Experiment CV

1

ABSTRACT

Boy's Gas Calorimeter is designed to ensure that the

heat from the burner flows up through the center of the

calorimeter container and back down again inside the

container and back up again before exhausting. This design

ensures maximum heat transfer to the cooling liquid and

hence accurate measurement of calorific value of gas. The

amount of heat liberated when a unit mass of fuel is burnt

completely is known as the calorific value. This calorific

value of gaseous fuel is determined using boys gas

calorimeter. The actual calorific value of LPG,propane and

butane are113.92 MJ/m3, 95.8 MJ/m3, and 126 MJ/m3 . With

this value, we can identify type and method that can be use

to optimize energy and produce complete combustion to

minimize heat losses to surrounding. Burner type and flame

velocity can be determined to decrease the heat loss and

complete combustion can be optimized.

INTRODUCTION

When the hydrocarbon fuel is being combusted under

specified condition, there are amount of heat released that

is known as calorific value. The calorific value (CV) or

heating value (HV) of the hydrocarbon fuel is depends on the

composition of the gas. There are two types of calorific

value of hydrocarbon fuel. It can be classified as

2

1. Gross or Higher Calorific Value (HHV or HCV) – can be

classified when the combustion product, water is in

liquid form where there are water vapor in flue gasses.

2. Net or Lower Calorific Value (LHV or LCV) – can be

classified when the combustion product, water is in

vapor form where during its phase changing to vapor,

there are difference between HCV and the latent heat.

In calorific value, the measurement unit of energy per unit

of the fuel involve are:

Btu/lb, J/kg, kcal/kg

The conversion unit involve are:

1. 1 Btu/lb = 0.5556 kcal/kg = 2326.1 J/kg

2. 1 J/kg = 2.39 x 10-4 kcal/kg = 0.00043 Btu/lb

3. 1 kcal/kg = 4187 J/kg = 1.80 Btu/lb

The instrument used for measuring the heat during the

combustion process is calorimeter. This instrument can be

used depends to the specified conditions. In this

experiment, the calorimeter involved is Boy’s Calorimeter.

Boy’s calorimeter is used for measuring calorific value of

large range of gaseous fuel. When the calorific value is

obtained, it is important in order to get temperature

3

profile and heating value for certain gaseous fuel. Other

than that, the calorimeter that can be used is Junker’s

calorimeter.

OBJECTIVE

At the end of this experiment, the student should be able:

1. To determine the calorific value (CV) for any selected

gaseous fuel.

2. To construct and understand an accurate equipment for

calorific value measurement.

3. To provide the simple and accurate method of

calorimeter for gaseous fuel.

4. To perform safety assessment analysis at the equipment.

BACKGROUND

Calorific value is the calories or thermal units contained

in one unit of a substance and released when the substance

is burned. Gross calorific value may be converted to net

calorific value by using the following equation:

Net calorific value = Gross calorific value - (10.02 x

Percent Moisture)

Dung cakes is the fuel that has least calorific value

which is 7 kilojoule. The gas that has highest calorific

4

value is hydrogen gas which is 150000 kilojoule. The order

of the calorific value of gas is coal-peat-lignite-dried

wood. The difference being the latent heat of condensation

of the water vapor produced during the combustion process is

fully condensed. This is due to the Technical Data for

Propane, Butane and LPG Mixtures by Alternate Energy Systems

Inc. For coal and oil, the difference between net calorific

value and gross calorific value is approximately 5%. For

most natural gas and manufactured gases, the difference is

approximately 9-10%.

METHODOLOGY.

1) The temperature on the gas inlet thermometer on the flow

meter, local barometric pressure and local ambient

temperature were read and recorded before commencing the

test.

2) Gas supply was connected to the Boys Calorimeter through

control valve and Hyde Meter. This gas supply should be not

at pressure greater than the meter can be with stand.

3) The control valve was slowly turned on and the burners

were lighted up simultaneously.

4) The calorimeter main body was slowly lower into the

calorimeter casing with the water outlet over the sink.

5

5) Water was turned on to the overhead funnel so that there

was flow established in the spill tube from the overhead

funnel and also be present through the calorimeter.

6) The gas flow rate was set so the time taken for one

revolution of the Hyde Meter to approximately between the

range of;

Tmin = 3 x CV / 100 Tmax = (3 x CV / 100) + 5

7) The gas was allowed to burn and water was allowed to run

through the calorimeter for at least 45 minutes to allow the

operating conditions to settle down.

8) Water was collected at the beginning of experiment

starting point was 100 on Hyde Meter.

9) The inlet temperature was recorded for every one

revolution of Hyde Meter until the end of the experiment.

10) The outlet temperature was recorded for every 1/4

revolution of Hyde Meter until the end of the experiment.

11) Water was stop collected at the end of the third

revolution of Hyde Meter.

12) Data was written in the given table.

6

7

RESULT

Experiment : propane

T inlet for water : 28.2 ºC

T indicator 1 (Coil) : 28.5 ºC

T indicator 2 (ambient) : 29.7 ºC

T for effluent gas : 30 ºC

Barometric pressure : 760 mmHg

Meter revolutions Inlet, T1ºC Outlet, T2 ºC

1 28.80 52.00

2 28.80 53.00

3 28.80 52.30

4 28.80 52.00

Mean 28.80 52.33

Volume of gas passed : 10 L

Volume of water passed : 8.5 L

Room temperature : 25 ºC

Volume of condensate collected : -

8

Experiment : butane







1 28.80 51.30

2 28.80 51.10

3 28.80 51.00

4 28.80 51.10

Mean 28.80 51.13





9

Experiment : LPG







1 28.90 52.10

2 28.90 52.40

3 28.90 52.30

4 28.90 52.30

Mean 28.90 52.28





10

CALCULATION

|| Information ||

Specific heat of water : 4.18 kJ/kg ºC

Density of water : 998 kg/m3

Fuel : Propane

Mass of water calculation

Mass of water passed through the unit = Volume of water (m3)

x density of water (kg/m3)

= 0.0085 m3 x 998 kg/m3

= 8.48 kg

Effluent gas correction,dHg

dHg = (30-28.8) x 26.83

= 32.20 kJ/m3

Calculation of High Calorific Value (HCV)

=83405.38 kJ/m3

The gross CV of the gas is

11

= 83405.38 + 32.20

= 83437.58 kJ/m3

= 83.44 MJ/m3

Theoretical HCV of Propane = 95.8 MJ/m3

Percentage of deviation

=

=

=12.9 %

12

Fuel : Butane




= 0.01109 m3 x 998 kg/m3

= 11.07 kg


dHg = (30-28.9) x 26.83

= 29.51 kJ/m3


= 103326.72 kJ/m3


= 103326.72 + 29.51

= 103356.23 kJ/m3

= 103.356 MJ/m3

Theoretical HCV of Butane = 126 MJ/m3

13


=

=

= 17.97 %

14

Fuel : LPG




= 0.0104m3 x 998 kg/m3

= 10.38 kg


dHg = (30-28.9) x 26.83

= 29.51 kJ/m3


= 101442.08 kJ/m3


= 101442.08 + 29.51

= 101471.59 kJ/m3

= 101.47 MJ/m3

15

Composition of GAS MALAYSIA LPG as follow

Propane = 40% v/v

Butane = 60% v/v

HCV of Propane = 95.8 MJ/m3

HCV of Butane = 126 MJ/m3

Thus HCV of LPG = (0.4x95.8) + (0.6x126) = 113.92 MJ/m3


=

=

= 10.92 %

16

CONCLUSION

From this experiment, we can determine the calorific

value of Liquefied Petroleum Gas(LPG) which contained 60% of

butane and 40% of propane in laboratory. We also can

determine the calorific value of propane anda butane. We

also study the technique how to determine the value of

gaseous fuels in industry using Boys Gas Calorimeter. From

this experiment, we find that calorific value for LPG is

101.47 MJ/m3 with standard deviation 10.92 %, close with the

theoretical value for LPG which is113.92 MJ/m3 . We also

find that calorific value for propane is 83.44 MJ/m3 with

12.9 % of standard deviation,which closely to the

theoretical value 95.8 MJ/m3. We also find that calorific

value for butane is 103.356 MJ/m3 with standard deviation

17.97 %,the calorific value is close to the theoretical

value which is 126 MJ/m3 . With this value, we can identify

type and method that can be use to optimize energy and

produce complete combustion to minimize heat losses to

surrounding. Burner type and flame velocity can be

17

determined to decrease the heat loss and complete combustion

can be optimized.

RECOMMENDATION

The experiment can be repeated when needed.

Before the experiment begin, make sure that all group

members should understand all component function,

safety procedure and operation system done.

We should check all the apparatus function well.

18

REFERENCES

1.Richard M.Felder and Ronald W.Rousseau,’Elementary Principles of

Chemical Processes’, Wiley & Sons, Inc. Third Edition 2000.

2. Gas Processing Lecturer note

3.Combustion Engineering Lecturer note

4. www.iea.org/work/2004.pdf

5. www.altenergy.com

http://www.iea.org/work/2004.pdf

Documents

Experiment CV