Environmental Engineering Reference
In-Depth Information
Proppant:
Sized particles mixed with fracturing fluid to hold fractures open after a
hydraulic stimulation.
Propylene (C
3
H
6
):
An olefinic hydrocarbon recovered from refinery or petro-
chemical processes which is gaseous at standard temperature and pressure.
Propylene is an important petrochemical feedstock.
Public land:
Land owned by the local, state, or federal government.
Public Utility Regulatory Policies Act of 1978 (PURPA):
Contains measures
designed to encourage the conservation of energy, more efficient use of
resources, and equitable rates. Principal among these were suggested retail
rate reforms and new incentives for production of electricity by cogenera-
tors and uses of renewable resources.
Pulpwood:
Roundwood, whole tree chips, or wood residues that are used for the
production of wood pulp.
Pumped-storage hydroelectric plant:
A plant that usually generates electric
energy during peak load periods by using water previously pumped into
an elevated storage reservoir during off-peak periods when excess generat-
ing capacity is available to do so. When additional generating capacity is
needed, the water can be released from the reservoir through a conduit to
turbine generators located in a power plant at a lower level.
Pyrolysis:
The thermal decomposition of biomass at high temperatures (greater than
400°F, or 200°C) in the absence of air. The end product of pyrolysis is
a mixture of solids (char), liquids (oxygenated oils), and gases (methane,
carbon monoxide, and carbon dioxide), with the proportions determined
by operating temperature, pressure, oxygen content, and other conditions.
Q
Quadrillion Btu (quad):
Equivalent to 10
15
Btu.
Qualifying facility (QF):
A cogeneration or small power production facility that
meets certain ownership, operating, and efficiency criteria established by
the Federal Energy Regulatory Commission (FERC) pursuant to the Public
Utility Regulatory Policies Act of 1978 (PURPA).
R
Radiant energy:
Energy that transmits away from its source in all directions.
Rankine cycle:
The thermodynamic cycle that is an ideal standard for comparing
the performance of heat engines, steam power plants, steam turbines, and
heat pump systems that use a condensate vapor as the working fluid; effi-
ciency is measured as work done divided by sensible heat supplied.
Ratoon crop:
A crop cultivated from the shoots of a perennial plant.
Rayleigh frequency distribution:
A mathematical representation of the frequency
or ratio that specific wind speeds occur within a specified time interval.
Reactance:
A phenomenon associated with AC power characterized by the exis-
tence of a time difference between volt and current variations.
