Gaseous Fuel
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Transcript of Gaseous Fuel
GASEOUS FUELS
Dr G NAGARAJAN
Professor
Department of Mechanical Engg.
Anna University Chennai
Chennai 600 025
G A S E O U S F U G A S E O U S F U E LE L ADVANTAGES
- Consistency in Quality
- Easily Combustible
- Absence of Mineral Impurities
- High Efficiency of Combustion
T Y P E S N a t u r a l l y O c c u r r i n g
- Natural Gas
- Methane from Coal Mines
Manufactured from Solid Fuels
1 Wood Gas 2 Coal Gas
3 Producer Gas 4 Water Gas
5 Blast Furnace Gas
Manufactured from Petroleum
- Refinery Gas
- Liquefied Petroleum Gas ( L P G )
- Gases from Oil Gasification Process
Fermentation of Organic Wastes
- Methane Gas / Biogas
C L A S S I F I C A T I O N
(c) L O W B T U G A S
1 Producer Gas : 4 000 k J / n m 3
( based on Calorific Value )
(a) H I G H B T U G A S
1 Liquefied Petroleum Gas : 1 25 610 kJ / nm3
2 Natural Gas : 35 170 – 38 102 kJ / nm3
(b) M E D I U M B T U G A S
1 Town Gas : 18 842 – 22 190 kJ / nm3
2 Industrial Fuel Gas : 9 210 – 12 980 kJ / nm3
• Paraffinic Hydrocarbon
• Principal Content – M e t h a n e
• High Btu gas ( C V : 35 000 kJ / nm3 & above )
N A T U R A L G A S
It occurs naturally in gas fields
and also in association with Crude
Petroleum in oil fields.
NATURAL GAS COMPOSITION
Components (% vol) Test Italian Russian Dutch AlgerianHelium - - 0.02 0.04 0.16Nitrogen 0.6 0.31 0.93 3.1 5.43Carbon Dioxide - 0.02 0.2 1.33 0.16Methane 90.2 99.59 97.32 90.3 83.66Ethane 8.5 0.04 0.94 3.89 7.75Propane 0.6 0.01 0.37 0.89 1.93Butane 0.1 - 0.14 0.26 0.64Pentane - - 0.04 0.08 0.15Hexane - 0.03 0.04 0.11 0.1
Density (kg/m3) 0.78 0.72 0.74 0.8 0.84Calorific Value
(MJ/m3) 38.4 35.8 36.1 36.3 37.9(MJ/kg) 49 49.7 48.4 45.6 47.1
Wobbe Index 94.4 48 47.8 46.3 47.1Methane Number 75 98 90 80 70H/C Ratio 3.82 4 3.95 3.86 3.73Air / Fuel Ratio
Stoichiometric (m3/m3) 10.22 - - - -(kg/kg) 16.86 17.12 16.81 15.68 15.49
Inert Mass 1 0.6 2.1 8.2 8.5
Incr
ease
in
en
erg
y co
nsu
mp
tio
n (
%)
0
10
20
30
40
ECE R49Duty Cycle
RefuseCollection
Bus Truck Average
ENERGY CONSUMPTION DIESEL vs NATURAL GAS
LOWER CALORIFIC VALUE AND DENSITY OF DIFFERENT FUELS
Lower calorific value Density
Fuel MJ/kg MJ/dm3 kg/dm3
Gasoline 40 29.9 0.748
Diesel Fuel 43 36 0.840
Methanol 20 16 0.794
Ethanol 27 21 0.792
Natural Gas 200 bar 50 6.3 0.128
Hydrogen 200 bar 120 1.9 0.016
Hydrogen 700 bar 120 5.0 0.042
Liquid Hydrogen 120 8.5 0.071
Biodiesel 37 33 0.88
Rape Seed Oil 38 35 0.92
NATURAL GAS ENGINE
• COMPRESSION IGNITION OF A NATURAL GAS/AIR – MIXTURE NOT FEASIBLE (TO HIGH AUTOIGNITION TEMPERATURE)
• DUAL FUEL OPERATION ALLOWS ‘DIESEL-LIKE‘ COMPRESSION RATIOS, BUT TWO COMPLETE FUEL - AND FUEL STORAGE - SYSTEMS ARE REQUIRED COMPLICATED OPERATION.
• NATURAL GAS TO BE USED IN SPARK IGNITION ENGINES EITHER WITH ONE OF THE FOLLOWING GAS ADMISSION SYSTEMS– SINGLE POINT– MULTI POINT – DIRECT INJECTION
NATURAL GAS ENGINE
• NATURAL GAS ENGINES SUITABLY APPLICABLE FOR CITY BUSES, DELIVERY VEHICLES AND GARBAGE COLLECTING VEHICLES AS WELL AS STATIONARY APPLICATIONS (GEN SETS, ETC).
• DUE TO FUEL STORAGE (COMPRESSED NATURAL GAS) NOT SUITED FOR LONG - DISTANCE HAULAGE
• IT WAS SUGGESTED TO ‘ENTER THE HYDROGEN USAGE‘ BY USING A MIXTURE OF NATURAL GAS AND HYDROGEN IN ROAD VEHICLES. THIS COULD BE DONE TECHNICALLY BUT WILL HAVE NEGATIVE EFFECT ON FUEL COST.
EMISSIONS COMPARED TO EUROPEAN STANDARDS
FUEL STORAGE RATIO - CNG
200 bar
200 bar
200 bar
200 bar
200 bar
11 55
Diesel
FUEL STORAGE RATIO - LNG
Diesel
= 0.83 kg/litre
-162OC
= 0.35 kg/litre
11 22
• Combustible gaseous mixture obtained
by blowing of air through an incandescent
bed of Solid Carbonaceous fuel
• Plant in which it is made is called as
GASIFIER• It is a fuel of low calorific Value
mainly containing C O & N 2
P R O D U C E R G A S
• Bituminous coal, anthracite and coke
are used as the raw material in gas producers.• With minor variations, Peat & Lignite can also be used.2 C + O2 + 3.76 N 2 2 C O + 3.76 N 2
- 5 8 7 3 0 kcal
M E R I TS1 G A S E O U S F U E L 2 C H E A P3 E A S E O F P R O D U C T I O N
Most widely used industrial fuel gas wherecheap solid fuels are abundant.
principal component
1 If air alone - (i) CO
- (ii) N2
2 If air + steam - (i) CO
- (ii) N2
- (iii) H2
C O M P O S I T I O NComposition % by volume
Produces Gas % by volumeMixed Blast With
Coal Coke Anthracite
CO2 4 . 0 5 . 0 6 . 0Cm Hm ( unsaturated ) 0 . 4 - -O2 - - -CO 2 9 . 0 2 9 . 0 2 6 . 0H2 1 2 . 0 1 1 . 0 1 7 . 0CH4 2 . 6 0 . 5 1 . 2N2 5 2 . 0 5 4 . 5 4 9 . 8Gross CV, kJ / nm3, dry 6500 5550 6000Specific gravity ( air = 1 ) 0 . 8 7 0 . 9 0 0 . 8 5Advantages
(i) Cheapness (ii) Ease of Production
(i) Low Calorific Value : 4500 kJ / nm3
( producer gas is a mixture of 33 % CO & 67 % N2 )
(ii)Low Cold Gas Efficiency < 7 0 %
(iii) 3 0 % of heating value of carbon is
liberated during the reaction. This
causes local heating & ash fusion.
D E M E R I T S
B L A S T F U R N A C E G A S
Blast furnaces may be regarded
as gas producers in which a few
other reaction take place in
addition to the usual producer
reactions.
The resultant gas has higher C O
and lower H2 content.
In Blast Furnaces combustion
gases raise thro’
the descending burden of coke,
ore & flux
Carbon Reduces C O 2 t o C O &
Decomposes Steam to H 2 and C O
Resultant gas known as Blast
Furnace Gas leaves the furnace at 2 0
0 0 C
C O M P O U N D % by vol.
C O 2 1 1C O 2 7H 2 2N 2 6 0
C O M P O S I T I O N
C V = 3 5 0 0 kJ / nm3
Gas Yield 2 4 0 0 nm3 / ton of pig iron
Higher dust content 2 0 - 3 0 g / m3.
Due its low C V it is necessary to
preheat the gas before usage
2 0 % used for preheating the blast
8 0 % for
Steam Raising / Open Hearth Firing
/ Reheating Furnaces / Coke Ovens
I T I N C L U D E S
i) Gases obtained during distillation,
cracking and other processing of
petroleum and petroleum fractions.
ii) Contains paraffins like Methane,
Ethane & Olefins like Ethylene,
Propene, H 2 S , H 2 , etc.,
R E F I N E R Y G A S R E F I N E R Y G A S
C O M P O U N D %H 2 S 6 - 8H 2 6 - 8C H 4 8 - 1 0C 2 H 4 + C 2 H 6 8 - 1 2
C 3 H 6 + C 3 H 8 4 0 - 5 5C 4 H 8 + C 4 H 10 < 3 0
C O M P O S I T I O N
C V 8 5 0 0 0 kJ / nm 3
L I Q U E F I E D L I Q U E F I E D P E T R O L E U M G P E T R O L E U M G A S A S In the gaseous hydrocarbons, C3 & C4
compounds can be liquefied at room
temperature and it can be stored.
It is known as L P G
Prepared from Wet Natural Gas,
Associated Gas & Refinery Gas
Lighter grade
Composition
C3H8
+
C3H6
Butane & iso - butane < 10 %
Ethane & Ethylene < 2 %
Higher grade
Butane, iso butane & Butene = 80 – 90 %
Propane & Propene < 20 %
Ethane & Ethylene < 2 %
= 90 %
1 Domestic Cooking
Butane major component
Storage pressure 3 atm
2 Industrial Usage for Thermal
Propane major component
Storage pressure 10 atm
3 In IC Engines as fuel .
4 Refinery process in the production of
Petrochemicals.
A P P L I C A T I O N S
Carbonization of Wood
at 4 0 0 0 C
Gas yield
1 2 5 nm3 / ton of dry wood
W O O D G A S W O O D G A S
C O 2 - 2 0 %
C n H m - 5 %
N 2 - R e s t
C A L O R I F I C V A L U E
1 3 8 7 0 k J / m3
C O M P O S I T I O N
C O - 2 5 %
C H 4 - 1 4 %
H 2 - 2 0 %
HYDROGEN
• CAN BE USED IN I.C. ENGINES AND IN FUEL CELLS
• HYDROGEN IS NOT AN ‘ENERGY SOURCE‘ .... BUT AN ENERGY CARRIER WHICH HAS TO BE PRODUCED AND THIS REQUIRES ENERGY
• EU COMMISSION WANTS TO FORCE EUROPE INTO A HYDROGEN ECONOMY BY THE YEAR 2050
HYDROGEN
• PRODUCTION OF HYDROGEN BY:
- HYDROLYSIS WHICH SHOULD UTILISE REGENERATIVE ELECTRICITY (SUN, WIND, HYDRO, GEOTHERMAL)
- STEAM REFORMING OF NATURAL GAS OR GASOLINE
- THERMAL SPLITTING OF WATER IN A HIGH-TEMPERATURE NUCLEAR REACTOR
- COAL GASIFICATION AT 900 ºC
- HYDROGEN PRODUCTION FROM BIOMASS
HYDROGEN PRODUCTION USING SOLAR
It is a High Btu gas
Calorific Value
1 2 0 MJ / kg
P R O P E R T I E S
Self ignition temperature is
high.
Extremely clear fuel, less toxic
and no carbonization in the
Engine
It has a wider flammability
range and higher burning velocity.
Gaseous form eliminates the
problem of atomization,
evaporation, mixing and
recondensation.
It is about 2.7 times heavier than
gasoline when compared on
mass basis.
It produces less pollution, main
pollutants is Nox from Nitrogen – Air
Engines.
Cryogenics & Hydrogen bomb
production
It is the most suitable renewable fuel
substitute for gasoline from
technical angles
P R O B L E M S W I T H H Y D R O G E N F U E L
Storage of Hydrogen is a problem.
Although energy per unit weight is
quite high, energy per unit volume
is low.
Vehicle range is limited due to
bulkiness of high pressure tanks.
In case of leak Hydrogen is much
more keen to ignite than gasoline.
Higher diffusivity and great
buoyancy of Hydrogen imply rapid
dispersal into atmosphere.
In the case of liquid Hydrogen
spilling it is far less hazardous than
gasoline.
Contd…
T W O W A Y O F G E T T I N G G A S F R O M B I O M A S
S
BIO CHEMICAL CONVERSION
BIO METHANATION
GASIFICATION ANAEROBIC DIGESTION
It is a High Btu gas
Calorific Value 38 000 kJ / nm3
Composition
55 – 60 % = CH4
40 – 45 % = CO2
Applications
Domestic cooking.
IC Engines.
BIOGAS LANTERN
EMISSION DETAILS
S.No FUEL CO2 ,kg / MWh SOx ,gm / MWh
NOx ,gm /
MWh
1. Natural Gas 179 1 136
2. Kerosene 240 23 190
3. Oil 264 500 690
4. Gasoline 262 505 417
5. Diesel 271 860 570
6. Coal 328 1770 1910
7. Biomass 0 46 1140
EMISSIONS FACTOR (source: Environment Protection Agency, EPA., USA)