Soc. [98] Benzene metabolism involves enzymes coded for by polymorphic genes. ; Daniels, F., Contact China Manufactory Wuhan Kaimubuke Pharmaceutical Technology Co., Ltd for the product BERYLLIUM CHLORIDE. [all data], Fortier, Benson, et al., 1976 C11H16 = 148.25. Flammable, irritating vapor is produced. phys. Solution Chem., 1987, 16, 745-752. Through calculating more than thirty parameters, Lonsdale demonstrated that the benzene ring could not be anything but a flat hexagon, and provided accurate distances for all carbon-carbon bonds in the molecule. NQ01 metabolizes benzoquinone toward polyphenols (counteracting the effect of MPO). Benzene production is currently expanding in the Middle East and in Africa, whereas production capacities in Western Europe and North America are stagnating. The reaction of the diazonium compound derived from aniline with hypophosphorus acid gives benzene. 1 lists the specific heats for various materials. As benzene can cause cancer, NIOSH recommends that all workers wear special breathing equipment when they are likely to be exposed to benzene at levels exceeding the recommended (8-hour) exposure limit of 0.1 ppm.[84]. Etude thermochimique dans la serie furanique, Benzene and cyclohexane have a similar structure, only the ring of delocalized electrons and the loss of one hydrogen per carbon distinguishes it from cyclohexane. J. Res. Reproductive toxicity Suspected of damaging fertility or the unborn child. The liquid product is 40.0 mole% B, and the vapor product is 68.4 mole% B. and Informatics, Vibrational and/or electronic energy levels, Electron-Impact Ionization Cross Sections (on physics web site), Computational Chemistry Comparison and Benchmark Database, X-ray Photoelectron Spectroscopy Database, version 4.1, NIST Polycyclic Aromatic Hydrocarbon Structure Index, NIST / TRC Web Thermo Tables, "lite" edition (thermophysical and thermochemical data), NIST / TRC Web Thermo Tables, professional edition (thermophysical and thermochemical data). The most widely practiced example of this reaction is the ethylation of benzene. ; Simonov, V.M. Czarnota, I., He gave the compound the name benzin. Anal. [all data], Tanaka, 1985 The heat capacity of the system benzene + diphenylmethane, Duff, G.M. Benzene vapor is heavier than air. The triple point of a substance is the temperature and pressure at which the three phases (gas, liquid, and solid) of that substance coexist in thermodynamic equilibrium. Tanaka, R., [all data], Richards and Wallace, 1932 [103], Under specific conditions and in the presence of other chemicals benzoic acid (a preservative) and ascorbic acid (Vitamin C) may interact to produce benzene. Only emails and answers are saved in our archive. If you want to promote your products or services in the Engineering ToolBox - please use Google Adwords. 2. Energy released when benzene converts from 100oC to 80oC (in this range it is gas as temperature>Boiling . Please read AddThis Privacy for more information. Note: (s) notation indicates equilibrium temperature of vapor over solid, otherwise value is equilibrium temperature of vapor over liquid. Many important chemical compounds are derived from benzene by replacing one or more of its hydrogen atoms with another functional group. This reaction is called Sandmeyer reaction. [17] Michael Faraday first isolated and identified benzene in 1825 from the oily residue derived from the production of illuminating gas, giving it the name bicarburet of hydrogen. Eliminate heat and ignition sources such as sparks, open flames, hot surfaces and static One way of understanding the carcinogenic effects of benzene is by examining the products of biological oxidation. Excess thermodynamic functions of the systems: benzene + p-xylene and benzene + p-dioxan, [all data], Rastorguev and Ganiev, 1967 Wear safety glasses and use protective gloves. [all data], Naziev, Bashirov, et al., 1986 In 2005, the water supply to the city of Harbin in China with a population of almost nine million people, was cut off because of a major benzene exposure. Rover's Latest Discovery Puts It 'On the Table', "Organic matter preserved in 3-billion-year-old mudstones at Gale crater, Mars", "A Crystallographic Study of Solid Benzene by Neutron Diffraction", Proceedings of the Royal Society of London, Series A, "Electronic structure of the benzene molecule", "Unicode Character 'BENZENE RING' (U+232C)", "Unicode Character 'BENZENE RING WITH CIRCLE' (U+23E3)", "Heterocyclic Chemistry: Heterocyclic Compounds", "A pervasive molecule is captured in a photograph", "Market Study: Benzene (2nd edition), Ceresana, August 2014", "Market Study: Toluene, Ceresana, January 2015", "Control of Hazardous Air Pollutants From Mobile Sources", "Traffic-related air pollution and the onset of myocardial infarction: disclosing benzene as a trigger? It is also used in water treatment chemicals, paper sizing, artificial sweeteners, flavor enhancers, cosmetics, and lubricants. on behalf of the United States of America. Vys. The new understanding of benzene, and hence of all aromatic compounds, proved to be so important for both pure and applied chemistry that in 1890 the German Chemical Society organized an elaborate appreciation in Kekul's honor, celebrating the twenty-fifth anniversary of his first benzene paper. Hydrogenation cannot be stopped to give cyclohexene or cyclohexadienes as these are superior substrates. 2 C6H6 + 15 0212 CO2 + 6HO + 1562 kcal How much heat is given off when 877 g (one liter) of benzene reacts with oxygen? Diffuse through otherliquids 6. Staveley, L.A.K. J. Chem. ; Shipova, V.A., The molecule is located on a crystallographic inversion center and the terminal aminophenoxy rings are almost perpendicular to the central benzene ring with a dihedral angle of 85.40 (4). Specific heat of benzenoid hydrocarbons, It is produced by the oxidation of benzene or n-butane in the presence of vanadium oxide catalysts. Mixtures containing N,N-dimethylformamide, *** Very flammable. Mean specific heat in homologous series of binary and ternary positive azeotropes, Tanaka, R., J. Chem. Lainez, A.; Rodrigo, M.M. Replacement of a second CH bond with N gives, depending on the location of the second N, pyridazine, pyrimidine, or pyrazine. J. Soc., 1925, 47, 1490-1503. [90] The NIOSH short-term exposure limit (STEL 15 min) is 1 ppm. Fortier, J.-L.; Benson, G.C. Acta, 1967, 37, 200-208. Aust. Willams, J.W. Trans. GSH is involved with the formation of phenylmercapturic acid. [88][89] In September 1995, NIOSH issued a new policy for developing recommended exposure limits (RELs) for substances, including carcinogens. NQ01 mutations result in loss of function and may result in decreased detoxification. It is a byproduct of the incomplete combustion of many materials. [citation needed], Several tests can determine exposure to benzene. [66], Toluene is now often used as a substitute for benzene, for instance as a fuel additive. [96], The paradigm of toxicological assessment of benzene is shifting towards the domain of molecular toxicology as it allows understanding of fundamental biological mechanisms in a better way. 3 mtr circ Lifting strap 1 Ton x 1.5m EWL round sling Hoist, 30PCS 3/8-16x1-3/4" Allen Socket Head Cap Screws Bolts Alloy Coarse Black Oxide, Drive 6 Point Deep Impact Socket 55433 x 1/2 in Steelman 13/16 in, Combustible Gas Leak LEL Natural Gas Detector Methane Benzene Propane Alarm, 1-Count Sharpie Twin-Tip . Archibald Scott Couper in 1858 and Johann Josef Loschmidt in 1861[36] suggested possible structures that contained multiple double bonds or multiple rings, but too little evidence was then available to help chemists decide on any particular structure. ; Wilhelm, E.; Hamedi, M.H., Expert Answer. Molecular Formula / Molecular Weight. The limit of the fusion process is the hydrogen-free allotrope of carbon, graphite. The specific heat of liquid water is 4.184 J/g C and the specific heat of steam is 1.99 J/g C. H vapof water = 40.8 kJ/mol. Contact. Chem. [44][45] Using large crystals of hexamethylbenzene, a benzene derivative with the same core of six carbon atoms, Lonsdale obtained diffraction patterns. Chem. 5. We don't save this data. Even if it is not a common substrate for metabolism, benzene can be oxidized by both bacteria and eukaryotes. J. Chem. Andrews, D.H.; Lynn, G.; Johnston, J., Rastorguev, Yu.L. Enthalpies of combustion of toluene, benzene, cyclohexane, cyclohexene, methylcyclopentane, 1-methylcyclopentene, and n-hexane, Benzene depletion in a laminar premixed flat stoichiometric low-pressure methane/air/benzene (1.5%) flame was investigated using a recently developed kinetic model that has been tested for low-pressure combustion of acetylene, ethylene, and benzene.Experimental flame structures of two stoichiometric methane/air flames (v =34.2 cm s 1, 5.33 kPa) with and without the addition of 1.5% of . Glutathione seems to play an important role by protecting against benzene-induced DNA breaks and it is being identified as a new biomarker for exposure and effect. Benzene, also commonly known as benzol, is a colorless liquid with a sweet pungent odor. Advertisement Advertisement New questions in Physics. Tohoku Imp. Chat now for more business. The EPA requires that spills or accidental releases into the environment of 10 pounds (4.5kg) or more of benzene be reported. If you want to promote your products or services in the Engineering ToolBox - please use Google Adwords. Benzene is a natural constituent of petroleum and is one of the elementary petrochemicals. Thermal data on organic compounds. Calculate the number of joules required to melt 57.4 g of benzene at 5.5 degrees; The specific heat of toluene, C_7H_8, is 1.13 J/g K. Inzh-Fiz. Add standard and customized parametric components - like flange beams, lumbers, piping, stairs and more - to your Sketchup model with the Engineering ToolBox - SketchUp Extension - enabled for use with the amazing, fun and free SketchUp Make and SketchUp Pro .Add the Engineering ToolBox extension to your SketchUp from the SketchUp Pro Sketchup Extension Warehouse! The molecular conformation is stabilized by NHO and NHN intermolecular hydrogen-bonding interactions. Hyder Khan, V.; Subrahmanyam, S.V., J. Chem. Benzene is a colorless and highly flammable liquid with a sweet smell, and is partially responsible for the aroma of gasoline. NBS, 1946, 36, 455-461. Surface area of the liquid c. Pressure 6. MSDS for benzene is available at AMOCO. Cp,gas : Ideal gas heat capacity (J/molK). The pure material, and any solutions containing it, constitute a fire risk. [68] European petrol specifications now contain the same 1% limit on benzene content. [all data], Duff and Everett, 1956 When gasoline burns, the benzene reacts with oxygen. [40] Some historians have suggested that the parody was a lampoon of the snake anecdote, possibly already well known through oral transmission even if it had not yet appeared in print. Except where noted otherwise, data relate to, This page was last edited on 14 February 2023, at 04:18. [67], As a gasoline (petrol) additive, benzene increases the octane rating and reduces knocking. In general, the evaluated uncertainty limits are on the order of (0.5 to 2.5) kJ/mol. [102], Inhaled benzene is primarily expelled unchanged through exhalation. Zhur. Engineering ToolBox - Resources, Tools and Basic Information for Engineering and Design of Technical Applications! Excess heat capacities of binary liquid mixtures determined with a Picker flow calorimeter, Due to the cyclic continuous pi bonds between the carbon atoms, benzene is classed as an aromatic hydrocarbon. In catalytic reforming, a mixture of hydrocarbons with boiling points between 60 and 200C is blended with hydrogen gas and then exposed to a bifunctional platinum chloride or rhenium chloride catalyst at 500525C and pressures ranging from 850 atm. Similar problems were reported by the FDA in the United States.[104]. [47][48] It was the German chemist Carl Grbe who, in 1869, first used the prefixes ortho-, meta-, para- to denote specific relative locations of the substituents on a di-substituted aromatic ring (viz, naphthalene). Hence the specific heat of benzene = 1716.475 J/kg.C. lifetime movies list 2023; what does a call back interview mean; stashbox vape bmm; mens burberry belt; boa account number and tax id pdf 2022; Excess properties of the mixture bis(2-dichlorethyl)ether (chlorex) + 2,2,4-trimethylpentane (isooctane), ; Smith, J.F. As the specific heat of water is the most, it means most heat is required to raise the temperature of 1 g of water by 1C and it is because the water molecules are strongly held together by hydrogen bonds. ; Ganiev, Yu.A., Measurement of air and water levels of benzene is accomplished through collection via activated charcoal tubes, which are then analyzed with a gas chromatograph. Univ. Vapors may form explosive mixtures with air. Temperature and Pressure - Online calculator, figures and table showing density and specific weight of benzene, C 6 H 6, at temperatures ranging from 5 to 325 C (42 to 620 F) at atmospheric and higher pressure - Imperial and SI Units. Hazardous Combustion Products Carbon monoxide (CO). Keep away from heat and sources of ignition. Birch reduction, a non catalytic process, however selectively hydrogenates benzene to the diene. Am. [65] More than half of the entire benzene production is processed into ethylbenzene, a precursor to styrene, which is used to make polymers and plastics like polystyrene. For example, mutations in CYP2E1 increase activity and result in increased generation of toxic metabolites. Myeloperoxidase mutations result in loss of function and may result in decreased generation of toxic metabolites. [all data], Reddy, 1986 [all data], Recko, 1968 ; Roux-Desgranges, G.; Berkane, M.; Jimenez, E.; Wilhelm, E., France, 1929, 45, 36-49. J. Chem. 80.0C Boiling Point Melting Point Heat of Vaporization: Heat of Fusion 10.0C 10.0 kJ/mol 30.0 kJ/mol 100.0 J/mol K 90.0 J/mol K 70.0 J/mol K heat capacity . If the sample is heated at constant pressure (P = 1 atm), calculate the amount of energy in kJ needed to raise the temperature of the sample to 102.70 C. Thermodynam., 1988, 20, 1183-1189. / Cincia & Tecnologia dos Materiais 26 (2014) 142-149 143 test specimen but depends on the methods of preparation of the specimen, presence of surface The empirical formula for benzene was long known, but its highly polyunsaturated structure, with just one hydrogen atom for each carbon atom, was challenging to determine. Chemical, physical and thermal properties of benzene:Values are given for liquid at 25oC /77oF / 298 K and 1 bara, if not other phase, temperature or pressure given. Molecular Weight 1 134.22 CAS 105-05-5 Other Names 1,4-DIETHYLBENZENE Benzene, p-diethyl- p-Diethylbenzene p-Ethylethylbenzene para-Diethylbenzene : Acentric Factor. (VIII. Benzeneis present in crude oils and is a product of oil-refining processes. [all data], Fiock, Ginnings, et al., 1931 J. Chem. [all data], Gorbunova, Grigoriev, et al., 1982 Benzene: Patient information sheet, "Drinking Water Contaminants | Organic Chemicals | Benzene", "Benzene Toxicity: Standards and Regulations", "Documentation for Immediately Dangerous to Life or Health Concentrations (IDLH): Introduction", "Blood concentrations of volatile organic compounds in a nonoccupationally exposed US population and in groups with suspected exposure", "100 tonnes of pollutants spilled into Chinese river", "Drinking water contamination from the thermal degradation of plastics: Implications for wildfire and structure fire response", "A Former Nazi Labor Camp in Austria, Now Billed as a Tourist Site", Dept. Chem. Ann. Prosen, E.J. It also shows the saturation pressure with changes in temperature. Explain how the vaporization of a liquid is affected by increasing the: a. [71] Highly instructive but of far less industrial significance is the Friedel-Crafts alkylation of benzene (and many other aromatic rings) using an alkyl halide in the presence of a strong Lewis acid catalyst. Williams, J.W. Some thermodynamice properties of the systems benzene + ethylene dichloride, benzene + carbon tetrachloride, acetone + chloroform, and acetone + carbon disulphide, (The density of benzene is 0.80 g/mL, its specific heat capacity is 1.74 J/g K, and its heat of fusion is 127 J/g.) ; Tupman, W.I. Acta, 1985, 88, 255-260. See also tabulated values of specific heat of gases, food and foodstuff, metals and semimetals, common solids and other common substances as well as values of molar heat capacity of common organic substances and inorganic substances. been selected on the basis of sound scientific judgment. Nitrobenzene is the precursor to aniline. Specific heat of liquids. Specific target organ toxicity - repeated exposure Due to partial or complete lack of data the classification is not possible. Neft Gaz. [18][19] In 1833, Eilhard Mitscherlich produced it by distilling benzoic acid (from gum benzoin) and lime. J. [all data], Vesely, Zabransky, et al., 1979 Aspiration hazard - Category 1 The signal word is danger. Given that demand for para-xylene (p-xylene) substantially exceeds demand for other xylene isomers, a refinement of the TDP process called Selective TDP (STDP) may be used. Chem., 1948, 79, 162-177. Kalali, H.; Kohler, F.; Svejda, P., Replacing one CH with N gives the compound pyridine, C5H5N. DH - Eugene S. Domalski and Elizabeth D. Hearing, Go To: Top, Condensed phase thermochemistry data, Notes, Roux, Temprado, et al., 2008 A. Pressions maxima des vapeurs du benzene et du cyclohexane aux temperatures moyennes et calcul de leurs chaleurs specifiques principales, J. Phys. Hydrogen chloride gas. [all data], Ferguson and Miller, 1933 [100] About 50% of the entire nationwide (United States) exposure to benzene results from smoking tobacco or from exposure to tobacco smoke. Experimental device for measurement of isobaric specific heat of electrolytes at elevated pressures, Data, 1969, 14, 102-106. Measurement of the heat capacity of a small volume of liquid by the piezo-thermometric method. Uber binare flussige Mischungen I. Mischungswarment, Volumseffekte und Zustandsdiagramme von chlorex mit benzol und n-alkylbenzolen, As its toxicity became obvious, benzene was supplanted by other solvents, especially toluene (methylbenzene), which has similar physical properties but is not as carcinogenic. Faraday Soc., 1956, 52, 753-763. Have definite shape (resist deformation) 2. Eng. ; Grigoriev, V.A. Study of the heat capacity of selected solvents, Storage class Storage class (TRGS 510): 3: Flammable liquids 7.3 Specific end use(s) Apart from the uses mentioned in section 1.2 no other specific uses are stipulated SECTION 8: Exposure controls/personal protection Proc. ; T = 280 to 353 K. Data also given by equation. Am. A typical reaction yield exceeds 95%. II., Benzene Formula:C6H6 Molecular weight:78.1118 IUPAC Standard InChI:InChI=1S/C6H6/c1-2-4-6-5-3-1/h1-6HCopy IUPAC Standard InChIKey:UHOVQNZJYSORNB-UHFFFAOYSA-NCopy CAS Registry Number:71-43-2 Chemical structure: This structure is also available as a 2d Mol fileor as a computed3d SD file The 3d structure may be viewed using Javaor Javascript. Maleic anhydride is widely used in resins, coating, pharmaceuticals, surfactants, agricultural products, and plastics. Sci. ; Picker, P., Using a precise scanning-microcalorimetric technique, the heat-capacity difference between water and an aqueous solution of benzene or of toluene has been measured for a broad temperature range (from 278 to 413 K) under excess pressure, and the partial specific heat capacity of these solutes has been determined. Sci. On this Wikipedia the language links are at the top of the page across from the article title. J. Chem. This is also used in SPECTROSCOPY, the science of analysing what something is made Continue Reading James Macklin When certain compounds are heated, light is emitted because the compounds CONVERT some of the energy from the heating into coloured light of specific colours. J. [all data], Ogawa and Murakami, 1985 Toluene is also processed into benzene. All rights reserved. The current ACGIH biological exposure limits for occupational exposure are 500 g/g creatinine for muconic acid and 25 g/g creatinine for phenylmercapturic acid in an end-of-shift urine specimen.[91][92][93][94]. J. [43], In 1929, the cyclic nature of benzene was finally confirmed by the crystallographer Kathleen Lonsdale using X-ray diffraction methods. [9], 1919, 11, 253-291. This is often called "on-purpose" methodology to produce benzene, compared to conventional BTX (benzene-toluene-xylene) extraction processes. Benzene is a liquid at standard conditions. [46], The German chemist Wilhelm Krner suggested the prefixes ortho-, meta-, para- to distinguish di-substituted benzene derivatives in 1867; however, he did not use the prefixes to distinguish the relative positions of the substituents on a benzene ring. Benzoic acid and its salts undergo decarboxylation to benzene. HHS Vulnerability Disclosure. Zhdanov, A.K., Z. Phys. Excess heat capacities for mixture of benzene with n-heptane at 293.15, 298.15 and 303.15 K, Sufficient heat is supplied to the reboiler to give, V /F = 0.855, and the reflux ratio L/D in the top of the column is constant at 0.50. As benzene is ubiquitous in gasoline and hydrocarbon fuels that are in use everywhere, human exposure to benzene is a global health problem. Czech. Isentropic compressibilities of binary liquid mixtures at 303.15 and 313.15 K, Huffman, H.M.; Parks, G.S. DRB - Donald R. Burgess, Jr. Hence it floats onwater. Heat capacities of some organic substances at low temperature, Please read AddThis Privacy for more information. Trans. errors or omissions in the Database. [all data], Czarnota, 1991 Heat capacities of some organic liquids determined with the mixing calorimeter, Ber. Data, 2008, 37, 4, 1855-1996. Instead, retain in a safe place in the laboratory (well away from any source of ignition). A.1.89 103 J B.54.4 J C. 840 J D.2.08 10-2 J E. 48.1 J C. 840 J [A 100-W lightbulb is placed in a cylinder equipped with a moveable piston. The title compound, C18H16N2O2, is a precusor for the synthesis of polyimides. In another human study, 30% of absorbed dermally applied benzene, which is primarily metabolized in the liver, was excreted as phenol in the urine. [all data], Aoyama and Kanda, 1935 Heat Stress Risk Assessment for Baseball and Softball Assignors . Ferguson, A.; Miller, J.T., Benzene, C6H6, is a clear colorless to light-yellow liquid, flammable with a petroleum-like, aromatic odor. [all data], Atalla, El-Sharkawy, et al., 1981 J. Chem. (2007), Last edited on 15 February 2023, at 05:01, United States Environmental Protection Agency, US Department of Health and Human Services, Agency for Toxic Substances and Disease Registry, Occupational Safety and Health Administration, National Institute for Occupational Safety and Health, an explosion at a China National Petroleum Corporation (CNPC) factory, Industrial Union Department v. American Petroleum Institute, Industrial & Engineering Chemistry Chemical & Engineering Data Series, "Surface tension measurements show that chaotropic salting-in denaturants are not just water-structure breakers", Proceedings of the National Academy of Sciences of the United States of America, "Benzene - an overview | ScienceDirect Topics", "On new compounds of carbon and hydrogen, and on certain other products obtained during the decomposition of oil by heat", Philosophical Transactions of the Royal Society, "ber das Benzol und die Suren der Oel- und Talgarten", Reports of the Proceedings of the Scientific Society of Freiburg, "On the oxidation of phenyl alcohol, and a mechanical arrangement adapted to illustrate structure in the non-saturated hydrocarbons", Proceedings of the Royal Society of Edinburgh, "Sur la constitution des substances aromatiques", "Ueber einige Condensationsproducte des Aldehyds", "An explanation of the laws which govern substitution in the case of benzenoid compounds", "Crocker, Not Armit and Robinson, Begat the Six Aromatic Electrons". Why is the liquid phase of water denser than the solid phase? Copper standard solution,CAS Number:7440-50-8,Specification:50mL ber das Verdampfungsgleichgewicht Benzol-1-2-Dichloraethan, Isotopic effect in the specific heat of some deutero compounds, ; T = 293 to 323 K. Data calculated from equation. Gorbunova, N.I. Table data obtained from CRC Handbook of Chemistry and Physics 44th ed. [105] Benzene leaked into the Songhua River, which supplies drinking water to the city, after an explosion at a China National Petroleum Corporation (CNPC) factory in the city of Jilin on 13 November 2005. Excess volumes and excess heat capacities of tetrachloroethene + cyclohexane, + methylcyclohexane, + benzene, and + toluene at 298.15 K, Grolier, J.-P.E. Am. National Institute of Standards and Heats of combustion and formation at 25C of the alkylbenzenes through C10H14, and of the higher normal monoalkylbenzenes, [all data], Prosen, Johnson, et al., 1946 Soc. Int. ; T = 9 to 80C, mean Cp, five temperatures. Ber. cHliquid : Standard liquid enthalpy of combustion (kJ/mol). Thermodynam., 1982, 14, 1199-1200. Sieg, L.; Crtzen, J.L. [all data], Grolier, Roux-Desgranges, et al., 1993 Short Commun. Today, most benzene comes from the petrochemical industry, with only a small fraction being produced from coal. Excess volumes and excess heaat capacitiies of some mixtures with trans,trans,cis-1,5,9-cyclododecatriene at 298.15K, Approximately 24,700,000 tons were produced in 1999. Chim., 1968, 16, 549-552. ; Bashirov, M.M. Substantial quantities of epidemiologic, clinical, and laboratory data link benzene to aplastic anemia, acute leukemia, bone marrow abnormalities and cardiovascular disease. Department of Health and Human Services. [all data], Rajagopal and Subrahmanyam, 1974 In this process, the xylene stream exiting the TDP unit is approximately 90% p-xylene. ), 1977, C9-1-C9-4. The affected batches were removed from sale. [all data], Subrahmanyam and Khan, 1969 Ahlberg, J.E. Wilhelm, E.; Faradjzadeh, A.; Grolier, J.-P.E., Recovery of the aromatics, commonly referred to as BTX (benzene, toluene and xylene isomers), involves such extraction and distillation steps.