Example 5. Example 1.

Coal Gas at 15℃, 760 torrs and saturated with water vapor is burned in the The octane number of gasoline is the % by volume iso-octane (C8H18) – n-heptane
furnace. Air with 60% RH is supplied at the rate of 5.7 m3/m3 coal gas and enters at the (C7H16) mixture with the same knocking tendency as the fuel. An automobile uses an
same temperature and pressure as the coal gas. The coal gas analyzes 14% CO2, 2.7% C2H2, unleaded gasoline with an octane number of 85. Air is supplied 30% in excess such that the
0.7% O2, 5.8% CO, 53.2% H2, 29.6% CH4, and 6.6% N2. The molar ratio of CO2 to CO in the molal ratio of CO2 to CO is the 5:2 and H2 to CO is 1:1 in the exhaust gas. Calculate the orsat
stack gas is 10:1. All the H2 in the fuel is burned to water. The stack gas leaves at 400℃ and analysis of the exhaust gases.
100kPa. Calculate: Density of iso-octane is 0.6918 and n-heptane is 0.684g/
a) % excess air Example 2.
b) Orsat Analysis of the stack gas An engine burns fuel on analyzing 88% C and 12% H with air supplied at 21℃,
c) m3 stack gas / m3 of coal gas normal barometric pressure and 80% RH. The air supplied is less than the theoretical
d) Dew Point of the stack gas amount required for complete combustion of the fuel oil; 25% of the C burns to CO, the
Example 6. remainder to CO2; O2 is all exhaust gas is 3:2. The exhaust gas leaves at 480℃ and
A pure saturated hydrocarbon (CnH2n+2) is burned with excess air. Orsat analysis of 745mmHg. Calculate:
the products of combustion shows 9.08% CO 2, 1.63% CO, 5.28% O2 and no free H2. a) % of the theoretical air that is supplies for combustion
Calculate: b) m3 air supplies / kg of oil
a) The formula of the hydrocarbon c) m3 exhaust gas/kg oil
b) % Excess air d) % of the calorific value of oil (43.616 MJ/kg) lost as
c) Kg dry air/ kg of hydrocarbon i) Unburnt CO in the exhaust
Example 7. ii) Sensible heat in the exhaust gas
Orsat analysis of the stack gas from the combustion of the gaseous mixture of Example 3.
acetylene and methane shows 9.82% CO2, 1.37% CO, 0.69% H2, 5.43% O2 and 82.69% N2. A furnace is fired with the fuel oil containing 86% C, 1% N, and 0.1% S with a
Determine: calorific value of 46.4 MJ/kg. Air is supplied at 25℃, 740 mmHg and saturated with water.
a) %Excess Air Average analysis of the stack gas shows 10.62% CO2, 1.17% CO, 6.34% O2, and 81.87% N2.
b) Mole % composition of the gaseous fuel The stack gas leaves at 400℃ and 765 mmHg. Calculate:
c) m3 wet air supplies at 26℃, 765 torrs and 70% RH per kg of fuel a) % excess air
Example 8. b) Complete elemental analysis of fuel oil
The burning of pure butane with excess air gives a stack gas which analyzes 11.55% c) m3 air / kg oil
CO2 on a dry basis. Assuming complete combustion, calculate: d) m3 stack gas / kg oil
a) % Excess Air e) % calorific value lost due to unburnt combustibles
b) Complete Orsat Analysis of the stack gas Example 4.
Example 9. Cetane numbers are used to indicate the quality of a diesel fuel for compression
A gaseous fuel at 22℃, 763 torrs and saturated with water vapor is burned with ignition engines. It is defined as the % by volume of cetane, C16H34 in a cetane-methyl
excess air. Air with 60% RH is supplies at the same temperature and pressure as the fuel. naphthalene (C11H10) mixture that has the same performance at the fuel. A high speed
The composition of the fuel shows 9.2% CO2, 0.4% C2H4, 20.9% CO, 15.6% H2, 1.9% CH4, and diesel engine burns diesel fuel to give and exhaust gas analyzing 7.14% CO2, 4.28% CO, 8.24
52% N2. The stack gas leaves at 400℃ and contains 13.16% CO2 and 1.84% CO on a dry % O2 and 80.34% N2. Calculate the cetane number of the fuel fired.
basis. Calculate: Density of cetane is 0.7751 and methyl naphthalene is 1.025 g/mL/
a) % Excess Air Example 5.
b) Complete analysis of the stack gas A low grade fuel oil (CV =46.4 MJ/kg) containing approximately 81% C, 8% H, 3%
c) Dew point of the stack gas O, 4% N, and 4% S is burned in a furnace that is well designed and well operated giving a
combustion gas, the partial orsat analysis of which shows 11.22% CO2 and 1.46% CO. The
molal ratio of H2 to CO in the combustion gas is 1:5. Calculate:
a) % excess air
b) m3 air (30℃, 760 mmHg)/ kg fuel oil
c) m3 stack gas (250℃, 765 mmHg)/ kg oil
d) % calorific value lost due to CO and H2
Example 6. Example 5.
Motor Benzole is a mixture of 3 lower aromatic hydrocarbons, benzene, toluene, A furnace burns coal containing 4.1% M, 24% VCM, 63% FC, 1.2% N, 1.8% S, and
xylene in proportions of 75%, 15%, and 10% by weight. Its calorific value is 41.9 MJ/kg. A 8.9 % ash. Its calorific value is 32 MJ/kg. Determine the % VCM, C and Calorific Value lost in
motor is run using benzole and gives an exhaust gas which analyzes 10.7% CO 2 and 1.07% the refuse if it analyzes:
CO. Calculate. a) 4.8 % VCM, 12.6% FC, and 82.6% ash
a) % Excess air b) 24% C and 76% ash
b) Complete Analysis of exhaust gas c) 7.5% VCM, 29.2% FC and 63.3% ash
c) % heat loss due to CO Example 6.
Example 1. A boiler is fired with coal analyzing 13.8% VCM, 3% M, 1.2% S, negligible N and a
A furnace is fired with Sub-bituminous B (Sub B) coal containing 10.3% moisture, calorific value of 32.95 MJ/kg. The dry refuse removed analyzes 5% VCM, 27% FC and 68%
34% VCM and 7.7% ash. It is also known to contain 1.2% N and 1.57% S. Its calorific value is ash. 60% excess air is supplied at 32℃, 758 mmHg with 85%RH. 90% of the carbon gasified
22 MJ/kg. Calculate its: burns to CO2 is 2:9. Calculate:
a) Proximate Analysis a) % C lost in the refuse
b) Modified Analysis b) m3 air/kg coal
c) Ultimate Analysis c) Orsat analysis of the stack gas
d) Analysis of VCM d) m3 stack gas / kg coal
e) Calorific Value of VCM e) total % CV Lost
Example 2. Example 7.
A furnace is fired with high volatile A bituminous coal whose ultimate analysis A furnace burns coal analyzing 78.35% C, 27% VCM, 1.3% N, 7.1% ash, and 0.95%S.
shows 75.2% C, 5.19% H, 8.72% O, 1.5% N, 7.8% ash, and 1.6% S. 60% excess air is supplied. Analysis of the refuse shows 6% VCM, 32 % FC and 62% ash. Air supplied is at 30℃, 735
Assume CO to CO2 ratio of 0.175. The stack gas leaves at 300℃, 740 torrs, Calculate: torrs with 90% RH. The stack gases at 250℃ and 745 torrs has a partial orsat analysis of
a) Complete analysis of the stack gas if air is supplied at 28℃, 100kPa and 9.79% CO2 and 1.47% CO. Assuming that 5.19 % of the C fired is lost in the refuse. Calculate:
essentially dry a) Complete ultimate analysis of coal
b) m3 air supplied / 100 kg oil coal b) Type of combustible in the refuse
c) Calorific Value of coal c) %Excess O2
d) % of the calorific value lost due to: d) Complete orsat analysis of the stack gas
i) Unburnt combustible e) m3 stack gas/ kg coal
ii) Uncondensed water Example 8.
iii) Sensible heat of the stack gas Coal fired in a furnace analyzes 34% VCM, 48% FC, 7.7% ash, 1.2% N and 1.57% S.
Example 3. The refuse contains 6.2% VCM, 8.75% FC, 35% ash and 50.05% H2O. Air supplied is at 35℃,
A high grade semi-anthracite coal was found to contain 90.04% C, 0.79% S, and 765 mmHg with 85% RH. The stack gases leave at 250℃, 766 mmHg with an orsat analysis
1.2% N on an ash and moisture free basis. If this coal were burned in excess air saturated of 9.3% CO2, 2.32% CO, 2.32% H2, 9.54% O2, and 76.52% N2. Calculate:
with water at 30℃ and 105 kPa a flue gas with the following orsat analysis results: 10.83% a) % C lost in the refuse
CO2, 1.08% CO, 0.22% H2, 8.17% O2 and 79.7% N2. Calculate. b) CV of coal
a) Ultimate analysis of coal (ash/moisture free) c) Ultimate analysis of coal
b) % excess air d) % Excess O2
Example 4. Example 9.
A medium volatile bituminous coal (mvb) has an “as received” analysis of 27.13% A furnace is fired with coal with the following analysis: 36.3% VCM, 49.6% FC,
VCM, 62.52% FC, 7.11% ash, 0.95% S, and 1.28%N. Its calorific value is 32.3 MJ/kg. This coal 10.7% ash, 3.4% M, 1.2% N, and 5.1% S. Its calorific value is 29.5 MJ/kg. Analysis of the
is burned in excess air supplied at 30℃ , 756 torrs with 80% RH. Partial orsat analysis of the wetted refuse shows 12% C, 65% ash and 23% H2O. Dry air is supplied at 27℃ and 1 am.
stack gas shows 9.78% CO2 and 2.45% CO. Calculate: The stack gases leaves at 350℃, 745mmHg with a partial orsat analysis of 8.71% CO2, 1.74%
a) % excess O2 CO, and 0.35% H2. Calculate:
b) Complete orsat analysis of the stack gas a) % Excess O2
c) m3 stack gas (270℃, 768 mmHg)/ kg coal b) Complete orsat analysis of the stack gas
c) m3 stack gas / kg coal
Example 10. Example 5.
The ultimate analysis of coal fired in a boiler showed 57.04% total C, 30.5% VCM, Raw Sulfur, 96% pure is burned in dry excess air producing a gas with an orsat
1.2% N, 9.7% ash and 6.3% S. Analysis of the wetted refuse showed 13.8% FC, 21.5% VCM, analysis of 18% SO2, 0.50% O2, and 81.50% N2. The burner gases are fed to a catalytic
47.8% ash and 16.9% H2O. Air is at 28℃, 756 mmHg with 76%RH. Orsat analysis of the stack converter together with 20% excess secondary air resulting in the oxidation of 60% of the
gas shows 7.92% CO2, 2.38% CO, 39% SO2, 1.19% H2, 10.65% O2 and 77.47% N2. Calculate: SO2 to SO3. The gases form the converter enter an absorber to produce the acid. Assuming
a) % VCM and C lost in the refuse no further oxidation of the SO2 taking place in the absorber, Calculate:
b) Ultimate analysis of coal a) Complete analysis of the burner gas
c) % excess air b) Complete analysis of the converter gas
d) Calorific Value of coal c) Wt of an 85% concentrated H2SO4 solution per kg raw S charged if the
Example 1. absorbing acid is 40% H2SO4.
Raw Sulfur analyzing 95% S and 5% inerts is burned with 65% excess air (S to SO2). d) Wt, of a 5% oleum formed per kg raw S charged if the absorbing acid is a 90%
Air is supplied at 30℃, 740 mmHg with 60% RH. Analysis of the cinder shows 10%S and 90% H2SO4 solution.
inerts. 88% of the S gasified burns to SO2, the rest to SO3. Calculate: Example 6.
a) % excess air ( S to SO3) 1000kg/hr Pyrites analyzing 81% FeS2 and 19% gangue is burned in excess air to
b) m3 air/ kg raw S produce a burner gas with an orsat analysis of 5.84% SO2, 9.72% O2 and 84.44% N2. Analysis
c) Complete analysis of the burner gas of the cinder shows 8.29% unburned FeS2 and 3.81% SO3. The gases from the burner enter
Example 2. a catalytic converter where SO2 is oxidized to SO3. Partial orsat analysis of the converter gas
Raw Sulfur analyzing 88% S and 12% inerts when burned produces a gas with an shows 1.87% SO2. No additional secondary air is supplied in the converted. The converter
orsat analysis of 9.79% SO2, 9.16% O2 and 81.05 N2. Dry air is supplied at 25℃ and 760 gases are then sent to an absorber where contact with acid takes place. The waste gas from
mmHg. Calculate: the absorbers analyze 0.95% SO2, 7.82% O2 and 91.23% N2. Calculate:
a) % excess air (S to SO2) a) Complete analysis of the burner gas
b) % excess air (S to SO3) b) % Conversion of SO2 to SO3 in the converter
c) m3 burner gas/ m3 air c) Wt of a 60% H2SO4 needed to produce a concentrated 90% H2SO4 solution/hr
Example 3. d) Wt of an 88& H2SO4 acid needed to produce 12% Oleum / hr
Pyrite Fines containing 85% FeS2 and 15% gangue are charged to a burner. An Example 7.
analysis of the cinder shows 11.11% FeS2, 66.63% Fe2O3, 2.67% SO3 and 19.6% gangue. Air Using the Pyrites and Burner Gas in Example 6, the burner gases are cooled and
is supplied 17.33% in excess (FeS2 to SO3) at 25℃, 740 mmHg and 80%RH. If 8% of the SO3 made to come into contact with Milk of Lime in an absorption tower. The dolomitic lime
formed is absorbed in the cinder. Calculate: used is 82% CaO, 16% MgO and 2% inerts. The bisulfite liquor produced containe 7.05%
a) % Excess Air (FeS2 to SO2) total SO2 of which 1.15% is “free” and the rest 5.9% being present as bisulfites. An analysis
b) % of the FeS2 charged lost in the cinder of the dry waste gas shows that it contains only O 2 and N2. Assuming no further oxidation
c) Orsat analysis of the burner gas of SO2 to SO3 and formation of H2SO4 in the tower. Calculate:
d) m3 of burner gas at 350℃ and 750mmHg/ kg pyrite a) Wt of the bisulfite liquor
Example 4. b) Lime consumption/ hr
Dry pyrite fines containing 82% FeS2 and 18% gangue are burned in a Herreshoff c) Wt of water used for slaking / hr
Burner. The cinder produced contained 3.06% SO3 and no unburned FeS2. Orsat analysis of Example 1.
the burner gas showed 8.15% SO2, 8.46% O2 and 83.38% N2. Calculate: The burning of limestone contaianing 65% CaCO3, 25% MgCO3 and 10% inerts using
a) % of the FeS2 charged converted to SO2 a gas mixture made up of 75% ethane and 25% propane produces a burner gas containing
b) % excess air (FeS2 to SO2) 22.07% CO2, 0.9% CO, 3.02% O2 and 74% N2. Calculate:
c) Complete analysis of the burner gas a) Fuel Ratio by wt
b) % Excess air
Example 2.
A vertical shaft kiln is charged with 4 tonnes/hr of limestone containing 54% CaCO3,
38% MgCO3, 3% SiO2, 1.2% R2O3 (iron oxide) and 3.8% H2O. 125 kg of fuel oil containing 86%
C, 10.5% H, 2.4% O, 1% N and 0.1% S is charged per tonne of limestone. The lime product
leaves the bottom and contains 2.3% CO2. Air supplied is at 25℃, 755mmHg and saturated
with water. Partial orsat analysis of the kiln as shows 20.61% CO2 and 1.18% CO. Calculate:
a) Kg of lime formed /hr
b) % Excess air
c) Complete analysis of the kiln gas
Example 3.
Limestone is calcined in a rotary kiln fired with blast furnace gas. Analysis of the
stone shows 52% CaO, 2.1% MgO, 1.2% H2O, 1.22% Al2O3, 0.33% SiO2 and 43.15% CO2, 5%
CH4, and 54% N2. The gases leaving the kiln contains 35.8% CO 2, 1% O2 and 63.2% N2.
Calculate:
a) % Excess Air
b) Fuel Ratio (kg/mole)
sExample 4.
A calcination plant manufacturing 10 tonnes lime/ day consisting of 83% CaO, 5%
CaCO3, and 12% inerts. The fuel used is coal gas analyzing 5.9% CO, 53.2% H 2, 29.6% CH4,
4.1 % CO2, 0.7% O2 and 6.5% N2 entering at 25℃, 740 mmHg with 80% RH. Orsat analysis
of the kiln gas shows 10.63% CO2, 0.66% CO, 0.66% H2, 6.75% O2 and 81.3% N2. Calculate:
a) Kg of limestone charged / day
b) m3 of coal gas / day
c) % Excess O2