Petroleum Pitch Research Articles

Novel carbon foam composites reinforced with carbon fiber felt developed from inexpensive pitch precursor matrix

Novel carbon foam composites derived from various pitch precursors have been fabricated and characterized. This paper specifically focuses on developing an effective process for fabricating the carbon foam composites from Polyacrylonitrile (PAN)-based carbon felt as a reinforcement and various readily available pitch matrix such as petroleum pitch, coal tar pitch, and mesophase pitch. The paper endeavors to develop the carbon foam composites and to carry out detailed morphological, thermal, and mechanical characterization. Traditional carbon foams have been known to offer poor mechanical performance, and hence, in this paper, the pitch-based carbon foams were innovatively reinforced with the PAN-based carbon fiber felt. Carbon foam composites were subjected to partial oxidation, and their morphological and mechanical response after the heat treatment was studied thoroughly. Thermal gravimetric analysis and thermal mechanical analysis techniques reveal an appreciable thermo-physical and thermo-mechanical response at elevated temperatures. Also, it was found out that the factors such as volatile content and quinoline insoluble fraction affect the morphology as well as the physical robustness on the composite foams.

Bioremediation of PAH-contaminated shooting range soil using integrated approaches

Serious contamination of polycyclic aromatic hydrocarbons (PAHs) occurs at outdoor shooting ranges due to the accumulation of clay target fragments containing coal tar or petroleum pitch. These contaminated sites are characterized with high-molecular-weight PAHs that are low in bioavailability and recalcitrant to bioremediation. We evaluated the effectiveness of different remediation strategies, used individually or in combinations, to decontaminate PAHs in a shooting range soil. The treatments included vegetation with bermudagrass [Cynodon dactylon (L.) Pers] or switchgrass [Panicum virgatum]), bioaugmentation of Mycobacterium vanbaalenii PYR-1, and addition of surfactants (Brij-35, rhamnolipid biosurfactant, or Brij-35/sodium dodecyl sulfate mixture). The initial total PAH concentration in the shooting range soil was 373 mg/kg and consisted of primarily high-molecular-weight PAHs (84%). Planting of bermudagrass and switchgrass resulted in 36% and 27% ∑16PAH reduction compared to the non-vegetated control, respectively. Bermudagrass enhanced soil dehydrogenase activity and both vegetation treatments also increased polyphenol oxidase activity. Bioaugmentation of M. vanbaalenii PYR-1 had a significant effect only on the dissipation of high-molecular-weight PAHs, leading to a 15% decrease (∑10PAH) compared to the control. In the non-vegetated soil, Brij-35/sodium dodecyl sulfate mixture increased PAH degradation compared to the no surfactant control. The increased PAH biodegradation in the vegetated and bioaugmented treatments improved lettuce [Lactuca sativa] seed germination, suggesting reduced toxicity in the treated soils. Phytoremediation using bermudagrass or switchgrass with bioaugmentation of M. vanbaalenii PYR-1 was an effective in situ remediation option for shooting range soils with heavy PAH contamination.

Comparative study on the carbon–carbon composites developed from petroleum pitch, coal tar pitch, and their mixture

Carbon–carbon composites, as developed from various pitch precursors and chopped carbon fiber reinforcement, have been characterized and compared on the prime basis of the precursor materials used as the matrix. Evaluation of the properties and characterization have been carried out by various techniques such as thermal analysis by thermogravimetric analysis, thermomechanical analysis, and flame ablation method, microstructural characterization by scanning electron microscopy and optical microscope, mechanical characterization by Universal Testing Machine (UTM), IZOD impact, and hardness and frictional characterization by a pin on disc tribometer were carried out. Petroleum pitch, coal tar pitch, and the mixture of both the kinds of the pitch have shown a difference in the ultimate properties on the finished composite materials. The presence of volatiles, quinoline insoluble content, and various softening point have proved to impart differences in behavior for different systems. Composites developed to form the three systems have shown robust characteristics with superior mechanical and thermal behavior. Microstructural analysis has shown good compatibility between the reinforcement and matrix, while it is also evidence of a uniform distribution of the reinforcement. The fiber–matrix interaction in all the three systems is appreciably weak, which is favorable for non-catastrophic failure.

Preparation of Porous Carbons from Petroleum Pitch and Polyaniline by Thermal Treatment for Methane Storage

The methane storage capacity of two series of activated carbons, obtained from a graphitizable (petroleum pitch) and a nongraphitizable precursor (polyaniline), has been evaluated after different t...

THERMAL CAPACITY OF ENRICHED FUEL BRIQUETS PRODUCED FROM THE FINE OF EKIBASTUS COAL

The object of research or development: The object of the research work was coal fines and processes of enrichment of Ekibastuz coal to produce fuel briquettes with increased calorific value and less ash content. Objective: Research, scientific substantiation of technology for obtaining high-calorific coal briquettes from fines of Ekibastuz coal using various binders and the possibility of further coking, designing and manufacturing equipment for the implementation of technology. Method or methodology of the work: The standard methods of theoretical and experimental research widely used in metallurgy, machine building, computer systems, etc. were used in the work. The results of the work and their novelty: The characteristics of briquettes on bio-binding and on petroleum pitch with enrichers in the form of rubber-technical soot and anode dust of electrolysers for aluminum production have been established. It is revealed that the calorific value of briquettes is higher than that of Ekibastuz coal(Pavlodar region) by 20-40%, and the heating value is the highest for briquettes with an enrichment agent in the form of anode dust and a binder in the form of petroleum pitch (-NH combustion = 6840.8 kcal / kg). The structures of the soot separator, sorting and sifting equipment, mixing laboratory equipment, the mouthend briquetting press, the briquetting press and the screw mixer with the heater have been designed. Based on the results of the research, the project manager and co-authors published 15 scientific publications, patents and theses of international conferences. Application area: Briquettes for bio-binding can be used as fuel for combustion in centralized village boiler houses, private houses and farms. Briquettes on petroleum pitch with an enrichment agent in the form of anodic dust of aluminum electrolysis can be used as industrial briquettes for further use in metallurgy. Forecasting assumptions about the development of the object of research: Further studies are required to assess the feasibility of using industrial briquettes for coking and use in metallurgy, the manufacture of laboratory and research equipment to further commercialize the project.

Express Method of Determining the Softening Point of Petroleum Pitch

A capillary method is proposed for determining the softening point of petroleum pitch. A pitch sample is heated in a glass capillary by an air flux and observed under a microscope. The softening point is measured at the instant when the pitch within the capillary shrinks and pulls away from the glass walls. The method is tested for two series of petroleum pitch samples: one is derived from heavy pyrolytic tar; and the other from decant oil (heavy gas oil from a catalytic cracking unit with microspherical catalyst). A broad range of softening point is found for these samples by the ring-and-ball method (90–200°C). Given the simplicity of the tests and the ability to determine the softening point over a broader range (up to 330–350°C) than in the traditional method, the capillary method may be recommended for use in determining the softening point of traditional binder and also of high-melting fiber-forming pitch.

Petroleum pitch: Exploring a 50-year structure puzzle with real-space molecular imaging

Petroleum pitch has played a significant role in carbon science as a key abundant resource for polycyclic aromatic hydrocarbons in making various higher value carbon materials. Despite many detailed studies using advanced characterization techniques over 50 years, the exact nature of the molecular structures of petroleum M-50 pitch and their mesophase products remains unclear, due to the molecular diversity and the low solubility of this material. In this study, we applied real-space single molecule imaging non-contact atomic force microscopy to obtain exact structures of individual molecules, and compared the results from other characterization techniques to validate some of the previously hypothesized average structures. We identified a diverse slate of largely catacondensed polycyclic aromatic hydrocarbons with short alkyl chains, such as methyl and methylene groups. Furthermore, both single core and multi-core structures have been observed, in contrast to previous assertions that only one type would be present. The presence of these structures enables a mechanistic rationalization for their formation and allows potential mechanisms for the thermal conversion of pitch into larger bonding networks to be postulated.

Comparison of Coal Tar Pitch and Petroleum Pitches in the Reactions of Thermal Solvolysis of Thermosetting Polymers

Comparison of Coal Tar Pitch and Petroleum Pitches in the Reactions of Thermal Solvolysis of Thermosetting Polymers

Change in Molecular Mass of Pitch on Thermodestructive Polycondensation of Heavy Pyrolysis Tar

By determining the molecular mass of pitch from heavy pirolysis tar, additional information may be obtained regarding the thermal polycondensation and quality of pitch. The weighted mean molecular mass of toluene-soluble components of the pirolysis pitch is determined by gel-permeation chromatography. The molecular mass of the components in specific petroleum-pitch fractions is studied as a function of the time and temperature employed in isothermal holding of the heavy pirolysis tar. The weighted mean molecular mass of toluene-soluble components depends on the heat treatment of the pirolysis tar and the softening temperature of the petroleum pitch.

Comparison of Coal Tar Pitch and Petroleum Pitches in the Reactions of Thermal Solvolysis of Thermosetting Polymers

Comparison of Coal Tar Pitch and Petroleum Pitches in the Reactions of Thermal Solvolysis of Thermosetting Polymers

ВОЛОКНООБРАЗУЮЩИЕ СВОЙСТВА НЕФТЯНЫХ ПЕКОВ

The relevance of the use and necessity of obtaining carbon fibers and materials based on their domestic oil raw materials is shown. The results of investigations of physical, chemical and fiber-forming properties of pitches made of heavy pyrolysis tar from ethylene production and asphaltite tar of West Siberian oil are presented. The possibility of obtaining pitch fibers is shown experimentally. Pitches with a softening temperature of 170-220 ° C in the temperature range of 220-300 ° C are able to form continuous fibers from the melt with a diameter of 8-42 microns and are stably formed at the maximum speed of pulling the thread 6.5-10.6 m/s. In the study of the fiber-forming ability of petroleum pitches, the influence of the softening temperature on the maximum speed of forming of pitch fibers and the specific number of flows on the fiber was determined. The values of melt viscosity and softening temperature of pitches that are optimal for the formability of the pitch fiber are found. The dependence of the maximum speed of thread pulling is determined.

Template-Oriented Synthesis of Fe–N-Codoped Graphene Nanoshells Derived from Petroleum Pitch for Efficient Nitroaromatics Reduction

In this study, we demonstrate noble metal-free Fe–N-codoped graphene nanoshells (Fe–N/GNS) derived from petroleum pitch as highly efficient and cost-effective catalysts for nitroaromatics reduction...

Fixation of Nitrogen to Ammonia with Photocatalytic on Petroleum Pitch-Based Graphene Oxide Supported Nickel/Nickel Oxide Composite Catalyst

In this paper, petroleum pitch-based GO was obtained by using petroleum pitch as carbon source, and Ni&NiO was prepared by reducing of NiSO4·6H2O. Then, Ni&NiO/GO was prepared by in situ loading Ni...

Carbon-Mineral Adsorbent from Petroleum Pitch and Precipitated Colloidal Silica

The carbon-mineral adsorbent was prepared according to a two-stage scheme, which, despite the hydrophilic nature of the surface of colloidal silica, made it possible to prepare pellets with a high specific surface area and compressive strength of up to 70 m2/g and 8 MPa, respectively. The proposed method consists in mixing petroleum pitch and colloidal silica in the first stage, followed by granulation and carbonization (at 1000 °C); the resulting carbon-mineral material is crushed and mixed with petroleum pitch in the second stage, after which it is also granulated and carbonized (at 700 °C). Based on the obtained carbon-mineral sorbent, a highly porous carbon adsorbent is produced by etching the silicate base in a concentrated solution of sodium hydroxide during boiling. The total pore volume of the obtained samples reached 3.5 cm3/g.

Effect of hybrid reinforcement of carbon fiber and stable particles on pitch based carbon carbon composites

Carbon matrix carbon (c/c) composites were investigated to study the effect of incorporating stable particulate reinforcement along with chopped carbon fibers to check the effect of hybrid reinforcement. Robust c/c composites were fabricated by isotropic petroleum pitch matrix in single-step carbonization without re-impregnation process. Dense and rigid composites with density ranging from 1.65–1.75 g cm−3 were developed. Distinctive properties comprising coefficient of friction, coefficient of thermal expansion, high temperature dimensional and weight stability, shrinkage, hardness, weight loss, breaking energy and compressive strength were assessed and compared with the reference c/c composite. Secondary stable additives such as silicon carbide, molybdenum di-silicide, graphite, CNT, fly ash and alumina were added 5% by weight in the composites. Specimens containing advanced ceramic particles showed appreciable improvement in hardness, thermal, and mechanical response while composites with fly ash and graphite addition showed the converse effects. From the research, we were able to alter the properties and tailor them according to the application such as compression and friction coefficient was improved to have application in brake discs for automobiles. Also, the thermal shielding has been improved by incorporating thermally dormant material such as fly ash and Incorporation of hard and stable reinforcement has brought about noticeable changes consequently hybrid reinforcement improved the overall performance of the material even after ablation in oxy-acetylene flames.

Mesophase Pitch-Derived Carbons with High Electronic and Ionic Conductivity Levels for Electric Double-Layer Capacitors.

We develop a temperature-programmed pretreatment strategy for converting aliphatic-rich petroleum pitch into a mesophase framework, which can then be activated using KOH to produce high-performance carbons for electric double-layer capacitors (EDLCs). In the pretreatment of pitch at an optimal temperature, both the temperature ramp and holding time influence the mesophase structure, which governs the pore structure and crystallinity of the resulting activated carbon. High carbon microporosity is beneficial to capacitance maximization but detrimental to ion transport. To resolve this problem, we develop a multistep ramp incorporating aliphatic species into the aromatic framework during mesophase formation. This incorporation process produces a mesophase framework that can be activated to form carbons with high crystallinity, thereby enhancing electronic conductivity and hierarchical porosity, which improves ionic conductivity. The resulting carbon electrode is used to assemble a symmetric EDLC, which exhibits a capacitance of 160 F g–1 and excellent high-rate retention in a propylene carbonate solution of N,N-diethyl-N-methylethanaminium tetrafluoroborate. The EDLC delivers a superior specific energy of 40 Wh kg–1 (based on the total carbon mass) within a voltage range of 0–2.7 V and sustained a high energy of 24 Wh kg–1 at a high power of 50 kW kg–1. The findings of this study demonstrate that incorporating aliphatic species into aromatic mesophase frameworks plays a crucial role in regulating the crystallinity and pore structure of pitch-derived carbons for charge storage.

Effect of petroleum pitch coating on electrochemical performance of graphite as anode materials

The electrochemical characteristics of artificial graphite coated with petroleum pitch were investigated as anode material in lithium ion batteries. Petroleum pitch with various softening points (SP 150, 200 and 250 °C) was prepared to coat the surface of artificial graphite using tetrahydrofuran as the solvent. Scanning electron microscopy and transmission electron microscopy were used to confirm the coating properties of the prepared anode materials. The electrochemical characteristics of the batteries were investigated by initial charge/discharge, cycle, rate performance, cyclic voltammetry and electrochemical impedance spectroscopy tests in the electrolyte of 1.0 M LiPF6 (EC: DEC=1:1 vol%). With the goal of optimizing the pitch coating process of graphite as an anode material, both the composition ratios of artificial graphite to petroleum pitch and the carbonization temperatures were varied. The best battery anode performance was found to be 10wt% coated carbon with heat treatment at 1,000°C on the artificial graphite using petroleum pitch with SP 250 °C. Pitch-derived amorphous carbon coating effectively decreases irreversible capacity and increases the cycle stability. The prepared anode materials have good initial efficiency (92.9%), discharge capacity (343 mAh/g), cycle stability (97%), and rate performance of 10 C/0.1 C (84.1%).

Friction and wear characteristics of robust carbon-carbon composites developed solely from petroleum pitch without reimpregnation

Friction and wear characteristics correlating the fiber reinforcement percentage of carbon-carbon (C/C) composites solely developed from petroleum pitch matrices were investigated. This study exhibits the tribo-characteristics of C/C composites developed in a single-step carbonization process for varying loads for the first time without a reimpregnation process. A pin-on-disc tribometer with a sliding speed of 0.5 m/s and loads of 5, 10, and 20 N with a flat tool grade stainless steel pin as a static partner was employed. Further, polarized light optical and scanning electron microscopes (SEM) were utilized for a morphological analysis. Elastic modulus and strength were determined by a compression test. A result analysis is conducted to analyze sliding wear accompanied with minor abrasion. The composites with a high percentage of reinforcement exhibit credible wear resistance and mechanical robustness.

Preparation and characterization of spinnable mesophase pitches: A review

Mesophase pitch-based carbon fibers have a higher modulus and thermal conductivity than other carbon fibers. A good spinnable mesophase pitch is key to prepare high performance carbon fibers. In this paper, the preparation and characterization of mesophase pitches are reviewed. Spinnable mesophase pitches have been prepared from petroleum pitch or coal tar pitch by heat and catalytic polycondensation. Sometimes, hydrogenation, catalytic polymerization and co-carbonization were used to modify the chemical structure of the pitch before polycondensation. Traditional characterization of mesophase pitch include the softening point, rheology properties, optical anisotropy, average molecule weight and chemical structure. With the rapid progress of characterization techniques, other characterization of the microstructure is possible, such as high resolution MALDI ToF MS which gives the elemental formula of thousands of molecular constituents, which helps improve our understanding of the molecular structure of spinnable mesophase pitches.

Co-carbonization of brominated petroleum pitch, coal tar pitch and benzoyl chloride to prepare cokes

Co-carbonization of brominated petroleum pitch, coal tar pitch and benzoyl chloride to prepare cokes