off gas was continuously analysed for CH4, CO and CO2 using an online infrared gas analyser (IR). The extent of reduction after ten minutes, level of carburisation and desulphurisation were determined for each carbonaceous reductant. The results show significant improvement in extent of reduction, level of carburisation and desulphurisation of the reduced metal when coke is blended with PET.

Effect of HDPE addition on the Pre-reduction of Mn3O4 to MnO by Metallurgical Coke

Abstract The effect of high density polyethylene (HDPE) addition on the pre-reduction of Mn3O4 to MnO by metallurgical coke (Coke) has been investigated through experiments conducted in a laboratory horizontal tube furnace coupled with off-gas analysis through an infrared (IR) gas analyser. Composite pellets of Mn3O4 with Coke, HDPE and blends of Coke with HDPE (in three different proportions) were rapidly heated at 1150 °C under pure argon gas and the off gas was analysed continuously for CO, CO2 and CH4. The extent of pre-reduction of Mn3O4 to MnO was then calculated by mass balance for removable oxygen. The results showed improvements in the extent of pre-reduction of Mn3O4 to MnO when coke is blended with HDPE. The time for complete pre-reduction was found to decrease with an increase in the amount of HDPE that was blended with coke. A decrease in CO2 emissions was observed with HDPE addition.

Effect of Blending Carbon-Bearing Waste with Coal on Mineralogy and Reactivity of Cokes

Because of rising costs, there is a constant demand to minimize coking coal use in favor of cheaper alternatives for ironmaking. A range of carbon-bearing additives were carbonized with a typical medium-rank Australian coking coal with the aims of minimizing the deterioration of coke quality while increasing the recycling of waste materials for ironmaking. Additives included two types of tire-recycling residues, coke breeze and a bituminous residue from the distillation column of benzol. Coke blends were prepared in a semi-pilot-scale coke oven, while a horizontal furnace was used to prepare char/coke samples of additives. The percentage of minerals in raw additive samples as well as coke blends was quantified by X-ray diffraction (XRD). Scanning electron microscopy (SEM) was used to determine the mode of occurrence of the minerals, while a fixed-bed reactor was used to measure the apparent reaction rate with CO2. After pyrolysis, recycling tire chars indicated the highest reactivity, which was attributed to zinc dispersion in the carbon matrix. Coke breeze showed the least reactivity but still greater than the base coke reactivity. The bituminous pitch residue char reactivity was significantly higher than the base coke reactivity. Under the test conditions, magnetite formation was noted to be the most notable change in the mineralogy of the coke blends. The higher reaction rate of the coke blends is related to the increase in the magnetite content as well as an enlargement of the micropore size. The apparent reaction rate of the coke blends is shown to be related to the coke strength after reaction (CSR). The study has implications for the use of various carbon-bearing wastes in a cokemaking process.

Reduction of FeO in EAF Steelmaking Slag by Blends of Metallurgical Coke and Waste Polypropylene

AbstractThe reduction of FeO-containing slag by blends of metallurgical coke and waste polypropylene (PP) has been investigated through experiments conducted in a laboratory scale horizontal tube furnace. Composite pellets of EAF slag (47.1% FeO) with coke, PP and blends of coke/PP (in three different proportions) were rapidly heated at 1500 °C under high purity argon gas and the off gas was continuously analysed for CO and CO2 using an online infrared gas analyser (IR). The extent of reduction after fifteen minutes, level of carburisation and desulphurization were determined for each carbonaceous reductant. The results show that FeO can be effectively reduced from EAF slag to produce metallic iron using waste PP and its blends with coke as reductants; improvements in the extent of reduction and levels of carburisation and desulphurisation of the reduced metal were observed when coke was blended with PP.

Vanadium and Nickel Speciation in Pulverized Coal and Petroleum Coke Co-combustion

Vanadium and nickel in emissions from fossil-fuel combustion and in the fly ash can be an environmental concern. The fly ash from the combustion of a 70% coal/30% petroleum coke blend in a 500 MW pulverized-fuel utility boiler was studied by a variety of X-ray, optical microscopy, and electron beam methods. The fly ash V and Ni are present in heterogeneous silicates, glass, sulfates, oxides and oxyhydroxides, and crystalline and/or amorphous mixed clay minerals, and also in Ni, detrital ferromagnesian silicates. Vanadium- and Ni-bearing spinels are incorporated into magnetite structures. Multiwalled nanotubes encapsulate V and Ni, and C60, C70, and C80 fullerenes and their derivatives are present.