Biomass Biomass that is used for energy production can be processed into solid fuels but also into liquid or gaseous fuels. In comparison, the term
biofuel is nowadays mainly (but not exclusively) used for
liquid or
gaseous fuels, used for transportation.
Pellet fuels are made from compressed organic matter or biomass. Pellets can be made from any one of five general categories of biomass: industrial waste and co-products,
food waste,
agricultural residues,
energy crops, and
untreated lumber. Wood pellets are the most common type of pellet fuel.
Wood Wood fuel can refer to several fuels such as
firewood,
charcoal,
wood chips sheets,
pellets, and
sawdust. The particular form used depends upon factors such as source, quantity, quality and application. In many areas, wood is the most easily available form of fuel, requiring no
tools in the case of picking up dead wood, or few tools. Today,
burning of wood is the largest use of
energy derived from a solid fuel
biomass. Wood fuel can be used for
cooking and
heating, and occasionally for fueling
steam engines and steam
turbines that
generate electricity. Wood may be used indoors in a furnace,
stove, or
fireplace, or outdoors in a furnace,
campfire, or
bonfire. As with any
fire, burning wood fuel creates numerous by-products, some of which may be useful (heat and steam), and others that are undesirable, irritating or dangerous. When harvested in a
sustainable fashion wood is usually considered to be a renewable solid fuel (
renewable energy). There is debate as to whether burning wood can be considered carbon neutral, as technically the wood cannot release more carbon than was sequestered during its growth, although this does not take account of other impacts such as deforestation and rotting has on the
carbon footprint.
Peat Peat fuel is an accumulation of partially
decayed vegetation or organic matter that can be burnt once sufficiently dried. It is used widely in the country districts of
Ireland and
Scotland where alternatives are absent or expensive. It has a relatively low
calorific value, even after essential drying.
Fossil fuels Coal Coal is a
combustible black or brownish-black
sedimentary rock usually occurring in
rock strata in layers or veins called coal beds or coal seams. Throughout history, coal has been used as an energy resource, primarily burned for the production of electricity and heat, and is also used for industrial purposes, such as refining metals. Coal is the largest source of energy for the
generation of electricity worldwide, as well as one of the largest worldwide The extraction of coal, its use in energy production and its byproducts are all associated with
environmental and
health effects. Variations such as smokeless coal can be formed naturally in the form of
anthracite, a
metamorphosed type of coal with a very high carbon content that gives off a smokeless flame when set alight. It is an important type of
smokeless fuel.
Coke Coke is a fuel with few impurities and a high
carbon content, usually made from
coal. It is the solid
carbonaceous material derived from
destructive distillation of low-ash, low-sulfur
bituminous coal. Cokes made from coal are grey, hard, and
porous. While coke can be formed naturally, the commonly used form is man-made. The form known as
petroleum coke, or pet coke, is derived from oil refinery coker units or other cracking processes.
Smokeless fuel Solid fuels which produce little smoke or volatiles are made from powdered
anthracite coal and supplied in the form of
briquettes usually for domestic use either in
stoves or open fireplaces. The fuel is replacing coal as a fuel for open fires because of the reduction in particulate emissions and its increased efficiency. Smokeless fuel burns at a higher temperature and more slowly than a coal fire. The term also includes
charcoal, made by restricted combustion of dry wood and widely used at open air
barbecues to cook food on an open fire.
Solid fuels for special applications Rocket propellant Solid rocket propellant consists of a solid oxidizer (such as
ammonium nitrate) bound with flakes or powders of energy compounds (such as
RDX) plus binders, plasticizers, stabilizers, and other additives. Solid propellant is much easier to store and handle than liquid propellant, and has a higher energy density so requires less space for the same amount of stored energy. ==Calorific value==