question: Can you melt wood without it combusting? If so, what is the end result?
comment: No, the wood will undergo pyrolysis if you prevent it from catching fire. This is how charcoal is made. Ultimately you can't melt wood, because the bonds that make up the 'mix of stuff' that is wood will break down at a lower temperature than the melting point of same. So it stops being wood before it can melt. If you keep applying more and more heat, the end products will either break down further, or melt, and eventually evaporate, but you no longer have wood well before that point.
passages: All wood will release creosote vapors when burned. Modern stoves will burn the vapors, either via direct secondary combustion or via a catalyst. Very little, if any, creosote will escape a properly operating modern stove's secondary combustion.
   Section::::Historical development.
  
  Wood has been used as fuel for millennia. Historically, it was limited in use only by the distribution of technology required to make a spark. Heat derived from wood is still common throughout much of the world. Early examples included a fire constructed inside a tent. Fires were constructed on the ground, and a smoke hole in the top of the tent allowed the smoke to escape by convection.
   Slow combustion stoves increase efficiency of wood heaters burning logs, but also increase particulate production. Low pollution/slow combustion stoves are a current area of research. 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 particulates while maintaining the efficiency of the system.
   Wood briquette
  
  Wood briquettes are made of dry, untreated wood chips (e.g. wood shavings). They are pressed with high pressure without any binder. By compacting the wood with this high pressure, it turns into a fuel like brown coal.
  
  Section::::Advantages.
   Fuel accelerants such as coal, grease, oil, gasoline, kerosene, plastics, and so on, also must never be added to firewood in a wood stove, since the flames produced may easily overwhelm the wood compartment and stove pipes and create a house fire.
  
  Section::::Safety and pollution considerations.:UK smoke control areas.
   Modern non-catalytic wood stoves will also reburn the gasses from the firebox, but require a much higher temperature for the secondary combustion. No catalyst is required. These models lose a large amount of efficiency at low burn rates, as they cannot maintain secondary combustion, but can be very efficient at higher temperatures that allow secondary combustion.
  
  There also exist hybrid stoves that employ both catalytic and non-catalytic secondary combustion.
  
  Stoves that do not employ any secondary combustion still exist, but are markedly less efficient than a modern stove due to their lack of secondary combustion.
  
  Section::::Fuel.:Pyrolyzing stoves.
   The carbonization of wood in an industrial setting usually requires a temperature above 280 °C, which liberates energy and hence this reaction is said to be exothermic. This carbonization, which can also be seen as a spontaneous breakdown of the wood, continues until only the carbonised residue called charcoal remains. Unless further external heat is provided, the process stops and the temperature reaches a maximum of about 400 °C. This charcoal, however, will still contain appreciable amounts of tarry residue, together with the ash of the original wood.
  
  Section::::Industrial safety in carbonization.
   The "Rudiger roll friction fire method", also known as the "fire roll" method, is believed to have been invented by World War 2 POWs. A German survival expert named Rüdiger Nehberg wrote about this method in one of his books. A small amount of wood ash is rolled up inside of cotton like a cigar. The cotton is then placed between two boards and rolled back and forth. Pressure and speed are both gradually increased. With proper technique ignition can occur in seconds.
  
  Section::::Methods.:Percussion.
   The discovery of how to make fire for the purpose of burning wood is regarded as one of humanity's most important advances. The use of wood as a fuel source for heating is much older than civilization and is assumed to have been 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 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 furnace, campfire, or bonfire.
   Thermally modified wood
  
  Thermally modified wood, is wood that has been modified by a controlled pyrolysis process of wood being heated ( 180 °C) in absence of oxygen inducing some chemical changes to the chemical structures of cell wall components (lignin, cellulose and hemicellulose) in the wood in order to increase its durability. Low oxygen content prevents the wood from burning at these high temperatures. Several different technologies are introduced using different media including nitrogen gas, steam and hot oil.
  
  Section::::Modification processes.
  
  The first technological approach of thermal modification processes of wood is the paper of Burmester.
   Section::::Combustion.:Methanol.
  
  Methanol (the simplest alcohol) behaves as a liquid at 25 °C, is toxic and corrosive, and in organic chemistry basic books is often called "the spirit of wood", since it can be obtained from wood fermentation. Rarely, when unwise wine-makers mix small chunks of wood and leaves with grapes, methanol can be found as a pollutant of the blend of water, ethanol and other substances derived from grape's fermentation.
  
  The best way to obtain methanol from wood is through syngas (CO, CO, H) produced by the anhydrous pyrolysis of wood, a method discovered by ancient Egyptians.
   Fire hardening
  
  Fire hardening, also known as "fire-danubing", is the process of removing moisture from wood, changing its structure and material properties, by slowly and lightly charring it over a fire. This has been thought to make a point, like that of a spear, or an edge, like that of a knife, more durable. An initial study suggests that the process might make the wood brittle but would reduce the time needed to make a spear point substantially.
   A catalytic wood stove will re-burn the gasses from the firebox in a catalyst- a matrix of steel or ceramic plated with a catalyst that allows combustion of these gasses at much lower temperatures than would ordinarily be possible. This is why among modern stoves, catalytic models tend to be much better at achieving low, even heat output, which is desirable in warmer weather.
   At about this time, the market for thermally modified wood expanded dramatically from its traditional application in sauna materials, to include exterior products, such as decking (terrace) and cladding (siding). While Ha-Serv continued to focus primarily on the Finnish sauna market, Brenstol established the Thermory brand and begin to export across Europe and to Japan and Thermory has become the most widely-recognized brand of thermally modified wood in these regions. The market for thermally modified exterior products increased very rapidly as European consumers increasingly looked for alternatives to tropical woods from Asia, Africa and South America. A Turkish producer, Nova Wood, also started producing of thermally modified wood and became a minor player in European markets. 
   A furnace can be lit by a small pilot flame or in some older models, by hand. Most pilot flames nowadays are lit by an ignition transformer (much like a car's spark plugs). The pilot flame in turn lights up the main flame. The pilot flame uses natural gas while the main flame can use both diesel and natural gas. When using liquid fuels, an atomizer is used, otherwise, the liquid fuel will simply pour onto the furnace floor and become a hazard. Using a pilot flame for lighting the furnace increases safety and ease compared to using a manual ignition method (like a match).
   Exhaust gas emission from an internal combustion engine is significantly lower on wood gas than on petrol. Especially the hydrocarbon emissions are low on wood gas. A normal catalytic converter works well with wood gas, but even without it, emission levels less than 20 ppm HC and 0.2% CO can be easily achieved by most automobile engines. Combustion of wood gas generates no particulates, and the gas renders thus very little carbon black amongst motor oil.
  
  Section::::Usage.:Stoves, cooking and furnaces.
   Humphry Davy discovered the use of platinum in catalysis. In which a catalytic body is interposed in the path of a combustible vapor and is heated upon its passage through the catalytic body sufficiently to unite with the air upon egress from the catalytic body and then to burn upon the surface of the catalytic body. These stoves are typically described as wind-resistant, infrared, or radiant.
  
  BULLET::::- Rechauds Catalytiques (1920, wicking)
  
  BULLET::::- Therm'x Explorer 57C (1965, wicking)
  
  BULLET::::- MSR Reactor (2007, pressurized)
  
  BULLET::::- Rechaud A Catalytise Trek 270 (2010, pressurized)
  
  Section::::Pressurized liquid fuel stoves.
  
  Section::::Pressurized liquid fuel stoves.:Primus stoves.
   There are also stove models that can switch from wood fuel to oil or gas sources that are installed in the house to supply heat to a separate water boiler. Stoves that readily convert to either oil or gas in addition to wood fuel have been manufactured in North America and Europe since the early 20th century, and are still manufactured. In some models, the oil or gas may fuel the stove through a pipe connection leading to a "pot burner" in the rear of the firewood compartment in the stove.\
   Wood pellet heating systems work with different techniques of charging and combustion: Today there are specifically developed loading techniques for pellet combustion like drop chute firing, underfeed firing, side-fed firing or the use of a roller grate system. The method of charging and combustion of the pellet fuel is divided into 5 technologies.
   One of the most common variables of the biomass briquette production process is the way the biomass is dried out. Manufacturers can use torrefaction, carbonization, or varying degrees of pyrolysis. Researchers concluded that torrefaction and carbonization are the most efficient forms of drying out biomass, but the use of the briquette determines which method should be used.
   The last reaction is also very unlikely since it involves three reaction products, as well as being endothermic — think of the reaction proceeding in reverse, it would require the three products all to converge at the same time, which is less likely than two-body interactions.
   Three of the processes are performed in one step, using oil (oil-heat treatment), nitrogen (Reti wood) and steam (Le-Bois Perdure). The Thermo wood process consists of drying, heat treatment and finally cooling/conditioning, and takes up to 72 hours. The Plato process consists of hydrothermolysis, dry curing and conditioning, and can take up to 7 days. The required time depends on wood species, width and initial moisture content.
  
  Section::::Description of the process.:Westwood Process.
   Wood-fired ovens are distinct from wood-fired stoves that have a hot cooking surface for pots and pans, like on a gas or electric stove. A wood stove may also have an oven separate from the fire chamber. Regardless of material they all have an oven chamber consisting of a floor (or hearth), a dome and an entry (oven opening).
   The growth in popularity of wood heat also led to the development and marketing of a greater variety of equipment for cutting, splitting and processing firewood. Consumer grade hydraulic log splitters were developed to be powered by electricity, gasoline, or PTO of farm tractors. In 1987 the US Department of Agriculture published a method for producing kiln dried firewood, on the basis that better heat output and increased combustion efficiency can be achieved with logs containing lower moisture content.
  
  The magazine "Wood Burning Quarterly" was published for several years before changing its name to "Home Energy Digest" and, subsequently, disappearing.
   Multi-fuel stoves are versatile, but usually perform poorly compared to a stove that is designed to burn one specific fuel as well as possible.
  
  Section::::Fuel.:Catalytic and non-catalytic stoves.
  
  Modern wood stoves universally have some method of secondary combustion to burn unburned gasses for greatly improved efficiency and emissions. One common method is via a catalyst.
  