Propanol is a primary alcohol which is listed third among the first four aliphatic alcohols. It is also known as propan-1-ol, 1-propyl alcohol, n-propyl alcohol, and n-propanol. It is also sometimes referred to as PrOH or n-PrOH. Propanol is a colourless liquid that is fully miscible in water and is highly miscible with all common solvents such as glycols, ketones, alcohols, aldehydes, ethers and aliphatic hydrocarbons.
The molecular formula of propanol is CH3CH2CH2OH or CH3(CH2)2OH or simply C3H8OH. Its molecular weight is 60.069 g/mol. Gustave C. B. Chancel was the first to discover propanol who obtained it in 1853 by fractional distillation of fusel oil, a by-product formed when certain amino acids when potatoes or grains are fermented to produce ethanol. Propanol is formed naturally as by-product during many chemical fermentation processes similar to the distillation of fusel oil, and these are not significant sources of propanol.
Propanol is a clear low-viscosity, neutral and colourless liquid with a sharp musty odour like rubbing alcohol. Its freezing point is -126 °C, while flash point is 22 °C. Autoignition temperature is 371 °C. Vapours of this liquid are heavier than air and mildly irritates the eyes, nose, and throat upon contact. Density is approximately 6.5 lb / gal. It has an isomer, that is a compound with same formula but a different arrangement of atoms and different properties. The isomer of propanol is isopropanol or 2-propanol, with a molecular formula of CH3CHOH CH3, the same atoms found in propanol with a different arrangement.
Manufacture and Storage:
1-Propanol is manufactured by catalytic hydrogenation of propionaldehyde. The propionaldehyde is usually produced via the oxo process or hydroformylation, of ethylene using carbon monoxide and hydrogen in the presence of a catalyst such as rhodium complex or cobalt octa carbonyl.
H2C=CH2 + CO + H2 → CH3CH2CH=O
CH3CH2CH=O + H2 → CH3CH2CH2OH
A traditional laboratory preparation of propanol involves treating n-propyl iodide with moist silver oxide.
Propanol should be stored under nitrogen; the storage temperature must not exceed 40 °C and there should be no moisture. Under such ideal conditions, a storage stability or shelf-life of 12 to 14 months can be expected.
Propanol is stored in bulk petrochemical facilities to regulate this product. Storage is normally in a dry, cool, well ventilated facilities away from oxidising agents, direct sunlight, heat and open flames.
Solvents such as propanol is stored in drummed containers such as iso-tanks made of aluminium, stainless steel and carbon steel.
Uses of propanol:
Propanol has a diverse range of uses due to its
miscibility, high flammability and its effects on the human body.
Some of the more prominent uses are
• As a Solvent
• Medical Use
As solvent / intermediate:
Propanol is used as solvent and an intermediate product. Propanol has a milder and more pleasant smell than higher alcohols and tends to absorb less water than lower alcohols.
As a solvent, propanol is employed mainly in printing inks, especially flexographic ink. In cleaning agent sector, it is added to floor polishes and metal degreasing agents. In adhesive manufacture, propanol serves as additional solvent.
Propanol is used in the coating industries as a semi-volatile alcohol for improving the drying properties, for example in the manufacture of alkyd resin paints, baking finishes and electrodeposition paints.
Propanol is also used as deicing fluids, as an extracting agent and as an entrainer in azeotropic distillations. Propanol quite easily forms esters and ethers, most of which are have high commercial value.
Most commonly propanol is itself used as a solvent or it is used to produce other solvents such as antifreezes, lacquer formulations, soaps, dye solutions, window cleaning agent and such other materials. Propanol acts as a chemical intermediate in the process of creating halides, propyl amines and propyl acetate and many other such chemicals. It is also used in manufacture of de-greasing fluids, adhesives and window cleaning agents.
Propanol also has uses in a number of medicines. Bottles of rubbing alcohol are mostly made up of propanol. It is also used as an antiseptic. Propanol is found in hand sanitizers whether it is in the form of solutions or wipes. Further, propanol is often used in inhalant products in the place of ethanol mostly in nebulizers.
n-Propyl alcohol can produce mild central nervous system depression and is thus used as pain relief medication.
A research in Chem Pharm Bull, Tokyo in 1980 showed that the activity of partially purified human erythrocyte acid phosphatase (eapase) is enhanced 3-fold by propanol. The extent of human prostatic acid phosphatase (papase) activation by n-propanol was lower than that of eapase.
Propanol Tablet is used for treatment, control, prevention, & improvement of Supraventricular arrhythmias, Ventricular tachycardias, Tachyarrhythmias of digitalis intoxication, Resistant tachyarrhythmias due to excessive catecholamine action during anaesthesia and other conditions.
Alcoholic beverages nearly always contain propanol as a product of fermentation. Beer contains up to 195 mg/l, wine up to 116 mg/l, various types of spirits up to 3520 mg/l, and neat ethanol up to 2910 mg/l. Propanol is present at low levels as a flavour volatile in a variety of foodstuffs and non-alcoholic drinks, for example kefir culture, cream culture, filberts
(roasted), raw milk, heat-treated milk, Kumazasa Sasa albomarginata, heated triolein, boiled buckwheat flour, tomato (ripe, juice, puree, and paste), Kogyoku apple, apple and apple juice, white bread, butter, cheddar/Swiss cheese, soy sauce, fish sauce, Amaranthus species used for feeding domesticated animals, Manila bean (raw/roasted), soybean (raw, roasted), potato tuber, roasted watermelon seeds, babco fruit, tilsit cheese, endive, Valancia orange juice. Propanol was identified in fermentation brine of pimentos used for stuffing olives. Propanol is found in over found in 31 commercial brines.
Propanol is also used in the production of herbicides and insecticides.
Propanol is often the main constituents in many different kinds cosmetics. An acetate is used as a remover for acrylic nails and fingernail polish due to its mild corrosive properties. It is used in soaps and hair care products. It is also used in aerosol perfumes, hand sanitizers and moisturizer
Propanol is a highly flammable liquid and it has a fire hazard rating of 2. Propanol has high octane numbers and it is suitable for fuel usage in internal combustion engines. However, the production of propanol is too expensive to make it a common fuel, hence this purpose is not commonly used. The anti-knock index (AKI) is found to be 108 while the research octane number (RON) of propanol is 118 when propane is used a fuel.
While the main use of propanol is acting as a solvent, other applications and uses of propanol are growing significantly in different parts around the world. Also, propanol is a relatively safer chemical to use than other synthetic alcohol solutions.