Petroleum Coke Research Articles

Optimization of the Carbonization Process for the Preparation of High-Grade Needle Coke Based on the Response Surface Method and Microstructure Analysis

Optimization of the Carbonization Process for the Preparation of High-Grade Needle Coke Based on the Response Surface Method and Microstructure Analysis

Heat transfer characteristics of petroleum coke particle packed bed: An experimental and CFD simulation study

AbstractDue to the complexity of the internal pore structure of petroleum coke loose particle‐packed beds, measuring their thermal conductivity has always been a challenging problem. This work independently developed an experimental apparatus for testing the thermal conductivity of petroleum coke particle‐packed beds and constructed a forward calculation model for the heat transfer process, which was based on one‐dimensional unsteady heat transfer. Using the Sparse Nonlinear OPTimizer (SNOPT) algorithm, a mathematical relationship between the thermal conductivity λ of the coke bed, temperature T, and equivalent particle diameter dp was established through inverse modeling. Concurrently, a digital model of the petroleum coke particle packed bed was derived utilizing three‐dimensional computed tomography (CT) scanning technology, and a pore‐scale gas–solid radiation heat transfer model was formulated based on CFD simulation technology, thereby further elucidating the heat transfer mechanism within the petroleum coke particle packed bed. The research results indicate that the temperature predicted by the established thermal conductivity model aligns well with experimental data. Further CFD simulation studies demonstrate that a smaller particle size leads to a larger temperature difference between the wall and the center of the packed bed, while a higher gas velocity results in a smaller temperature difference, with a linear correlation observed between these two factors. At high temperatures, thermal radiation between particles in the porous petroleum coke‐packed bed plays a dominant role. The research outcomes can offer significant theoretical support for a profound analysis of the heat transfer behavior of petroleum coke‐packed beds within a vertical shaft calciner.

Preparation of needle coke from low-temperature coal tar pitch based on modification, component separation and component blending

Needle coke is widely used in the production of ultra-high power electrodes, special carbon materials, carbon fibers, and their composites. How to prepare needle coke with excellent performance through directional adjusting of raw material components is a hot research topic. In this paper, coal tar pitch (CTP) was extracted from low-temperature coal tar (Low-coal tar). To further increase the content of quinoline-soluble, CTP was modified by formaldehyde via chemical polymerization. By adjusting the blending ratio of hexane-insoluble toluene-soluble (HI-TS) and toluene-insoluble tetrahydrofuran-soluble (TI-AS) obtained by modified coal tar pitch (HCTP) separation adopting solvent extraction, a series of green needle coke and needle coke were prepared. The physicochemical structures were analyzed using FTIR, TG, Py-GC/MS, XRD, PM, and SEM, and the electrochemical properties were evaluated and analyzed. The results show that the Lc and La of green needle coke and needle coke firstly increase and then decrease with the decrease of TI-AS content, while the ID/IG demonstrated the opposite tendency. When the content of TI-AS is 16.67%, it is favorable to improve the micro-morphology of needle coke and increase the content of the ideal graphite lattice (from 24.47% to 31.88%) and needle coke yield (44.03%). In this paper, the composition distribution of CTP was adjusted, and the effect of the blending ratio of HI-TS and TI-AS on the structure of green needle coke and needle coke was investigated, improving the added value of Low-coal tar and providing data reference for the directional regulation of needle coke.

Enhanced graphitization of CO2-derived carbon anodes via Joule heating reformation for high-performance lithium-ion batteries

Molten salt electrolysis of CO2 represents a promising technology for highly efficient CO2 capture and the production of economically valuable CO2-derived carbon materials. In this study, we established a 100-A-scale molten salt CO2 electrolysis cell to synthesize hundreds of grams of CO2-derived carbon. Subsequent Joule heating at 2800 °C transformed these materials into high-quality graphite. Further composite modification with asphalt and petroleum coke effectively reduced surface area, resulting in high-performance graphite for lithium-ion battery. The CO2-derived graphite anodes demonstrated high reversible capacities ranging from 297.7 to 378.1 mAh g−1, exhibiting outstanding rate capability and stability over 300 charge-discharge cycles at a current density of 1 A g−1. Finally, we assembled a coin full-cell using AG-2/2/6 anode and LFP cathode, which demonstrated good cycling performance. XPS analysis revealed a significant reduction in oxygen content by the post-reformation, facilitating the formation of highly graphitized structures. This study not only pioneers the up-class synthesis of CO2-derived carbon but also underscores its potential for sustainable energy applications, particularly in lithium-ion battery technology.

Sustainable Processing of Ultralow-Cost Petroleum Cokes Into Ultrastable Self-Doped Fe3C@CNT Catalysts for High-Efficiency HER.

Petroleum cokes are largely used as low-cost anodes in aluminum industries and general fuels in cement industries, where large amounts of CO2 are generated. To reduce CO2 release, it is challenging to develop green strategies for processing abundant petroleum cokes into high-value products, because there are abundant hetero-atoms in petroleum cokes. To overcome such issues, a sustainable electrochemical approach is proposed to convert ultralow-cost high sulfur petroleum coke and iron powders into high-efficiency catalysts for hydrogen evolution reaction (HER). During molten-salt electrolysis, raw petroleum cokes are converted into CNTs via heteroatom removal and the catalytic effect of Fe, forming Fe3C nanoparticles on the sulfur and nitrogen co-dopped carbon nanotubes (Fe3C@S, N-CNTs). The electrochemical reaction analysis using the continuum model suggested that the rate-determining step referred to the slow transport of mobile ions inside the porous cathode. Because the self-doped S and N atoms massively alleviated the energy barrier for H* absorption and H2 desorption (i.e., promoting HER kinetics), the as-prepared Fe3C@S, N-CNTs exhibited low overpotentials at 10mAcm-2 in acidic (96mV) and alkaline (106mV) solutions with ultralong-term duration (200h). This study offers a sustainable approach to convert ultralow-cost petroleum cokes into ultrastable catalysts for high-efficiency HER.

Improved electrochemical properties of lithium-ion batteries prepared using oxygen plasma-treated needle coke-based anode materials

High-rate capacities and specific capacities are important indicators for evaluating lithium-ion battery (LIB) anodes. To improve the electrochemical properties of needle coke-based anode materials, oxygen plasma treatment was used. Various analyses were performed to assess the impact of the oxygen plasma treatments on the chemical, structural, and morphological properties of the needle coke samples. The oxygen plasma treatment effectively introduced oxygen functional groups (hydroxyl, ether, carbonyl, and carboxyl groups) without significant structural changes to the needle coke samples, and the O/C ratio increased to 0.23 after the plasma treatment. The synergistic effect of the increased oxygen content and the defects formed on the surface by plasma treatment improved the electrochemical properties of the needle coke-based anodes. The discharge capacity of the oxygen plasma-treated needle coke-based LIBs increased to a maximum of 20.48 %, and the retention rate was 74.51 % at 5 C with respect to 0.1 C. The oxygen plasma-treated needle coke material prepared via a simple method could have an important role in improving the rate capacities and specific capacities of LIBs.

Problems and solutions to protection of carbon-graphite electrodes

This paper presents literature review of the existing problems and solutions in protecting carbongraphite electrodes from the destructive environment of arc steel-making furnaces, magnesium and aluminum cells. The most significant publications on the corrosion resistance of cathodes and anodes in relation to physical, chemical, and electrochemical wear, to oxidizing environments, to active components of the introduction and destruction of the carbon structure are discussed. An analysis of various proposals and engineering solutions for reducing or eliminating the impact of aggressive environments on electrodes under specific operating conditions of metallurgical units is carried out. It was established that losses from lateral oxidation of the electrode surface of arc steel-making furnaces, when passing the temperature zone of 600–800°C, may reach 40–60% of the total consumption. Carbon-graphite products are subject to a significant destructive effect of the specific interaction of carbon with elements and compounds of the working environment, which can be introduced (intercalate) into the interlayer structure of carbon. The existing engineering and technological solutions mainly apply to the protection of the product surface; moreover, they perform their functions for a short time, rather than during the entire service life of the metallurgical unit. In this connection, it is proposed to focus on ensuring volumetric protection of electrodes from the effects of an aggressive environment. Intermediate results obtained in the field of synthesis of carbonbased composite materials adapted to the conditions of electrode production at existing enterprises are presented, along with the results of studies into the oxidizability of these composites. The existing and proposed engineering solutions for protecting the surface of carbon products have not received wide recognition or are not used in the metallurgical industry. Among the most probable reasons are the limited period of electrode surface protection, the complexity of reproduction, or the lack of profitability due to the high cost of protective components. In this regard, synthesis of C – TiC/TiB2 composite electrodes based on petroleum coke and graphite seems to be a promising research direction.

Vitreous silica supported metal catalysts for direct non-oxidative methane coupling

Direct non-oxidative methane coupling (NMC) transforms methane into valuable chemicals and hydrogen, which is a promising pathway to boost industrial decarbonization. The reaction, however, is challenged by high C-H bond activation temperature, catalyst coking, and low selectivity towards hydrocarbon products. Here we studied the efficacy of five vitreous silica supported 3d transition metal (Mn, Fe, Co, Ni, and Cu) catalysts (denoted as M/SiO2-v) for NMC. These catalysts were prepared by flame fusion of mixtures of quartz and metal silicate precursors. The metal species in the as-synthesized catalysts were fully or partially oxidized, with their stability following the order of Mn > Fe ≈ Co > Ni > Cu in the NMC reaction. The Cu species has low methane reaction rate, due to the high adsorption and dissociation energies of methane. The Mn and Ni species have high methane reaction and coke formation rates, which is supported by easy kinetics of methane deep dehydrogenation to carbon. In contrast, Fe and Co species showed the best hydrocarbon product selectivity. Particularly, the Co species emerged as the optimal catalyst for NMC, showcasing a balanced methane activation, hydrocarbon formation, and low coke yield. The relationship between the evolved metal species under reaction conditions and their NMC performance was discussed. The present study screens and provides effective catalyst formulations for NMC reactions.

Electrochemical Performance of Coal-Based Needle Coke Anode for Lithium Ion Batteries

Lithium-ion capacitors (LICs) with the capability of high energy and high power are considered to be attractive for advanced energy storage applications. However, the design and fabrication of suitable electrode materials with desirab-le properties by a facile approach using cost-effective precursors are still a great challenge. In this work, we have utilized needle cokes, an commercial carbon material with high carbon content and soft carbon structure, as a single carbon source for anode material. A lithium-ion battery fabricated using four kinds of needle cokes exhibits a maximum high energy density of 1357mAhg-1. Systematic characterization analysis demonstrates that unique characteristics of the green coke including large interlayer spacing, turbostratic and disordered microstructures that are composed of surface defects, nanopores or voids, and graphitic domains. That contribute synergistically to the outstanding performance of the needle coke-based LIC. More importantly, anode materials from a single source is an effective way for high value-added utilization of needle coke at the commercial level.

EFFECT OF ALTERNATIVE RAW MATERIALS OVER CLINCKER QUALITY AND CO2 EMISSIONS

In the cement industry, the actual challenges are the preservation of the raw materials and energy resources, as well as reduction of pollutant emissions. In this context, the cement producers demand studies to reduce of the production costs and atmospheric emissions. One way to achieve these objectives, is to use alternative fuels or by-product raw materials. Any reduction in the required energy has a beneficial influence both on the viability of the cement plant and on the environment. One of the approaches aimed at reducing thermal energy consumption is the partial substitution of traditional raw materials (limestone, clay, gypsum) with other alternative materials, with a melting effect, among which stand out byproducts of the steel industry such as furnace and steel slag. Another way for preservation of energy resources is using alternative fuels instead of traditional fuels like coal, petroleum coke or gas. The clinkering process and clinker quality can be influenced by any additions, in this study was determined these influences.

Synergy Effect of High K-Low Ca-High Si Biomass Ash Model System on Syngas Production and Reactivity Characteristics during Petroleum Coke Steam Gasification

The synergy effect of high K-low Ca-high Si biomass ash-based model system (BAMS) on the synthesis gas output and reaction characteristics of petroleum coke (PC) steam gasification process was studied using three biomass ash (BA) components, KCl, SiO2, and CaCO3, which were used as the model compounds. In the ternary model system, the steam gasification experiment of PC was conducted using a fixed bed reactor and gas phase chromatography. The synergistic effects of binary and ternary components in the ternary model system on the gasification of PC were obtained. These investigations were based on the data from the gas analysis and examined the gasification reaction process, syngas release behavior, and reaction characteristics. This study examined the effects of binary and ternary components in the ternary model system on the evolution of semi-char structure during PC gasification. This correlation revealed the synergistic effect of the model system on PC gasification. Scanning electron microscope (SEM) and Raman spectroscopy were used to characterize the structure and surface microstructure of the gasification semi-char. The results showed that the yields of different gases in the ternary model system were in H2 > CO > CO2. Compared with single PC gasification, the yields of H2, CO, syngas, and carbon conversion were increased by 29.42 mmol/g, 20.40 mmol/g, 56.68 mmol/g, and 0.35, respectively. All other components in the ternary model system with high K-low Ca-high Si demonstrated catalytic effect, except for SiO2 and the Ca-Si system, which showed inhibitory effects on syngas release and reaction features. Integrating SEM and Raman spectroscopic analyses, it was elucidated that CaCO3 and KCl diminished the degree of graphitization in semi-char through interactions with the carbonaceous matrix. This phenomenon facilitated the gasification process and exhibited a synergistic effect. Secondly, SiO2 will react with CaCO3 and KCl, producing inert silicates and inactivating these compounds, leading to the decline of catalysis.

Modeling and 3-D simulation of petroleum coke calcination process: investigation of the effect of main operating variables

Abstract Coke calcination is a process that involves heating green petroleum coke to purify it and eliminate volatile materials for subsequent processing. Due to the complexity of the rotary kiln used in this process, conducting experimental studies can be challenging and restricted. However, quantitative analyses based on developed models can provide a foundation for optimizing and controlling the process, which can significantly enhance the design efficiency. A three-dimensional simulation model of a rotary calcining kiln for petroleum coke was created using COMSOL Multiphysics in a steady-state mode. This model accounted for all relevant physical and chemical phenomena in the gas stream and coke bed flow, including heat transfer, combustion, and the evolution of volatile matter and coke dust. The mathematical modeling yielded distributions of temperature and mass fractions within the kiln, as well as the velocity field. The results revealed two distinct peak temperatures in the gas phase: 1,780 K near the primary air injection point and 1,605 K near the tertiary air injection points. The findings were analyzed, and the impact of key variables was explored. The simulation data indicated that for every decrease of 10–15 m/s in air flow, the gas peak temperature dropped by approximately 100°. Additionally, an increase in the input oxygen concentration led to enhanced combustion, resulting in higher peak concentrations of CO2. The developed simulation model has proven to be a valuable and promising tool for the design and optimization of petroleum coke rotary kilns.

Analysis of the thermal performance of the lining and the reasons for its destruction in petroleum coke calcination furnaces

Analysis of the thermal performance of the lining and the reasons for its destruction in petroleum coke calcination furnaces

Treatment of bio-treated coking wastewater in a 3DEF system with Fe-loaded needle coke particle electrodes

As one of the most representative hard-to-biodegrade industrial wastewater, coking wastewater is poor in biodegradability and has a high concentration of organic matter. Consequently, even after treatment using biochemical technology, the discharge standards cannot be reached. We used the self-developed Fe-loaded needle coke electrodes (Fe-NCPEs) as particle electrodes and established a three-dimensional electro-Fenton (3DEF) system for the treatment of bio-treated coking wastewater (BTCW) in this study. The 3DEF system's conditions for treating BTCW were optimized using Response Surface Method (RSM). When the initial pH was 4.69, the applied voltage was 11.1 V, the Fe-NCPE dosage was 11.63 g L−1, and the COD was reduced from 387 to 57.3 mg L−1 and the colour removal rate reached 99 % after 3 h of reaction, meeting local coking wastewater discharge standards. The power consumption is only 15 kWh per ton of BTCW, indicating that this system can treat the BTCW with high efficiency and low energy consumption. UV-Vis, FTIR, and GC-MS analysis illustrated that cyclic aromatic compounds, esters, and ethers can be efficiently degraded to alkanes and olefins by the 3DEF system. The ·OH quenching experiments showed that in the 3DEF system, the ·OH is the main reactive group, which can oxidize the large hard-to-degrade organic compounds in BTCW to small organic compounds, and even to CO2 and H2O. Dynamic experiments showed that the 3DEF system can successfully remove pollutants from BTCW under continuous flow conditions with an HRT of 3 h, allowing it to meet emission standards.

Effect of changes in the structure and composition of medium–low-temperature coal tar pitch on the quality of needle coke

Effect of changes in the structure and composition of medium–low-temperature coal tar pitch on the quality of needle coke

Investigation of demetallization of Ni and V in crude oil using spherical polyelectrolyte brushes with adjuvant

Nickel and vanadium in crude oil adversely affects the quality of petroleum coke and refining process. Polymer brushes bearing high-density ligands have shown promising nickel removal ability. In this work, submicron polybutadiene (PB) grafted by aminodithio- carbamate acrylamide (PAMDTC@PB) was prepared and characterized by the infrared spectroscopy, dynamic light scattering, and elemental analysis. Based on results of molecular simulation, PAMDTC was selected as ligand molecule at first. Then the nickel and vanadium removal rates by PAMDTC@PB and traditional polyacrylic acid brushes (PAA@PB) were evaluated through the electric desalination process, both in the model and real oil samples. The result shows that S atom in AMDTC is most likely to chelate with metal porphyrin compounds and AMDTC molecule presents highest chelating activity. Compared with PAA@PB, the removal rate of Ni and V porphyrin compounds with the aid of PAMDTC@PB increases significantly, with an optimized removal rate of 46.91 % and 56.81 %. To achieve better metal removal efficiency and higher utilization rate of prepared polymer brushes, sodium dimethyl dithiocarbamate (SDD) is introduced into the electric desalination process as a adjuvant. The results indicate that the addition of SDD leads to a increment of 10–30 % to the removal rate of Ni and V and a reduction of brush dosage by 200–400 ppm in the electric desalination process, exhibiting great potential of industrial applications of novel desalination process with adjuvant.

Combustion and co-combustion of biochar: Combustion performance and pollutant emissions

Biomass is a renewable and clean energy source, offering the potential to reduce fossil fuel consumption and greenhouse gas emissions when it is used as a biofuel. However, the disadvantages of raw biomass such as poor grindability, high moisture content, and low calorific value hinder its widespread industrial combustion. Thermochemical conversion techniques are widely used to convert biomass to biochar, which serves not only as an adsorbent and soil amendment but also as solid fuels alternative to fossil energy. The upgraded biochar exhibits better physicochemical properties and improved combustion performance. This paper focuses on the properties and combustion behavior of biochar as a solid fuel, reviewing common production techniques of biochar and their effects on yields and properties of biochar. It also examines the combustion characteristics and kinetics of biochar in single- and co-combustion scenarios with other fuels, such as coal, sludge, and petroleum coke, analyzing the influencing factors of combustion behavior and kinetic parameters. This study further investigates the emission characteristics during the combustion of biochar, including gaseous pollutants (such as CO, NOx, SOx, and HCl), ash-related issues, and particulate matter (PM) emissions. Additionally, a new fuel type named “bioslurry”, which is developed with biochar as a main material, is introduced. Furthermore, this paper discusses the techno-economic and environmental aspects of biochar application, exploring the feasibility of its industrial production and utilization.

Introducing a novel Hierarchy-Connectivity factor for characterizing micro-mesoporous materials

To provide a comprehensive description of hierarchical pore networks and optimize micro-mesoporous materials, it is essential to consider pore connectivity as a parameter. This study introduces an innovative hierarchy-connectivity factor (HCF) that includes the volume, size, and connectivity data of pores within the pore network. This study covers micro-mesoporous biosourced carbons, with ordered or disordered mesoporous structures, and three commercial activated carbons derived from petroleum coke and biomass. A dual-shape slit-cylinder model was employed to precisely assess the textural properties of these carbons. The proposed methodology evaluates connectivity exclusively through gas adsorption–desorption isotherm analysis, providing a rapid and practical tool for characterizing the porous network of carbon materials. The efficacy of this HCF is demonstrated in the examination of carbon materials functioning as electrodes for supercapacitors. Overall, this research transcends the field of gas adsorption-based studies, highlighting the importance of evaluating the pore network connectivity within carbon materials in order to optimize them for a particular application. Importantly, this contribution could be extended beyond the scope of carbon materials, encompassing a broader spectrum of porous materials.

Petroleum coke-derived carbon nanotubes decorated by gold nanoparticles towards highly selective Pb2+ electrochemical sensing

The utilization of petroleum coke with a simple and eco-friendly way is still a challenging task. In this study, an in-situ texturing strategy has been proposed for the preparation of the N-doped carbon nanotubes (N-CNTs), which employs cheap petroleum coke as carbon source and graphitic carbon nitride (g-C3N4) as template and nitrogen source. The synergistic effect between N-CNTs with multilayer adsorption and Au nanoparticles (AuNPs) with remarkable electrocatalytic properties is conducive to constructing a promising N-CNTs/AuNPs nanocomposite as sensing flatform for monitoring the trace amount of heavy metal ions. The sensitivity of N-CNTs/AuNPs-modified glassy carbon electrode (GCE) for lead (II) ion (Pb2+) detection is as high as 26.1 μA·μM−1, which has 42.5 and 3.0-times enhancement compared to bare GCE (0.6 μA·μM−1), and N-CNTs-modified GCE (6.5 μA·μM−1), respectively. Additionally, the corresponding limit of detection of N-CNTs/AuNPs-modified GCE has achieved as low as 0.011 μM (S/N = 3). Encouragingly, the interference of co-existing ions could be negligible, which allows the accurate detection of Pb2+ in real water samples for further practical applications with a satisfactory recovery between 95.7 % and 106.6 %. The exceptional anti-interference performance can be ascribed to the robust chemical interaction between Pb2+ and N-CNTs/AuNPs nanocomposite, which has been proved by the X-ray photoelectron spectroscopy analyses. This work not only opens up a new avenue for the high added-value and efficient utilization of petroleum coke, but also provides valuable insights into harnessing synergistic catalysis of noble metal nanoparticles to improve the electrochemical activity of electrode materials in the electrochemical analysis field.

Sucrose‐Based Dense, Pure, and Highly‐Crystalline Graphitic Materials for Lithium‐Ion Batteries

AbstractAt present, most synthetic graphite materials commonly used as anode active ingredients in lithium‐ion cells are produced by graphitization of petroleum cokes. The carbon footprint associated with synthetic graphite production is significant. Thus, bio‐derived and cheap precursors, such as saccharides, would be an attractive alternative for the sustainable production of graphitic carbons. However, they are non‐graphitizing at temperatures as high as 3000 °C, preserving the curved, fullerene‐like structure of graphene layers and microporosity. Consequently, many lithium ions are consumed during the formation of solid electrolyte interphase films and passivated in the nanovoids. Here, a method for the production of pure, crystalline, graphitic materials based on sucrose disposed of microporosity is presented, which also works with a variety of saccharides and other organic precursors of hard carbons—generally considered incapable of such transformation. This process employs catalytic graphitization by Si particles at high temperatures. The electrochemical response of such derived sucrose‐based graphite in Li‐ion half‐cells demonstrated its feasibility to serve as an anode active material for rechargeable Li‐ion batteries.