DEFINITION: Any combustible substance which is obtainable in bulk, which may be burnt in atmospheric air in such a manner that the het evolved is

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1 -Ms. Neha Patni

2 DEFINITION: Any combustible substance which is obtainable in bulk, which may be burnt in atmospheric air in such a manner that the het evolved is capable of being economically used for domestic and industrial purposes for heating and generation of power. FUEL + O2 Products + Heat

3 The composition of coal varies according to the degree of coalification. In order to compare the coals for the consumer, prize fixation and many other factors,the analysis of coal is carried out Coal analysis are of two types : 1. Proximate analysis 2. Ultimate analysis

1.SUITABILITY: For instance, coke made out of bituminous coal is most suitable for blast furnace, inspite of the fact that charcoal or anthracite may also be used. 2.

4 1.SUITABILITY: For instance, coke made out of bituminous coal is most suitable for blast furnace, inspite of the fact that charcoal or anthracite may also be used. 2.COST: The fuel should have a low cost and on prolong storage it should not change its properties significantly. 3.CALORIFIC VALUE: The fuel must possess high calorific value (heat per unit mass or volumes)and produces no hazardous gases which might pollute the atmosphere. 4.IGNITION TEMPERATURE OR KINDLING TEMPERATURE: The minimum temperature at which the substance ignites and burns without further addition of heat from outside. Fuel should possess a moderate ignition temperature. Too high ignition temperature causes difficulty in kindling while too low ignition temperature may create safety problems during storage, transport and use of the fuel. The presence of moisture and foreign material in the fuel always decreases the ignition temperature. 5.Flame temperature: The highest temperature at which an substance can be heated by flame is called flame temperature. The flame temperature generally increases with the increases in the number of combustibles.

5 6.MOISTURE: It should be very low. High moisture content lowers the effective calorific value of the fuel. 7.NON COMBUSTIBLE MATTER CONTENT: The non combustible matter forms clinkers after combustion and it reduces the heating value and involves the cost of disposal after the combustion. 8.VELOCITY OF COMBUSTION: Velocity of combustion should be moderate. Too high velocities of combustion are not required whereas too low velocities causes loss of heat due to radiation. 9.Control of the process: The fuel should be such that its combustion can easily be controlled i.e. It can be easily started or stopped. 10.Ash: It should produce minimum quantity of ash upon combustion. The Higher proportion of ash may have lower calorific values. 11.Sulphur and Oxygen: The fuel should have minimum quantity of sulphur and oxygen because higher sulphur contents may create corrosion, while oxygen decrease ignition temperature. 12.Safety: It should be safe while transporting and storage. 13.Production of side products: It should not produce any undesirable products(i.e. Noxious gas and pollutants) upon combustion which are harmful to the atmosphere.

6 Characteristics of a good fuel (REVISION)

7 Calorific value

8 G.C.V. (Gross calorific value) or H.C.V. (High calorific value) Definition : Total amount of heat liberated when unit mass bond and products are cool down. They are not allow to escaped. G.C.V = N.C.V + LATENT HEAT. N.C.V (Net Calorific value ) or L.C.V (Low calorific value) Definition : Total amount of heat liberated when unit mass of fuel bond and products are allowed to escaped.

10 GCV = 1\100 (8080C (H O\8)+2240S) NCV=[GCV 0.09 H * latent heat of condensation] Where, C= percentage of carbon H=percentage of hydrogen O=percentage of oxygen S=percentage of sulphur

11 - Most useful compound to human kind

12 Peat Lignite Sub-bituminous Bituminous Anthracite

13 Peat, considered to be a precursor of coal, has industrial importance as a fuel in some regions. In its dehydrated form, peat is a highly effective absorbent for fuel and oil spills on land and water

14 Lignite, also referred to as brown coal, is the lowest rank of coal and used almost exclusively as fuel for electric power generation

15 Sub-bituminous coal, whose properties range from those of lignite to those of bituminous coal are used primarily as fuel for steamelectric power generation. Important source of light for the chemical synthesis industry.

16 Bituminous coal, dense sedimentary rock, black but sometimes dark brown, often with well-defined bands of bright and dull material, used primarily as fuel in steam-electric power generation, with substantial quantities also used for heat and power applications in manufacturing and to make coke

17 Anthracite, the highest rank; a harder, glossy, black coal used primarily for residential and commercial space heating. It may be divided further into metamorphically altered bituminous coal and petrified oil, as from the deposits in Pennsylvania

23 Proximate analysis is a empirical rather than true analysis. It includes the determination of the following: 1. Moisture content 2. Volatile matter 3. Ash 4. Fixed carbon

24 Moisture content : Moisture content should be low. Reason: 1. For every percent of moisture present 1% of heat is lost. 2. Increases transport cost. However about 5-10% moisture is desirable as it produces a uniform fuel bed and less of fly ash.

Moisture content is determined by 1. Heating a known quantity of air-dried coal to 105-110 C for an hour. 2. It is cooled and then weighed. 3.

25 Moisture content is determined by 1. Heating a known quantity of air-dried coal to C for an hour. 2. It is cooled and then weighed. 3. Loss in weight of coal is reported as moisture content on percentage basis Percentage moisture= (W-w) x 100 /W Where, W=weight of sample before heating w= weight of sample after heating

26 VOLATILE MATTER : Volatile matter consists of a mixture of gaseous and liquid products resulting from the thermal decomposition of coal.eg : H2,CO,CH4 It does not include moisture of coal. Volatile matter must be low. Reason: 1. A high percentage of volatile matter indicates that a large part fuel is burnt as a gas which may escape unburnt. 2. Higher volatile matter means more smoke and more pollution.

27 %C= (12/44)*(x/w)*100 %H=(2/18)*(y/w)*100 (where, x=weight of CO2 absorbed y=weight of H20 absorbed w=weight of original sample)

28 It is determined by: 1. Heating a known weight of moisture free coal at around 950 C for 7 minutes. 2. It is then cooled. 3. Loss in weight is reported as volatile matter. Percentage volatile matter =(x-y) X 100 / w where x=weight of the sample before heating y=weight of sample after heating

29 ASH CONTENT : Ash usually consists of silica, alumina, iron oxide and small quantities of lime, magnesium etc. Ash content should be low. Reason: 1. It reduces calorific value. 2. In furnace grate, the ash may restrict the passage of air and lower the rate of combustion.

30 It is determined by : 1. Heating a known weight of coal sample at 750 C for about 1 hour. 2. The remaining mass is then cooled and weighed. 3. The remaining mass in terms of percentage is reported and ash content. Percentage ash= z X 100/ W Where z=weight of residue left W=weight of coal sample.

31 FIXED CARBON : Fixed carbon content must be high. Reason : 1. Higher fixed carbon content means greater calorific value. Percentage of fixed carbon = 100 [% moisture + %volatile matter + %ash]

The ultimate analysis gives the composition of the biomass in weight percentage of carbon, hydrogen and oxygen (the major components) as well as sulphur and nitrogen (if any).

32 The ultimate analysis gives the composition of the biomass in weight percentage of carbon, hydrogen and oxygen (the major components) as well as sulphur and nitrogen (if any). Helps determine if the fuel is good for a particular application (as opposed to proximate analysis that gives only the general usability of a fuel). Also called Elemental Analysis.

33 Required for detailing and accurating heat balance for equipments in which coal is used Useful in estimating calorific value of coal Used in designing furnaces

34 The ultimate analysis determines the elemental analysis of the fuel sample like : 1. Carbon 2. Hydrogen 3. Sulphur 4. Nitrogen 5. Oxygen.

35 A known mass of organic compound is heated in the presence of pure oxygen. The carbon dioxide and water formed are collected and weighed. The percentages of carbon and hydrogen in the compound are calculated from the masses of carbon dioxide and water.

36 Leibig s Apparatus

37 PROCEDURE : A known amount of coal( x gm) Is taken in a combustion tube and burnt in excess of oxygen(no C02 or moisture).the hydrogen and carbon are converted into H2O and CO2. C(s) + O2(g) CO2(g) 12gm 2 X 16 gm 44gm H2 + ½O2(g) H2O 2gm 16gm 18gm

38 The other oxidation products sulphur(s) and chlorine(cl) are also obtained which are trapped by silver gause heated at C, while CO2 and H2O are absorbed in preweighed KOH solution and anhydrous CaCl2. 2KOH +CO2 K2CO3+ H2O CaCl2 + 7H2O CaCl2.7H2O

39 Let, Weight of coal sample=w gm Increase in weight of CaCl2=y gm Increase in weight of KOH=x gm 44 gm of CO2 = 12 gm of C Y gm of CO2 =(12/44) X y gm of carbon Therefore, % carbon=(12/44) X (x X 100)/w Similarly, % hydrogen= (2/18) X (y X100)/w

40 Greater the percentage of carbon, greater the calorific value Higher percentage of carbon reduces the size of the combustion chamber required. Higher percentage of hydrogen also increases the calorific value of the fuel.

41 The nitrogen content present in coal is estimated by Kjeldahl s method. Procedure: A known weight of coal sample long with K2SO4 + HgSO4 is taken which acts as a catalyst is heated with conc. H2SO4. Nitrogen present gets converted into (NH4)2SO4. The contents are then transferred into a round bottom flask and the contents are then heated with excess NaOH. The NH3 gas thus liberated is absorbed in a known volume of standard acid. The unused acid is then determined b titrating with NaOH. From volume of acid used by NH3, nitrogen content can be calculated.

44 (NH4)2SO4 + 2NaOH Na2SO4 + 2NH3 + 2H2O NH3 + H2SO4 (NH4)2SO4 Let, weight of coal sample = W gm Volume of acid used= V1 ml Normality of the acid = N1 V1 ml of N1 acid= V2 ml of N2 NH3 V2 ml of 1N NH3= V1 X N1 ml of acid But 1000 ml of 1 N ammonia solution= 17g of NH3=14g of nitrogen Therefore, V2 ml of 1 normal ammonia solution = (14 X N1 X V1)/1000 Percentage nitrogen=(1.4 X N1 X V1)/W

45 Procedure: Sulphur present in the coal is oxidized by fuming nitric acid and sulphuric acid. The sulphurinc acid is precipitated as BaSO4 by addition of BaCl2. The precipitate of BaSO4 is filtered and heated to a constant weight. From the weight of BaSO4,sulphur content is calculated. Let, Weight of coal sample= W gm the mass of precipitate = x gm 233 gm of BaSO4 = 32 g of sulphur W gm of BaSO4 = (32/233) gm Percentage of sulphur = (32/233) X (x/w) X 100

46 ASH:- It is determined in the same way as in proximate analysis. DETERMINATION OF OXYGEN: The percentage of oxygen can be calculated by deducting the percentage of all the element present in the coal from 100 by using following formula. % of oxygen = 100 [% C + % H +% N + % S + % Ash] Significance : Less is the oxygen content better is the coal. Oxygen is in combined form with hydrogen in coal and thus hydrogen available for combustion is lesser than the total hydrogen present.

47 PROXIMATE ANALYSIS : REVISION

48 Ultimate analysis : Revision

50 The mixture of Carbon dioxide, Carbon monoxide and Oxygen releasing out of combustion chamber is known as flue gases. Analysis of flue gases gives idea regarding the efficiency of the combustion process. 1. More carbon monoxide content in flue gases indicate that oxygen supply is less and combustion is Incomplete. 2. If there high percentage of oxygen, it indicates that combustion is complete but the supply of oxygen is excessive. 3. If there is high percentage of carbon dioxide, it indicates proper combustions of fuel and adequate

51 E -Entrance for flue gas. U -contains glass wool for, retaining moisture and smoke. V -three way stopcock. S1,s2,s3 -are stopcocks connecting to bulbs b1,b2,b3 respectively.

52 FLUE GAS ANALYSIS by ORSAT s APPARATUS

53 Different Solutions filled in bulbs of Orsat Solution Apparatus Filled Function Absorption Bulb B1 B2 B3 Ammonical Cuprous Chloride (100 gm CuCl ml liq. NH3 +75 ml H2O) Alkaline Pyrogallic acid (25 gm Pyrogallic acid gm KOH ml H2O) Potassium Hydroxide Solution (200 gm KOH ml H2O) Working of Orsat Apparatus It can absorb CO,O2,CO2 It can absorb CO2,O2 It absorb 1. Apparatus is thoroughly cleaned. Stoppers are cleaned, greased and tested for air tightness. Solutions are filled in bulbs as per above. The jacket and separating funnel are filled with water. 2. Close S1,S2,S3 and open valve V to connect the atmosphere and separating funnel and fill water in gas burette. CO2

54 3. Now close V and open S3 and lower down the separating funnel so water will run to B3 and suck the required quantity of water and close the valve. 4. Similarly other two bulbs are also brought to the required mark. 5. Open valve V to connect B1 and atmosphere, adjust separating Funnel till glass bulb is filled with water. Connect V and E and allow the Gas to be analysed in glass tube. 6. In this way gas is expelled, suck again to remove trace amount of air in glass tube and untill exactly 100ml of gas at atmosphere is collected. 7. Close V and open S3,raise level of SF to get gas in B2,lower the SF to Get gas in GB and repeat till complete absorption of CO2 in KOH. 8. Lower SF until solution in the bulb remains at the fixed mark

55 BIODIESEL ETHANOL HYDROGEN METHANOL NATURAL GAS CNG LNG LPG 55

56 Biodiesel is a domestically produced, renewable fuel that can be manufactured from vegetable oils, animal fats, or recycled restaurant greases. Biodiesel is safe, biodegradable, and reduces air pollutants such as particulates, carbon monoxide, hydrocarbons, and air toxics. Biodiesel can also be used in its pure form but it may require certain engine modifications to avoid maintenance and performance problems and may not be suitable for wintertime use. Need to heat storage tanks in colder climates to prevent the fuel from gelling

57 IT IS ALCOHOL BASED FUEL PRODUCED BY FERMENTING AND DISTILLING STARCH CROPS. ETHANOL PRODUCED FROM CELLULOSIC BIOMASS SUCH AS TREES AND GRASSES IS CALLED AS BIOETHANOL. E85,E95,E10 ARE USED AS FUELS IN VEHICLES. 57

58 Gasoline with ethanol is still gasoline. It's not an alternative fuel. An increasing number of new vehicles can use E85 (15% gasoline, 85% ethanol), which is an alternative fuel. 58

59 Methanol, also known as wood alcohol, can be used as an alternative fuel in flexible fuel vehicles that run on M85 The benefits include lower emissions, higher performance, and lower risk of flammability than gasoline Methanol can easily be made into hydrogen for hydrogen fuel cell vehicles in the future. Methanol is extremely corrosive, requiring special materials for delivery and storage.

60 H2 HAS BEEN USED EFFECTIVELY IN A NUMBER OF INTERNAL COMBUSTION ENGINE VEHICLES AS PURE H2 MIXED WITH NATURAL GAS. H2 AND O2 FROM AIR FED INTO A PROTON EXCHANGE MEMBRANE(PEM) FUEL CELL STACK PRODUCE ENOUGH ELECTRICITY TO POWER AN ELECTRICITY TO POWER AN ELECTRIC AUTOMOBILE,WITHOUT PRODUCING HARMFUL EMISSIONS. TWO COMMON METHODS TO PRODUCE H2 ARE: (I)STEAM REFORMING OF NATURAL GAS (II)ELECTROLYSIS OF WATER IT HELPS IN: (I)ENERGY SECURITY (II)GLOBAL CLIMATE CHANGE (III)AIR QUALITY

Automakers and experts speculate that a fuel cell vehicle will be commercialized soon.

61 Individual fuel cells can be placed in a series to form a fuel cell stack The stack can be used in a system to power a vehicle. Automakers and experts speculate that a fuel cell vehicle will be commercialized soon. Fuel cell buses are currently in use in North and South America, Europe, Asia and Australia. Trains, planes, boats, scooters, forklifts and even bicycles are utilizing fuel cell technology as well.

62 NATURAL GAS ARE DOMESTICALLY PRODUCED,HAVE CLEAN BURNING,AND HAS LESS HARMFUL EMISSIONS. IT IS THE MIXTURE OF HYDROCARBONS MAINLY CH4 AND IS PRODUCED EITHER FROM GAS WELLS OR IN CONJUCTION WITH DRUDE OIL PRODUCTION. SMOG PRODUCING GASES SUCH AS CO AND Nox ARE REDUCED BY 90% AND 60%. 62

63 CO 79% NO x VOCs 53% 44% CO 2 33% Particulates 25% Lead 13% SO 2 7% Still a major contributor, despite reductions in new vehicle emissions achieved over the last decade

64 LNG IS ALMOST PURE METHANE AND BECAUSE IT IS A LIQUID HAS AN ENERGY STORAGE DENSITY MUCH CLOSER TO GASOLINE THAN CNG. IT IS TYPICALLY USED IN HEAVY-DUTY APPLICATIONS SUCH AS TRANSISTS BUSES,HEAVY DUTY,LONG-HAUL TRUCKS OR LOCOMOTIVES. 64

65 CNG is made by compressing natural gas which is mainly composed of methane, to less than 1% of the volume it occupies at standard atmospheric pressure. CNG HAS LOW HYDROCARBON EMISSIONS AND VAPOURS ARE NON-OZONE PRODUCING. CNG IS 70%-90% METHANE 10%-20% ETHANE 2%-8% PROPANE AND DECREASING QUANTITES OF HCs UP TO PROPANE. 65

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ALSO KNOWN AS BOTTLED GAS OR REFINERY GAS WHICH IS OBTAINED AS A PRODUCT DURING THE CRACKING OF HEAVY OILS OR FROM NATURAL GAS IS PREDOMINANTELY PROPANE WITH

67 ALSO KNOWN AS BOTTLED GAS OR REFINERY GAS WHICH IS OBTAINED AS A PRODUCT DURING THE CRACKING OF HEAVY OILS OR FROM NATURAL GAS IS PREDOMINANTELY PROPANE WITH iso- BUTANE AND n-butane. LPG CONSISTS OF HYDROCARBONS OF SUCH VOLATILITY THAT THEY CAN EXIST AS GAS UNDER ATM. PRESSURE BUT CAN BE READILY LIQUEFIED UNDER PRESSURE.

68 Propane or liquefied petroleum gas (LPG) is a popular alternative fuel choice for vehicles because there is already an infrastructure of pipelines, processing facilities, and storage for its efficient distribution. LPG produces fewer vehicle emissions than gasoline. Propane is produced as a by-product of natural gas processing and crude oil refining. The cost of a gasoline-litre equivalent of propane is generally less than that of gasoline.

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70 CNG More economical Kit more expensive More wear and tear on engine Safer in case of leakagelighter than air Does not contaminate and dilute the crankcase oil LPG Higher Calorific Value Easily Available Wears out piston heads with heavy loads Stored at lower pressures Non-corrosive and free of tetra-ethyl lead or any additives 70

R.K.Yadav/Automobile Engg Dept/New Polytechnic Kolhapur. Page 1

R.K.Yadav/Automobile Engg Dept/New Polytechnic Kolhapur. Page 1 Fuel : A fuel is defined as a substance (containing mostly carbon and hydrogen) which on burning with oxygen in atmospheric air, produces a large amount of heat. fuel. The amount of heat generated is known