Coal Tar Distillation Research Articles

Comparation Study of The Use Naftalena From Coal Tar Waste with Camper Naphtalene As Concrete Admixture

Concrete is a mixture of Portland cement or other hydraulic cement, fine aggregate, coarse aggregate, and water, with or without additives (admixture). The naphthalene superplasticizer used comes from the distillation of coal tar and a little from the rest of petroleum, but there is also camphor naphthalene. Where camphor grains contain 250-500 mg of naphthalene. Naphthalene is mostly produced from coal tar distillation, and a little from the rest of the fractionation of petroleum, by the molecular formula (C10H8) and in the form of two unified benzene rings. This compound is volatile, volatile even in the form of solids. The vapor produced is flammable. The purpose of this study was to determine the effect of the use of naphthalene from coal tar waste with camphor naphthalene as concrete admixture, and determine the effect of naphthalene from coal tar waste with camphor naphthalene on concrete toughness, density, water absorption, of concrete compressive strength. It is expected that the use of naphthalene can reduce the use of cement, and reduce water use. But it does not reduce the strength of the concrete so as to reduce costs in making concrete. The variations in the use of camphor naphthalene and coal tar naphthalene are 20%, 30%, 40%.

Structural Evaluation of Coal Tar Pitch by Multiple Techniques

Coal tar pitch (CTP) is an important heavy carbon resource. Its effective utilization largely depends on the full structural evaluation of CTP. In this paper, the CTP from Shanxi Datuhe coal tar distillation plant was adopted as the sample (DCTP). Multiple analytical equipments including X-ray diffractometer spectrometer, solid-state 13C nuclear magnetic resonance spectrometer, and X-ray photoelectron spectrometer were used to directly characterize DCTP, and DCTP was further catalytically oxidized over ruthenium ion. The typical characteristics of structures in DCTP were investigated by combining the two methods. It was demonstrated that aromatic structures dominated in DCTP, in which the aromaticity was up to 95 %. Specifically, aromatic structures were abundant in peri-condensed aromatic structures, poor in cata-condensed aromatic structures, but short of polyaryl structures. There were about 4 rings in each aromatic cluster, and the aromatic clusters were lowly substituted by a few methyl side chains. Furthermore, the nitrogen and sulfur atoms mainly existed in the heterocyclic ring, while the oxygen one was principally in Car‒O group.

Characterization and Partitioning Behavior of Creosote in Different Matrices: Soil, Water, and Air

Creosote is a multicomponent oil classified as a dense non-aqueous phase liquid (DNAPL) produced from coal tar distillation. The concept of phase distribution is critical in decision-making to remediate contaminated sites. The creosote mass transfer between sorbed, aqueous, vapor, and DNAPL phases is controlled by physicochemical characteristics, geology of the site, and environment conditions. This study evaluated phase distribution of the main polycyclic aromatic hydrocarbons (PAHs) of creosote in a sandy soil with low organic matter content. The creosote was collected from a contaminated site in Sao Paulo, Brazil, and was characterized by gas chromatography–mass spectrometry (GC-MS). Clean soil was collected upgradient from the same area. Initially, the soil was artificially contaminated with creosote. After, the contaminated soil was put in contact with clean water in sealed vials for 72 h. Samples of the soil, vapor, and liquid phases were collected and analyzed by GC-MS. In total, 50 compounds were identified in the creosote, and 9 PAHs were selected to be studied, which represented around 30% of total creosote mass. The major contaminant concentration was detected in the sorbed phase. For instance, naphthalene mass was distributed in sorbed (33.0%), DNAPL (1.5%), aqueous (3.4%), and vapor (0.2%) phases. The results provided an understanding of the contaminant species partitioning that occurs in a real contaminated site.

Comparation Study of the Use Naftalena from Coal Tar Waste with Camper Napthtalene as Concrete Admixture

Concrete is a mixture of Portland cement or other hydraulic cement, fine aggregate, coarse aggregate, and water, with or without additives (admixture).
 The naphthalene superplasticizer used comes from distillation of coal tar and a little from the rest of petroleum, but there is also camphor naphthalene. Where camphor grains contain 250-500 mg of naphthalene. Naphthalene is mostly produced from coal tar distillation, and a little from the rest of the fractionation of petroleum, by the molecular formula (C10H8) and in the form of two unified benzene rings. This compound is volatile, volatile even in the form of solids. The vapor produced is flammable.
 The purpose of this study was to determine the effect of the use of naphthalene from coal tar waste with camphor naphthalene as concrete admixture, and determine the effect of naphthalene from coal tar waste with camphor naphthalene on concrete toughness, density, water absorption, of concrete compressive strength. It is expected that the use of naphthalene can reduce the use of cement, and reduce water use. But it does not reduce the strength of the concrete so as to reduce costs in making concrete. The variations in the use of camphor naphthalene and coal tar naphthalene are 20%, 30%, 40%.

Innovative Coal-Tar Products at PAO Koks

Information is presented regarding the output of byproducts at coke plants in Russia and around the world. Traditional approaches to coal-tar processing are discussed. The variation in coal-pitch parameters with change in temperature and isothermal-holding time in coal-tar distillation at PAO Koks is described. Coal tar may be regarded as a potential source of innovative products characterized by high added value and global market demand.

Kinetic Parameter Calculation and Trickle Bed Reactor Simulation Based on Pilot-Scale Hydrodesulfurization Test of High-Temperature Coal Tar.

At present, a few chemicals can be separated after further processing of high-temperature coal tar (HTCT) distillates, which have a lower utilization. However, hydrogenation to produce clean fuel oil has not been widely reported in literature. Thus, due to the use of new feedstocks and the implementation of more severe environmental legislations, deep hydrodesulfurization (HDS) of HTCT will face formidable challenges. A series of HDS experiments were performed in a continuous isothermal trickle bed reactor in which the reactor temperature was varied from 648 to 678 K, the pressure from 12 to 16 MPa, and the liquid hourly space velocity (LHSV) from 0.25 to 0.35 h–1, and hydrogen-to-oil ratio kept constant at 2000 L/L. Based on the experimental data, possible reaction pathways of HDS reaction were investigated, and a modified Langmuir–Hinshelwood (LH) HTCT desulfurization kinetic model was established. gPROMS software was used to obtain optimal kinetic parameters that are as follows: EA = 26,842, K0 = 93,958, α = −1.14, n = 1.65, and m = 0.86. The model can well reproduce various working conditions and has better prediction accuracy. Some characteristics of HTCT HDS reactions were discovered; the reaction order (n) of HTCT HDS is slightly higher than that of crude oil and medium/low-temperature coal tar (M/LTCT), but the activation energy (EA) is relatively smaller. The established reactor model was used to predict the changes of the concentration of hydrogen, hydrogen sulfide, and sulfur compounds in the gas, liquid, and solid phases along the length of the reactor, respectively. The model was also used to predict the effects of pressure, temperature, and LHSV on the conversion rate of sulfur and catalyst effectiveness factors. The results showed that the LHSV has a greater impact on the conversion rate, and the pressure and temperature are less pronounced at high-severity operating conditions; the effectiveness factor is significantly smaller than that of other HDS processes, temperature has a greater effect on the effectiveness factor, followed by pressure and LHSV. The conclusion can provide a basis for further understanding the HTCT hydrotreating process.

Activated carbon xerogels derived from phenolic oil: Basic catalysis synthesis and electrochemical performances

The competitiveness of European coal tar distillation plants could be improved by the revaluation of coal-derived liquids and rejects such as phenolic oils, which currently lack high-end applications. In this study, carbon gels were successfully prepared for the first time from phenolic oil by base-catalysed sol-gel polymerisation, by taking advantage of all the major components of phenolic oil rather than the pure, single-component phenolic precursors that are normally used in sol-gel routes. To increase the feasibility of industrial applications, the organic gels were dried under subcritical conditions and the resultant xerogels were submitted to carbonisation and chemical activation in a one-step process, using different KOH to organic gel mass ratios. The resultant ACs were applied as supercapacitor electrodes and attained higher electrochemical performances than carbon gels previously obtained from classic precursors: high capacitance retention up to 74.9% at 12 A g−1, energy and power densities up to 7.37 W h kg−1 and 5.70 kW h kg−1, respectively, high cycling stabilities up to 94.8% after 10,000 charge-discharge cycles, high rate capability of 66% under 1 V s−1 scan rate, and fast frequency response of 0.45 s.

Oxidative DNA Due to Occupational Exposure to Polycyclic Aromatic Hydrocarbons among Coal Tar Workers

Introduction: Polycyclic Aromatic hydrocarbons (PAHs) are compounds of occupational and environmental concern as they are toxic, carcinogenic, mutagenic, and/or teratogenic (causing birth defects). Occupational exposure during coal tar distillation process may cause numerous symptoms and diseases through generation of coal tar fumes that contain principally polycyclic aromatic hydrocarbons (PAHs). Benzopyrene is the most important member of those PAHs. Aim of work: To assess the health effect due to occupational exposure to PAHs; specifically their effects on DNA damage and oxidative stress status among coal tar workers. Materials and methods: A comparative cross sectional study was carried out on two groups, exposed and unexposed group. The exposed group was consisted of 40 coal tar workers and the unexposed group was also composed of 40 matched individuals not occupationally exposed to coal tar .All examined individuals were subjected to full occupational history and estimation of 1-hydroxypyrene (1-OHPyrene) level in urine, blood levels of Benzopyrene-DNA adducts, oxidative stress enzymes (superoxide dismutase and glutathione peroxidase), Cytochrome P450 and Complete blood picture. Results: There was a statistically significant higher urinary level of 1-OHPyrene and higher blood levels of benzopyrene DNA adducts at the exposed workers compared to unexposed ones, in the other hand there were significant reduction in serum levels of superoxide dismutase and glutathione peroxidase among workers exposed to PAHs compared to the unexposed group that might be consumed by oxidative stress status. Conclusion: Oxidative stress and DNA damage might be one of the pathogenesis that may cause adverse health effects associated with occupational exposure to PAHs among coal tar workers.

Application of ferric-carbon inner electrolysis coupling Fenton process pretreatment of coal tar distillation wastewater with a focus on optimization by the response surface method

Application of ferric-carbon inner electrolysis coupling Fenton process pretreatment of coal tar distillation wastewater with a focus on optimization by the response surface method

Assessing the feasibility of sequential aerobic respiration and heterotrophic denitrification of a high-strength mixture of phenol and its derivatives in the field single-well-drift test

Biological degradation of high strength phenol and its derivatives in groundwater is problematic because these compounds are toxic to human and microbes. To evaluate the feasibility of in situ bioremediation using sequential aerobic respiration and heterotrophic denitrification, a field single-well-drift test (SWDT) was conducted in groundwater contaminated with coal tar distillates. To stimulate indigenous phenol degrading microorganisms, a 1400 L of oxygen-saturated test solution containing bromide (3.96 ± 0.179 mmol-Br/L) and nitrate (5.34 ± 0.187 mmol NO3−-N/L) was injected into an aquifer. After injection of the test solution, significant consumption of dissolved oxygen (DO) was immediately observed; then, degradation of the methyl derivatives o-cresol and m,p-cresol was observed with average zero-order rate coefficients of 0.047 mmol/L/d and 0.23 mmol/L/d, respectively. After 73% of the injected DO was consumed, significant NO3− consumption was observed along with degradation of phenol and the dimethyl derivatives 2,4-xylenol and 3,5-xylenol, which had average zero-order rate coefficients of 0.17 mmol/L/d, 0.060 mmol/L/d, and 0.018 mmol/L/d, respectively. The production of CO2, NO2−, and N2O along with significant consumption of DO and NO3− suggest that phenolic compounds were biologically degraded by sequential aerobic respiration and heterotrophic denitrification. The results of 16s RNA analysis revealed that, after injection of the test solution, a bacterium that shared a 99% 16s rRNA sequence similarity with an uncultured bacterium revealed to be Pseudomonas stutzeri, a facultative heterotrophic denitrifier, was found in the aquifer. Thus, these results suggest that simultaneous injection of DO and NO3− is an appropriate in situ bioremediation strategy for degrading mixtures of high-strength phenolic compounds in an aquifer.

Ordered mesoporous carbons obtained from low-value coal tar products for electrochemical energy storage and water remediation

Ordered mesoporous carbons (OMCs) obtained by the hard-templating method are usually prepared using complicated infiltration procedures and/or relatively high-priced carbon precursors. In this work, OMCs were obtained using creosote, a modestly priced substance obtained from the distillation of coal tar, as a carbon precursor and an ordered mesoporous silica (SBA-15) as the template. The porous network of the template was infiltrated using a simple, one-step method in acidic medium at a moderate temperature, making it potentially scalable for mass production. Optimization of the synthesis conditions led to OMCs with a very well ordered porosity with a very narrow pore size distribution in the mesopore region, together with a high surface area. This material was tested as an electrode for electrochemical energy storage devices and as an adsorbent for pollutant removal. Owing to its well-developed hierarchical pore network, the present OMC showed a good performance as a supercapacitor electrode in aqueous electrolyte and high rate of methylene blue dye adsorption.

Preparation of High‐Purity 2,6‐Naphthalenedicarboxylic Acid from Coal Tar Distillate

AbstractUsing coal tar distillate as the starting material, a novel high‐purity 2,6‐naphthalenedicarboxylic acid (2,6‐NDA) preparation method was developed. Firstly, the 2,6‐dimethylnaphthalene (2,6‐DMN) precursor was separated by successive vacuum distillation, melt crystallization, and solvent crystallization from the 250–270 °C fraction of the coal tar distillate. Then, over Co‐Mn‐Br as catalysts, oxidation of 2,6‐DMN was carried out in acetic acid to produce crude 2,6‐NDA with molecular oxygen. By high‐temperature hydrogenation, the crude 2,6‐NDA was further purified to obtain high‐purity 2,6‐NDA. From the coal tar distillate to pure 2,6‐NDA, the operation parameters and reaction conditions of each process were optimized and evaluated, indicating that the proposed 2,6‐NDA synthesis method has great potential for industrial application to create cheap feedstock in viable yields.

Valuable Products from Coal Tar

Research on the production and properties of coal pitch is conducted in the laboratory at PAO Koks. One topic of interest is the distillation of coal tar to produce a broad tar and pitch fraction, whose quality is analyzed. It is possible to regulate the characteristics of pitch: its ash content and content of components insoluble in toluene (the α fraction) and components insoluble in quinoline (the α1 fraction).

Selective hydrodeoxygenation of p-cresol as a model for coal tar distillate on Ni-M/SiO2 (M = Ce, Co, Sn, Fe) bimetallic catalysts.

Ni–M/SiO2 with different binary metals M (M = Ce, Co, Sn, Fe) prepared by an incipient impregnation method was used in the hydrodeoxygenation (HDO) of low-temperature coal tar distillate, which is rich in phenolic compounds. p-Cresol, as a model compound of the distillate, was used to evaluate the activity and selectivity of BTX products on the series of reduced Ni–M/SiO2 catalysts in a fixed bed reactor. The properties of the catalysts were characterized by N2 adsorption–desorption, ICP-AES, XRD, H2-TPR, and XPS. Benzene and toluene as the direct deoxygenation (DDO) products and cyclohexane and methylcyclohexane as the hydrogenolysis (HYD) products were detected to evaluate the selectivity of the path in the deoxygenation process. In this series of catalysts, the order of reactivity was Ni–Ce > Ni–Sn > Ni–Co > Ni–Fe > monometallic Ni. Meanwhile, the addition of Ce and Co loaded in the Lewis acid sites of the catalyst affected the electron distribution of nickel atom and its atomic arrangement on the surface of the carrier. Compared to monometallic Ni, the DDO path become dominant on Ni–Ce and Ni–Co and the selectivity for BTX products increased from 58.8% to 77.4% and 71.1%, respectively. The binary metal Sn, unlike the former two metals, formed a Ni3Sn crystal form with Ni, which resulted in significant enhancement of the HYD path while obviously increasing the reactivity.

Response of soil phosphatase activities to contamination with two types of tar oil.

Tar oil is a complex mixture of hydrocarbon compounds obtained from high-temperature distillation of coal tar. It has been used for over 100years from now to protect wood and has been applied to wood products, primary utility poles, and railroad ties by pressure methods. Composition of the tar oil depends on the source and typically consists of 85% polycyclic aromatic hydrocarbons (PAHs), 10% phenolic compounds, and 5% heterocyclic compounds. In this research, we performed the laboratory experiment to compare two types of tar oil: C and GX-Plus, and their effects on P-cycling enzymes (phosphatases) in sandy loam and loamy sand. Tar oil was applied to soil samples at the following doses: 2, 10, and 50gkg-1. Soil without tar oil was used as a control sample. The experiment showed that the contamination of soil with tar oil affects the enzyme activities measured and with this most probably the P-cycle in soil. Phosphomonoesterases were the most sensitive to the contamination of soil with both type of tar oil: typeC and type GX-Plus. Greater changes in the enzymatic activity were observed in the loamy sand. Moreover, the type C tar oil demonstrated higher toxicity for phosphatases than type GX-Plus.

STRUCTURAL OPTIMIZATION OF THE NAPHTHALINE DISTILLATION SCHEME BASED ON PHASE EQUILIBRIUM ANALYSIS

The research main aim is to analyze the presence, composition and naphthalene azeotropes type with impurities in the naphthalene fractions obtained by the distillation of coal tar. The presence of mentioned impurities significantly complicates the process of obtaining a pure product – naphthalene. The most difficult problem is the separation of naphthalene-thionaphthene mixture.Based on the simulations of the vapor-liquid equilibrium of the these mixtures components at different pressures, which were carried out in the HYSYS simulation environment using the UNIFAC method and the NRTL activity model, it has been shown that there are positive homogeneous azeotropes of 2,3-xylenol – naphthalene and naphthalene – thionaphthene. Azeotrope of xylenol – naphthalene – thionaphthene existence in the mixture was predicted. At atmospheric pressure, the azeotrope composition is presented: xylenol - 43 mass %, naphthalene - 5 mass % and thionaphthenes - 52 mass %. The boiling point is 201°C.Based on the analysis of phase equilibria, a unified energy efficient naphthalene separation method was proposed. Scheme consist of two columns, which operate under different pressures: the first column at a residual pressure of 100 mm Hg, the second at atmospheric pressure. The required regimes and efficiency of the columns were determined, ensuring the production of a commercial product with a main substance content of more than 99 % from naphthalene fractions with different composition with minimal loss of naphthalene.The conditions for the formation of the power-energy unit were determined in order to use the upper product condensation heat in the second column to heat the column operating under vacuum. This principal reduces the energy costs of obtaining the pure naphthalene (99 mass %) by 35 % in comparison with the design scheme without linking the heat fluxes.

Catalytic hydrogenation of Low temperature coal tar into jet fuel by using two-reactors system

The experiment of the jet fuel fraction through hydrogenation was investigated via hydrogenation in two-stage fixed beds reactor filled with hydrofining catalyst and hydroisomerization catalyst with low-temperature coal tar (LTCT) distillate (<360 °C) as the feedstock. The reaction of coal tar on the catalyst was studied through analyzing the yield of product, the saturation performance, the carbon number distribution and the chemical components of the jet fuel fraction. In current study, the experimental conditions included the temperature at 340∼400 °C, the pressure of 6∼12 MPa and the liquid hourly space velocity (LHSV) of 0.4∼1.0 h−1. The results showed that at a fixed pressure (10 MPa), reaction temperature (380 °C), LHSV (0.8 h−1) and the H2/oil ratio of (1600:1), the yield of the jet fuel fraction and the content of saturated hydrocarbons in the prodcuts were 58.0% and 60.7%, respectively. Finally, by GC–MS analysis, cyclanes and i-alkanes were dominant components in the jet fuel fraction, approximately accounting for 63.08% and 20.25%, respectively.

Characteristics of an improved collector derived from a waste of coal-processing plant for the beneficiation of Indian coking coal fines by froth flotation

ABSTRACTIn the present study, a collector reagent in the form of three distillation fractions from coal tar suitable for froth flotation was developed for the flotation of Indian coking coal fines. The developed tar fractions were compared with known reagent such as diesel, N-dodecane and kerosene oil. Tar fractions were found to be more efficient than the other known collectors. A particular coal tar distillate fraction (B) was found the best, which, in combination with methyl isobutyl carbinol (MIBC) as frother, successfully produced a yield of about 83.4% with low-ash 16.9%. In this way, a higher yield of coal fines was successfully obtained compared with other collectors. To illustrate this point, compared with other known collectors, the yields with diesel, N-dodecane and kerosene as collectors were only 71.4%, 66.7% and 61.1, respectively. The effect of three important variables of coal flotation process, namely collector dosages, frother dosages and pulp density, was also studied. A comparative study was performed of the FTIR (Fourier transform infra red) spectra on a Perking Elmer GX FTIR spectrometer at 2 cm−1 of tar fractions A, B, C and diesel oil to examine the role of various functional groups and structural aspects in their behavior and performance as a collector agent.

Production of Clean Fuels by Catalytic Hydrotreating a Low Temperature Coal Tar Distillate in a Pilot-Scale Reactor

China is one of the largest coal producers in the world and abundant coal tar is produced from coal gasification and carbonization every year. Thus, catalytic hydrotreating coal tar for the production of clean fuel has received substantial attention. In this work, clean liquid fuel was obtained from the catalytic hydrogenation of a low temperature coal tar (LTCT) distillate in a four-stage fixed bed reactor with various catalyst combinations on the pilot scale. Effects of dominant hydrotreating parameters, reaction temperature (290–390 °C), H2 pressure (8–15 MPa), and liquid hourly space velocity (0.2–0.6 h–1), on hydrotreating activity, the intermediate and final products, and chemical components of the hydrogenated oils were evaluated. Meanwhile, a possible reaction scheme for the conversion of alkyl-naphthalenes (AN) and phenols in feedstock was probed. The results showed that the four-stage reacting system was capable of removing sulfur and nitrogen to less than 10 μg/g. Furthermore, after hydrotreati...

Staying in the black

Orion Engineered Carbons has no aspirations to be something it is not. It makes carbon black. Its strategy is simple, too. Whenever possible, it makes and sells the most sophisticated grades of carbon black it can. Orion was founded in 2011 when two private equity firms, Rhone Capital and Triton Partners, bought Evonik Industries’ carbon black business for about $1.2 billion. Three years later, the newly independent firm launched a public offering on the New York Stock Exchange. Along with other players such as Cabot Corp. and Birla Carbon, Orion is among the world’s largest carbon black producers. Carbon black is essential for reinforcing rubber goods, especially tires. It’s also blended into plastics, printing inks, and paints, lending black pigmentation as well as properties such as strength, electrical conductivity, and protection from ultraviolet light. Producers normally make carbon black via the incomplete combustion of coal tar distillates, residual fuel oil,