where:T=P= gas pressure in psia

gas specific gravity, dimensionless

InputsGas CompositionGas mol fraction mol wtMethane 0.82 16.043Ethane 0.09 30.07Propane 0.08 44.097i-Butane 58.123n-Butane 0.01 58.123i-pentane 72.15n-pentane 72.15n-hexane 86.177n-heptane 100.204

1CalculationsGas Mol wt 19.97

0.690

InputsPressure, P 1000.00 psia

0.69

Calculations

62.75 °F

17.08 °C

Prepared by: Ankur SrivastavaChemical Engineer

Reference: Motiee. M., "Estimate Possibility of Hydrates,"Hydrocarbon Processing, Vol. 70, No. 7, July 1991, pp. 98-99

hydrate formation temperature in ˚F

g =

=MWng / MWair

Gas Sp. Gr, g

Gas Sp. Gr, g (Enter calculated value from cell "B27" or any other value of interest)

Hydrate formation temp., T

T=−238 .24469+78 .99667×log(P )−5 .352544×[ log (P ) ]2+349 .473877×γ+150 .854675×γ2−27 .604065×log(P )×γ

Hydrocarb. Proc. 84(4), 61–62 (2005).

where:T=P= gas pressure in psia

gas specific gravity, dimensionless

Note: The above equation is accurate up to 65˚F. Above this value it over estimates the hydrate formation temperature.

InputsGas CompositionGas mol fraction mol wtMethane 0.82 16.043Ethane 0.09 30.07Propane 0.08 44.097i-Butane 58.123n-Butane 0.01 58.123i-pentane 72.15n-pentane 72.15n-hexane 86.177n-heptane 100.204

1CalculationsGas Mol wt 19.97

0.690

InputsPressure, P 1000.00 psia

0.69

Calculations

64.27 °F

17.93 °C

Reference: Towler, B.F., and Mokhatab, S., Quickly estimate hydrate formation conditions in natural gases.

hydrate formation temperature in ˚F

g =

=MWng / MWair

Gas Sp. Gr, g

Gas Sp. Gr, g (Enter calculated value from cell "B30" or any other value of interest)

Hydrate formation temp., T

T=13 .47 ln(P )+34 .27 ln(γ )−1 .675× [ ln(P )×ln (γ )]−20 .35

where:T=P= gas pressure in psia

gas specific gravity, dimensionless

Note: The above equation is accurate for pressures up to 1000 psia

InputsGas CompositionGas mol fraction mol wtMethane 0.82 16.043Ethane 0.09 30.07Propane 0.08 44.097i-Butane 58.123n-Butane 0.01 58.123i-pentane 72.15n-pentane 72.15n-hexane 86.177n-heptane 100.204

1CalculationsGas Mol wt 19.97

0.690

InputsPressure, P 1000.00 psia

0.69

Calculations

64.48 °F

18.05 °C

Reference: Fundamentals of Natrural Gas Processing, Arthur J. Kidnay, William R. Parrish

hydrate formation temperature in ˚F

g =

=MWng / MWair

Gas Sp. Gr, g

Gas Sp. Gr, g (Enter calculated value from cell "B30" or any other value of interest)

Hydrate formation temp., T

T=−16 .5−6 .83

γ 2+13 .8×ln(P)

Reference: A novel correlation for estimation of hydrate forming condition of natural gasesby Alireza Bahadori & Hari. B. Vuthaluru; Journal of Natural Gas Chemistry 18(2009) –

where:T =P = gas pressure in kPa (abs)

where:a, b, c & d are constants as a function of molecular weight of gasM = molecular weight of gas, kg / kg-mole

Tuned Coefficients (M<23 & 1200 kpa(abs) < P < 5000 kPa (abs)

-4.181213278423 45284.97500018 -83170750.73225 5858977399.3386

1.472639349108 -6862.812444981 12604810.249225 -966349625.35354

-7.27453863E-02 342.4072186041 -630185.79466138 51347314.2241307

1.189779588E-03 -5.642533019 10408.848430973 -887818.586492

Pressure greater than 1200 kPa(abs) & less than 5000 kPa(abs) & Molecular Weight less than 23InputsP = 4,500 kPa (abs)M = 19.97 kg / kg-mole

Calculationsa = 5.692E+00b = -1.505E+02c = 1.253E+05d = -3.230E+07bx1/P = -3.345E-02

0.0061865959331

-0.000354509025ln (T) = 5.664321T = 288.39 K

15.2459.44 ˚F

hydrate formation temperature in K

Ai, Bi, Ci & Di are tuned coefficients with i = 1 to 4

A1 A2 A3 A4

B1 B2 B3 B4

C1 C2 C3 C4

D1 D2 D3 D4

cx(1/P)2 =

dx(1/P)3

˚C

ln (T )=a+b( 1P )+c ( 1P )2

+d ( 1P )3

a=A1+B1M+C1M2+D1M

3

b=A2+B2M+C2M2+D2M

3

c=A3+B3M+C3M2+D3M

3

d=A4+B4M+C4M2+D4M

3

Tuned Coefficients (M<23 & 5000 kpa(abs) < P < 40,000 kPa (abs)

7.095970394759 -125846.4942159 921903822.83151 -2105354862621.1

-0.218060300708 18993.11176634 -140304105.67488 321399259721.900

0.0113059334398 -952.6005812723 7082041.7989994 -16274767262.739

-0.000192720320 15.80682008903 -118187.63471949 272488432.4573

Pressure greater than 5000 kPa(abs) & less than 40,000 kPa(abs) & Molecular Weight less than 23InputsP = 6,895 kPa (abs)M = 19.97 kg / kg-mole

Calculationsa = 5.715E+00b = -5.657E+02c = 3.103E+06d = -7.291E+09bx1/P = -8.204E-02

0.0652651880246

-0.022242213476ln (T) = 5.676272T = 291.86 K

18.7165.68 ˚F

Tuned Coefficients (M>23 & 1200 kpa(abs) < P < 40,000 kPa (abs)

6.418507110535 -8642.6289140 11596430.30462 -4020095147.5377

-0.088017107876 1024.33078523 -1385902.7774109 479133183.3062

0.0035573429357 -40.9663925466 55353.148270822 -19036325.296009

-0.000047499844 0.54450050758 -733.9994547645 251132.97404156

Pressure greater than 1200 kPa(abs) & less than 40,000 kPa(abs) & Molecular Weight greater than 23InputsP = 10,000 kPa (abs)M = 23.5 kg / kg-mole

Calculationsa = 5.698E+00b = -1.281E+02c = 7.074E+04d = -1.410E+07bx1/P = -1.281E-02

0.0007073799402

-1.41036391E-05ln (T) = 5.686085T = 294.74 K

21.5970.86 ˚F

A1 A2 A3 A4

B1 B2 B3 B4

C1 C2 C3 C4

D1 D2 D3 D4

cx(1/P)2 =

dx(1/P)3

˚C

A1 A2 A3 A4

B1 B2 B3 B4

C1 C2 C3 C4

D1 D2 D3 D4

cx(1/P)2 =

dx(1/P)3

˚C