Unit - II Petroleum Products - II.pptx
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BFST:402 Forensic Chemistry IV Unit II Petroleum Products - II Mr. Smitesh S. Nalage Dept. Of Forensic Science, YCIS, Satara,(Autonomous). Petroleum Products - II Analysis of kerosene and ATF Analysis of traces of kerosene...
BFST:402 Forensic Chemistry IV Unit II Petroleum Products - II Mr. Smitesh S. Nalage Dept. Of Forensic Science, YCIS, Satara,(Autonomous). Petroleum Products - II Analysis of kerosene and ATF Analysis of traces of kerosene and ATF in forensic exhibits Comparison of kerosene and ATF Adulteration of kerosene and ATF Petroleum Products - II Adulteration Legal Perspective Indian standards for petroleum Sampling Preliminary Examination of petroleum Instrumental Examination Definitions: As per “THE MOTOR SPIRIT AND HIGH SPEED DIESEL (PREVENTION OF MALPRACTICES IN SUPPLY AND DISTRIBUTION) ORDER 1993 by Section 3 of Essential Commodities Act (E.C. Act) (Central Act 10 of 1955) Adulteration: Means the introduction of any foreign substance into motor spirit / high speed diesel illegally / unauthorized. Malpractices: it shall include the following acts of omission, commission in respect of motor spirit and high speed diesel: Adulteration Pilferage Stock variation Unauthorized exchange Unauthorized purchase Unauthorized sale Sampling of Products by Sample Drawing Authority (EC ACT 1955) Power of Search and Seizure: Any officer of the State Government, not below the rank of an Inspector, in the department of Food and Civil Supplies duly authorized and notified in the Official Gazette by such State Government, or any officer of an Oil Company not below the rank of a Sales officer may, with a view to securing compliance with the Provisions of this order, or for the purpose satisfying himself that this order or any order made there under has been complied with. Sampling: The Officer authorized shall draw the sample from the tank, nozzle vehicle or receptacle as the case may be to check whether density of the product confirms to the requirements indicated in Schedule. The officer authorized shall take, sign and seal three samples of 1 litre each of the product, one to be given to the dealer, transporter or concerned person under acknowledgement with instructions to preserve the sample in a safe custody till the testing/investigations are completed, the second sample to be kept by the concerned Department and the third for laboratory analysis. Samples shall be taken in clean glass or aluminium containers. (Plastic containers shall not be used for drawing samples. The authorized officer shall send the third sample of the product within 10 days to the laboratories. All Forensic Science Laboratories in Central/States/UTs are authorized under Schedule III of Clause 8(5) of EC Act 1955 for testing of Petroleum Product Samples. AVIATION TURBINE FUELS (ATF – KEROSENE) Introduction Aviation Turbine Fuels (ATF) are manufactured predominantly from straight run Kerosene's or Kerosene/naphtha blends which are obtained from the atmospheric distillation of crude oil. Previously, jet fuels were manufactured from straight run kerosene which were produced from thermally cracking or catalytic cracked stocks. These jet fuels does not conform to IS specification. In recent years however hydro cracking processes have been introduced which produce high quality kerosene fractions ideal for jet fuel. The most important characteristics governed by IS: 1571 are chemical composition, volatility namely distillation, flash point, etc., density, smoke point and the most important property Freezing point. Normally, Forensic Science Laboratory receives ATF as a case of pilferage or some times as a case of adulteration. Test Methods as per IS 1571/1985 Density: (P:16 IS 1448 Methods of Test) A typical Standard ATF-Kerosene is having density (gm/cm3) at 15C 0.775 – 0.830 Distillation: (P:18 IS 1448 Methods of Test : IP 123 :ASTM D 86) It gives an idea of volatility characteristics of the fuel. It can be determined by Non-fractionating type ASTM – Manual Non-fractionating type ASTM – Automatic The entire sample should distill below 300C. Distillation points of 10, 20, 50 and 90 percent specified in IS are characteristic of this fuel. The distillation range of typical ATF is 150C to 240C. Flash Point : (P 20 IS 1448 Methods of Test : ASTM D 56 & 6450) The flash point of typical standard ATF is 40C -- 45C. Viscosity: (P: 25 IS 1448 methods of test: IP 71: ASTM D 445 and 2170) The Viscosity is the property of its resistance to flow. Different units of viscosity are in use, based on a number of seconds taken for a specific and measured quantity of oil to flow in a standard apparatus at a fixed temperature. The universally accepted method is Kinematic Viscosity and is a measure of resistance to gravity flow of fluid, the pressure head being proportional to density. For the determination of Kinematic Viscosity, the time is measured in seconds for a fixed volume of liquid flow under gravity, through a standard capillary of a calibrated viscometer at a closely controlled temperature. The Kinematic Viscosity is the product of time in seconds and calibration constant of the viscometer and is measured in centistokes at 40C for Kerosene and Diesel. Canon Penske Viscometer – routine BS/IP U tube or any equivalent calibrated Viscometer Freezing Point (P11 IS 1448 Methods of Test : IP 16 : ASTM 2386 ) Aviation fuels must have acceptable freezing points and low- temperature pump ability characteristics so that adequate fuel flow to the engine is maintained during long cruise periods at high altitude. ASTM test for Freezing-Point of Aviation fuels (D 2386 / IP 16) and its associated specification limits guard against the possibility of solidified hydrocarbons separating from chilled fuel and blocking fuel lines, filter, nozzles, etc., Method The automatic freezing point detection system provides automated sample testing with the accuracy and repeatability in accordance with ASTM D 2386. The sample is cooled in the test chamber with constant stirring. The sophisticated dynamic measurement system emits a light pulse every 0.5C from a coaxial fiber optic cable positioned above the test sample. The light pulse is then reflected off the silvered bottom test jar to an optical sensor. The advanced software package analyzes the response of light pulse. The initial appearance of crystallization is monitored by light scattering. The sample is then warmed up and the temperature at which the hydrocarbon crystals disappear is recorded as the freezing point. All clear and transparent fuels are readily measured by the detection system, regardless of sample colour. The rapid cooling feature combined with a consistent cooling profile system provides repeatable results with high-test reproducibility. The freezing point of a typical standard ATF is --40C to -55C Smoke point (P 31 IS 1448 Methods of Test: IP 57 : ASTM D 1322) It is the maximum height in mm at which kerosene will burn without smoke in a smoke point lamp. It is an indication of degree of illumination of sample. Higher the smoke point the large will be smoke free flame therefore better illumination. Method Smoke point is an indicator of the combustion qualities of aviation turbine fuels and kerosene. The fuel sample is burned in the Smoke Point lamp and the maximum flame height obtainable without smoking is measured. The Smoke point of a typical standard ATF is 20 mm to 25mm Gas Chromatograph Detailed explanation and experimental conditions etc., are given in Section 2. Hydrocarbon composition (P: 23 IS 1448 methods of test) GC-DHA method gives an entire profile of hydrocarbon composition of ATF, which is very much useful to fix the quality of the fuel. Detailed explanation and experimental procedures are given in Section 2. Aromatics % by volume 22 (max) Olefins % by Volume 5 (max) KEROSENE / SUPERIOR KEROSENE OIL (SKO) Introduction Fuel oils are complex mixtures of compounds of Carbon and Hydrogen, they cannot be classified rigidly or defined exactly by chemical formulae or definite physical properties. Two broad classifications are generally recognized: 1.“ distillate fuel oils” & 2. “Residual fuel oils”. The latter are often referred to as heavy fuel oils and may contain cutter stock or distillates. eg., furnace oil. Distillate fuel oils are Petroleum fractions that have been vaporized and condensed. They are produced by distillation process in which petroleum is separated into fractions according to their boiling range. Distillate fuel oils may be produced not only from “straight run” crude oils but also from subsequent refinery process such as thermal or catalytic cracking. Kerosene and Diesel (gas oil) are typical examples of distillate fuels. Kerosene normally boils in the range of 150C – 250C (max: 300C) and consists of C11 – C18 hydrocarbons. Kerosene is a blend of Paraffins, Naphthenes and Aromatics wherein Paraffins and Naphthenes as major components and aromatics as minor components. The most important characteristics governed by IS 1459/1974 (reaffirmed 1996) are distillation, colour, flash point, smoke point and burning quality. Two types of Kerosene are normally available commercially. Kerosene (colorless) Regular Blue dyed Kerosene for Public Distribution Supply (PDS) (Blue dye is Di-alkyl amino anthraquinone) Test Methods as per IS 1459/1974 Density: (P: 16 IS 1448 Methods of Test) Methods are same as described in Petrol. This parameter is not included in Bureau of Indian Standard Specifications. A typical Standard Kerosene is having density (gm/cm3) at 15C 0.78 – 0.82. Distillation: (ASTM D 86, IP 123, P: 18 IS 1448 Methods of test) It gives an idea of volatility characteristics of the fuel. It can be determined by Non-fractionating type ASTM – Manual Non-fractionating type ASTM – Automatic Procedure is similar to that of Petrol. The entire sample should distill below 300C. Flash Point : ( P 20 IS 1448 methods of test : ASTM D 56 & D 6450 ) Test method is similar as mentioned in Section 3. Viscosity: (P: 25 IS 1448 methods of test: IP 71 : ASTM D 445) The Viscosity is the property of its resistance to flow. Different units of viscosity are in use, based on a number of seconds taken for a specific and measured quantity of oil to flow in a standard apparatus at a fixed temperature. The universally accepted method is Kinematic Viscosity and is a measure of resistance to gravity flow of fluid, the pressure head being proportional to density. For the determination of Kinematic Viscosity, the time is measured in seconds for a fixed volume of liquid flow under gravity, through a standard capillary of a calibrated viscometer at a closely controlled temperature. The Kinematic Viscosity is the product of time in seconds and calibration constant of the viscometer and is measured in centistokes at 40C for Kerosene and Diesel. Canon Penske Viscometer – routine BS/IP U tube or any equivalent calibrated Viscometer Method The sample is put in a viscometer and kept in a viscosity bath to attain the temperature. Sample is sucked with the help of rubber sucker (bellow) & time of flow is noted. The time of flow in seconds multiplying with the constant of viscometer will give viscosity in cst. Smoke point –(IP 57 : P 31 IS 1448 methods of test : ASTM D 1322): It is the maximum height in mm at which Kerosene will burn without smoke in a smoke point lamp. It is an indication of degree of refinement. Higher the smoke point the larger will be smoke free flame therefore better illumination and degree of refinement of kerosene. Paraffins have the highest smoke point, aromatics the lowest and naphthenes the intermediate. Method Smoke point is an indicator of the combustion qualities of Aviation Turbine Fuels and Kerosene. The fuel sample is burned in the Smoke Point lamp and the maximum flame height obtainable without smoking is measured. The Smoke point of a typical standard Kerosene is 18 mm to 22 mm Colour: (Blue dyed Kerosene) as per IS 1459 (second revision reaffirmed in 1991) Visual : Note down the colour of the sample visually UV – Visible Spectrophotometry : Note down the wavelength for maximum absorption for BLUE using visible spectrophotometer. Equipment : Spectrophotometer Method : Scan - Ordinate mode Scan Speed : 120nm / min Lamp : Tungsten (Visible region) Wavelength : 600 nm – 700 nm Peak threshold : 0.02 Oil Blue dye : max -- 645nm – 655 nm (Di alkyl amino anthraquinone dye is normally used for coloring PDS kerosene) Thin Layer Chromatographic methods for the detection of oil soluble dyes. The standard Kerosene sample (2 l), reference standard dyes namely oil blue in solvent ether (2 l) each were spotted on TLC (Silica Gel 60 G) plates or Silica Gel (60 F 254) Alumina pre- coated plates along with case samples. The plates were developed in the saturated chambers containing Hexane:Toluene: Acetic Acid [ 50 : 50 : 2 ] as solvent systems and run the plate upto 10 cm distance and remove the plate from the chamber and dry it. Detection: Blue dye from Kerosene (Standard) sample shows one blue colour spot at Rf around 0.4. This blue dye was found to be oil blue dye used for colouring Kerosene (PDS - Kerosene). Gas Chromatograph Conclusion SKO is normally used as a domestic fuel for illumination and cooking. This may also be used for the industrial and the commercial application. SKO may be misused by the transporters etc for adulterating Petrol and High Speed Diesel. Also there is every chance of the subsidized SKO being given to commercial applications by the dealers. To avoid misuse and adulteration using SKO, it is doped with blue dye. Toxicity Ingestion of kerosene is harmful. Kerosene is sometimes recommended as a folk remedy for killing head lice, but health agencies warn against this as it can cause burns and serious illness. A kerosene shampoo can even be fatal if fumes are inhaled. People can be exposed to kerosene in the workplace by breathing it in, swallowing it, skin contact, and eye contact. The US National Institute for Occupational Safety and Health (NIOSH) has set a recommended exposure limit of 100 mg/m3 over an 8-hour workday. Comparison of kerosene and ATF SKO Kerosene ATF Composition of Paraffin, Composition of Paraffin, Isoparaffin, And Naphtha Isoparaffin, Naphtha, Benzene Distillation out in between 1500 c Distill below 3000 c The Range of – 3000 c typical ATF is 1500 c – 2400 c Density :- 0.78 – 0.82 gm/cm3 Density :- 0.775 – 0.830 gm/cm3 Flash Point :- 370 c – 650 c Flash Point :- 400 c – 450 c Viscosity :- Variable Viscosity :- Not specific Smoke Point :- Not specific Smoke Point :- 20mm to 25mm Freezing point :- 400 c Freezing point :- -400 c to -550 c Summary 1. What is Aviation Turbine Fuel Aviation Turbine Fuel is a specialized by product of crude or petroleum used to power aircraft. It must meet performance guidelines for both the rich mixture condition required for take-off power settings and the cleaner mixtures used during cruise to reduce fuel consumption. Aviation Turbine Fuel (ATF) are manufactured predominantly from straight run Kerosene's or Kerosene/naphtha blends which are obtained from the atmospheric distillation of crude oil. Previously, jet fuels were manufactured from straight run kerosene which were produced from thermally cracking or catalytic cracked stocks. These jet fuels does not confirm IS specification. In recent years however hydro cracking processes have been introduced which produce high quality kerosene fractions ideal for jet fuel. The most important characteristics governed by IS : 1571 are chemical composition, volatility namely distillation, flash point, etc. density, smoke point and the most important property Freezing point. Normally, Forensic Science Laboratory receives ATF as a case of pilferage or some times as a case of adulteration. 1.1 Test Methods as per IS 1571/1985 1.1.1 Density: ( P : 16 IS 1448 Methods of Test) 1.1.2 Distillation : ( P:18 IS 1448 Methods of test: IP 123: ASTM D 86) 1.1.3 Flash Point: ( P :20 IS 1448 Methods of Test: ASTM D 56 & 6450) 1.1.4 Viscosity: (P: 25 IS 1448 methods of test: IP 71: ASTM D 445 & 2170) 1.1.5 Method The Specific details of operation vary for the different types of viscometers. In all cases, the following procedure is followed: 1.1.6 Freezing Point (P11 IS 1448 Methods of Test: IP 16 : ASTM 2386) 1.1.7 Smoke Point (P 31 IS 1448 Methods of Test: IP 57: ASTM D 1322) 1.2 Gas Chromatograph 1.3 Hydrocarbon composition (P: 23 IS 1448 Methods of Test) Kerosene 2.Introduction Kerosene, also known as paraffin, is a combustible hydrocarbon liquid which is derived from petroleum. It is widely used as a fuel in aviation as well as households. Fuel oils are complex mixtures of compounds of carbon and Hydrogen, they cannot be classified rigidly or defined exactly by chemical formulae or definite physical properties. Two broad classification are generally recognized: 1. “ distillate fuel oils” & 2. “Residual fuel oils”. The latter are often referred to as heavy fuel oils and may contain cutter stock or distillates. eg., furnace oil. Distillate fuel oils are petroleum fractions that have been vaporized and condensed. They are produced by distillation process in which petroleum separated into fractions according to their boiling range. 2.2 Test Methods as per IS 1459/1974 2.2.1 Density: ( P: 16 IS 1448 Methods of Test) 2.2.2 Distillation: (ASTM D 86, IP 123, P: 18 IS 1448 Methods of test) 2.2.3 Flash point : (P: 20 IS 1448 Methods of test: ASTM D 56 & D 6450) 2.2.4 Viscosity: (P: 25 IS 1448 Methods of Test: ASTM D 445) 2.2.5 Smoke Point: (IP 57 : P 31 IS 1448 Methods of Test : ASTM D 1322) 2.2.6 Colour: (Blue Dyed Kerosene) As per IS 1459 (second revision reaffirmed in 1991) 2.2.7 Gas Chromatograph
