Method and apparatus for production of cellulose based fuel pellets
AssigneeArbaflame Technology AS
InventorRune Brusletto
Life of this patent
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Abstract
A method and apparatus for production of cellulose based fuel pellets from wood logs includes steps of comminuting the wood logs to particulate wood material. The particulate material heat treated in a reactor and the pressure is reduced in a manner causing defibration of the particulate material. The material is pelletized using the softened lignin at least partially as a binder for the pellets. The comminution of the wood logs is effected as a single-step operation in which the wood logs are charged to a comminution station where at least one rotating drum provided with cutting teeth is arranged in a manner to fully comminute the wood logs. The particulate material may be fractioned and a selected size fraction used for the further treatment.
Claims13
An apparatus for production of cellulose based fuel pellets from elongate pieces of wood material comprising:
- a. a comminution station configured to comminute elongate pieces of wood into smaller particulate wood material,
- b. a process plant configured to
- (i) heat the particulate wood material to a temperature and a pressure in a presence of steam and for a period of time sufficient to soften lignin present in the particulate wood material, and
- (ii) thereafter reduce the pressure, thereby causing defibration of the particulate material and yielding treated particulate wood material, and
- c. pelletizing equipment to thereafter pelletize the treated particulate wood material, wherein
- the comminution station is configured to comminute the elongate pieces of wood material in a single-step operation via a cutting drum provided with cutting teeth, and
- the cutting teeth are sized and the cutting drum is rotated at a rotational speed to cut the elongate pieces of wood to a predetermined particle size, and
- the cutting drum comprises a stack of individual saw blades that allow for separate replacement of each individual blade.
An apparatus for production of cellulose based fuel pellets from wood logs, comprising:
- a. a comminution station configured to comminute the wood logs into particulate wood material,
- b. a fractionating section located at a position below the comminution station and configured for fractionating the particulate wood material into a fine particle fraction and a coarse particle fraction,
- c. a chute configured to convey the particulate wood material, assisted by gravity, to the fractionating section,
- d. a process plant configured to
- (i) heat one or both of the fine particle fraction and the coarse particle fraction to a temperature and a pressure in a presence of water vapor and air and for a period of time sufficient to soften lignin present in the particulate wood material, and
- (ii) thereafter reduce the pressure, thereby causing defibration of the particulate material and yielding treated particulate wood material, and
- e. pelletizing equipment to thereafter pelletize the treated particulate wood material, wherein
- the comminution station is configured to comminute the wood logs in a single-step operation via a cutting drum provided with cutting teeth, and
- the cutting teeth are sized and the cutting drum is rotated at a rotational speed to cut the wood logs to a predetermined particle size.
An apparatus for production of cellulose based fuel pellets from elongate pieces of wood material, comprising:
- a. a comminution station configured to comminute elongate pieces of wood into smaller particulate wood material,
- b. a fractionating section for fractionating the particulate wood material into a fine particle fraction and a coarse particle fraction,
- c. a process plant configured to
- (i) heat one or both of the fine particle fraction and the coarse particle fraction to a temperature and a pressure in a reactor containing water vapor or steam and for a period of time sufficient to soften lignin present in the particulate wood material, and
- (ii) thereafter reduce the pressure in the reactor, thereby causing defibration of the particulate material and yielding treated particulate wood material, and
- d. pelletizing equipment to thereafter pelletize the treated particulate wood material, wherein
- the comminution station is configured to comminute the elongate pieces of wood material in a single-step operation via a cutting drum provided with cutting teeth, and
- the cutting teeth are sized and the cutting drum is rotated at a rotational speed to cut the elongate pieces of wood to a predetermined particle size, and
- the cutting drum comprises a stack of individual saw blades that allow for separate replacement of each individual blade.
Dependencies are inferred from the claim text.