- Total Acid Number
The Total Acid Number is the amount of
potassium hydroxidein milligrams that is needed to neutralize the acids in one gram of oil. It is an important quality measurement of crude oil. The TAN value indicates to the crude oil refinerythe potential of corrosionproblems. It is usually the naphthenic acids in the crude oil that causes corrosion problems. This type of corrosion is referred to as naphthenic acid corrosionor NAC.
TAN value can be deduced by a couple of different methods, eg: by color indicator titration, by potentiometric titration.
The sample is normally dissolved in toluene and propanol with a little water and titrated with alcoholic potassium hydroxide (if sample is acidic). A glass electrode and reference electrode is immersed in the sample and connected to a voltmeter/potentiometer. The meter reading (in millivolts) is plotted against the volume of titrant. The end point is taken at the distinct inflection of the resulting curve corresponding to the basic buffer solution.
Color Indicating Titration
An appropriate pH color indicator eg: Phenolphthalein, is used. Titrant is added to the sample by means of a burette. The volume of titrant used to cause a permanent color change in the sample is recorded and used to calculate the TAN value.
* [http://www.cpieng.com/lab-services_total-acid-number.htm TAN test]
Wikimedia Foundation. 2010.
Look at other dictionaries:
Total Base Number — (TBN) is a measure of a lubricant s reserve alkalinity. It is measured in milligrams of potassium hydroxide per gram (mg KOH/g). TBN determines how effective the control of acids formed will be during the combustion process. The higher the TBN,… … Wikipedia
Acid value — In chemistry, acid value (or neutralization number or acid number or acidity ) is the mass of potassium hydroxide (KOH) in milligrams that is required to neutralize one gram of chemical substance. The acid number is a measure of the amount of… … Wikipedia
Acid rain — is rain or any other form of precipitation that is unusually acidic. It has harmful effects on plants, aquatic animals, and infastructure. Acid rain is mostly caused by human emissions of sulfur and nitrogen compounds which react in the… … Wikipedia
Total parenteral nutrition — (TPN), is the practice of feeding a person intravenously, bypassing the usual process of eating and digestion. The person receives nutritional formulas containing salts, glucose, amino acids, lipids and added vitamins.General usageTotal… … Wikipedia
Acid erosion — Classification and external resources ICD 10 K03.2 MeSH D014077 Acid erosion, also known as dental erosion, is the irreversible loss of tooth structure due to chemical dissolution by acid … Wikipedia
Total dissolved solids — (often abbreviated TDS) is an expression for the combined content of all inorganic and organic substances contained in a liquid which are present in a molecular, ionized or micro granular (colloidal sol) suspended form. Generally the operational… … Wikipedia
Acid dissociation constant — Acetic acid, a weak acid, donates a proton (hydrogen ion, high … Wikipedia
Acid mine drainage — Yellow boy in a stream receiving acid drainage from surface coal mining. Acid mine drainage (AMD), or acid rock drainage (ARD), refers to the outflow of acidic water from (usually abandoned) metal mines or coal mines. However, other areas where… … Wikipedia
Acid house — Infobox Music genre name=Acid house bgcolor=silver color=black stylistic origins=House cultural origins=1980s, United States, United Kingdom instruments=Synthesizer Drum machine Sequencer Keyboard Roland TB 303 Roland TR 808 popularity= late… … Wikipedia
Number of amino acids per protein molecule — ▪ Table Number of amino acids per protein molecule protein* amino acid Cyto Hb alpha Hb beta RNase Lys Chgen Fdox lysine 18 11 11 10 6 14 4 histidine 3 10 9 4 1 2 1 arginine 2 3 3 4 11 4 1 aspartic acid** 8 12 13 15 21 23 13 threonine 7 9 7 10 7… … Universalium