Hexamine fuel tablet

Last updated
Esbit brand hexamine tablets Esbit brand Hexamine tablets.JPG
Esbit brand hexamine tablets

A hexamine fuel tablet (or heat tablet, Esbit) is a form of solid fuel in tablet form. The tablets burn smokelessly, have a high energy density, do not liquefy while burning and leave no ashes. Invented in Murrhardt, Germany, in 1936, the main component is hexamine, which was discovered by Aleksandr Butlerov in 1859. Some fuel tablets use 1,3,5-trioxane as another ingredient.

Contents

Esbit is a genericized trademark that people often use to refer to similar products made by other companies. In most countries from the former Soviet bloc, fuel tablets are called dry alcohol .

Uses

Folding hexamine stove with packaged fuel Pocket-size collapsible cooker.jpg
Folding hexamine stove with packaged fuel

The tablets are used for cooking by campers, militaries, and relief organizations. They are often used with disposable metal stoves that are included with field ration packs. Another common use is to provide a heat source for model steam engines, such as those manufactured by Wilesco and Mamod, and other external combustion engines such as Stirling engines and pop pop boats.

Advantages and disadvantages

Hexamine is prepared by the reaction of formaldehyde and ammonia. In an acidic environment hexamine is converted to toxic formaldehyde, where the main hazard for toxicity is by ingestion.

As with trioxane, hexamine has an almost unlimited shelf life if stored properly, in a sealed dry container. However, the heat given off cannot be easily adjusted, so water can be boiled, but cooking requiring simmering is more difficult. Tablets are a powerful stove fuel (30.0 MJ/kg), and are sensitive to wind and dampness.

Esbit's Safety Data Sheet states combustion can create formaldehyde, ammonia, nitrogen oxide, hydrogen cyanide and ingestion may cause nausea, vomiting, gastrointestinal disturbances, and kidney damage. When burned, the chemical oxidation of the fuel yields noxious fumes, which requires cooking foods in a container, such as a pot or pan, with a tight fitting lid. Burned tablets leave a sticky dark residue on the bottom of pots. If tablets are stored or used under damp conditions they can break up while burning and shed burning fragments, though this claim is hard to verify or reproduce. [1]

Hexamine is a precursor for the simplest synthesis of the chemical explosive RDX; [2] in many areas its availability is tightly regulated due to this. [3]

See also

Related Research Articles

<span class="mw-page-title-main">Combustion</span> Chemical reaction between a fuel and oxygen

Combustion, or burning, is a high-temperature exothermic redox chemical reaction between a fuel and an oxidant, usually atmospheric oxygen, that produces oxidized, often gaseous products, in a mixture termed as smoke. Combustion does not always result in fire, because a flame is only visible when substances undergoing combustion vaporize, but when it does, a flame is a characteristic indicator of the reaction. While activation energy must be supplied to initiate combustion, the heat from a flame may provide enough energy to make the reaction self-sustaining.

<span class="mw-page-title-main">RDX</span> Explosive chemical compound

RDX (abbreviation of "Research Department eXplosive") or hexogen, among other names, is an organic compound with the formula (CH2N2O2)3. It is white, odorless and tasteless, widely used as an explosive. Chemically, it is classified as a nitroamine alongside HMX, which is a more energetic explosive than TNT. It was used widely in World War II and remains common in military applications.

<span class="mw-page-title-main">Fire</span> Rapid and hot oxidation of a material

Fire is the rapid oxidation of a material in the exothermic chemical process of combustion, releasing heat, light, and various reaction products. At a certain point in the combustion reaction, called the ignition point, flames are produced. The flame is the visible portion of the fire. Flames consist primarily of carbon dioxide, water vapor, oxygen and nitrogen. If hot enough, the gases may become ionized to produce plasma. Depending on the substances alight, and any impurities outside, the color of the flame and the fire's intensity will be different.

<span class="mw-page-title-main">Smoke</span> Mass of airborne particulates and gases

Smoke is a suspension of airborne particulates and gases emitted when a material undergoes combustion or pyrolysis, together with the quantity of air that is entrained or otherwise mixed into the mass. It is commonly an unwanted by-product of fires, but may also be used for pest control (fumigation), communication, defensive and offensive capabilities in the military, cooking, or smoking. It is used in rituals where incense, sage, or resin is burned to produce a smell for spiritual or magical purposes. It can also be a flavoring agent and preservative.

<span class="mw-page-title-main">Portable stove</span> Cooking stove specially designed to be portable and lightweight

A portable stove is a cooking stove specially designed to be portable and lightweight, used in camping, picnicking, backpacking, or other use in remote locations where an easily transportable means of cooking or heating is needed. Portable stoves can be used in diverse situations, such as for outdoor food service and catering and in field hospitals.

A propellant is a mass that is expelled or expanded in such a way as to create a thrust or another motive force in accordance with Newton's third law of motion, and "propel" a vehicle, projectile, or fluid payload. In vehicles, the engine that expels the propellant is called a reaction engine. Although technically a propellant is the reaction mass used to create thrust, the term "propellant" is often used to describe a substance which contains both the reaction mass and the fuel that holds the energy used to accelerate the reaction mass. For example, the term "propellant" is often used in chemical rocket design to describe a combined fuel/propellant, although the propellants should not be confused with the fuel that is used by an engine to produce the energy that expels the propellant. Even though the byproducts of substances used as fuel are also often used as a reaction mass to create the thrust, such as with a chemical rocket engine, propellant and fuel are two distinct concepts.

<span class="mw-page-title-main">Hexamethylenetetramine</span> Chemical compound

Hexamethylenetetramine, also known as methenamine, hexamine, or its trade name Urotropin, is a heterocyclic organic compound with the formula (CH2)6N4. This white crystalline compound is highly soluble in water and polar organic solvents. It has a cage-like structure similar to adamantane. It is useful in the synthesis of other organic compounds, including plastics, pharmaceuticals, and rubber additives. It sublimes in vacuum at 280 °C.

<span class="mw-page-title-main">Solid fuel</span> Solid material that can be burnt to release energy

Solid fuel refers to various forms of solid material that can be burnt to release energy, providing heat and light through the process of combustion. Solid fuels can be contrasted with liquid fuels and gaseous fuels. Common examples of solid fuels include wood, charcoal, peat, coal, hexamine fuel tablets, dry dung, wood pellets, corn, wheat, rice, rye, and other grains. Solid fuels are extensively used in rocketry as solid propellants. Solid fuels have been used throughout human history to create fire and solid fuel is still in widespread use throughout the world in the present day.

<span class="mw-page-title-main">Stove</span> Device used to generate heat or to cook

A stove or range is a device that generates heat inside or on top of the device, for local heating or cooking. Stoves can be powered with many fuels, such as electricity, natural gas, gasoline, wood, and coal.

<span class="mw-page-title-main">Beverage-can stove</span> Alcohol stove of DIY construction

A beverage-can stove, or pop-can stove, is a do it yourself, ultralight, alcohol-burning portable stove. It is made using parts from two aluminium beverage cans. Basic designs can be relatively simple, but many variations exist.

<span class="mw-page-title-main">Sterno</span> Brand of denatured alcohol fuel in gel form

Sterno is a brand of jellied, denatured alcohol sold in and meant to be burned directly in its can. Popular both in commercial food service and home entertainment, its primary uses are in as a fuel for heating chafing dishes in buffets and serving fondue. Other uses are for portable stoves and as an emergency heat source. It is also used with toy and model steam and other external combustion engines.

<span class="mw-page-title-main">Buddy Burner</span>

A Buddy Burner is a simple stove made from a can and part of a corrugated paper box. It is usually fueled by paraffin wax but other fuels, such as boiled butter, animal fat or diesel fuel, can be used. It is usually used for cooking but can also provide heat.

<span class="mw-page-title-main">1,3,5-Trioxane</span> Chemical compound

1,3,5-Trioxane, sometimes also called trioxane or trioxin, is a chemical compound with molecular formula C3H6O3. It is a white, highly water-soluble solid with a chloroform-like odor. It is a stable cyclic trimer of formaldehyde, and one of the three trioxane isomers; its molecular backbone consists of a six-membered ring with three carbon atoms alternating with three oxygen atoms.

A pyrotechnic composition is a substance or mixture of substances designed to produce an effect by heat, light, sound, gas/smoke or a combination of these, as a result of non-detonative self-sustaining exothermic chemical reactions. Pyrotechnic substances do not rely on oxygen from external sources to sustain the reaction.

The Tommy cooker was a compact, portable stove, issued to the troops of the British Army ("Tommies") during World War I and World War II.

<span class="mw-page-title-main">Smokeless fuel</span>

Smokeless fuel is a type of solid fuel which either does not emit visible smoke or emits minimal amounts during combustion. These types of fuel find use where the use of fuels which produce smoke, such as coal and unseasoned or wet wood, is prohibited.

<span class="mw-page-title-main">Wood-burning stove</span> Type of stove

A wood-burning stove is a heating or cooking appliance capable of burning wood fuel, often called solid fuel, and wood-derived biomass fuel, such as sawdust bricks. Generally the appliance consists of a solid metal closed firebox, often lined by fire brick, and one or more air controls. The first wood-burning stove was patented in Strasbourg in 1557. This was two centuries before the Industrial Revolution, so iron was still prohibitively expensive. The first wood-burning stoves were high-end consumer items and only gradually became used widely.

<span class="mw-page-title-main">Fuel</span> Material used to create heat and energy

A fuel is any material that can be made to react with other substances so that it releases energy as thermal energy or to be used for work. The concept was originally applied solely to those materials capable of releasing chemical energy but has since also been applied to other sources of heat energy, such as nuclear energy.

<span class="mw-page-title-main">Rocket propellant</span> Chemical or mixture used as fuel for a rocket engine

Rocket propellant is the reaction mass of a rocket. This reaction mass is ejected at the highest achievable velocity from a rocket engine to produce thrust. The energy required can either come from the propellants themselves, as with a chemical rocket, or from an external source, as with ion engines.

<span class="mw-page-title-main">Kenya Ceramic Jiko</span>

The Kenya Ceramic Jiko is a portable, charcoal-burning stove used for cooking, found primarily in urban homes in Kenya. It was developed through the collaboration of both local and international groups, to reduce fuel consumption.

References

  1. Warning leaflet packed with Mamod brand fuel tablets
  2. Luo, K.-M.; Lin, S.-H.; Chang, J.-G.; Huang, T.-H. (2002), "Evaluations of kinetic parameters and critical runaway conditions in the reaction system of hexamine-nitric acid to produce RDX in a non-isothermal batch reactor", Journal of Loss Prevention in the Process Industries, 15 (2): 119–127, doi:10.1016/S0950-4230(01)00027-4.
  3. "You can make a difference! - Sell chemical products responsibly" (PDF). www.gov.uk. Home Office . Retrieved 2018-11-18.