diesel index aniline point and pour point of lubricating oil

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1. Determine the diesel value , pour point and aniline point of lubricating oil

2. Lubricating oil Lubricating oil , sometimes simply called  lubricant/lube , is a class of oils used to reduce the friction, heat, and wear between mechanical components that are in contact with each other. Lubricating oil is used in motorized vehicles, where it is known specifically as  motor oil  and  transmission fluid . There are two basic categories of lubricating oil: mineral and synthetic.  Mineral oils  are lubricating oils refined from naturally occurring crude oil.  Synthetic oils  are lubricating oils that are manufactured.

3. Formulation Typically lubricants contain 90% base oil (most often petroleum fractions, called mineral oils) and less than 10% additives.  Vegetable oils or synthetic liquids such as hydrogenated polyolefins, esters, silicones, fluorocarbons and many others are sometimes used as base oils. Additives deliver reduced friction and wear, increased viscosity, improved viscosity index, resistance to corrosion and oxidation, aging or contamination, etc.

4. Properties A good lubricant generally possesses the following characteristics: A high boiling point and low freezing point (in order to stay liquid within a wide range of temperature) A high viscosity index Thermal stability Hydraulic stability Demulsibility Corrosion prevention A high resistance to oxidation

5. Additives Pour point depressants are compounds that prevent crystallization of waxes. Long chain alkylbenzenes adhere to small crystallites of wax, preventing crystal growth. Anti-foaming agents  are typically silicone compounds , glycerols Viscosity index improvers (VIIs) polyacrylates and butadiene. Antioxidants aromatic amines,phenols,sulphides and phosphates Detergents   ensure the cleanliness of engine components Corrosion inhibitors amino salt and salt of sulphonic acid Anti-wear agents tricresyl phosphate Friction modifiers reduce friction and wear, particularly in the boundary lubrication regime where surfaces come into direct contact

6. Functions of lubricants: Keep moving parts apart Reduce friction Transfer heat Carry away contaminants and debris Transmits power Protects against wear Prevents corrosion Seal for gases

7. Diesel index Diesel index is just as same as cetane number. Cetane number , Cetane number (or CN) is an inverse function of a fuel's ignition delay, and the time period between the start of injection and the first identifiable pressure increase during combustion of the fuel. Significance Generally, diesel engines operate well with a CN from 48 to 50. Fuels with lower cetane number have longer ignition delays, providing more time for the fuel combustion process to be completed. Hence, higher speed diesel engines operate more effectively with higher cetane number fuels. Alkyl nitrates and di- tert -butyl peroxide are used as additives to raise the cetane number

8. Aniline point The  aniline point  of an oil is defined as the minimum temperature at which equal volumes of aniline (C 6 H 5 NH 2 ) and the lubricant oil are miscible, i.e. form a single phase upon mixing. Significance The lower the aniline point, the greater is the content of aromatic compounds in the oil. Higher aniline point indicate lower % of hydrocarbons. Thus aniline point is used as an indication of deterioration of rubber sealing.

9. Pour point Pour point is the temperature at which lubricant just ceases to flow when cooled. Significance: It indicate suitability of lubricant in cold temp hence must be low. It can be lowered by lowering the viscosity of the oil which can be lowered by removing the viscous constituents of the oil. A high pour point can lead to solidification of the lubricant that can cause jamming of the machine.

10. Appartus Test tubes Burner Gravity bottle Reagents Aniline Diesel oil

11. Procedure Equal volumes of aniline 5ml and diesel 5ml are taken in a test tube. The test tube is heated at burner till the aniline layer and diesel become miscible and then as a single layer, this is the transition temperature. Above this temp, turbidity occurs. Stop the heating and allow the solution to cool and when immiscibility of two layers occur then temperature is noted. The specific gravity bottle is taken and by calculations measure the density of oil.

12. Observation and calculations Aniline point: 78 degrees=172.4F Room temp= 21 degrees= 69.8F Weight of specific gravity bottle= W1= 13.4 g Weight of bottle and diesel oil = W2 = 33.9g Weight of oil= W= 20.5g Volume of oil= 22.5ml Density of oil= weight of oil/volume of oil = 20.5/22.5 =0.92g/ml

13. Specific gravity of oil at room temp= 0.91/0.99 =0.912 Specific gravity of oil in API= 141.5-131.5/0.912 = 10.96API API AT 60F = [0.002{60-OBSERVED TEMP}+1] X [Observed specific gravity] = [0.002{60-69.8}+1] x [10.96] =10.74 API

14. DIESEL INDEX= aniline point x specific gravity at 60F/100 =10.74 X 172.4/100 = 18.51 RESULT: The aniline point is 172.4F And diesel index is 18.51