Anti knock

A presentation on anti-knocking value and requisites of good quality fuel. Includes production and usage of gasoline other fuels like kerosene, diesel, naphtha and aviation turbine fuel.

1. ANTI-KNOCK VALUE & REQUISITES OF GOOD QUALITY FUEL Presented by Group-7 1711027 1711032 1711037 1711042 1711047

2. 01 KNOCKING OCTANE NUMBER ANTI-KNOCKING VALUE GASOLINE & ATF Definition, Order, Cetane Number, Advantages 03 04 02 Definition, Determination, Advantages, Disadvantages Production, Requisites of Good Quality Gasoline, Aviation Turbine Fuel Definition, Reasons, Effect TABLE OF CONTENTS

3. KNOCKING The rattling noise produced from the combustion chamber of an engine . It was first observed by  Harry Ricardo between 1916 and 1919 . 01

4. WHAT CAUSES KNOCKING IN PETROL ENGINE IN DIESEL ENGINE Preignition Imbalanced combustion Delay of ignition 02

5. OTHER REASONS Contaminated fuel Characteristics of fuel Design operation of engine 03

6. EFFECTS OF KNOCKING Reduces engine life Lo w ers the efficiency of engine Results in w ear and tear of engine parts 04

7. OCTANE NUMBER A figure indicating the anti-knock properties of a fuel, based on a comparison with a mixture of isooctane and n - heptane . The octane number of n - heptane is assigned . The octane number of isooctane is assigned 100. 05

8. Example- Octane number 80 means it gives as much knocking as 80 % isooctane and 20 % normal heptane. The greater the octane number, the better- q uality fuel it is. 06

9. DETERMINATION OF OCTANE NUMBER Three methods are used- Motor Method Research Method Aviation Method 07

10. Process- 08

11. ADVANTAGES OF HIGH OCTANE NUMBER Octane number can be increased by adding Tetra Ethyl Lead (TEL) to fuel. Increase in cruising speed Decreases takeoff distance Increase in payload weight 09

12. DISADVANTAGES OF HIGH OCTANE NUMBER Gum formation Susceptible to pre-ignition 10

13. ANTI-KNOCKING VALUE Anti-knock value is the measure of resistance to knocking. Anti-knocking value increases when- Molecules are compact Fuel component has cyclic structure Fuel component contains double bond 11

14. Order of anti-knock value- Aromatics > iso - paraffins > napthenes > olefins > paraffins 12

15. OCTANE NUMBER OF BLENDS Paraffin – Paraffin Paraffin – Aromatics Paraffin - Olefins 13

16. CETANE NUMBER Measure of knocking in a diesel engine, relative to cetane ( C 16 H 34 ) as a standard. Order of cetane number- Paraffins > olefins > napthenes > iso - paraffins > aromatics High octane number has a low cetane number and vice-versa. 14

17. ADVANTAGES OF HIGH CETANE NUMBER Faster engine starting Faster engine warm up Reduced exhaust smoke Increased engine efficiency Improved combustion control 15

18. PRODUCTION OF GASOLINE Gasoline is another name for Petrol . The following production methods are followed- PROCESS PRODUCT Distillation of crude oil Straight run gasoline Cracking of fuel oil Cracked gasoline Alkylation of refinery gases Gasoline Reforming of heavy gasoline and naphtha Reformed gasoline Condensation of natural gas Natural gasoline 16

19. 17                               Atm Column Hydrotreater 300-400° C 30-130 atm     Light Naptha Heavy Naptha Low Sulfur Kerosene Isomerization Reformation Gasoline Kerosene Hydrocracker Hydrocracked Lube Oil Motor Oil Vacuum Unit 370-380° C < 1 atm Heavy Vaccum Residum Light Vaccum Residum Asphalt Residual Gas Oil   Alkylation Gasoline Vapour 0-30 ° C Naptha 30-180 ° C Kerosene 180-260 ° C Gas Oil 260-350 ° C Lubricants 300-350 °C Residue > 580 ° C Distillation Industrial Fuel Diesel Fuel Natural Gas Production of Gasoline and Other Fuels

20. REQUISITES OF GOOD GASOLINE High calorific value Low freezing point Optimum flash point Controlled volatility Limited vapor pressure 18

21. USES OF DIFFERENT TYPE OF FUELS GASOLINE DIESEL Fuel for IC engine Aviation fuel Automobiles Power generators Industrial application 19

22. NAPTHA KEROSENE Jet fuels Used as solvent Producing synthesis gas Domestic fuel Lighting purpose Manufacturing insecticides 20

23. AVIATION TURBINE FUEL The fraction of crude oil obtained in the range of 150-270° C . Comprises mainly of paraffins and napthenes . Produced by hydrocrac k ing of residual stocks and hydrotreating of petroleum distillates. K erosene type ATF and gasoline type ATF are widely used. 21

24. DESIRABLE PROPERTIES OF ATF High smoke point High luminometer number Denser molecular structure Low olefins content Low freezing point 22

25. ADDITION OF ADDITIVES TO ATF Antio x idants – Prevent gum formation Metal deacti v ator – Removes dissolved Cu Anti - icing additi v e – Avoids freezing of water Anti - smo k e additi v e – Reduces smoke Fuel soluble biocides – Inhibits microbial growth 23