Tar Bases Research Articles

Prospects for synthetic-fuel production in the coke-hot metal-steel cycle. Part 1

Theoretical analysis indicates that synthesis gas for the manufacture of synthetic liquid fuel may be pro� duced by gasification of coal using a steam-oxygen blast in outofservice blast furnaces and that this pro� cess is economically viable (1). At the same time, the use of highpotential secondary energy resources formed at integrated steel works with a closed cycle seems more efficient. The secondary energy resources are gases with fixed content of fuel components (CO, H2, CH4, CmHn, etc.). Their thermal value and unit yield, as a rule, are determined by the composition of the batch, and the particular physicochemical pro� cesses employed. In all, secondary energy resources account for about 50% of the total energy balance at the steel plant (2-4). Undoubtedly, in traditional blastfurnace production with a developed infrastruc� ture (for the production of coke, hot metal, steel, and so on), the sources of secondary energy resources are geographically distributed, as a rule, operate at differ� ent time periods, and differ in their thermodynamic parameters (temperature, pressure, composition, etc.). That considerably complicates the creation of a closed system permitting energy conservation and environmental protection in steelproducing regions. However, the energy efficiency of steel production may be considerably improved by combining even a few processes (for example, steel smelting in oxygen converters and coke production) in terms of the cap� ture and use of secondary energy resources and the production of synthesis gas by means of the chemical energy from the cokeoven and converter gases. For example, cokeoven gas is sent to the gassup� ply system of the steel plant after removing the tar, raw benzene, and pyridine bases in the coke plant's chem� ical shop. It is usually employed as a fuel in various processes.

Thermal cracking of black oil fuel in a mixture with shale

The results of studies performed for the development of a new process of the thermal cracking of tar as a suspension with ground Baltic oil shale in order to obtain motor fuel components are reported. The experimental results suggest undoubted advantages of the process over industrial thermal cracking because the deep degradation of tar (the yields of a gasoline fraction with bp to 180°C, middle distillates with bp of 180–360°C, and feedstock for catalytic cracking with bp of 360–520°C were ~12, 43–44, and ~15–16 wt % on an initial tar basis) was achieved upon the single-stage processing of the raw material under relatively mild conditions (5 MPa, 425°C, and a feed space velocity of 1.0 h−1). The resulting coke-like products and V and Ni contained in the raw material were deposited on the mineral matter of shale and removed from the reaction zone with the liquid products of the process.

Monoamine oxidase inhibitory activity in tobacco smoke varies with tobacco type

BackgroundIt has been suggested that inhibition of monoamine oxidase (MAO) activity by components of cigarette smoke may impact on smoking addiction, but it is unclear to what extent the known...

Production of chemicals by cracking pyrolytic tar from Loy Yang coal over iron oxide catalysts in a steam atmosphere

Iron oxide catalysts containing metal promoters were tested to evaluate whether they could be applied to the coal tar obtained from the pyrolysis of Loy Yang coal. Catalytic cracking of the coal tar in a steam atmosphere was conducted in a fixed-bed reactor at 773 K and ambient atmospheric pressure. For iron oxide catalysts containing cerium, zirconium, and aluminium, the total yield of monocyclic aromatic hydrocarbons, phenols, and ketones exceeded 40 mol-C% on a tar basis, while about 97 wt.% of the initial heavy tar was decomposed. The combination of cerium, zirconium, and aluminium improved the activity of the iron oxide catalyst. Moreover, the addition of steam to the tar vapour increased the yield of ketones and made the catalyst more durable.

Understanding the pyrolysis of CCA-treated wood: Part II. Effect of phosphoric acid

The pyrolysis process of chromated copper arsenate-treated wood impregnated with phosphoric acid (2–6 wt.%) has been investigated using a Kugelrohr short-path distillation apparatus. The presence of phosphoric acid is shown to change the overall pyrolysis kinetics and yields of products resulting in a decrease in the amount of volatile products and an increase in the char formation. The yield of levoglucosan was found to decrease in the presence of relatively higher concentrations of phosphoric acid, while the yield of levoglucosenone increased. The pyrolysis of chromated copper arsenate-treated wood in the presence of phosphoric acid gave rise to 22% (on water-free tar basis) levoglucosenone. Such data demonstrates the potential for a new pathway toward the rational utilization of chromated copper arsenate-treated wood waste.

Toxicological evaluation of glycerin as a cigarette ingredient

Glycerin is applied to cigarette tobacco at levels in the range of about 1–5% to improve moisture holding characteristics of tobacco and act as a surface active agent for flavor application. Neat material pyrolysis studies, smoke chemistry and biological activity studies (bacterial mutagenicity, cytotoxicity, in vivo micronucleus, and sub-chronic rodent inhalation) with mainstream smoke, or mainstream smoke preparations from cigarettes containing various target levels (5%, 10%, and 15%) of the glycerin were performed to provide data for an assessment of the use of glycerin as a cigarette tobacco ingredient. The actual levels of glycerin in the respective test cigarettes were determined to be 3.2%, 6.2% and 8.4% after cigarette production. At simulated tobacco burning temperatures up to 900 °C, neat glycerin did not pyrolyze extensively suggesting that glycerin would transfer intact to mainstream smoke (smoke was not analyzed for glycerin in this study). On a tar basis, nicotine in smoke was significantly decreased at 10% and 15% glycerin while water was increased at all addition levels. Addition of 10% or 15% glycerin also resulted in a statistically significant increase in acrolein (9%) and a decrease in acetaldehyde, propionaldehyde, aromatic amines, nitrogen oxides, tobacco specific nitrosamines, and phenols. Addition of 5% glycerin produced the same decrease in smoke constituents as the 10% and 15% groups but there was no concomitant increase in acrolein. Biological tests indicated no relevant differences in the genotoxic or cytotoxic potential of either mainstream smoke (or smoke preparations) from cigarettes with added glycerin compared to control cigarettes. Cigarette smoke atmosphere dilution, coupled with the lower nicotine delivery in the test cigarettes containing glycerin resulted in a lower nicotine delivery to the glycerin cigarette smoke exposed rats of the 90-day inhalation study. Smoke atmosphere acrolein was also reduced in a concentration-related manner. Incorporation of glycerin at target levels up to 15% did not produce any adverse effects in rats exposed for 90-days. The major observation in the study was a reduced biological activity of the smoke as indicated by a reduction in the severity and/or incidence of focal macrophage accumulation in the lungs and goblet cell hyperplasia/hypertrophy in the nose (level 1), and goblet cell staining depletion in the nose (level 1). The results of these studies with glycerin applied to cigarette tobacco suggest that adding glycerin to cigarette tobacco at typical use levels does not adversely alter the smoke chemistry or biological effects normally associated with exposure to mainstream cigarette smoke.

Removal of tar base from coal tar aromatics employing solid acid adsorbents

Aromatic compounds from coal tar generally contain a small amount of tar bases, such as quinoline and isoquinoline. These nitrogen-containing compounds can poison the acid-type catalysts and downgrade the aromatic products because of stinking odor. Four solid acid catalysts, silica-alumina, HY, NH4-mordenite, and γ-alumina are used to remove tar bases by adsorption. Wash oil (WO), refined naphthalene (RN), and an intermediate distillate from the China Steel coke plant (Taiwan) contain quinoline ranged from 0.03 to 8.9%. Quinoline and isoquinoline can be selectively removed from a mixture due to their strong chemisorption on acidic sites, thus the remaining compounds are not disturbed following adsorption. Naphthalene, a neutral compound, is physically adsorbed on solid acids, and is desorbed near its boiling point. Silica–alumina gives the best adsorption results because its wide-ranging pore sizes are accessible to the bulky quinoline molecule. The adsorption of HY and mordenite are significantly decreased because of the extremely diffusion limitation of quinoline in pore channels. Solid acids can be completely regenerated in air at 500–600°C. The adsorption ability of silica–alumina can be completely restored even after three cycles of regeneration. The adsorption rate increases with temperature although the capacity decreases. This work demonstrates that the adsorption through the use of solid acids is an effective method that can be used to reduce the amount of tar bases in coal tar aromatics.

Recovery of wax from Neyveli lignite tar and its structural characterization

An efficient method is described for the recovery of wax from lignite tar by solvent extraction followed by isolation of the wax from the extract. Light petroleum (boiling range 60–80°C) was used as the solvent. Under optimum conditions (i.e. solvent:feed ratio = 4 and time of reflux 1 h at 70°C), up to 85% of the tar could be extracted. In the next stage, almost the entire amount of wax present in the extract was precipitated by first distilling off the solvent and then treating the residual tar oil with acetone at 10°C. The yield of wax was found to be 14.6% on a dry tar basis. The recrystallized wax was characterized by elemental analysis, Fourier transform i.r. and 1H n.m.r. spectroscopy and molecular weight determination. The studies revealed that the wax obtained from Indian lignite tar primarily consists of long-chain (∼C 30) paraffins together with small amounts of long-chain fatty acids and their esters, in addition to unsaturates of the type RCHCH 2; RCHCHR 1 and RR 1CCH 2.

Extraction of tar acids with glycols

Recovery of tar acids from low temperature tar oil fraction boiling up to 270°C was investigated using glycols as solvent. AR grade ethylene glycol, diethylene glycol and triethylene glycol effected a recovery of 89%, 95.5% and 93.5%, respectively, of tar acids in two stages of extraction using a feed-solvent ratio of 1:1 by weight. Considerable amounts of neutral oil and tar bases were also extracted with solvents. Aqueous ethylene glycol (80 wt%) in the solvent-feed ratio of 1:1 was found to effect a recovery of 84% of the tar acids present in the tar oils in two extraction stages with 82% purity of tar acids. The purity of the extracted tar acids could be improved by the use of petroleum ether as a counter-solvent. The phase-equilibrium characteristics of the system, tar acids-neutral oil-80% aqueous ethylene glycol were studied. It has been shown that two theoretical extraction stages could effect the recovery of 98% of tar acids from a feed oil containing 45% of tar acids at the feed-solvent ratio of 1: 2 (by weight) and the highest degree of purity that could be achieved for tar acids is 87%.

SELECTIVE ISOLATION AND CHARACTERIZATION OF “MINA DO LEÃO” COAL TAR BASES

ABSTRACT Selective isolation of coal tar bases was performed by using two different separation methods: liquid-liquid extraction (LLE) and column liquid chromatography (CLC). Two cuts, A (boiling range 100°C – 230°C) and B (boiling range 230°C – 300°C), obtained by distillation of “Mina do Leao” coal tar oil, are compared after the isolation of bases by both methods through elemental analysis, infra-red spectroscopy and mass yield. In addition, cut A and its bases generated by both LLE and CLC were investigated by GC/MS. Pyridines, quinolines and anilines are the major classes found in the base fractions obtained by both methods. Although both showed to be equally selective for base isolation, the column liquid chromatography method demonstrated better recovery.

CHARACTERIZATION OP MEDIUM DISTILLATE CUT (100-230°C) OIL FROM HIGH-ASH “MINA DO LEÃO” BRAZILIAN COAL TAR

ABSTRACT Brazilian coal tar oil has been characterized by combined spectroscopic and chromatographic methods. A coal tar cut (100-230°C) obtained from a Gasifier Plant operating with “Mina do Leau” high-ash coal was fractionated into ABN “acid-base-neutral”groups. Infrared spectra and elemental analysis of each fraction has demonstrated the success of the fractionation step. GC/MS analysis of the total cut before the ABN fractionation revealed only hydrocarbons present in the sample. However, after the pre-fractionation step several nitrogen containing compounds of environmental concern were positively identified by GC/MS in the tar bases fraction.

Hydroliquefaction of Raniganj coal

Hydroliquefaction of a high volatile bituminous coal (Raniganj) was carried out in a batch autoclave. The activities of Harshaw CoMo 0402 T, Fe 2O 3 and SnCl 2 catalysts were evaluated on the basis of the amounts of organic tetrahydrofuran and benzene insolubles. The 250°C + product fraction was separated into preasphaltenes, asphaltenes, neutral oil, tar acids and tar bases by Integrated Solvent Recycle Chromatography. The average molecular weight of each fraction was determined by Size Exclusion Chromatography. The neutral oil fraction (250°C +) was further separated by Gradient Elution Chromatography. The effects of catalyst on the distribution of the above fractions are discussed.

CGC‐MS characterization of tar bases from a Brazilian high ash coal

Journal of High Resolution ChromatographyVolume 10, Issue 10 p. 579-581 Short Communication CGC-MS characterization of tar bases from a Brazilian high ash coal† E. S. Cararnão, E. S. Cararnão instituto de Química/UFRGSSearch for more papers by this authorL. M. F. Gomes, L. M. F. Gomes instituto de Química/UFRGSSearch for more papers by this authorM. D. de Oliveira, M. D. de Oliveira instituto de Química/UFRGSSearch for more papers by this authorF. M. Lanças, Corresponding Author F. M. Lanças Instituto de Física e Química de São Carlos, USP, 13.560- São Carlos - (SP) BrazilInstituto de Física e Química de São Carlos, USP, 13.560- São Carlos - (SP) BrazilSearch for more papers by this author E. S. Cararnão, E. S. Cararnão instituto de Química/UFRGSSearch for more papers by this authorL. M. F. Gomes, L. M. F. Gomes instituto de Química/UFRGSSearch for more papers by this authorM. D. de Oliveira, M. D. de Oliveira instituto de Química/UFRGSSearch for more papers by this authorF. M. Lanças, Corresponding Author F. M. Lanças Instituto de Física e Química de São Carlos, USP, 13.560- São Carlos - (SP) BrazilInstituto de Física e Química de São Carlos, USP, 13.560- São Carlos - (SP) BrazilSearch for more papers by this author First published: October 1987 https://doi.org/10.1002/jhrc.1240101014Citations: 14 † Based on a paper presented at the 1st COLACRO meeting, Rio de Janeiro, Brazil, March 17–19, 1986. AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat Citing Literature Volume10, Issue10October 1987Pages 579-581 RelatedInformation

Characterization of coal hydrogenation products by integrated solvent recycle chromatography

A column Chromatographic technique has been developed for the fractionation of coal hydrogenation products, boiling above 250 °C, into asphaltenes, tar acids, tar bases, neutral nitrogen compounds and neutral oils. The method involves extraction of coal hydrogenation products by n-pentane and the extract is passed through successive columns specially developed for selective retention of tar acids, tar bases and neutral nitrogen compounds. Solvent is simultaneously distilled and recycled. The technique provides a convenient means of characterizing coal hydrogenation products within 10–12 h.

Coal Tar Base Fractions as Pickling Inhibitors in Hydrochloric and Sulphuric Acid Solutions

AbstractFour coal-tar-base fractions were found to be effective in preventing the dissolution of low-carbon steel and in limiting the absorption of hydrogen by steel during pickling in 2 N- and 4 N-hydrochloric acid at 100° and 150°F. The crude quinoline bases and distilled quinoline bases were also effective inhibitors in 2 N-sulphuric acid solutions at 100°F, but at 200°F these same fractions afforded no better than 78% inhibition when tested at 0·25 vol.-%.Previous investigations have shown that NaCl, NaBr and NaI are moderately effective inhibitors in 2 N-sulphuric acid at 200°F. In the presence of coal-tar bases, these and other inorganic halides display a remarkable synergistic effect. When used at relatively low halide concentrations, the inhibitor properties of the mixtures are much better than those of the halides or tar bases used alone in sulphuric acid. The superior performances of the tar-base fractions in HCl may be associated with the fact that HCl is a halogen acid. Moreover, the tar base–...

Extraction of tar acids from tar oils by aqueous acetamide

AbstractAqueous acetamide has been found to be a good solvent for the extraction of tar acids from low temperature carbonisation tar oils. Saturated acetamide solution at 15–30° in the molar ratio acetamide/tar acids of 3 : 1 effects a recovery of about 90% of tar acids originally present in the oil in two extraction stages. The tar acids are obtained in 77% purity, the impurities consisting of neutral oils and tar bases. Re‐extraction with light petroleum can raise the purity of tar acids to 94%. Tar acids can be separated from the purified acetamide extract by suitable dilution with water.The system tar acids—(bases + neutral oils)—saturated aqueous acetamide has been studied. It has been shown that three theoretical counter‐current extraction stages are required to effect a recovery of 95% of tar acids from a feed oil containing 45% tar acids. 98% recovery of the tar acids could be achieved in four stages.

Extraction of tar acids from low‐temperature tar oils by acetic acid

AbstractAqueous acetic acid has been found to be a good solvent for the extraction of tar acids from low‐temperature tar oils. Acetic acid 60% (w/w) at 25° in the solvent/feed ratio of 1 : 0.8 effects a recovery of more than 89% of the tar acids present in the tar oils in two extraction stages. Besides tar acids, the acetic acid also extracts tar bases and neutral oils present in the oil to some extent. Re‐extraction with light petroleum reduces the neutral oil carry‐over by about 50%.The phase‐equilibrium characteristics of the system tar acids‐(bases + neutral oils)‐60% aqueous acetic acid have been studied. It is seen that two theoretical extraction stages could effect the recovery of 96% of tar acids from a feed oil containing 45% of tar acids. Use of light petroleum could reduce the neutral oil contamination of the extract by 76.2%. The tar acids could be recovered from the extracts by distillation.

Separations of Lutidines, Collidines and 2,3-Cyclopentenopyridines from Coal Tar Bases

Separations of Lutidines, Collidines and 2,3-Cyclopentenopyridines from Coal Tar Bases

Isolation of 2, 3-Cyclopenteno-5-methylpyridine from Coal Tar Bases

Isolation of 2, 3-Cyclopenteno-5-methylpyridine from Coal Tar Bases

高沸点夕ール塩基類のエタノールによる分離

高沸点夕ール塩基類のエタノールによる分離