A briquette (French: [bʁikɛt]; in English also spelled briquet or brickette) is a compressed block of coal dust or other combustible biomass material (e.g. charcoal, sawdust, wood chips, peat, or paper) used for fuel and kindling to start a fire. The term is a French word meaning "small brick".
Coal briquettes
Coal briquettes have long been produced as a means of using up 'small coal', the finely broken coal inevitably produced during the mining process. Otherwise this is difficult to burn as it is hard to arrange adequate airflow through a fire of these small pieces; also such fuel tends to be drawn up and out of the chimney by the draught, giving visible black smoke. The first briquettes were known as culm bombs and were hand-moulded with a little wet clay as a binder. These could be difficult to burn efficiently, as the unburned clay produced a large ash content, blocking airflow through a grate. With Victorian developments in engineering, particularly the hydraulic press, it became possible to produce machine-made briquettes with minimal binder content. A tar or pitch binder was used, obtained first from gas making and later from petrochemical sources. These binders burned away completely, making it a low-ash fuel. A proprietary brand of briquettes from the South Wales coalfield was Phurnacite, developed by Idris Jones for Powell Duffryn. These were intended to emulate a high-quality anthracite coal, such as that from the Cynheidre measures. This involved blending a mixture of coals from different grades and colliery sources. Phurnacite used the following mix:
Bituminous coal, 25% Steam coal, 45% Dry steam coal, 22% Pitch, 8% Early briquettes were large and brick-shaped. Phurnacite briquettes later adopted a squared oval shape. This regular shape packed well as a good firebed, with plentiful airflow. They are also easy to mechanically feed, allowing the development of automatically controlled heating boilers that could run for days without human intervention.
Charcoal briquettes
Charcoal briquettes sold for cooking food can include:
Wood charcoal (fuel) Lignite coal (fuel) Anthracite coal (fuel) Limestone (ash colourant) Starch (binder) Borax (release agent) Sodium nitrate (accelerant) Sawdust Wax (some brands: binder, accelerant, ignition facilitator). Chaff (rice chaff and peanut chaff) As a rule of thumb, a charcoal briquette will heat a camping Dutch oven by approximately 25 °F (14 °C), so 20 charcoal briquettes will heat it by 500 °F (280 °C).
East-Asian briquettes
Home made charcoal briquettes (called tadon) were found after charcoal production in Japanese history. In the Edo period, polysaccharide extracted from red algae was widely used as a binder. After the imports of steam engines in the Meiji period, coal and clay became major ingredients of Japanese briquettes. These briquettes, rentan and mametan, were exported to China and Korea. Today, coal briquettes are avoided for their sulfur oxide emission. Charcoal briquettes are still used for traditional or outdoor cooking. Woody flakes such as sawdust or coffee dust are major ingredients of modern mass-consumed briquettes (e.g., Ogatan).
Use in China
Throughout China, cylindrical briquettes, called "fēng wō méi" (beehive coal 蜂窩煤 / 蜂窝煤) or "Mei" (coal 煤) or "liàn tàn" (kneaded coal 練炭 / 练炭), are used in purpose-built cookers. The origin of "Mei" is "Rentan" (kneaded coal 練炭) of Japan. Rentan was invented in Japan in the 19th century, and spread to Manchukuo, Korea and China in the first half of the 20th century. There were many Rentan factories in Manchukuo and Pyongyang. Although Rentan went out of use in Japan after the 1970s, it is still popular in China and Vietnam ("than tổ ong" coal). The cookers are simple, ceramic vessels with metal exteriors. Two types are made: the single, or triple briquette type, the latter holding the briquettes together side by side. These cookers can accommodate a double stack of cylinders. A small fire of tinder is started, upon which the cylinder(s) is placed. When a cylinder is spent, another cylinder is placed on top using special tongs, with the one below igniting it. The fire can be maintained by swapping spent cylinders for fresh ones, and retaining a still-glowing spent cylinder. Each cylinder lasts for over an hour. These cookers are used to cook, or simmer, pots of tea, eggs, soups, stews, etc. The cylinders are delivered, usually by cart, to businesses, and are very inexpensive.
Peat briquettes
In Ireland, briquettes made from peat, the product of the decomposition of marsh plants in a low-oxygen environment, are a common type of solid fuel, largely replacing sods of raw peat as a domestic fuel. These briquettes consist of shredded peat, compressed to form a virtually smokeless, slow-burning, easily stored and transported fuel. Although often used as the sole fuel for a fire, they are also used to light a coal fire quickly and easily. Peat briquettes are also sometimes used for grilling meats and vegetables as they bring a unique aroma to the food. Bord na Móna is the Irish state owned company in charge of peat, which also handles production of peat briquettes.
Biomass briquettes
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