Diluent

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A diluent (also referred to as a filler, dilutant or thinner) is a diluting agent. Certain fluids are too viscous to be pumped easily or too dense to flow from one particular point to the other. This can be troublesome, because it might not be economically feasible to transport such fluids in this state. To ease this restricted movement, diluents are added. This decreases the viscosity of the fluids, thereby also decreasing the pumping/transportation costs.

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One industrial application is the transport of crude oil via pipelines. Heavy crude oil/bitumen are fluids with high viscosity, especially at low temperatures. The addition of a diluent enables the diluted fluid (dilbit in the case of bitumen) to meet pipeline specifications in order for it to be efficiently transported. Typical diluent in this case is naphtha or condensate. [1]

Types of diluents more familiar to the general public include paint thinner and nail polish thinner, both of which improve the consistency and applicability of the products to which they are added. Diluent is also used as a term in solvent extraction for an inert solvent in which a metal extraction agent (extractant) is dissolved. In solvent extraction the diluent has potentially several uses. It can be used as a solvent (in the purely chemical sense rather than the solvent extraction sense) to dissolve an extractant which is a solid and so render it suitable for use in a liquid–liquid extraction process. In other cases such as PUREX nuclear reprocessing the diluent (kerosene) is used to reduce the maximum metal loading which the organic layer can reach. If the organic layer was to acquire too much metal then a solid metal complex might form, or more worryingly in a nuclear process the potential for a criticality accident if the fissile metal concentration in the organic phase becomes too high. Commonly in both lab and industrial solvent extraction of metals petroleum kerosene is used as a diluent, but in recent times it has been shown that Neste's second generation biodiesel which was formed by hydrodeoxygenation can be used as a diluent. [2]

Water is probably the most common and familiar diluent, but many substances, such as oils, do not dissolve well in water and therefore require different diluents to be diluted effectively without separating into parts.

Medications

Diluents are also very important in the pharmaceutical industry. They are inactive ingredients that are added to tablets and capsules in addition to the active drug. For example, a Tylenol 325 mg tablet does not weigh 325 mg. This is the weight of the active acetaminophen, while the tablet weighs more due to other additives known as diluents. These additives may be used as binders, disintegrants (help the tablet break apart in the digestive system), or flavor enhancers. Some very common diluents in tablets include starch, cellulose derivatives, and magnesium stearate (a lubricant). (See also Excipient.)

Diluents are also used in vaccines such as MMR to reconstitute the vaccine after storage. [3]

Breathing gas

In underwater diving a diluent gas is generally used to reduce the oxygen fraction of the breathing gas to a non-toxic level appropriate to the ambient pressure at which it is to be breathed. Diluent gases for this use are metabolically inert and non-toxic, but may have some level of narcotic effect at high partial pressure. The commonly used diluents for breathing gases are nitrogen, provided in the form of air, and helium, provided as heliox, or both nitrogen and helium together as trimix. The diluent used in scuba rebreathers contains enough oxygen to support life as it is also used as a bailout gas.

Helium is also useful as a breathing gas diluent to reduce work of breathing of gases, both at high ambient pressures, and for medical purposes, but it is an expensive gas, which limits its utility.

Drugs

The 1985 diethylene glycol wine scandal was an incident in which several Austrian wineries illegally adulterated their wines using the toxic substance diethylene glycol (a primary ingredient in some brands of antifreeze) to make the wines appear sweeter and more full-bodied in the style of late harvest wines. [4]

Related Research Articles

Kerosene, or paraffin, is a combustible hydrocarbon liquid which is derived from petroleum. It is widely used as a fuel in aviation as well as households. Its name derives from Greek: κηρός (kērós) meaning "wax", and was registered as a trademark by Nova Scotia geologist and inventor Abraham Gesner in 1854 before evolving into a generic trademark. It is sometimes spelled kerosine in scientific and industrial usage.

<span class="mw-page-title-main">Paint</span> Pigment applied over a surface that dries as a solid film

Paint is a liquid pigment that, after applied to a solid material and allowed to dry, adds a film-like layer, in most cases to create an image, known as a painting. Paint can be made in many colors and types. Most paints are either oil-based or water-based, and each has distinct characteristics.

<span class="mw-page-title-main">Ethylene glycol</span> Organic compound ethane-1,2-diol

Ethylene glycol is an organic compound with the formula (CH2OH)2. It is mainly used for two purposes, as a raw material in the manufacture of polyester fibers and for antifreeze formulations. It is an odorless, colorless, flammable, viscous liquid. It has a sweet taste, but is toxic in high concentrations. This molecule has been observed in outer space.

<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), 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.

Brake fluid is a type of hydraulic fluid used in hydraulic brake and hydraulic clutch applications in automobiles, motorcycles, light trucks, and some bicycles. It is used to transfer force into pressure, and to amplify braking force. It works because liquids are not appreciably compressible.

Hydrometallurgy is a technique within the field of extractive metallurgy, the obtaining of metals from their ores. Hydrometallurgy involve the use of aqueous solutions for the recovery of metals from ores, concentrates, and recycled or residual materials. Processing techniques that complement hydrometallurgy are pyrometallurgy, vapour metallurgy, and molten salt electrometallurgy. Hydrometallurgy is typically divided into three general areas:

A coolant is a substance, typically liquid, that is used to reduce or regulate the temperature of a system. An ideal coolant has high thermal capacity, low viscosity, is low-cost, non-toxic, chemically inert and neither causes nor promotes corrosion of the cooling system. Some applications also require the coolant to be an electrical insulator.

Tributyl phosphate, known commonly as TBP, is an organophosphorus compound with the chemical formula (CH3CH2CH2CH2O)3PO. This colourless, odorless liquid finds some applications as an extractant and a plasticizer. It is an ester of phosphoric acid with n-butanol.

Supercritical fluid extraction (SFE) is the process of separating one component (the extractant) from another (the matrix) using supercritical fluids as the extracting solvent. Extraction is usually from a solid matrix, but can also be from liquids. SFE can be used as a sample preparation step for analytical purposes, or on a larger scale to either strip unwanted material from a product (e.g. decaffeination) or collect a desired product (e.g. essential oils). These essential oils can include limonene and other straight solvents. Carbon dioxide (CO2) is the most used supercritical fluid, sometimes modified by co-solvents such as ethanol or methanol. Extraction conditions for supercritical carbon dioxide are above the critical temperature of 31 °C and critical pressure of 74 bar. Addition of modifiers may slightly alter this. The discussion below will mainly refer to extraction with CO2, except where specified.

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

Diethylene glycol (DEG) is an organic compound with the formula (HOCH2CH2)2O. It is a colorless, practically odorless, and hygroscopic liquid with a sweetish taste. It is a four carbon dimer of ethylene glycol. It is miscible in water, alcohol, ether, acetone, and ethylene glycol. DEG is a widely used solvent. It can be a normal ingredient in various consumer products, and it can be a contaminant. DEG has also been misused to sweeten wine and beer, and to viscosify oral and topical pharmaceutical products. Its use has resulted in many epidemics of poisoning since the early 20th century.

<span class="mw-page-title-main">Liquid–liquid extraction</span> Method to separate compounds or metal complexes

Liquid–liquid extraction, also known as solvent extraction and partitioning, is a method to separate compounds or metal complexes, based on their relative solubilities in two different immiscible liquids, usually water (polar) and an organic solvent (non-polar). There is a net transfer of one or more species from one liquid into another liquid phase, generally from aqueous to organic. The transfer is driven by chemical potential, i.e. once the transfer is complete, the overall system of chemical components that make up the solutes and the solvents are in a more stable configuration. The solvent that is enriched in solute(s) is called extract. The feed solution that is depleted in solute(s) is called the raffinate. Liquid-liquid extraction is a basic technique in chemical laboratories, where it is performed using a variety of apparatus, from separatory funnels to countercurrent distribution equipment called as mixer settlers. This type of process is commonly performed after a chemical reaction as part of the work-up, often including an acidic work-up.

Heavy crude oil is highly viscous oil that cannot easily flow from production wells under normal reservoir conditions.

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

Thiodiglycol, or bis(2-hydroxyethyl)sulfide (also known as 2,2-thiodiethanol or TDE), is the organosulfur compound with the formula S(CH2CH2OH)2. It is miscible with water and polar organic solvents. It is a colorless liquid. It is structurally similar to diethylene glycol.

Dilbit is a bitumen diluted with one or more lighter petroleum products, typically natural-gas condensates such as naphtha. Diluting bitumen makes it much easier to transport, for example in pipelines. Per the Alberta Oil Sands Bitumen Valuation Methodology, "Dilbit Blends" means "Blends made from heavy crudes and/or bitumens and a diluent, usually natural-gas condensate, for the purpose of meeting pipeline viscosity and density specifications, where the density of the diluent included in the blend is less than 800 kg/m3." If the diluent density is greater than or equal to 800 kg/m3, the diluent is typically synthetic crude and accordingly the blend is called synbit.

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

Chloroauric acid is an inorganic compound with the chemical formula H[AuCl4]. It forms hydrates H[AuCl4nH2O. Both the trihydrate and tetrahydrate are known. Both are orange-yellow solids consisting of the planar [AuCl4] anion. Often chloroauric acid is handled as a solution, such as those obtained by dissolution of gold in aqua regia. These solutions can be converted to other gold complexes or reduced to metallic gold or gold nanoparticles.

<span class="mw-page-title-main">Di(2-ethylhexyl)phosphoric acid</span> Chemical compound

Di(2-ethylhexyl)phosphoric acid (DEHPA or HDEHP) is an organophosphorus compound with the formula (C8H17O)2PO2H. The colorless liquid is a diester of phosphoric acid and 2-ethylhexanol. It is used in the solvent extraction of uranium, vanadium and the rare-earth metals.

Solvent impregnated resins (SIRs) are commercially available (macro)porous resins impregnated with a solvent/an extractant. In this approach, a liquid extractant is contained within the pores of (adsorption) particles. Usually, the extractant is an organic liquid. Its purpose is to extract one or more dissolved components from a surrounding aqueous environment. The basic principle combines adsorption, chromatography and liquid-liquid extraction.

Bitumen froth treatment is a process used in the Athabasca oil sands (AOS) bitumen recovery operations to remove fine inorganics—water and mineral particles—from bitumen froth, by diluting the bitumen with a light hydrocarbon solvent—either naphthenic or paraffinic—to reduce the viscosity of the froth and to remove contaminants that were not removed in previous water-based gravity recovery phases. Bitumen with a high viscosity or with too many contaminants, is not suitable for transporting through pipelines or refining. The original and conventional naphthenic froth treatment (NFT) uses a naphtha solvent with the addition of chemicals. Paraffinic Solvent Froth Treatment (PSFT), which was first used commercially in the Albian Sands in the early 2000s, results in a cleaner bitumen with lower levels of contaminates, such as water and mineral solids. Following froth treatments, bitumen can be further upgraded using "heat to produce synthetic crude oil by means of a coker unit."

<span class="mw-page-title-main">DEG monobutyl ether</span> Chemical compound

Diethylene glycol butyl ether is an organic compound, one of several glycol ether solvents. It is a colorless liquid with a low odour and high boiling point. It is mainly used as a solvent for paints and varnishes in the chemical industry, household detergents, brewing chemicals and textile processing.

<span class="mw-page-title-main">Diethylene glycol diglycidyl ether</span> Chemical compound

Diethylene glycol diglycidyl ether (DEGDGE) is an organic chemical in the glycidyl ether family with the formula C10H18O5.. The oxirane functionality makes it useful as a reactive diluent for epoxy resin viscosity reduction.

References

  1. Aoyama, Tomoki; Kayukawa, Tomoki; Fujimoto, Takayoshi (2018). Technology Division, Technology Innovation Center (ed.). "SCWC Process, Result of Pilot Plant Testing in Canada and Scaling Up to Commercia Unit" (pdf). 日揮技術ジャーナル (in Japanese). JGC Corporation. 6 (5): 3. Retrieved 2021-04-24.
  2. https://pubs.rsc.org/en/content/articlelanding/2024/su/d3su00078h#!divCitation https://doi.org/10.1039/D3SU00078H Mark R. StJ. Foreman, Richard K. Johansson, Gloria Mariotti, Ingmar Persson, Behabitu E. Tebikachew and Mikhail S. Tyumentsev, RSC Sustainability 2024
  3. Storage and handling of MMR vaccine
  4. Sonntagsblitz, July 10, 2005: Im Wein war nicht nur Wahrheit Archived 2007-09-28 at the Wayback Machine ("In wine was not only truth") (in German)