Wood fuel

Wood fuel (or fuelwood ) is a fuel, such as firewood , charcoal , chips , sheets, pellets , and sawdust . Source, quantity, quality and application. In many areas, wood is the most readily available form of fuel, requiring tools in the box of picking up dead wood, or just tools, as in any industry, specialized tools, such as skidders and hydraulic wood splitters, have been developed to mechanize production. Sawmill waste and construction industry by-productsalso include various forms of lumber tailings. The discovery of how to make fire is considered to be one of the most important advances. The use of wood as a fuel source for heating is much older than civilization and is assumed to be used by Neanderthals . 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 sometimes for fueling steam engines and steam turbines that generate electricity . Wood may be used indoors in a furnace,stove , or fireplace , gold outdoors in a furnace, campfire , gold bonfire .

In permanent structures and in caves, hearths are constructed or built-surfaces of stone or another noncombustible material. Smoke escaped through a smoke hole in the roof.

In contrast to civilizations in relatively arid regions (such as Mesopotamia and Egypt), the Greeks, Novels, Celts, Britons, and Gauls all had access to forests. Over the centuries there was a partial deforestation of climax forests and the evolution of the remainder to coppice with standards woodland as the primary source of wood fuel. These woodlands involved a continuous cycle of new stems from old stumps, one rotations between seven and thirty years. One of the earliest printed on woodland management, in English, was John Evelyn’s “Sylva, or discourse on forest trees” (1664) advising landowners on the proper management of forest estates. HL Edlin, in “Woodland Crafts in Britain”, 1949 outlines the extraordinary techniques employed, and range of wood products that have been produced from these managed forests since pre-Roman times. And throughout this time the preferred form of woodfuel is the branches of cut coppice stems bundled into faggots . Larger, bent or deformed stems that were of no use to the woodland craftsmen were converted to the end of World War Two. Since then much of these woodlands have been converted to broadscale agriculture. Total demand for fuel Increased considerably with the industrial revolution purpose of this MOST Increased demand Was places by the new fuel sourcecoal , which was more compact and more suited to the larger scale of the new industries.

During the period of Japan, wood was used for many purposes, and the consumption of wood Japan to develop a forest management policy during that era. [1] Demand for timber resources, but also for construction of ships and buildings, and deforestation was widespread. As a result, forest fires occurred, along with floods and soil erosion. Around 1666, the shogun made it a policy to reduce logging and increasing the planting of trees. This policy decreed that only the shogun, or a daimyō , could authorize the use of wood. By the 18th century, Japan had developed scientific knowledge about silviculture and plantation forestry .

Fireplaces and stoves

The development of the chimney and the fireplace for the effective exhaustion of the smoke. Masonry heaters or stoves went a step further by capturing much of the heat of the heat and burning in a large thermal mass, becoming much more efficient than a fireplace alone.

The metal stove was a development competitor with the industrial revolution . Stoves are manufactured or built to the extent that they can be used in a controlled manner. Stoves have been made of a variety of materials. Cast iron is among the most common. Soapstone ( talc ), tile , and steel have been used. Metal stoves are often lined with refractory materials such as firebricks , since the hottest part of a woodburning fire will burn away over the course of several years’ use.

The Franklin stove was developed in the United States by Benjamin Franklin . More than a fireplace stove, it had an open front and a heat exchanger in the back that was designed to draw air from the cellar and heat it before releasing it out the sides. The heat exchanger was never a popular feature and was omitted in later versions. So-called “Franklin” stoves today are made in a great variety of styles, though none resembles the original design.

The 1800s became the high point of the cast iron stove. Each local would make their own design, and their stoves, stoves, box stoves, camp stoves, railroad stoves, portable stoves, cooking stoves and so on. Elaborate nickel and chrome edged models, with cast ornaments, feet and doors. Wood or coal could be burnt in the stoves and thus they were popular for over one hundred years. The action of the fire, combined with the causticity of the ash, ensured that the stove would eventually disintegrate or crack over time. Thus a steady supply of stoves was needed. The maintenance of stoves, requiring to be blacked, their smokiness, and the need to split wood

The airtight stove , originally made of steel, is a better control of combustion, being more tightly fitted than other stoves of the day. Airtight stoves became common in the 19th century.

Use of wood heat decreased in popularity, the other labor-intensive fuels. Wood heat gradually Was Replaced by coal and later by fuel oil , natural gas and propane heating except in rural areas with available forests.

After the 1967 Oil Embargo , many people in the United States used wood as fuel for the first time. The EPA provided information on clean stoves, which burned much more efficiently. [2]


A brief resurgence in popularity occurred during the 1973 energy crisis , when some believed that fossil fuels would be used as a preclude. A period of innovation followed, with many small manufacturers producing stoves based on old and new designs. Notable innovations that include the Ashley heater , a thermostatically controlled stove with an optional perforated steel enclosure that prevents accidental contact with hot surfaces. The term also includes a number of dual-fuel furnaces and boilers made, which utilizes ductwork and piping to deliver heat throughout a house or other building.


The growth in popularity of wood heat is also a factor in the development and marketing of firewood. Consumer grade hydraulic log splitters were developed by electricity, gasoline, or PTO of farm tractors. In 1987 the US Department of Agriculture published a method for producing kiln dried firewood, on which the basis of improved heat output and increased efficiency. [3]

The magazine “Wood Burning Quarterly” was published for several years before “Home Energy Digest” and, subsequently, disappearing.


A pellet stove is an appliance that burns compressed wood or biomass pellets . Wood heat continues to be used where firewood is abundant. For open fireplaces, stoves, fireplace inserts, and furnaces are most commonly used today. In rural, forested parts of the US, freestanding boilers are increasingly common. They are installed outdoors, some distance from the house, and connected to a heat exchangerin the house using underground piping. The mess of wood, bark, smoke, and dust is reduced. The boilers are large enough to hold a fire, and can burn larger parts of wood. There is no need to retrofit a chimney in the house. However, outdoor wood boilers emit more wood smoke and associated pollutants than other wood-burning appliances. This is due to design features such as the water-filled jacket surrounding the firebox, which acts to cool the fire and leads to incomplete combustion. Outdoor wood boilers also have a number of other wood-burning appliances, contributing to the environment. An alternative that is increasing the popularity of wood gasification boilers, which burn wood at very high efficiencies (85-91%) and can be placed indoors or in an outbuilding. There are plenty of ways to fuel wood and the inventions today are maximizing by the minute.

Wood is still used today for cooking in many places, or in a stove or an open fire. It is also used as a fuel in many industrial processes, including smoking meat and making maple syrup .

As a sustainable energy source, wood fuel also remains viable for generating electricity in areas with easy access to forest products and by-products.

Measurement of firewood

In the metric system , firewood is normally sold by the cubic meter or stere (1 m³ = ~ 0.276 cords).

In the United States and Canada, firewood is usually sold by the cord , 128 ft³ (3.62 m³) Corresponding to a woodpile 8 ft wide x 4 ft high of 4 ft-long logs. The cord is legally defined by statute in most US states. A “thrown cord” is firewood that has not been stacked and is defined as 4 ft wide x 4 ft tall x 10 ft long. The additional volume is to make it equivalent to a standard stacked string, where there is less void space. It is also common to see the face cord, which is usually notlegally defined, and varies from one area to another. For example, in a state of a pile of wood 8 feet wide × 4 feet high of 16 “-long logs will often be a” face cord “, though its volume is only one-third of a cord. or even another area of ​​the same state, the volume of a face cord may be considerably different, therefore, it is risky to buy wood sold in this manner, as the transaction is not based on an enforceable unit of measure.

In Australia , it is normally sold by the ton .

Energy content

A common hardwood, red oak, HAS happy year energy ( heat value ) of 14.9 mega joules per kilogram (6,388 BTU per pound), and 10.4 mega joules recoverable if burned at 70% efficiency. [4]

The Sustainable Energy Development Office (SEDO), part of the Government of Western Australia states that the energy content of wood is 16.2 megajoules per kilogram (4.5 kWh / kg). [5]

According to the Bioenergy Knowledge Center , the energy content of wood is more closely related to its moisture content than its species. The energy content improves the moisture content decreases. [6]

In 2008, wood for fuel cost $ 15.15 per 1 million BTUs (0.041 EUR per kWh). [7] [ unreliable source? ]

Environmental impacts

Combustion by-products

As with any fire , burning wood fuel can be used, some of which may be useful (heat and steam), and others that are undesirable, irritating or dangerous.

One by-product of burning wood is wood ash , qui in moderate water equivalent is a fertilizer (Mainly potash ) Contributing minerals, goal is Strongly alkaline as it contains potassium hydroxide [8] (lye). Wood ash can also be used to manufacture soap .

Smoke , containing water vapor , carbon dioxide and other chemicals and aerosol particulates, including caustic alkali fly ash , which can be irritating (and potentially dangerous) by-product of partially burnt wood fuel. A major component of wood is a large part of particulate air pollution in some regions. During cooler months, wood heating accounts for as much as 60% of fine particles in Melbourne , Australia . [9]

Slow burning increases wood burning efficiency, but also increases particle production. Low pollution / slow combustion is a current area of ​​research. citation needed ] An alternative approach is to use pyrolysis to produce several useful biochemical byproducts, and clean burning charcoal, or to burn fuel extremely quickly inside a large thermal mass, such as a masonry heater. This has the effect of allowing the fuel to burn completely without producing particles while maintaining the efficiency of the system. quote needed ]

In some of the most efficient burners, the temperature of the smoke is much higher (where 609 ° C [10] for igniting carbon monoxide gas). This may also be helpful in providing additional heat from the process. By using a catalytic converter , the temperature can be reduced. Some US jurisdictions prohibit the use of converters. quote needed ]

Combustion by-product effects on human health

Depending on the population, the conditions of combustion, and the use of air pollution , particularly particulates . The conditions in which wood is burnt will greatly influence the content of the emission. citation needed ] Particulate air pollution can contribute to human health problems and increased hospital admissions for asthma & heart diseases. [9]

The technique of compressing wood pulp into pellets or artificial logs can reduce emissions. The combustion is cleaner, and the increased wood density and reduced water content can eliminate some of the bulk transport. The fossil fuel consumed in transport is reduced and represents a small fraction of the fossil fuel consumed in production and distributing heating oil or gas. [11]

Wood burning products can include toxic and carcinogenic substances. Generally, the heartwood of a tree contains the highest amounts of toxic substances, but should be taken if one is burning wood of an unknown nature, since some trees can be highly toxic. [12] [ not in quote given ]

Harvesting operations

Much wood fuel comes from native forests around the world. Plantation wood is rarely used for firewood, but it is more valuable than timber or wood pulp , however, some wood fuel is being planted by crops, also known as agroforestry . [13] The collection or harvesting of this wood can have serious environmental implications for the collection area. The concerns are often specific to the area, but can include all the problems that regular logging create. The heavy removal of forest can cause habitat destruction and soil erosion. However, in many countries, for example in Europe and Canada, the forest residues are being collected and tested with minimal impact on the environment. Consideration is given to soil nutrition and erosion. The environmental impact of using wood as a fuel depends on how it is burnt. Higher temperatures result in more complete combustion and less noxious gases as a result of pyrolysis. Some may look at the burning of wood from a sustainable source as carbon-neutral . A tree, over the course of its lifetime, absorbs as much carbon (or carbon dioxide) as it releases when burnt.

Some firewood is harvested in ” woodlots ” managed For That purpose, in order Heavily wooded areas it is more Often harvested as a byproduct of natural forests . Deadfall That Has not started to rot is preferred, since it is already Partly seasoned . Standing dead is considered better still, as it is both seasoned, and has less rot. Harvesting this form of timber reduces the speed and intensity of bushfires . Harvesting timber for firewood is Normally the carried out by hand with chainsaws. Thus, longer parts – requiring less manual labor, and less chainsaw fuel – are less expensive and only limited by the size of their firebox. Also vary with the distance from wood lots, and quality of the wood. Firewood is usually about construction or construction . Firewood is a renewable resource . The shortage of suitable firewood In Some places HAS local populations seen Damaging huge tracts of bush Possibly leading to further Top desertification .

Greenhouse gases

Wood burning creates more atmospheric CO 2 than biodegradation of wood in a forest (in a given period of time) because of the time the bark of a dead tree has rotted, the log has to sequester the CO 2 by integrating the hydrocarbons of the wood into their own life cycle. Wood harvesting and transportation operations Produce varying, degrees of greenhouse gas pollution. Inefficient and incomplete combustion of wood can result in elevated levels of greenhouse gases other than CO 2 , qui May result in positive emission Where the byproducts-have Greater Carbon dioxide equivalent gains. [14]In an attempt to quantitatively Provide information about the relative output of CO 2 to Produce electricity of domestic heating, the United Kingdom Department of Energy and Climate Change ( DECC ) HAS published a comprehensive model Comparing the burning of wood (wood chip) and other fuels , based on 33 scenarios. [15] The model’s output is kilogram of CO 2 Produced per megawatt hour of energy Delivered. Scenario 33 for example, which relates to the production of heat from wood chips produced by the production of small quantities of wood, which produces 377 kg of CO 2 while burning woodchip releases 1501 kg of CO 2 per MW h delivered energy.

The intentional and controlled incorporation of carbon and its incorporation into the soil is an effective method for carbon sequestration as well as an important technique for improving soil conditions for agriculture, particularly in heavily forested regions. It forms the basis of the rich soils known as Terra preta .

Regulation and Legislation

The environmental impact of burning wood fuel is debatable. Several cities have moved towards setting standards of use and / or bans of wood burning fireplaces. For example, the city of Montreal, Quebec passed a resolution to ban wood fireplace installation in new construction. HOWEVER Many wood burning advocates claim weasel words ] That Properly harvested wood is carbon-neutral, therefore off-setting the negative impact of by-product particles off Given During the burning process. In the context of forest wildfires, wood removed from the forest, and the use of fuel oil in the form of fuel oil.

Potential use in renewable energy technologies

  • Efficient stove for developing nations
  • Pellet stove
  • Sawdust can be pelletized
  • Wood pellets


Some European countries produce a significant fraction of their electricity needs from wood or wood wastes. In Scandinavian countries the costs of manual labor to firewood is very high. Therefore, it is common to import firewood from countries with cheap labor and natural resources. citation needed ] The main exporters to Scandinavia are the Baltic countries (Estonia, Lithuania, and Latvia). In Finland , there is a growing interest in using wood waste as fuel for home and industrial heating, in the form of compacted pellets .

In the United States, wood fuel is the second-leading form of renewable energy (behind hydro-electric ). [16]


A pile of firewood logged in Barmah Forest in Victoria

About 1.5 million households in Australia uses firewood as the main form of domestic heating. [17] As of 1995, approximately 1.85 million cubic meters of firewood (1m³ equals approximately one car trailer load) was used in Victoria annually, with half being consumed in Melbourne . [18] This amount is comparable to that of all Victoria’s sawlog and pulplog forestry operations (1.9 million cubic meters). quote needed ]

Species used as sources of firewood include:

  • Red Gum , from forests along the Murray River (the Mid-Murray Forest Management Area, including the Barmah and Gunbower Forests, provides about 80% of Victoria’s red gum timber). [19]
  • Stringybark Box and Messmate , in southern Australia.
  • Sugar gum , a wood with high thermal efficiency that usually comes from small plantations. quote needed ]
  • Jarrah , in the Southwest of Western Australia. It is a greater heat than most other available woods and is usually sold by the ton.


In 2014, the construction of the largest pellet mill in the Baltic region was started in Võrumaa , Sõmerpalu , with an expected output of 110,000 tons of pellet / year. Different types of wood will be used in the process of pellet making (firewood, woodchips, shavings). The Warmeston OÜ plant started its activity by the end of 2014. [20] [21] In 2013, the pellet consumers in Europe were the UK, Denmark, the Netherlands, Sweden, Germany and Belgium, as EU’s annual report on biofuels states . In Denmark and Sweden, pellets are used by power plants, households and medium scale consumers for district heating, compared to Austria and Italy, where pellets are mainly used for small – scale private residential and industrial boilers for heating.[22]

See also

  • Biofuel
  • Biomass
  • Forestry
  • Renewable heat
  • Wood gas
  • Wood-fired oven
  • woodchips


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  19. Jump up^ NRE 2002 Forest Management Plan for the Mid-Murray Forest Management Area
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  21. Jump up^ http://www.warmeston.ee/index.php?lang=2
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