1. BY Dr. P M V Subbarao Mechanical Engineering Department I I T Delhi
Analysis of Oil & Gas BY
Dr. P M V Subbarao
Mechanical Engineering Department
I I T Delhi
An analysis to know the Rate of Generation of Natural Fuels...

2. ONE TIME RESOURCE INCOMING RESOURCE THERMAL FOSSIL FUEL SOLAR
SOLAR ENERGY
INCOMING
RESOURCE
CO2 + H2O
PHTOSYNTHESIS
SOLAR
RADIATION
WINDS
VEGETATION
VELOCITY
CHEMICAL ENERGY
THERMAL
WAVE
WIND ENERGY
CLOUDS
OCEAN
THERMAL
ENERGY
FOSSILIZATION
RAINS
HYDRO ENERGY
COAL
FOSSIL FUEL
PETROLEUM
NATURAL GAS

3. Energy Cycle in Living Things
                                                                            

5. 180 million years BC, UK under sea.
                  Today

6. Theory of Oil Formation
The prevailing explanation for the formation of oil and gas deposits is that they are the remains of plant and animal life that died millions of years ago and were compressed by heat and pressure over millions of years.
Russian and Ukranian geologists argue that formation of oil deposits requires the high pressures only found in the deep mantle.
The hydrocarbon contents in sediments do not exhibit sufficient organic material to supply the enormous amounts of petroleum found in supergiant oil fields.

7. Formation of Oil and Gas

12. Fats
Fatty acids consist of the elements carbon (C), hydrogen (H) and oxygen (O) arranged as a carbon chain skeleton with a carboxyl group (-COOH) at one end.
Saturated fatty acids (SFAs) have all the hydrogen that the carbon atoms can hold, and therefore, have no double bonds between the carbons.
Monounsaturated fatty acids (MUFAs) have only one double bond. Polyunsaturated fatty acids (PUFAs) have more than one double bond.
CH3CH2CH2CH2CH2CH=CHCH2CH=CHCH2CH2CH2CH2CH2CH2CH2COOH: 9,12-octadecadienoic acid   (Linoleic Acid).
Abbrevation: CH3(CH2)4CH=CHCH2CH=CH(CH2)7COOH

13. Kerogens
Kerogens : a mixture of molecules that are residues from once-living organisms, i.e., biogenic material.
Kerogens consist of many different, typically aromatic (i.e., benzene ring-containing), C-O-H molecules.
Such molecules are classified as "organic" in traditional chemical nomenclature.
The definitive identification of kerogen in geologic materials is based on the fact that poorly ordered carbonaceous materials.
Type I
containing alginite and amorphous organic matter (AMO)
Hydrogen:Carbon ratio > 1.25
Oxygen:Carbon ratio < 0.15
Shows great tendency to readily produce liquid hydrocarbons, but its occurrence is extremely limited and does not warrant the attention given to it.
It derives principally from lacustrine algae and forms only in anoxic lakes and several other unusual marine environments
Has few cyclic or aromatic structures
Formed mainly from proteins and lipids

14. Type II
Hydrogen:Carbon ratio < 1.25
Oxygen:Carbon ratio 0.03 to 0.18
Tend to produce a mix of gas and oil.
Several types: exinite, cutinite, resinite, and liptinite
Exinite: formed from pollen and spores
Cutinite: formed from terrestrial plant cuticle
Resinite: terrestrial plant resins, animal decomposition resins
Liptinite: formed from terrestrial plant lipids (hydrophobic molecules that are soluble in organic solvents) and marine algae
They all have great tendencies to produce petroleum and are all formed from lipids deposited under reducing conditions.
Type III
Hydrogen:Carbon ratio < 1
Oxygen:Carbon ratio 0.03 to 0.3
Material is thick, resembling wood or coal.
Tends to produce coal and gas
Has very low hydrogen because of the extensive ring and aromatic systems

18. Hydro carbon Chemistry & Classification of Crude Oils
Paraffin based crudes (a waxy residue)
Asphalt based crudes (an asphalt type residue)
Mixed type-based crudes ( a combination residue)
Components of Crude Oils.
Paraffins (CnH(2n+2))
Olefins
Aromatics
Ultimate Analysis
C : % ; H : % ; O : % ; N : % ; S : %

19. Product contents of Crude oils

20. petroleum refining : Basic refinery processes
Functions of Refinery Units:
(1) separating the many types of Hydrocarbon present in crude oils into fractions of more closely related properties,
(2) chemically converting the separated hydrocarbons into more desirable reaction products, and
(3) purifying the products of unwanted elements and compounds.
Types of Distillation:
Fractional Distillation
Vacuum Distillation
Super fractionation
Thermal Cracking
Catalytic Cracking

23. Boiling range, and molecule size for typical refinery
BOILING Temperature # CARBON ATOMS
Refinery Gas <25oC
Gasoline oC
Naptha oC
Kerosene oC
Diesel Fuel oC
Residual Oil >400oC >25

24. Properties of Petroleum Derivatives
Specific Gravity
Calorific Value
Viscosity
Flash Point
Fire Point
Pour Point
Volatility
Ash content
Carbon Residue
Octane Number / Cetane Number / Performance Number

25. Specific Gravity
Specific Gravity = (Weight of fuel/unit volume)/(weight of water/unit volume at 15oC)
API Gravity = 141.5/(SG15.6/15.6oC)
Significance of SG: Origin of the fuel Combustion characteristics
A high API G : Paraffin fuel with good ignition quality; low c/H ratio.
A high API G : aromatic asphaltic fuel with poor combustion characteristics
APT G < 10 : Difficult or impossible to separate-out water and solid.
Good quality paraffin straight run fuels : (API G)
Aromatic fules :

26. Calorific Value:
HCV (MJ/kg) = { * (SG)2} * {1 - (M+A+S)} * S
LCV = { * (SG) *(SG)} * {1 - (M+A+S)} *S * M
Flash Point: The temperature at which the oil must be heated under prescribed conditions for sufficient vapour to be given off to form an flammable mixture with air.
Determines the type of blend
indicates safe sotrage temperatures.
Gasoline : 40oC; Kerosene: 40oC; Diesel Oile: oC
Fire Point: The temperature at which continuous flame is seen .
Indication of fire risk.

27. Ash content: Amount of totally non combustible products
Ash content: Amount of totally non combustible products. Contaminants such as dirt, sand, rust and scales.
Solid ash forming compounds can cause
Severe abrasive wear in IC enginescylinder liners.
High temperature slagging in fire tubes and super heater tubes.
Blade deposition on gas turbine blades.

28. Viscosity: Kinematic viscosity (Centi Stokes) and Dynamic viscosity (Centi Dynes).
Design of burners/ IC engine injectors.
Decreases with increasing temperature but becomes constant at 120oC
Heating of fuel helps in atomization.
Maximum viscosity for easy atomization in commercial burners : 25 cStokes.
For easy pumping 1200 cStokes.
Diesel fules : Low viscosity causes exessive leakage.
High viscosity produces coarse drops. -- results in formation of engine deposits -- incomplete combustion.
VISCOSITY IS NOT AN PROPORTIONATE PROPERTY.

29. Octane Number Also called ANTIKNOCK RATING
Measure of the ability of a fuel to resist knocking when ignited in a mixture with air in the cylinder of an internal-combustion engine.
The octane number is determined by comparing, under standard conditions, the knock intensity of the fuel with that of blends of two reference fuels: iso-octane, which resists knocking, and heptane, which knocks readily.
The octane number is the percentage by volume of iso-octane in the iso-octane-heptane mixture that matches the fuel being tested in a standard test engine.
Iso Octane is rated as 100 Octane number fuel
Normal Heptane is rated as 0 Octane number
1.1 CC of TEL lead added to 1 litre of gasoline :
MTBE
Non linear scale : ON increase from 97 to 100 give much more power than ON from 70 to 73.

30. Cetane Number
In CI engines the time between start of injection and onset of combustion is known as the ignition delay.
CN is a measure of ignition delay.
Normal paraffin cetane or n-Hexa Decane (C16H34) CN
Iso Cetane or Heptamethylnonane CN
CN = % n-Hexa Decane * (% Heptamethylnonane).
Injection is fixed at 13o before TDC and compression ratio is changed until combustion starts at TDC.
Standard mixture is found which gives the same ignition delay at these fixed conditions of injection timing and compression ratio.
Performance Number
The Indicated power developed by supercharged engine without detonation relative to power developed by iso-octane.

31. Gaseous Fuels
Can be easily piped into furnace -- no physical handling is required.
Natural Gas -- True Fossil fuel
Odorless and colorless
Mainly CH4 + heavier HCs
HHV = 55,000 kJ/kg.
Manufactured Gases
LPG -- light distillates of petroleum. -- Heavier than air!!!
Stored and transported under pressure ( Mpa).
SNG : Produced from coal by Hydrogenation -- cheap and clean..
Pressurized Hydrogen at 9000C is combined with coal to produce a number of light HCs.
Producer gas, Bio-gas, Water gas, Coke-oven gas etc….