Some Patents about Torrefied Wood:
 | United States Patent
4,954,620, September 4, 1990 and
4,816,572,
March 28,
1989 Thermocondensed lignocellulose material, and a method and an oven for obtaining it. Bourgeois This material which has a hemi-cellulose content of less than 2%, a benzopyrene content of less than 2 ug/kg and a calorific value which is about 20% greater than that of the starting material is obtained by isothermal treatment between 220.degree. C. and 280.degree. C. for a period of thirty minutes using crossed flows of treated material and of oxygen-free hot gases in an oven including stirring means and a gas generator with the gas being circulated by a fan. |
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U.S.
Patent 4,787,917, November
29, 1988 Method for producing torrefied wood, product obtained thereby, and application to the production of energy New product consisting of wood which is torrefied between 250.degree. and 280.degree. C. in a non oxidizing atmosphere, in the form of sticks of uniform length: 15 mm for example and having a diameter comprised between 5 and 20 mm, which are not disbarked. The preparation of the method comprised the obtention by culture of rectilinear ligneous rejections, the cutting, drying and torrefaction thereof preferably in a vertical reactor where the material to be torrefied is traversed by a gas stream circulating at high speed. |
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U.S.
Patent 4,553,978, November 19, 1985 Process for converting ligneous matter of vegetable origin by torrefaction, and product obtained thereby Yvan; Schwob (Paris, FR) The present invention relates to a process for converting ligneous matter of vegetable origin by torrefaction, and to the product obtained. Wood or any other ligneous matter is subjected in a neutral atmosphere to a treatment of torrefaction at a temperature of between 200.degree. and 280.degree. C., and preferably between 240.degree. and 260.degree. C. for a duration of 30 mins. to 5 hours. The product of the invention is not fermentable, it has a specific mass close to 0.25 kg/dm.sup.3, a calorific power of at least about 5000 kcal/kg, a content of fixed carbon of 35 to 40% and can be broken up by hand; it may be used as fuel in boilers and in gas generators. |
| United States Patent 3,950,143,
April 13, 1976 Process for producing solid industrial fuel Pyle |
A solid, low-sulfur, industrial fuel having a fuel value similar to bituminous coal, and a continuous process for producing the fuel from woody materials are presented. The process includes the step of initially predrying the materials if they are moist until the water content thereof is less than about 15%. The woody materials are then subjected to a limited carbonization. The materials are heated in a furnace or kiln until noticeable carbonization begins, and carbonization is permitted to continue until the fiberous structure of the materials disappears to thereby maximize production of solid fuel having a high content of volatile combustible matter. Subsequently, the solid fuel is cooled and conditioned against spontaneous combustion. The solid fuel may then be pulverized or compacted, and immediately used, stored, or transported. The process of this invention optionally may also produce a small quantity of gas having a fuel valve sufficiently high for use as burner fuel in the predryer.
