| Key Terms |
Definition |
| Biomass Gas |
A medium Btu gas containing methane and
carbon dioxide, resulting from the action of microorganisms
on organic materials such as a landfill.
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| Blast-furnace Gas |
The waste combustible gas generated in a blast furnace when iron ore is being reduced with coke to
metallic iron. It is commonly used as a fuel within steel works.
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| British Thermal Unit (Btu) |
The quantity of heat required to
raise the temperature of 1 pound of water by 1 degree Fahrenheit.
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| Coke-oven Gas |
The mixture of permanent gases produced
by the carbonization of coal in a coke oven at temperatures in
excess of 1,000 degrees Celsius.
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| Manufactured Gas |
A gas obtained by destructive distillation
of coal, or by the thermal decomposition of oil, or by the reaction
of steam passing through a bed of heated coal or coke. Examples
are coal gases, coke oven gases, producer gas, blast furnace gas,
blue (water) gas, carbureted water gas. Btu content varies
widely.
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| Propane-air |
A mixture of propane and air resulting in a gaseous
fuel suitable for pipeline distribution.
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| Refinery Gas |
Noncondensate gas collected in
petroleum refineries.
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| Supplemental Gaseous Fuels Supplies |
Synthetic natural
gas, propane-air, coke oven gas, refinery gas, biomass gas, air
injected for Btu stabilization, and manufactured gas commingled
and distributed with natural gas.
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| Synthetic Natural Gas (SNG) |
Also referred to as substitute
natural gas. A manufactured product, chemically similar in
most respects to natural gas, resulting from the conversion or
reforming of petroleum hydrocarbons that may easily be substituted
for or interchanged with pipeline-quality natural gas.
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Annual data on nonhydrocarbon gases removed from marketed production-carbon dioxide, helium,
hydrogen sulfide, and nitrogen are reported by state agencies on the voluntary
Form EIA-895A. Approximately one-third of the 33 producing states report data on
nonhydrocarbon gases removed.
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Annual data are published from Form EIA-176.
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All monthly data are considered preliminary until after the publication of the
Natural Gas Annual for the year in which the report month falls. Monthly estimates are
based on the annual ratio of supplemental gaseous fuels to the sum of dry gas production,
net imports, and net withdrawals from storage. This ratio is applied to the monthly sum of
these three elements to compute a monthly supplemental gaseous fuels figure.
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Monthly data are revised after publication of the Natural Gas Annual.
Final monthly data are estimated based on the revised annual ratio of supplemental gaseous
fuels to the sum of dry gas production, net imports, and net withdrawals from storage.
This ratio is applied to the revised monthly sum of these three elements to compute final
monthly data.
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