Diluent
Encyclopedia
A diluent 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 problematic, 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.
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
.
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. 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.
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
.)
In the black market in illegal drugs such as cocaine
, drugs may be "cut"
with diluents or fillers to give the appearance of a larger quantity.
Diluents are also used in vaccines to reconstitute the vaccine after storage, such as MMR.
Concentration
In chemistry, concentration is defined as the abundance of a constituent divided by the total volume of a mixture. Four types can be distinguished: mass concentration, molar concentration, number concentration, and volume concentration...
agent.
Certain fluids are too viscous
Viscosity
Viscosity is a measure of the resistance of a fluid which is being deformed by either shear or tensile stress. In everyday terms , viscosity is "thickness" or "internal friction". Thus, water is "thin", having a lower viscosity, while honey is "thick", having a higher viscosity...
to be pumped easily or too dense to flow from one particular point to the other. This can be problematic, 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.
One industrial application is the transport of crude oil via pipelines. Heavy crude oil
Heavy crude oil
Heavy crude oil or extra heavy crude oil is any type of crude oil which does not flow easily. It is referred to as "heavy" because its density or specific gravity is higher than that of light crude oil. Heavy crude oil has been defined as any liquid petroleum with an API gravity less than 20°.Extra...
/bitumen are fluids with high viscosity, especially at low temperatures. The addition of a diluent enables the diluted fluid (dilbit
Dilbit
Dilbit is diluted bitumen. Per the Alberta Oil Sands Bitumen Valuation Methodology, "Dilbit Blends" means "Blends made from heavy crudes and/or bitumens and a diluent usually condensate, for the purpose of meeting pipeline viscosity and density specifications, where the density of the diluent...
in the case of bitumen) to meet pipeline specifications in order for it to be efficiently transported. Typical diluent in this case is naphtha
Naphtha
Naphtha normally refers to a number of different flammable liquid mixtures of hydrocarbons, i.e., a component of natural gas condensate or a distillation product from petroleum, coal tar or peat boiling in a certain range and containing certain hydrocarbons. It is a broad term covering among the...
or condensate
Natural gas condensate
Natural-gas condensate is a low-density mixture of hydrocarbon liquids that are present as gaseous components in the raw natural gas produced from many natural gas fields....
.
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. 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
PUREX
PUREX is an acronym standing for Plutonium - URanium EXtraction — de facto standard aqueous nuclear reprocessing method for the recovery of uranium and plutonium from used nuclear fuel. It is based on liquid-liquid extraction ion-exchange.The PUREX process was invented by Herbert H. Anderson and...
nuclear reprocessing
Nuclear reprocessing
Nuclear reprocessing technology was developed to chemically separate and recover fissionable plutonium from irradiated nuclear fuel. Reprocessing serves multiple purposes, whose relative importance has changed over time. Originally reprocessing was used solely to extract plutonium for producing...
the diluent (kerosene
Kerosene
Kerosene, sometimes spelled kerosine in scientific and industrial usage, also known as paraffin or paraffin oil in the United Kingdom, Hong Kong, Ireland and South Africa, is a combustible hydrocarbon liquid. The name is derived from Greek keros...
) 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
Complex (chemistry)
In chemistry, a coordination complex or metal complex, is an atom or ion , bonded to a surrounding array of molecules or anions, that are in turn known as ligands or complexing agents...
might form, or more worryingly in a nuclear process the potential for a criticality accident
Criticality accident
A criticality accident, sometimes referred to as an excursion or a power excursion, is an accidental increase of nuclear chain reactions in a fissile material, such as enriched uranium or plutonium...
if the fissile
Fissile
In nuclear engineering, a fissile material is one that is capable of sustaining a chain reaction of nuclear fission. By definition, fissile materials can sustain a chain reaction with neutrons of any energy. The predominant neutron energy may be typified by either slow neutrons or fast neutrons...
metal concentration in the organic phase becomes too high.
Uses of diluents in pharmaceuticals
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 TylenolTylenol
Tylenol is a North American brand of drugs advertised for reducing pain, reducing fever, and relieving the symptoms of allergies, cold, cough, and flu. The active ingredient of its original, flagship product, paracetamol , is marketed as an analgesic and antipyretic...
325 mg tablet does not weigh 325 mg. This is the weight of the active acetaminophen
Paracetamol
Paracetamol INN , or acetaminophen USAN , is a widely used over-the-counter analgesic and antipyretic . It is commonly used for the relief of headaches and other minor aches and pains and is a major ingredient in numerous cold and flu remedies...
, 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
Starch
Starch or amylum is a carbohydrate consisting of a large number of glucose units joined together by glycosidic bonds. This polysaccharide is produced by all green plants as an energy store...
, cellulose derivatives, and magnesium stearate
Magnesium stearate
Magnesium stearate, also called octadecanoic acid, magnesium salt, is a white substance which is solid at room temperature. It has the chemical formula . It is a salt containing two equivalents of stearate and one magnesium cation...
(a lubricant). (See also Excipient
Excipient
An excipient is generally a pharmacologically inactive substance used as a carrier for the active ingredients of a medication. In many cases, an "active" substance may not be easily administered and absorbed by the human body; in such cases the substance in question may be dissolved into or...
.)
In the black market in illegal drugs such as cocaine
Cocaine
Cocaine is a crystalline tropane alkaloid that is obtained from the leaves of the coca plant. The name comes from "coca" in addition to the alkaloid suffix -ine, forming cocaine. It is a stimulant of the central nervous system, an appetite suppressant, and a topical anesthetic...
, drugs may be "cut"
Cutting agent
A cutting agent is a chemical used to "cut" illicit drugs with something less expensive than the drug itself.-Overview:The classical model of drug cutting A cutting agent is a chemical used to "cut" (dilute) illicit drugs with something less expensive than the drug itself.-Overview:The classical...
with diluents or fillers to give the appearance of a larger quantity.
Diluents are also used in vaccines to reconstitute the vaccine after storage, such as MMR.