PETROLEUM TESTING LABORATORY DEPARTMENT OF CHEMICAL ENGINEERING M.TECH. PETROLEUM REFINING AND PETROCHEMICALS
CONTENTS Sl.No.
Date
Name of the Experiment
1
Flash and Fire point
2
Redwood Viscometer
3
Saybolt Viscometer
4
Engler Viscometer
5
Distillation Characteristics
6
API Gravity
7
Moisture content Determination
8
Softening Point
9
Smoke Point
10
Aniline Point
11
Cloud and Pour Point
12
Melting Point of Wax
13
Copper Strip Corrosion Test
14
Congealing Point of Wax
Page No.
FLASH POINT AND FIRE POINT BY PENSKY MARTENS APPARATUS
AIM To determine the flash point and fire point of fuel oils by using Pensky Martens apparatus (closed type). DEFINITION FLASH POINT The lowest temperature of the sample, corrected to a barometric pressure of 101.3 kPa 760 mm Hg , at which application of a test flame causes the vapour of the sample to ignite under specified conditions of test. FIRE POINT The fire point, is defined as the temperature at which the vapour continues to burn after being ignited. SUMMARY OF METHOD The sample is heated at a slow, constant rate with continual stirring. A small flame is directed into the cup at regular intervals with simultaneous interruption of stirring. The flash point is the lowest temperature at which application of the test flame causes the vapour above the sample to ignite. SIGNIFICANCE • • •
Flash point measures the response of the sample to heat and flame under controlled laboratory conditions. It is only one of a number of properties which must be considered in assessing the overall flammability hazard of a material. Flash point is used in shipping and safety regulations to define ‘flammable’ and ‘combustible’ materials.
APPARATUS
Pensky Martens Closed Tester
Thermometers (Two standard thermometers shall be used with the Pensky-Martens tester)
TABULATION
S.No.
SAMPLES
FLASH POINT (ºC)
FIRE POINT(ºC)
PREPARATION OF SAMPLE Samples of asphalts or very viscous materials may be warmed until they are reasonable fluid before they are tested. However, no sample should be heated more than is absolutely necessary. It shall never be heated above a temperature of 17°C ( 30°F ) below its expected flash point. APPARATUS SPECIFICATIONS A typical assembly of the apparatus, gas heated, is shown in Fig. The apparatus shall consist of a test cup, cover, and stove conforming to the following requirements. Cup - The cup shall be of brass, or other non-rusting metal of equivalent heat conductivity, and shall conform to the dimensional requirements Cover Proper - The cover shall be brass, and shall have a rim projecting downward almost to the flange of the cup. The rim shall fit the outside of the cup with a clearance not exceeding 0.36 mm 0.014 in on the diameter. Shutter - The cover shall be equipped with a brass shutter approximately 2.4 mm ( 3/32 in ) thick operating on the plane of the upper surface of the cover. cover openings shall be exactly open and the tip of the exposure tube shall be fully depressed. Flame Exposure Device - The flame-exposure device shall have a tip with an opening 0.69 to 0.79 mm (0.027 to 0.031 in) in diameter. This tip shall be made preferably of stainless steel, although it may be fabricated of other suitable metals Pilot Flame - A pilot flame shall be provided for automatic relighting of the exposure flame. Stirring Device - The cover shall be equipped with a stirring device mounted in the centre of the cover and carrying two 2-bladed metal propellers. Stove Heat shall be supplied to the cup by means of a properly designed stove which is equivalent to an air bath. The stove shall consist of an air-bath and a top plate on which the flange of the cup rests. Air Bath The air bath shall have a cylindrical interior and shall conform to the dimensional requirements in Fig. Top Plate
The top plate shall be of metal, and shall be mounted with an air gap between it and the air bath.
PROCEDURE The oil cup was cleaned using solvent. The cup was filled with fresh sample up to the mark. The cup was placed in the apparatus bath. The lid is placed on the cup and the thermometer was also inserted. The electrical heater was turned to 50% of input volts and oil is heated. After that spring handle was rotated at every degree rise from this point. The temperature was noted at which the flash occurs. The fire point was noted at which the fuel burnt continuously for 5 seconds. The experiment was repeated for different samples.
RESULT
Flash point and fire point of given samples are ________________
is _______ oC
REDWOOD VISCOMETER AIM To determine the kinematic viscosity of the given sample of oil at various temperatures and to study corresponding variation with respect to temperature. APPARATUS REQUIRED •
Red wood viscometer with accessories
•
Measuring flask
•
Thermometer
•
Stop watch
•
Red wood viscometer is based on the principle of laminar flow through the capillary tube of standard dimension under falling head. The viscometer consists of vertical cylinder with an orifice at the center of the base of inner cylinder.
•
The cylinder is surrounded by a water bath, which can maintain temperature of the liquid to be tested at required temperature. The water bath is heated by electric heater.
•
Cylinder which is filled up to a fixed height with liquid whose viscosity is to be determined is heated by water bath to the desired temperature.
•
Then orifice is opened and the time required to pass the 50cc of oil is noted. With this arrangement variation of viscosity with temperature can be studied.
THEORY
FORMULA •
In this case of red wood viscometer, the kinematic viscosity (v) of liquid and the time (t) required to pass 50cc of liquid are correlated by expression. ν =0.0026 – 1.175/t
Where, •
ν = Kinematic viscosity
•
t =time in seconds to collect 50cc of oil.
OBSERVATION Sl.No. Temperature (0C)
Time taken to collect 50cc of oil (sec)
Kinematic viscosity (centistokes)
SIGNIFICANCE •
Pump design can be done with the help of viscosity.
•
Pump operation of the engine depends on the proper viscosity of the liquid fuel.
•
It’s very important to know about the fluid flow through various objects.
•
Conveying of fluid can be done effect by means of viscosity data.
PROCEDURE •
The instrument was leveled with the help of the circular bubble and by leveling foot screws.
The water bath was filled with water. The orifice is closed with the ball valve and the cylinder is filled up to index mark with oil. The steady state temperature of oil was recorded. The procedure is repeated for different by heating oil with water bath.
RESULT The kinematic viscosity for the given sample was determined and the graph was plotted and it was observed that the kinematic viscosity of the given sample decreases with increases in temperature.
SAYBOLT VISCOMETER
SAYBOLT VISCOMETER
AIM To determine the viscosity of the given petroleum products and to study the variation of viscosity with respect to temperature. APPARATUS REQUIRED ∗ Saybolt viscometer apparatus ∗ Thermometer (0 – 100 deg) ∗ Sample ∗ Stop watch ∗ Beaker (100 ml capacity) THEORY Viscometers are used to define the viscous properties of a fluid at ambient or defined temperatures. They are commonly available in the form of a calibrated capillary tube through which a liquid is allowed to pass at a controlled temperature in a specified time period. Other methods include rotational viscometry and falling ball tests. Viscometers can have a few different technologies by which they operate. For rotational viscometry, torque is required to rotate a spindle at constant speed while immersed into the sample fluid. The torque is proportional to the viscous drag on the immersed spindle, and thus to the viscosity of the fluid. For falling ball technology, the
viscosity is proportional to the time required for a ball to fall through the test liquid contained in a precise an temperature controlled glass tube. Capillary viscometers measure the flow rate of a fixed volume of fluid through a small orifice at a controlled temperature. The time it takes for a specific volume of fluid to pass through the orifice is proportional to the fluid viscosity. However, it also depends on the density of the fluid since the denser the fluid, the faster it will flow through the orifice. The property being measured is then the kinematic viscosity and not the dynamic viscosity. TYPES OF VISCOMETERS • Reverse flow viscometers • Small volume viscometers • Viscometers • Vacuum viscometers • Cylinder viscometers • Hydra motion viscometers
OBSERVATION
S.No.
Temperature (0C)
Time (seconds)
Kinematic viscosity (centistokes)
FORMULA Kinematic viscosity, ν = At-B/t Where, A=0.00226, B=1.95 A and B are constants. SAFETY PRECAUTIONS • Do not connect bath to a power supply unless the bath is filled with oil. • Do not leave unit unattended, especially when operating at high bath temperatures. • This could create a potential fire hazard. SIGNIFICANCE • It is used to find the viscosity of the fluid. • Pump design can be done with the help of viscosity. • Pump operation of one engine depends on the proper viscosity of fuels. • Conveying of fluids can be done with the help of viscosity data. • It is very important to know about the fluid flow through various objects. EXPERIMENTAL PROCEDURE • The viscometer was turned on after making sure that the bath was filled with oil. • The bath was heated by means of water heater. • The power switch was turned on. The bath temperature was maintained at various temperatures. • The bath was allowed to reach a steady temperature.
• • • • •
The cork stopper is used to block off the outlet of one of the Saybolt viscometer tubes. A measured quantity (+60 ml) of the sample was poured into the tube. The sample temperature was allowed to equilibrate with that of the bath (about 25 minutes). Simultaneously the Saybolt tube was uncorked (using the pull chain) and the stopwatch was started. When the oil has reached the 60 ml mark, the stopwatch was stopped. The time was recorded. The experiment was repeated for various temperatures.
RESULT Thus the kinematic viscosity for given sample was determined for different temperatures and tabulated. The graph was plotted and it was found that the kinematic viscosity decreases with increase in temperature.
ENGLER VISCOMETER
DETERMINATION OF KINEMATIC VISCOSITY BY ENGLER VISCOMETER
AIM
To determine the kinematic viscosity of the given fluid using Engler viscometer.
APPARATUS REQUIRED
•
Engler viscometer
•
Timing device
•
Thermometer
•
Sample
THEORY Specific viscosity of a substance in the Engler scale is the time required in seconds for the flow of 100cc of the sample divided by the time taken for the flow of equal volume of water. This viscometer allows direct comparison of viscosities of various samples without lead to calculate their actual viscosities.
Viscosity
. Viscosity is the ratio between the shear stress and the velocity gradient. In other words, viscosity is the resistance offered by the fluid. The unit of viscosity is centipoises. In SI, kg/ms.
Newton’s law of viscosity
The shear stress is the product of absolute viscosity and velocity gradient. τ = µ (dv/dx) Kinematic viscosity
It is defined as the ratio between the absolute viscosity and density, denoted by ν. ν=µ/ρ The unit of kinematic viscosity is centistokes.
Range of Engler viscometer
Temperature measurement range 0-100oC Viscosity range of fluids
28.8 – 35.2 centistokes
OBSERVATION TIME (sec) S.No
KINEMATIC VISCOSITY
TEMPERATURE (OC )
SAMPLE
WATER
t (sec)
(centistokes)
SIGNIFICANCE •
In the determination of specific viscosity of tars and the fluid properties.
•
In the determination of lubricating properties of fuel oils.
FORMULA 1) ν = At – (B/t) where ν = kinematic viscosity (centistokes) A, B = constants A = 0.076, B = 0.04
2) t = (t1-t2)/60 where t = efflux time in seconds t1 = time taken for collecting sample (sec) t2 = time taken for collecting water (sec)
EXPERIMENTAL SETUP It consists of a water bath having oil cup with lid. The water stirring device is mounted on a stand. Thermometer is dipped in water bath with help of clamp. The lid of the oil cup has a thermometer holder. The bath is fitted with water heater. It can be operated on 200 volt AC mains.
PROCEDURE •
The given sample was filled in the cup of the Engler viscometer up to the level marked.
•
The lid was closed to prevent vaporisation of sample.
•
The heater was switched on and the water temperature was noted.
•
The water was stirred well to promote uniform heat distribution around the oil.
•
When the temperature reaches specific value, heating was stopped and the stalk was removed.
•
The time taken for flow of 100ml sample was noted.
•
The orifice is closed again and the sample was refilled into the cup.
•
The procedure was repeated for different temperatures and the readings were tabulated.
•
The above procedure was also repeated by filling the cup with water.
RESULT The viscosity of the given sample was determined at various temperatures and graph was plotted. It is found that kinematic viscosity decreases with increase in temperature.
DISTILLATION CHARACTERISTICS SCOPE To determine the distillation characteristics (boiling range) of the given sample using the distillation apparatus. DISTILLATION This method of test covers the distillation of motor gasoline, aviation gasoline, aviation turbine fuels, special boiling point spirits, naphtha, white spirit, kerosene, gas oils, distillate fuel oils and similar petroleum products. A 100 ml sample is distilled under prescribed conditions which are appropriate to its nature. Systematic observations of thermometer readings and volumes of condensate are made, and from the data, the results of the test are calculated and reported. The distillation (volatility) characteristics of hydrocarbons have an important effect on their safety and performance, especially in the case of fuels and solvents. The boiling range gives information on the composition, the properties, and the behavior of the fuel during storage and use. Volatility is the major determinant of the tendency of a hydrocarbon mixture to produce potentially explosive vapors. The distillation characteristics are critically important for both automotive and aviation gasoline, affecting starting, warm-up, and tendency to vapor lock at high operating temperature or at high altitude, or both. The presence of high boiling point components in these and other fuels can significantly affect the degree of formation of solid combustion deposits. Distillation limits are often included in petroleum product specifications, in commercial contract agreements, process refinery/control applications, and for compliance to regulatory rules. This test method can be applied to contaminated products or hydrocarbon mixtures. This is valuable for fast product quality screening, refining process monitoring, fuel adulteration control, or other purposes including use as a portable apparatus for field testing. SIGNIFICANCE Distillation (volatility) characteristics of petroleum products are indicative of performance in their intended applications. Petroleum product specifications generally include distillation limits to ensure products of suitable volatility performance. The empirical results obtained by use of this distillation method have been found to correlate with automotive equipment performance factors and with other characteristics of petroleum products related to volatility. For motor spirit the 10% distillation value gives an indication of the engine start conditions, also the final boiling point.
OBSERVATION
S.No Volume of Distillate collected Temperature ºC (ml)
TERMINOLOGY
Initial Boiling Point The thermometer reading which is observed at the instant that the first drop of condensate falls from the lower end of the condenser tube, End-Point or Final Boiling Point The maximum thermometer reading obtained during the test. This usually occurs after the evaporation of all liquid from the bottom of the flask. The term ‘maximum temperature’ is a frequently used synonym. Dry Point The thermometer reading observed at the instant the last drop of liquid evaporates from the lowest point in the flask. Any drops or film of liquid on the side of the flask or on the thermometer are disregarded. Decomposition Point The thermometer reading which coincides with the first indication of thermal decomposition of the liquid in the flask. Percent Recovered The volume in ml of condensate observed in the receiving graduate, in connection with a simultaneous thermometer reading. Percent Recovery The maximum percent that is recovered. Percent Total Recovery The combined percent recovery and residue in the flask. Percent Loss 100 minus the percent total recovery. Percent Residue The percent total recovery minus the percent recovery, or the volume of residue in milliliters if measured directly. Percent Evaporated The sum of the percent recovered and the percent loss.
PROCEDURE
The given flask is to be thoroughly cleaned using solvent and dried. The given test sample is then taken inside the flask and the cork with appropriate thermometer is placed on the neck of the flask. The flask is placed on the asbestos board and fixed to the metal condensers with a cork. The asbestos board is raised of lowered till the flask is properly supported. The 100cc measuring cylinder is placed below the condenser outlet. The heater is then switched on and the temperature variation is noted. The temperature at which the first drop of distillate is collected in the measuring cylinder is noted and reported as the initial boiling point. Heat is controlled, so that the distillation process is at a uniform state. Middle boiling point is the temperature at which 50% of oil distills off.
RESULT The Distillation characteristics are studied for the given samples and the values are noted as follows: 1. Initial boiling point
=
º C
2. Middle boiling point
=
º C
3. Percentage of recovery
=
4. Percentage of non-volatile residue
=
5. Film boiling point
=
º C
API GRAVITY - DIAGRAM
DETERMINATION OF API GRAVITY OF CRUDE PETROLEUM AND LIQUID PETROLEUM PRODUCTS BY HYDROMETER METHOD AND SPECIFIC GRAVITY BOTTLE METHOD
AIM To determine the API gravity of crude petroleum and liquid petroleum products by hydrometer method and specific gravity bottle method. THEORY This method covers the laboratory determination, using a glass hydrometer, of the density, relative density, or API gravity of crude petroleum, petroleum products, or mixtures of petroleum and non-petroleum products normally handled as liquids and having a Reid vapour pressure of 1.8 bar (179 KPa) or less. The values are measured on a hydrometer at convenient temperatures, readings of density being reduced to 15 oC, and that of specific gravity and API gravity to 15.6 oC, by means of international standard tables. CLASSIFICATIONS OR GRADES Crude oil is classified as light, medium or heavy, according to its measured API gravity. • • •
Light crude oil is defined as having API gravity higher than 31.1 °API. Medium oil is defined as having API gravity between 22.3 °API and 31.1 °API. Heavy oil is defined as having API gravity below 22.3 °API.
SIGNIFICANCE Accurate determination of density, relative density, or API gravity of petroleum and its products is necessary for the conversion of measured volumes to volumes at standard temperature of 15°C. FORMULA API Gravity A special function of specific gravity at 15.6/15.6 oC is represented by: API gravity, degrees
= [141.5 /Specific gravity at 15.6/15.6 oC] - 131.5
APPARATUS REQUIRED • • •
Hydrometer Hydrometer cylinders Specific gravity bottle
OBSERVATIONS
SPECIFIC GRAVITY Sl.No
SAMPLES
At room temperature At room temperature using Hydrometer using Specific gravity bottle method
SPECIFIC GRAVITY BOTTLE METHOD Weight of the empty specific gravity bottle
=
Weight of the specific gravity bottle with sample 1
=
Weight of the specific gravity bottle with sample 2
=
Weight of the specific gravity bottle with sample 3
=
Weight of the specific gravity bottle with sample 4
=
PROCEDURE Hydrometer method •
The samples were transferred to hydrometer cylinders without any splashing to avoid air bubbles. • The cylinders containing samples were placed in vertical position in a location free from air currents. • The hydrometer was gently lowered into the sample in cylinders such that the hydrometer should not touch the walls of the cylinder. • The hydrometer was allowed to float and when it comes to rest, the specific gravity indicated by the hydrometer for different samples at room temperature were noted. • From the specific gravity values the API gravity for the given samples were calculated. Specific gravity bottle method • • •
The samples were taken in each specific gravity bottle. The specific gravity bottle with the samples and the weight of the empty specific gravity bottle were measured. The readings were tabulated and the specific gravity for different samples was calculated. From the specific gravity values the API gravity for the given samples were calculated.
RESULT The API gravity of the given samples using hydrometer and specific gravity bottles were calculated and tabulated as follows API gravity Sl.No.
Samples Hydrometer method
Specific gravity bottle method
DETERMINATION OF MOISTURE CONTENT BY DEAN AND STARK METHOD
SCOPE To estimate the moisture content of the given liquid fuel using Dean and Stark Apparatus. EXPERIMENTAL SETUP The Dean-Stark apparatus or Dean-Stark receiver or distilling trap is a piece of laboratory glassware used in synthetic chemistry to collect water (or occasionally other liquid) from a reactor. It is used in combination with a reflux condenser and a batch reactor for continuous removal of the water that is produced during a chemical reaction performed at reflux temperature. It was invented by E. W. Dean and D. D. Stark in 1920 for determination of the water content in petroleum. The Dean-Stark trap (1920) changed the distillation procedure from a simple distillation to a multiple distillation by a change in design where by a refluxing condenser was introduced .This change resulted in a smaller boiling flask and required less distilling liquid. It renewed the interest in the distillation procedure, for it enabled the last traces of water. DEAN AND STARK APPARATUS Two types of Dean-Stark traps exist – one for use with solvents with a density less than water and one for use with solvents with a density greater than water. The Dean-Stark apparatus in the laboratory typically consists of vertical cylindrical piece of glass (the trap, in figure), often with a volumetric graduation on its full length and a precision tap on the bottom very much like a burette. The top of the cylinder is fit with the bottom of the reflux condenser. Protruding from the top the cylinder has a side-arm sloping toward the reaction flask. At the end the side-arm makes a sharp turn so that the end of the side arm is vertical as well. This end connects with the reactor. SIGNIFICANCE This piece of equipment is usually used in azeotropic distillations. A common example is the removal of water generated during a reaction in boiling toluene. The Dean-Stark method is commonly used to measure moisture content of items such as bread in the food industry. This equipment can be used in cases other than simple removal of water. One example is the esterification of butanol with acetic acid catalyzed by sulfuric acid The Dean and Stark procedure can be used to measure the water content of a diverse range of samples, and has been extensively used in industrial laboratories to measure water in petroleum oils.
PRINCIPLE During the reaction in , vapors containing the reaction solvent and the component to be removed travel out of reaction flask up into the condenser ,and then drip into the distilling trap .Here, immiscible liquids separate into layers. When the top (less dense) layer reaches the level of the side-arm it can flow back to the reactor, while the bottom layer remains in the trap. The trap is at full capacity when the lower level reaches the level of the side-arm-beyond this point, the lower layer would start to flow back into the reactor as well. It is therefore important to syphon or drain the lower layer from the Dean-Stark apparatus as much as needed. More rarely encountered is the model for solvents with a density greater than water. This type has a tube at the bottom of the side-arm to allow the organic solvent at the bottom to flow back into the reaction vessel. The water generated during the reaction floats on top of the organic phase. An azeotropic mixture of toluene and water distills out of the reaction, but only the toluene (density=0.865 g/ml) returns, since it floats on top of the water (density=0.998 g/cm3), which collects in the trap. This equipment can be used in cases other than simple removal of water. One example is the esterification of butanol with acetic acid catalyzed by sulfuric acid. The vapor contains 63% ester, 24% water and 8% alcohol at reflux temperature and the organic layer in the trap contains 86% ester, 11% alcohol and 3% water which is reintroduced. The water layer is 97% pure. Another example is the esterfication of benzoic acid and n-butanol where the ester product is trapped and the butanol, immiscible with the ester flows back into the reactor. Removing water in the course of these esterfications shifts the chemical equilibrium in favour of ester formation. PROCEDURE A known volume of the fuel sample is to be placed in a flask with equal volume of organic solvent such as xylene of toluene. The organic solvent is chosen such that it is insoluble in water. It should have a higher boiling point than water and it should be safe to use. The flask containing the sample with the organic solvent is then attached to a condenser by a side arm and the mixture is heated up. The water in the sample gets evaporated and moves into the condenser where it is cooled and converted back into liquid water. The water trickles into the graduated tube. The distillation is then stopped and the water present in the liquid fuel is measured.
RESULT The amount of moisture content present in the sample was found using the Dean and Stark apparatus to be
SOFTENING POINT AIM To determine the softening point of the given sample bitumen using ball and ring apparatus. APPARATUS REQUIRED
Ring and ball apparatus Steel balls Brass rings Thermometer Stirrer Water bath
SIGNIFICANCE To find the consistency of bitumen It is regarded by same indication of viscosity It is used in the designation of hard as oxidized bitumen. THEORY The temperature at which the substance attains a particular degree of softness under specified condition of test is called softening point. Bitumen is specified by softening point. Bitumen being amorphous does not melt sharply but gradually becomes softer and less viscous as the temperature rises. For this reason, the determination of the softening point must be made by fixed arbitrary and closely defined method. The softening point of bitumen is rounded out by the ball and ring test. APPLICATION Used in annealing of bitumen. Processing of plastics. Determining the quality of bitumen.
PROCEDURE A beaker is taken and filled with ¾ of it with water. The sample is placed in the ring and the steel ball is kept over the sample at the middle of the ring. The whole ring and ball is immersed into the beaker which is filled with water. The water in the beaker is heated by electrical coil. A thermometer is inserted to note the temperature. As the temperature increase, the sample gets softens and the steel ball over the sample gets immersed and finally drops out. The temperature at which the ball falls down from the ring is noted as softening point of the sample. The ring is washed and replaced with another sample and the process is repeated.
RESULT The softening point of given first sample
=
The softening point of given second sample =
FLAME HEIGHT
A-Too high B- Correct C-Too low
SMOKE POINT AIM This method is intended for the determination of smoke point of kerosene and other volatile liquid fuels including gas turbine (jet) fuels. DEFINITION The maximum flame height in millimetres at which kerosene or other volatile liquid fuels including gas turbine (jet) fuels will burn without smoking, when determined in the apparatus and under specified conditions. OUTLINE OF THE METHOD The sample is burned in a standard lamp in which it is possible to adjust the flame height against a background of a graduated millimetre scale. The smoke point is measured by raising the wick until a smoky flame is produced and then lowering to the point where the smoky tail just disappears. This flame height, measured to the nearest millimetres, is the smoke point of the sample REQUIREMENTS:
Smoke point apparatus
Fuel samples
Wick
Smoke Point Lamp - Constructed according to the specification given. The lamp consists of an oil container provided with a wick tube and air vent, a gallery fitted with a wick guide and provided with air inlets, a lamp body, and a chimney provided with a 50-mm scale specified Oil Container - This shall conform to the following dimensions (mm): Body Oil Container: Internal diameter External diameter Length, without cap Thread on cap
21.25 ± 0.25 Sliding fit in holder 109-00 ± 0.05 9’5 mm dia screwed 1.0 mm pitch
Wick Tube: Internal diameter External diameter Length
4’7 ± 0.05 Close fit in wick guide 82.00 ± 0.05
OBSERVATION
S. No.
Sample(ml)
Smoke Point(mm)
Air Vent: Internal diameter Length
3.50 ± 0’05 90.00 ± 0.05
Lamp - This shall conform to the following dimensions in mm: Internal diameter of socket of oil container 23.80 ± 0.05 Internal diameter of wick guide 6.00 ± 0.02 Diameter of each of 20 air inlets 2.90 ± 0.05 x: External diameter of gallery 35.00 ± 0.05 Diameter of each of 20 air inlets in the gallery 3.50 ± 0.0.5 Internal diameter of lamp body 81.0 ± 1.0 Internal depth of lamp body 81.0 ± 1.0 Internal diameter of chimney 40.0 ± 1.0 Height, top of chimney to centre of lamp body 130.0 ± 1.0 Other Requirements - The lamp shall also comply with the following requirements: a)The top of the wick guide shall be exactly level with the zero mark on the scale; b) The scale shall be marked in white lines on black glass on each side of a white or black strip, 2mm in width. It shall have a range of 50 mm, graduated in one millimetre, figured at each 10mm, and with longer lines at each 5 mm; c) A device for raising or lowering the flame shall also be provided. The total distance of travel shall be not less than 10 mm, and the movement shall be smooth and regular. Further, with the oil container in the lowest position and the .wick projecting 6 mm above the top of the oil container, the top of the wick shall not project above the wick guide (zero on the scale ); d) The glass of the door shall be curved to prevent the formation of multiple images; and e) The joint between the base of the oil container and its body shall be oil-tight. Wick - Woven solid circular wick of cotton yarn and complying with the following requirements shall be used: Number of Threads
Casing Filling Picks
17 ends 9 ends 6 per cm
PRECAUTIONS •
•
The test shall normally be carried out at a room temperature of not less than 15°C; it is recommended that the room temperature and the barometric pressure be recorded. Place the lamp in a vertical position completely protected from draughts.
PROCEDURE • • •
•
• •
20 ml of the previously filtered sample is introduced in the clean, dry oil container. A piece of wick is extracted, not less than 12’5 cm in length, with a suitable volatile solvent and it is dried for half an hour at 100 to 110°C. The wick is soaked in the sample under test and is placed in the wick holder, carefully easing out any twists arising from this operation. It is advisable to re-soak the burning end of the wick in the sample. The wick holder is placed in the container and ensured that the air inlet is free from oil. The wick is cut horizontally and trimmed to free the frayed ends so that 6 mm of wick projects from the container. The oil container is maintained at a temperature of 20 to 25°C for 10 minutes. The lamp is inserted and the wick is lighted. The wick is adjusted so that the flame is about 1 cm high and allows the lamp to burn for 5 minutes. The wick is raised until a smoky tail appears, then lowered slowly through the following stages of flame appearances: a) A long tip, smoke slightly visible, erratic and jumpy flame. b) An elongated pointed tip with the sides of the tip appearing concave upward. c) The pointed tip just disappears leaving a very slightly blunted flame Jagged, erratic, luminous flames are sometimes observed near the true flame tip. These are to be disregarded. d) The height flame is estimated to the nearest millimetre.
•
•
The smoke point is recorded as observed. To eliminate errors due to parallax, the eye of the observer should be slightly to one side of the centre line, so that a reflected image of the flames seen on the scale on one side of the central vertical white line, and the flame itself is seen against the other side of the scale. A sighting device may also be used to eliminate parallax and to facilitate reading the flame height. The reading for both observations should be identical.
SIGNIFICANCE • • • •
• •
This is an important test for illumination oils for their ability to burn without producing smoke. It is used in the assessment of burning quality of aviation fuel. Higher the smoke point better is its domestic use. To find aromatic content of the kerosene. This test method provides an indication of the relative smoke producing properties of kerosene’s and aviation turbine fuels in a diffusion flame. The smoke point is related to the hydrocarbon type composition of such fuels. Generally the more aromatic the fuel the smokier the flame. A high smoke point indicates a fuel of low smoke producing tendency. The smoke point (and Illuminometer number with which it can be correlated) is quantitatively related to the potential radiant heat transfer from the combustion products of the fuel. Because radiant heat transfer exerts a strong influence on the metal temperature of combustor liners and other hot section parts of gas turbines, the smoke point provides a basis for correlation of fuel characteristics with the life of these components.
RESULT S. No.
Sample(ml)
Smoke Point(mm)
Thus the smoke point experiment was performed and is tabulated below:
ANILINE POINT
AIM To determine the aniline point of the given sample. APPARATUS •
The tube approximately 25mm in diameter and 150mm in length made of heatresistant glass.
•
A Jacket-approximately 37 to 42mm in diameter and 175mm in length made of heatresistant glass.
•
A Stirrer-manually operated, approximately 2mm in diameter soft iron wire.
THEORY Aniline point Aniline is a poor solvent for aliphatic hydrocarbons and excellent one for aromatics. This property is used in the aniline point test. Aniline point of oil is the lowest temperature at which the oil is completely miscible with an equal volume of aniline. Equal volumes of the sample and aniline (5 ml each) are heated or cooled with stirring in a jacketed test tube and temperature at which complete miscibility occurs is noted. High aniline point indicates that the fuel is highly paraffinic and hence has a high diesel index and very good ignition quality. In case of aromatics the aniline point is low and the ignition quality is poor Diesel index Diesel index is an indication of the ignition quality of a diesel fuel. This is determined by calculation from the specific gravity and the aniline point of the sample. Although it is of the same order as the cetane number, it may differ widely from the cetane number. Higher the diesel index better is the ignition quality of the diesel fuel. It is normally used as a guide to ignition quality of the diesel fuel in the absence of test engine for the direct measurement of cetane number. The diesel index is calculated as follows: (a) Diesel index = (Aniline point,ºF ׺API)/100 (b) Diesel index = (Aniline gravity constant)/100 (c) Diesel index = (Cetane number −10)/0.72
Cetane number
Cetane number is related to the ignition delay of a fuel in a diesel engine, i.e. how rapidly combustion begins after injection of the fuel into the combustion chamber. The shorter the ignition delay period, higher is the cetane number of the fuel Cetane number is the index of the ignition quality of a fuel. High cetane number fuels will facilitate easy starting of compression ignition engines, particularly in cold weathers, and faster warm up. These also result in increased engine efficiency and power output, reduced exhaust smoke and odour and combustion noise. In the absence of test engine, the diesel index or the calculated cetane index will give an approximate idea of the ignition quality of the fuel. Cetane number= 0.72×Diesel index + 10
PROCEDURE •
The apparatus was dried and cleaned.
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10ml of aniline and 10ml of the sample were dried and pipetted into the test tube fitted with stirrer and thermometer.
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The thermometer in the test tube was centered to make the immersion mark at the liquid level; it is assured that the thermometer bulb does not touch the side of the tube.
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In the case of not mixing of aniline-sample at normal temperature, heat is applied directly to the jacket tube so that the temperature raised at a rate of 1-3ºC/min till complete miscibility was obtained.
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Stirring is continued and the mixture is allowed to cool at a rate of 0.5 to 1ºC/min.
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Cooling is continued to a temperature of 1 to 2ºC below the first appearance of turbidity.
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The temperature at which the mixture suddenly became cloudy throughout is recorded as the aniline point.
RESULT Results for the aniline point experiment were found to be •
Aniline point =
•
Diesel index
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Cetane number =
=
CLOUD AND POUR POINT EXPERIMENTAL SETUP
CLOUD AND POUR POINT DETERMINATION
AIM To determine the Cloud point and pour point of the given sample.
REQUIREMENTS Cloud and pour point apparatus, Thermometer, Ice crystals.
DEFINITIONS The cloud point of a fluid is the temperature at which dissolved solids are no longer completely soluble, precipitating as a second phase giving the fluid a cloudy appearance. This term is relevant to several applications with different consequences. Also, the pour point can be defined as the lowest temperature expressed in multiples of 3ºC at which the oil is observed to flow when cooled and examined under prescribed conditions.
THEORY Cloud point and pour point are indicators of the lowest temperature of utility for petroleum products. Cloud Point gives a rough idea of temperature above which the oil can be safely handled without any fear of congealing or filter clogging. The sample is periodically examined while it is being cooled in the cloud and pour point apparatus. The highest temperature at which haziness is observed (cloud point), or the lowest temperature at which the oil ceased to flow is observed (pour point), is reported as the test result. The cold filter plugging point test is used to determine the extent to which diesel fuel or gas oil will flow, even though the temperature is below that at which wax crystals normally appear, i.e. cloud point.
Pour point is a well established test to estimate the temperature at which a sample of oil becomes sufficiently solid to prevent its movement by pumping. The pour point indicates the waxy nature of the oils.
SAMPLES SHOWING CLOUD AND POUR POINT
PROCEDURE Measuring cloud point of petroleum product: The test oil is required to be transparent in layers 40mm in thickness (in accordance with ASTM D2500). The crystals of the sample typically first form at the lower circumferential wall with the appearance of a whitish or milky cloud. The cloud point is the temperature at which these crystals first appear. The test sample is first poured into a test jar to a level approximately half full. A cork carrying the test thermometer is used to close the jar. The thermometer bulb is positioned to rest at the bottom of the jar. The entire test subject is then placed in a constant temperature cooling bath on top of a gasket to prevent excessive cooling. At every 1°C, the sample is taken out and inspected for cloud then quickly replaced. Successively lower temperature cooling baths may be used depending on the cloud point. Lower temperature cooling bath must have temperature stability not less than 1.5 K for this test. Measuring pour point of petroleum product: Two pour points can be derived which can give an approximate temperature window depending on its thermal history. Within this temperature range, the sample may appear liquid or solid. This peculiarity happens because sample crystals form more readily when it has been heated within the past 24hrs and contributes to the lower pour point. The upper pour point is measured by pouring the test sample directly into a test jar. The sample is then cooled and then inspected for pour point as per the usual pour point method. The lower pour point is measured by first pouring the sample into a stainless steel pressure vessel. The vessel is then screwed tight and heated to above 100 oC in an oil bath. After a specified time, the vessel is removed and cooled for a short while. The sample is then poured into a test jar and immediately closed with a cork carrying the thermometer. The sample is then cooled and then inspected for pour point as per the usual pour point method
RESULT The pour point of the given sample was found to be
---------0C.
The cloud point of the given sample was found to be
---------0C
MELTING POINT DETERMINATION AIM To determine the melting point of given sample. And also its solidification point. APPARATUS REQUIRED
Thermometer
Test tube
Hot plate
Burette stand
DEFINITION When a solid substance is heated, typically it will melt; that is to say, at some temperature the solid will begin to liquefy and by some slightly higher temperature all of the solid will have become liquid. The melting point (actually melting point range) of a compound is then defined as the temperature at which an observer can first see liquid forming from the solid to the temperature where the last particle of solid has become liquid. PURPOSE There are several purposes for doing this experiment. The first is to learn how to determine the melting range of a solid substance accurately. When a solid substance is prepared its melting point is usually determined to aid in its identification and to get some idea of its purity.
The second is to observe the effect of the purity of a substance on its melting behavior. Pure substances usually have melting point ranges of a degree or two; impure substances (which are mixtures of two or more substances) often have wider ranges.
The third is to use a physical constant of an unknown substance – its melting point – to identify it from among several possibilities.
PROCEDURE
Melting points are usually determined by placing one or two milligrams of the material is to be tested into a melting point capillary, and heating the capillary and a thermometer together, and observing over what temperature range the material melts. The melting point capillary is a thin-walled glass tube, about 100 mm in length and not more than 2 mm in outside diameter, sealed at one end.
The bulb end of the thermometer is inserted, along with the attached capillary tube. The capillary tube and the thermometer are clamped to the stand.
The accurate melting point is achieved by heating the sample at a rate of 1 to 2 degrees per minute.
If you have no idea what the melting point of your sample is, you have two choices at this point. (1) You could start at room temperature and warm at the recommended rate until the solid melts. This could take more than an hour. (2) You could start at room temperature and warm at about 10 degrees a minute and obtain an approximate melting point.
Then, after the apparatus has cooled below the sample's melting point, replace the sample (and capillary) with a new one, and heat slowly until the sample has melted, thus getting an accurate melting point.
The test tube is kept in air bath and the temperature is noted for every 30 seconds until it gets completely solidified.
SIGNIFICANCE It is used for compound identification and estimation of purity MELTING POINT RANGE OF DIFFERENT COMPOUNDS
RESULT Thus the melting point range of sample was determined from the graph. It is found to be
COPPER STRIP CORROSION TEST – TEST BOMB
COPPER STRIP CORROSION TEST
AIM To detect the corrosiveness of the given sample using copper strip corrosion test.
PRINCIPLE The method covers the detection of corrosiveness to copper of aviation gasoline from tractor fuel, solvent, kerosene, diesel, fuel oil, lube oil, certain other petroleum products. A polished copper strip is immersed in a given quantity of sample and heated at a temperature and for a time characteristics of the material being tested. At the end of this period, the copper strip is removed, washed and compared with copper strip corrosion standards. It is particularly important that all types of feed sample which should pass a tarnished strip classification. We collected clean glass bottles, plastic bottles or other suitable containers that will not affect the corrosiveness properties of the sample.
REQUIREMENTS •
Copper strip corrosion test bomb
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Constant temperature water bath
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Polishing ice
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Glass test tube
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Polishing paper
SIGNIFICANCE AND USE
This test method is suitable for setting specifications, for use as an internal quality control tool, and for use in development or research work on industrial aromatic hydrocarbons and related materials. It also gives an indication of the presence of certain corrosive substances which may corrode equipment, such as acidic compounds or sulfur compounds.
PROCEDURE
RESULT
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The test is to be operated at 50oC constant temperature.
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The bath is set at the desired working temperature and waits for 20 minutes of time after the start.
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The copper strip is prepared for performing test. It is washed properly with solvent (acetone) and surface of strip is prepared by rubbing with silicon carbide grid paper.
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Clamp the strip with ice and polish it until uniform rubbing, when strip is clean immerse it in prepared sample.
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The strip is kept into 30 ml of sample which is kept inside the test bomb and the lid is screwed tight.
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After two hours in the bath the bomb is withdrawn and it is cooled with water.
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The bomb is opened, the test tube is taken out and carefully the strip is withdrawn from the sample.
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The strip is compared with ASTM corrosion standards comparison chart and report the tarnish level.
The corrosiveness of the given sample is found out using the copper strip and comparing it with ASTM standards and its value is found to be ---------------------------
CONGEALING POINT OF WAX
AIM To determine the congealing point of given sample wax.
DEFINITION Congealing point may be defined as the temperature of which molten petroleum wax when cooled under prescribed conditions ceases to flow.
OUTLINE A sample of wax is melted and droplet is made to adhere to the bulb of the thermometer. Using a pre warmed flask as an air jacket, the droplet on the bulb is allowed to cool at a fixed rate until it congeals. The congealing point is observed as the temperature at which the droplet ceases to flow as the thermometer is turned.
APPARATUS REQUIRED Thermometer, Erlenmeyer flask, Cork or Rubber stopper.
PROCEDURE The thermometer is adjusted through the stopper so that the bottom of the bulb will be 10 to 15 mm above the bottom of the Erlenmeyer flask when the stopper is fitted snugly in the flask. After making this adjustment, the thermometer and stopper are removed from the flask, carefully without changing the position of the stopper relative to the thermometer stem. Approximately 50gm of sample is placed, which is representative of the material under inspection in a porcelain evaporating dish or other suitable container. The empty Erlenmeyer flask is placed (without the thermometer assembly) and the container holding the sample in a temperature-controlled oven set at 99 ± 3 0c (210 ± 50f) until the sample and flask reach oven temperature.
The sample is removed from the oven and the thermometer bulb is completely immersed without covering any part of the thermometer stem with sample. The sample is stirred gently with the thermometer until the mercury column has stopped rising. While holding the thermometer bulb in the molten wax sample, the heated flask is removed from the oven, using a towel or gloves to project the hands. Now carefully the thermometer from the sample adhering to the bulb is removed. The thermometer is held in a position firmly and is fit and stoppered into the flask. The assembly is kept in a horizontal position. While the drop on the thermometer bulb is observed at an eye level position. The thermometer and flask are rotated about a horizontal axis. a steady and even rate are used for each continuous full revolution, and each revolution is completed in not less than 2 sec not more than 3 sec. The completion of each revolution should not be paused any longer than required to reindex the fingers for the next full and continuous rotation. When the drop is observed to rotate with the bulb immediately the thermometer to the nearest 0.25 0c (0.50F) is read and this determination is recorded. A repeat determination is made on the wax sample. If the variation of these two determinations does not exceed 10c (20f) the average of these determinations is recorded as a congealing point of the sample under test. If the variation of two determinations is greater the 10c (20c) additional reading is recorded, and the average of the three determination is recorded as the congealing point. SIGNIFICANCE Congealing point is a wax property that is of interest to many petroleum wax consumers. It indicates temperature at which sample when cooled under prescribed conditions develop a se or resistance to flow. At that temperature the wax maybe at or close to the solid state or it may be semisolid and quite unctuous depending on the composition of the wax congealing property is associated with the formation of a gel structure as the sample cools.
RESULT The average of the multiple determinations as the congealing point of the given sample
