GLOSSARY 291
Digester: An airtight vessel or enclosure in which bacteria decomposes biomass in water to produce biogas.
Direct-injection engine: A diesel engine in which fuel is injected
directly into the cylinder.
Distillate: Any petroleum product produced by boiling crude oil
and collecting the vapors produced as a condensate in a separate vessel, for example gasoline (light distillate), gas oil (middle distillate), or fuel oil (heavy distillate).
Distillation: The primary distillation process which uses high
temperature to separate crude oil into vapor and fluids which
can then be fed into a distillation or fractionating tower.
Downdraft gasifier: A gasifier in which the product gases pass
through a combustion zone at the bottom of the gasifier.
Dutch oven furnace: One of the earliest types of furnaces, having
a large, rectangular box lined with firebrick (refractory) on the
sides and top; commonly used for burning wood.
E
E85: An alcohol fuel mixture containing 85 percent ethanol and
15 percent gasoline by volume, and the current alternative fuel
of choice of the U.S. government.
Effluent: The liquid or gas discharged from a process or chemical
reactor, usually containing residues from that process.
Emissions: Substances discharged into the air during combustion,
e.g., all that stuff that comes out of your car.
Emissions: Waste substances released into the air or water.
Energy crops: Crops grown specifically for their fuel value; include
food crops such as corn and sugarcane, and nonfood crops such
as poplar trees and switch grass.
Energy balance: The difference between the energy produced by
a fuel and the energy required to obtain it through agricultural
processes, drilling, refining, and transportation.
Energy crops: Agricultural crops grown specifically for their energy
value.
Energy-efficiency ratio: A number representing the energy stored
in a fuel as compared to the energy required to produce, process,
transport, and distribute that fuel.
Enhanced recovery: Methods that usually involves the application
of thermal energy (e.g., steam flooding) to oil recovery from the
reservoir.
Digester: An airtight vessel or enclosure in which bacteria decomposes biomass in water to produce biogas.
Direct-injection engine: A diesel engine in which fuel is injected
directly into the cylinder.
Distillate: Any petroleum product produced by boiling crude oil
and collecting the vapors produced as a condensate in a separate vessel, for example gasoline (light distillate), gas oil (middle distillate), or fuel oil (heavy distillate).
Distillation: The primary distillation process which uses high
temperature to separate crude oil into vapor and fluids which
can then be fed into a distillation or fractionating tower.
Downdraft gasifier: A gasifier in which the product gases pass
through a combustion zone at the bottom of the gasifier.
Dutch oven furnace: One of the earliest types of furnaces, having
a large, rectangular box lined with firebrick (refractory) on the
sides and top; commonly used for burning wood.
E
E85: An alcohol fuel mixture containing 85 percent ethanol and
15 percent gasoline by volume, and the current alternative fuel
of choice of the U.S. government.
Effluent: The liquid or gas discharged from a process or chemical
reactor, usually containing residues from that process.
Emissions: Substances discharged into the air during combustion,
e.g., all that stuff that comes out of your car.
Emissions: Waste substances released into the air or water.
Energy crops: Crops grown specifically for their fuel value; include
food crops such as corn and sugarcane, and nonfood crops such
as poplar trees and switch grass.
Energy balance: The difference between the energy produced by
a fuel and the energy required to obtain it through agricultural
processes, drilling, refining, and transportation.
Energy crops: Agricultural crops grown specifically for their energy
value.
Energy-efficiency ratio: A number representing the energy stored
in a fuel as compared to the energy required to produce, process,
transport, and distribute that fuel.
Enhanced recovery: Methods that usually involves the application
of thermal energy (e.g., steam flooding) to oil recovery from the
reservoir.