Petroleum benzine

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Petroleum benzine is a hydrocarbon-based solvent mixture that is classified by its physical properties (e.g. boiling point, vapor pressure) rather than a specific chemical composition. This complicates distinction within the long list of petroleum distillate solvent mixtures: mineral spirits, naphtha, petroleum naptha, white gas, white spirits, turps substitute, mineral turpentine, petroleum ether, ligroin, and Stoddard solvent.

The chemical composition of a petroleum distillate can also be modified to afford a solvent with reduced concentration of unsaturated hydrocarbons, i.e. alkenes, by hydrotreating and/or reduced aromatics, e.g. benzene, toluene, xylene, by several dearomatization methods. [1] In a document that attempts to draw more concise distinctions between hydrocarbon solvents, conservator Alan Phenix[ who? ] explains that the most important distinction amongst the various hydrocarbon solvents is their boiling/distillation ranges (and, by association, volatility, flash point, etc.) and aromatic content. [2]

Given the toxicity/carcinogenicity of some aromatic hydrocarbons, most notably benzene, the aromatic content of petroleum distillate solvents, which would typically be in the 10-25% (w/w) range for most petroleum fractions, can be advantageously reduced when their unique solvation properties are not required, and a less odorous, lower toxicity solvent is desired, especially when present in consumer products.

Phenix further points out, "To all intents and purposes, petroleum benzine appears synonymous with petroleum spirit." Petroleum spirit is generally considered to be the fractions between the very lightest hydrocarbons, petroleum ether, and the heavier distillates, mineral spirits. For example, petroleum benzine with a boiling range of 36 - 83 °C sold by EMD Millipore under CAS-No. 64742-49-0 is identified in the product MSDS as hydrotreated light petroleum distillates comprising ≥ 90% C5-C7 hydrocarbons, n-alkanes, isoalkanes, and < 5% n-hexane, while Santa Cruz Biotechnology sells a petroleum ether product under the same CAS-No.

Fisher Scientific offers a product 'Benzine (Petroleum Naphtha)' that retails for a high price that would suggest it is a specialty product but conforms to Marathon Petroleum's 'VM&P Naphtha' (Varnish Makers & Painters’ Naphtha) found widely distributed in many hardware stores in North America. [2]

According to their corresponding MSDS, most commercially offered petroleum benzine solvents consist of paraffins (alkanes) with chain lengths of C5 to C9 (i.e. n-pentane to n-nonane and their isomers), cycloparaffins (cyclopentane, cyclohexane, ethylcyclopentane, etc.) and aromatic hydrocarbons (benzene, toluene, xylene, etc.).

The TSCA Definition 2008 describes petroleum benzine as "a complex combination of hydrocarbons obtained by treating a petroleum fraction with hydrogen in the presence of a catalyst. It consists of hydrocarbons having carbon numbers predominantly in the range of C4 through C11 and boiling in the range of approximately -20°C to 190°C."

Health concerns

Beginning in the 1960s and 70s, the high incidence rate of polyneuropathy amongst industrial workers chronically exposed to petroleum benzine and other hydrocarbon solvents prompted investigations into the safety of chronic exposure to petroleum distillates. [3] [4] [5]

Many of the cases of polyneuropathy amongst workers chronically exposed to vapors of petroleum benzine and similar solvents have been attributed to the n-hexane component of these mixtures.

Using an animal model (Wistar-strain male rats), Ono and coworkers [6] reported that chronic exposure (12 h a day for 24 weeks) to hydrocarbon solvent vapors conspicuously impaired peripheral nerve function in the 500 ppm n-hexane group, slightly impaired in the 200 ppm n-hexane group and petroleum benzine II group (containing 500 ppm n-hexane), and barely impaired in the petroleum benzine I group (containing 200 ppm n-hexane).

These results suggest that some components in petroleum benzine are likely to antagonize the neurotoxic effects of n-hexane to the peripheral nerves, possibly by inhibiting the oxidation of n-hexane to its more toxic metabolites 2-hexanone and 2,5-hexanedione.

Ono and coworkers also observed depressed body weight gains amongst the exposed groups compared to the control group in the order: petroleum benzine II > petroleum benzine I (containing 200 ppm n-hexane) >> 500 ppm n-hexane > 200 ppm n-hexane. These results suggest that other components found in petroleum benzine may have additive, synergistic or potentiative effects on the biological effects of n-hexane. [7] Namely, 1000 ppm n-hexane, 3000 ppm n-heptane, and 1000 ppm toluene were reported to have depressing effects on the body weight gain of rats. [8]

Related Research Articles

<span class="mw-page-title-main">Hydrocarbon</span> Organic compound consisting entirely of hydrogen and carbon

In organic chemistry, a hydrocarbon is an organic compound consisting entirely of hydrogen and carbon. Hydrocarbons are examples of group 14 hydrides. Hydrocarbons are generally colourless and hydrophobic; their odor is usually faint, and may be similar to that of gasoline or lighter fluid. They occur in a diverse range of molecular structures and phases: they can be gases, liquids, low melting solids or polymers.

<span class="mw-page-title-main">Toluene</span> Chemical compound

Toluene, also known as toluol, is a substituted aromatic hydrocarbon with the chemical formula C6H5CH3, often abbreviated as PhCH3, where Ph stands for the phenyl group. It is a colorless, water-insoluble liquid with the odor associated with paint thinners. It is a mono-substituted benzene derivative, consisting of a methyl group (CH3) attached to a phenyl group by a single bond. As such, its systematic IUPAC name is methylbenzene. Toluene is predominantly used as an industrial feedstock and a solvent.

<span class="mw-page-title-main">Solvent</span> Substance dissolving a solute resulting in a solution

A solvent is a substance that dissolves a solute, resulting in a solution. A solvent is usually a liquid but can also be a solid, a gas, or a supercritical fluid. Water is a solvent for polar molecules, and the most common solvent used by living things; all the ions and proteins in a cell are dissolved in water within the cell.

<span class="mw-page-title-main">Petrochemical</span> Chemical product derived from petroleum

Petrochemicals are the chemical products obtained from petroleum by refining. Some chemical compounds made from petroleum are also obtained from other fossil fuels, such as coal or natural gas, or renewable sources such as maize, palm fruit or sugar cane.

<span class="mw-page-title-main">Hexane</span> Chemical compound

Hexane or n-hexane is an organic compound, a straight-chain alkane with six carbon atoms and the molecular formula C6H14.

<span class="mw-page-title-main">Xylene</span> Organic compounds with the formula (CH3)2C6H4

In organic chemistry, xylene or xylol are any of three organic compounds with the formula (CH3)2C6H4. They are derived from the substitution of two hydrogen atoms with methyl groups in a benzene ring; which hydrogens are substituted determines which of three structural isomers results. It is a colorless, flammable, slightly greasy liquid of great industrial value.

Naphtha is a flammable liquid hydrocarbon mixture. Generally, it is a fraction of crude oil, but it can also be produced from natural-gas condensates, petroleum distillates, and the fractional distillation of coal tar and peat. In some industries and regions, the name naphtha refers to crude oil or refined petroleum products such as kerosene or diesel fuel.

Cyclohexane is a cycloalkane with the molecular formula C6H12. Cyclohexane is non-polar. Cyclohexane is a colourless, flammable liquid with a distinctive detergent-like odor, reminiscent of cleaning products. Cyclohexane is mainly used for the industrial production of adipic acid and caprolactam, which are precursors to nylon.

<span class="mw-page-title-main">White spirit</span> Petroleum-derived clear, transparent liquid

White spirit (AU, UK and Ireland) or mineral spirits (US, Canada), also known as mineral turpentine (AU/NZ/ZA), turpentine substitute, and petroleum spirits, is a petroleum-derived clear liquid used as a common organic solvent in painting. There are also terms for specific kinds of white spirit, including Stoddard solvent and solvent naphtha (petroleum). White spirit is often used as a paint thinner, or as a component thereof, though paint thinner is a broader category of solvent. Odorless mineral spirits (OMS) have been refined to remove the more toxic aromatic compounds, and are recommended for applications such as oil painting.

Ligroin is the petroleum fraction consisting mostly of C7 and C8 hydrocarbons and boiling in the range 90‒140 °C (194–284 °F). The fraction is also called heavy naphtha. Ligroin is used as a laboratory solvent. Products under the name ligroin can have boiling ranges as low as 60‒80 °C and may be called light naphtha.

Petroleum ether is the petroleum fraction consisting of aliphatic hydrocarbons and boiling in the range 35–60 °C, and commonly used as a laboratory solvent. Despite the name, petroleum ether is not an ether; the term is used only figuratively, signifying extreme lightness and volatility.

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Hydrocarbon mixtures are a group of various volatile, highly flammable, mixtures used chiefly as nonpolar solvents.

<span class="mw-page-title-main">PEG 400</span> Chemical compound

PEG 400 is a low-molecular-weight grade of polyethylene glycol. It is a clear, colorless, viscous liquid. Due in part to its low toxicity, PEG 400 is widely used in a variety of pharmaceutical formulations.

Hydroskimming is one of the simplest types of refinery used in the petroleum industry and still represents a large proportion of refining facilities, particularly in developing countries. A hydroskimming refinery is defined as a refinery equipped with atmospheric distillation, naphtha reforming and necessary treating processes. A hydroskimming refinery is therefore more complex than a topping refinery and it produces gasoline. The addition of catalytic reformer enables a hydroskimming refinery to generate higher octane reformate; benzene, toluene, and xylene; and hydrogen for hydrotreating units. However, a hydroskimming refinery produces a surplus of fuel oil with a relatively unattractive price and demand.

<span class="mw-page-title-main">Benzene</span> Hydrocarbon compound

Benzene is an organic chemical compound with the molecular formula C6H6. The benzene molecule is composed of six carbon atoms joined in a planar hexagonal ring with one hydrogen atom attached to each. Because it contains only carbon and hydrogen atoms, benzene is classed as a hydrocarbon.

Gadiv Petrochemical Industries Ltd. גדיב תעשיות פטרוכימיה בע"מ, is an Israeli petrochemical company, part of Bazan Group owned by Israel Corporation Ltd. Gadiv offices are located in Haifa, Israel. The company manufactures and markets over 500 thousand tons of petrochemical products each year including aromatics, aliphatic solvents and intermediates for the chemical, pharmaceutical, plastic and food industries. Gadiv is wholly owned by Oil Refineries Ltd.

Petroleum naphtha is an intermediate hydrocarbon liquid stream derived from the refining of crude oil with CAS-no 64742-48-9. It is most usually desulfurized and then catalytically reformed, which rearranges or restructures the hydrocarbon molecules in the naphtha as well as breaking some of the molecules into smaller molecules to produce a high-octane component of gasoline.

<span class="mw-page-title-main">BTX (chemistry)</span> Mixtures of benzene, toluene, and the three xylene isomers

In the petroleum refining and petrochemical industries, the initialism BTX refers to mixtures of benzene, toluene, and the three xylene isomers, all of which are aromatic hydrocarbons. The xylene isomers are distinguished by the designations ortho –, meta –, and para – as indicated in the adjacent diagram. If ethylbenzene is included, the mixture is sometimes referred to as BTEX.

The water associated fraction (WAF), sometimes termed the water-soluble fraction (W.S.F.), is the solution of low molecular mass hydrocarbons naturally released from petroleum hydrocarbon mixtures in contact with water. Although generally regarded as hydrophobic, many petroleum hydrocarbons are soluble in water to a limited extent. This combination often also contains less soluble, higher molecular mass components, and more soluble products of chemical and biological degradation.

References

  1. ↑ Böttger, Arne; Perez-Salando, Alvaro (2016). "Solubility of methane in n-hexane and a petroleum benzine at ambient temperatures". The Journal of Chemical Thermodynamics. 99 (1): 97–104. Bibcode:2016JChTh..99...97B. doi:10.1016/j.jct.2016.03.038.
  2. 1 2 Phenix, A. Generic Hydrocarbon Solvents: a Guide to Nomenclature. WAAC Newsletter Volume 29 Number 2 May 2007.
  3. ↑ Patty, F.A.: Industrial hygiene and toxicology, Vol. II, 2nd revised ed., pp. 1198-1201. New York: Interscience Publisher 1962
  4. ↑ ACGIH: Documentation of the threshold limit values for substances in workroom air, pp.121, 124, 126, 191 and 200 (1971)
  5. ↑ Browning, E.: Toxicity and metabolism of industrial solvents, pp.145-171. London: Elsevier 1965
  6. ↑ Ono, Yuichiro; Takeuchi, Yasuhiro; Hisanaga, Naomi; Iwata, Masamitsu; Kitoh, Junzoh; Sugiura, Yasuo (1982-08-01). "Neurotoxicity of petroleum benzine compared with n-hexane". International Archives of Occupational and Environmental Health. 50 (3): 219–229. Bibcode:1982IAOEH..50..219O. doi:10.1007/BF00378084. ISSN   0340-0131. PMID   7129648. S2CID   25219089.
  7. ↑ Takeuchi Y, Mabuchi C, Takagi S ( 1975) Polyneuropathy caused by petroleum benzine. Int Arch Arbeitsmed 34:185-197
  8. ↑ Takeuchi Y, Ono Y, Hisanaga N ( 1981) An experimental study on the combined effects of n-hexane and toluene on the peripheral nerve of the rat Br J Ind Med 38:14-19
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