The Hydrogen Economy: Opportunities, Costs, Barriers, and R&D Needs (2004)

Chapter: Appendix H: Useful Conversions and Thermodynamic Properties

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Suggested Citation: "Appendix H: Useful Conversions and Thermodynamic Properties." National Research Council and National Academy of Engineering. 2004. The Hydrogen Economy: Opportunities, Costs, Barriers, and R&D Needs. Washington, DC: The National Academies Press. doi: 10.17226/10922.
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Appendix H
Useful Conversions and Thermodynamic Properties

TABLE H-1 Conversion Factors

metric ton (tonne) = 1000 kg = 1.1023 short tons

Btu = 1055 J

quad = 1015 Btu = 1.055 EJ

liter = 0.2642 gallons U.S.

cubic meter (m3) = 35.31 cubic feet

conversions for hydrogen:

1 million scf/day = 2.65 short tons/day

1 kg = 11.13 N-m3 (0 degrees Celsius and 1 atmosphere)

1 kg = 415.6 scf (60 degrees Fahrenheit and 1 atmosphere)

NOTE: scf = standard cubic feet; Btu = British thermal unit; EJ = exajoule = 1018 joules; N-m3 = normal cubic meter; kg = kilogram.

TABLE H-2 Thermodynamic Properties of Chemicals of Interest

Parameter

Value

Hydrogen HHV (ΔH)

–286 kJ/mol

Hydrogen LHV (ΔH)

–242 kJ/mol

Methane gross heat of combustion HHV (ΔHc)

–891 kJ/mol

Energy content of 1 kg hydrogen

141.9 MJ (HHV) = 39.4 kWh

120.1 MJ (LHV) = 33.3 kWh

of 1 N-m3 hydrogen

12.7 MJ (HHV)

of 1 pound of hydrogen

64.4 MJ (HHV) = 61.0 kBtu

of 1 gallon gasoline

121.3 MJ (LHV); 115,000 Btu (LHV)

NOTE: HHV = higher heating value; LHV = lower heating value; ΔH = enthalpy; J = joule; Btu = British thermal unit; M = million; k = thousand; mol = mole; N-m3 = normal cubic meter; kWh = kilowatt hour. SOURCE: NIST (2003), except DOE (2003f) for gasoline data.
Page 240 Cite Bookmark
Suggested Citation: "Appendix H: Useful Conversions and Thermodynamic Properties." National Research Council and National Academy of Engineering. 2004. The Hydrogen Economy: Opportunities, Costs, Barriers, and R&D Needs. Washington, DC: The National Academies Press. doi: 10.17226/10922.
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