How to calculate the heating value, HHV-LHV, of natural gas?

Heating value of natural gas = Sum [ (x1) (HV1) + (x2) (HV2) + (x3) (HV3) + … ]
Where: HVn = heating value of gas component n, in BTU/SCF
xn = mole or volume fraction of gas component n. The table below contains the list of individual component LHV & HHV.

 

Definitions:

Heating Value: The heating value of any fuel is the energy released per unit mass or per unit volume of the fuel when the fuel is completely burned (ANSI/ASABE S593.1 2011). The heat of combustion for fuels is expressed as the HHV, LHV, or GHV.

 The term calorific value is synonymous to the heating value. Typical units for expressing calorific or heating value are MJ/kg & MJ/m3 in SI units or Btu/lb & BTU/SCF in English units. The heating value of a fuel depends on the assumption made on the condition of water molecules in the final combustion products.

 The higher heating value (HHV) refers to a condition in which the water is condensed out of the combustion products. The higher heating value includes the sensible heat and latent heat of vaporization especially for water. In other words, HHV assumes all the water component is in liquid state at the end of combustion

 The lower heating value (LHV), on the other hand refers to the condition in which water in the final combustion products remains as vapor (or steam); i.e. the steam is not condensed into liquid water and thus the latent heat is not accounted for.  The LHV assumes that the latent heat of vaporization of water in the fuel and the reaction products is not recovered.

 The term net heating value (NHV), net calorific value (NCV) or lower calorific value (LCV) refers to LHV.

 The term gross heating value (GHV) or higher calorific value (HCV) refers to HHV.

 Gross heating value:Gross heating value accounts for water in the exhaust leaving as vapor, and includes liquid water in the fuel prior to combustion. This value is important for fuels like wood or coal, which will usually contain some amount of water prior to burning.

 

     

LHV

HHV

S.G.

Btu/sft3

Btu/sft3

Component

Formula

MW(2)

Btu/lbm

Btu/lbm

Nitrogen

N2

28.01

0

0

Carbon Dioxide

CO2

44.01

0

0

Hydrogen Sulfide

H2S

34.08

587

637

Methane

CH4

16.04

909

1010

Ethane

C2H6

30.07

1619

1770

Propane

C3H8

44.10

2315

2516

I-Butane

C4H10

58.12

3000

3252

n-Butane

C4H10

58.12

3011

3262

I-Pentane

C5H12

72.15

3699

4001

n-Pentane

C5H12

72.15

3704

4009

n-Hexane

C6H14

86.18

4404

4756

n-Heptane

C7H16

100.20

5100

5503

n-Octane

C8H18

114.23

5796

6249

n-Nonane

C9H20

128.26

6494

6997

n- Decane

C10H22

142.29

7190

7743

Oxygen

O2

32.00

0

0

Hydrogen

H2

2.02

274

324

Helium

He

4.00

0

0

Water

H2O

18.02

0

50

Carbon Monoxide

CO

28.01

321

321

Ethylene

C2H4

28.05

1499

1600

Propylene

C3H6

42.08

2182

2333

Butylene

C4H8

56.11

2876

3077

Benzene

C6H6

78.11

3591

3742

Argon

Ar

39.95

0

0

Ammonia

NH3

17.03

0

0

Air

Air

28.97

0

0

 

8 thoughts on “How to calculate the heating value, HHV-LHV, of natural gas?”

    1. Currently the default units in Aspen HYSYS for the higher and lower heating properties do not include BTU/ft3. To use these units you must create a user unit conversion, as described in the steps below:

      1. Select the Preferences command in the Tools menu.
      2. Select the Variables tab.
      3. Select any one of the three default unit sets and click the Clone button.
      4. From the list of Display Units scroll down until you find Volume Specific Energy and click on the corresponding units.
      5. Click the Add button.
      6. In the User Conversion window provide the name for your user unit and specify a conversion rate of 26.85 * MJ/m3.

      Note that the volume is specified at standard conditions. For Metric these are 1 atm and 15°C; for Imperial these are 1 atm and 60°F.

    1. The main difference is in the water content (latent heat of vaporization). HHV assumes that no water will vaporize and therefore no heat will be consumed to heat and vaporize the water in the gas. LHV will assume that water will vaporize.

  1. This is a very nice details about heating value.
    Is it possible to get mathematical steps for calculation of high or low heating value?

  2. Are you sure about the metric temp and pressue. Usually metric standard cubic meter is defined in 0 (zero) celicius and 101,325 kPa i.e. in NTP conditions. NTP conditions are different in different standards , see web page of engineering toolbox for the NTP defination in different standards.

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