CA1036356A - Process for utilising straw - Google Patents
Process for utilising strawInfo
- Publication number
- CA1036356A CA1036356A CA213,506A CA213506A CA1036356A CA 1036356 A CA1036356 A CA 1036356A CA 213506 A CA213506 A CA 213506A CA 1036356 A CA1036356 A CA 1036356A
- Authority
- CA
- Canada
- Prior art keywords
- straw
- briquettes
- pressing
- particles
- straw particles
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B27—WORKING OR PRESERVING WOOD OR SIMILAR MATERIAL; NAILING OR STAPLING MACHINES IN GENERAL
- B27N—MANUFACTURE BY DRY PROCESSES OF ARTICLES, WITH OR WITHOUT ORGANIC BINDING AGENTS, MADE FROM PARTICLES OR FIBRES CONSISTING OF WOOD OR OTHER LIGNOCELLULOSIC OR LIKE ORGANIC MATERIAL
- B27N3/00—Manufacture of substantially flat articles, e.g. boards, from particles or fibres
- B27N3/04—Manufacture of substantially flat articles, e.g. boards, from particles or fibres from fibres
-
- A—HUMAN NECESSITIES
- A23—FOODS OR FOODSTUFFS; TREATMENT THEREOF, NOT COVERED BY OTHER CLASSES
- A23K—FODDER
- A23K10/00—Animal feeding-stuffs
- A23K10/30—Animal feeding-stuffs from material of plant origin, e.g. roots, seeds or hay; from material of fungal origin, e.g. mushrooms
- A23K10/32—Animal feeding-stuffs from material of plant origin, e.g. roots, seeds or hay; from material of fungal origin, e.g. mushrooms from hydrolysates of wood or straw
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B30—PRESSES
- B30B—PRESSES IN GENERAL
- B30B15/00—Details of, or accessories for, presses; Auxiliary measures in connection with pressing
- B30B15/0005—Details of, or accessories for, presses; Auxiliary measures in connection with pressing for briquetting presses
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B27—WORKING OR PRESERVING WOOD OR SIMILAR MATERIAL; NAILING OR STAPLING MACHINES IN GENERAL
- B27K—PROCESSES, APPARATUS OR SELECTION OF SUBSTANCES FOR IMPREGNATING, STAINING, DYEING, BLEACHING OF WOOD OR SIMILAR MATERIALS, OR TREATING OF WOOD OR SIMILAR MATERIALS WITH PERMEANT LIQUIDS, NOT OTHERWISE PROVIDED FOR; CHEMICAL OR PHYSICAL TREATMENT OF CORK, CANE, REED, STRAW OR SIMILAR MATERIALS
- B27K3/00—Impregnating wood, e.g. impregnation pretreatment, for example puncturing; Wood impregnation aids not directly involved in the impregnation process
- B27K3/02—Processes; Apparatus
- B27K3/0278—Processes; Apparatus involving an additional treatment during or after impregnation
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B27—WORKING OR PRESERVING WOOD OR SIMILAR MATERIAL; NAILING OR STAPLING MACHINES IN GENERAL
- B27K—PROCESSES, APPARATUS OR SELECTION OF SUBSTANCES FOR IMPREGNATING, STAINING, DYEING, BLEACHING OF WOOD OR SIMILAR MATERIALS, OR TREATING OF WOOD OR SIMILAR MATERIALS WITH PERMEANT LIQUIDS, NOT OTHERWISE PROVIDED FOR; CHEMICAL OR PHYSICAL TREATMENT OF CORK, CANE, REED, STRAW OR SIMILAR MATERIALS
- B27K3/00—Impregnating wood, e.g. impregnation pretreatment, for example puncturing; Wood impregnation aids not directly involved in the impregnation process
- B27K3/52—Impregnating agents containing mixtures of inorganic and organic compounds
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B27—WORKING OR PRESERVING WOOD OR SIMILAR MATERIAL; NAILING OR STAPLING MACHINES IN GENERAL
- B27K—PROCESSES, APPARATUS OR SELECTION OF SUBSTANCES FOR IMPREGNATING, STAINING, DYEING, BLEACHING OF WOOD OR SIMILAR MATERIALS, OR TREATING OF WOOD OR SIMILAR MATERIALS WITH PERMEANT LIQUIDS, NOT OTHERWISE PROVIDED FOR; CHEMICAL OR PHYSICAL TREATMENT OF CORK, CANE, REED, STRAW OR SIMILAR MATERIALS
- B27K9/00—Chemical or physical treatment of reed, straw, or similar material
Landscapes
- Life Sciences & Earth Sciences (AREA)
- Engineering & Computer Science (AREA)
- Polymers & Plastics (AREA)
- Chemical & Material Sciences (AREA)
- Mechanical Engineering (AREA)
- Zoology (AREA)
- Health & Medical Sciences (AREA)
- Biotechnology (AREA)
- Botany (AREA)
- Molecular Biology (AREA)
- Mycology (AREA)
- Physiology (AREA)
- Animal Husbandry (AREA)
- Forests & Forestry (AREA)
- Wood Science & Technology (AREA)
- Manufacturing & Machinery (AREA)
- Food Science & Technology (AREA)
- Processing Of Solid Wastes (AREA)
- Dry Formation Of Fiberboard And The Like (AREA)
- Lubricants (AREA)
- Fertilizers (AREA)
Abstract
ABSTRACT
A process for economically utilising straw in which the straw is compressed into briquettes having a density of at least 500 kg/m3, preferably at least 1000 kg/cm3 for subsequent use in a thermal, chemical or microbiological plant.
A process for economically utilising straw in which the straw is compressed into briquettes having a density of at least 500 kg/m3, preferably at least 1000 kg/cm3 for subsequent use in a thermal, chemical or microbiological plant.
Description
lb363S6 This invention relates to a proceRs for utilizing straw.
As agricultural operations become divided to a continuously increasing extent into cattle rearing and cereal cultivation, and stables which require no bedding are becoming increasingly used, the amount of unutilisable straw is steadily increasing. Various ways have already been considered of using the straw, but none of the previous proposals have been fully satisfactory. The possibility of its use as fodder is quantitatively limited, its use as a fertilizer would require costly processing of the straw since when the straw is distributed in the earth it decomposes too slowly and the danger of formation of isolated straw layers in the earth exists, and its use in producing industrial products such as building matarials involves technical difficulties and is often uneconomical.
For these reasons straw is now mostly burnt in the field, because the collection and transportation of straw bales is uneconomical because of the time and labour - 20 involved, and because of the large volume of the bales and the consequent size of the necessary storage space.
However, the burning of straw in the field causes not only considerable danger to the surroundings but also pollution of the environment due to the bur~t gases and residues, and in addition valuable earth bacteria and useful small wild life such as game maybe destroyed because of such fires. Moreover the smoke from such fires maybe a nuisance, ;03S3S~
and may for example cause traffic accidents due to obstruction of ~iew by the ~mo~e.
~ However, in addition economically significant heat quantities are lost. The use of straw as an energy source on account of its high calorific value, which is of the order of 4000 kcal, would be very desirable, but such use suffers from the same dif~iculties as the use of straw for industrial purposes. ~he usual units in which ~traw is produced and transported are too voluminous and unmanageable, and they need to be stacked in order to save space in storage or transport, and the handling of such units requires an uneconomical expenditure of labour, time and equipment. ~he thermal use of straw bàles would also ~ -require a special costly combustion plant.
An object of the present invention is to provide a process for economically utilizing straw by which the aforementioned disadvantages and difficulties are avoided ~nd whioh can be carried out with comparatively simple ; readily-available equipment.
As agricultural operations become divided to a continuously increasing extent into cattle rearing and cereal cultivation, and stables which require no bedding are becoming increasingly used, the amount of unutilisable straw is steadily increasing. Various ways have already been considered of using the straw, but none of the previous proposals have been fully satisfactory. The possibility of its use as fodder is quantitatively limited, its use as a fertilizer would require costly processing of the straw since when the straw is distributed in the earth it decomposes too slowly and the danger of formation of isolated straw layers in the earth exists, and its use in producing industrial products such as building matarials involves technical difficulties and is often uneconomical.
For these reasons straw is now mostly burnt in the field, because the collection and transportation of straw bales is uneconomical because of the time and labour - 20 involved, and because of the large volume of the bales and the consequent size of the necessary storage space.
However, the burning of straw in the field causes not only considerable danger to the surroundings but also pollution of the environment due to the bur~t gases and residues, and in addition valuable earth bacteria and useful small wild life such as game maybe destroyed because of such fires. Moreover the smoke from such fires maybe a nuisance, ;03S3S~
and may for example cause traffic accidents due to obstruction of ~iew by the ~mo~e.
~ However, in addition economically significant heat quantities are lost. The use of straw as an energy source on account of its high calorific value, which is of the order of 4000 kcal, would be very desirable, but such use suffers from the same dif~iculties as the use of straw for industrial purposes. ~he usual units in which ~traw is produced and transported are too voluminous and unmanageable, and they need to be stacked in order to save space in storage or transport, and the handling of such units requires an uneconomical expenditure of labour, time and equipment. ~he thermal use of straw bàles would also ~ -require a special costly combustion plant.
An object of the present invention is to provide a process for economically utilizing straw by which the aforementioned disadvantages and difficulties are avoided ~nd whioh can be carried out with comparatively simple ; readily-available equipment.
2~ The present invention provides a process for utilizing str~w comprising compressing the straw into briquettes having a density of at least 500 kg/m~, preferably at least 1000 kg/m3, for subsequent use in a desired process. ~ne briquettes may be fed to a thermal and/or chemical and/or microbiological plant, for exa~ple for use in firing, or in the production of cellulose, albumen or alcohol.
The straw, in the form of such highly compressed ~0363S6 briquet~es, which may be handled as loose lump material, may be rationally supplied to the desired utilisation and processing facility, e.g. to a thermal power station or a chemical factory. ~he briquettes may be transported by any suitable means for conveying loose material, for ex~nple containers, car5 and conveyors.
In producing the briguettes extensive destruction of the blades of the straw taXes place and because of the exceptionally low air content of the briquettes they may be considered as a homogeneous material, or even to a certain extent as pure straw, a~ are accordingly much more suitable for utilisation than straw pressed i~to bales even if such bales are highly compressed. Due to the extensive destruction of the blades of the straw in the briquettes, the briguettes may either before or during their utilisation be divided or disintegrated without difficulty, e.~. crumbled, pulverised or ground, and in the latter case further handled as granuled or pulverised loose material.
~o limits are imp~sed on the possible thermal, industrial, chemical or microbiological utilisation of such a homogeneous, compact, lump granular or ground straw briquette. It is however essential that the briquettes have a very high briquette density. Although a density of 5 kg/m3 is sufficient for most uses, it is expedient because of smaller space requirements to produce briquettes with a density of at l0ast 1000 Xg/m3. Suitable high pressure presses are readily available for such compression and are already used for producing hay and straw briquettes intended for fodder, i.e. for feeding domestic animals. ~o this end, the straw is digested with soda lye and/or mixed with molasses before pressing.
Such briquettes have not previously been considered for thermal o~ industrial utilisation.
It is particularly expedient to at least partially extract the air contained in the straw to be pressed, before and/or during the pressing operation. ~en pressing the straw to the above-mentioned minimum density,the accompanying pressing of too much air contained in the straw should be avoided, because the compressing or accompanying air considerably lowers the strength of the produced bri~uettes, and under certain circumstances the briquettes can be shattered after their production by expansion. This can be prevented only by very high pressing pressure, which causes such a compression of the straw that the expansion of the air contained in the briquettes is prevented.
On ths other hand, if the air content is largely extracted from the straw before or during pressing, briquettes can be produced having a density approaching the specific gravity of pure air-free straw.
~ Air extraction may be carried out by various methods, whether the air contained in the straw is extracted by suction or by pressure. Ihis suction or pressure ex-traction of the air may be carried out either before the actual pressing operation or advantageously simultaneously with the pressing operation~
It is also found to be extremely advantageous to treat the straw before pressing with one or more liquids, which because of their low surface tension have good wetting capacity for straw, and/or which because of their electrical conductivity reduce the static electricity charge on the straw and/or improve adhesion of the straw.
Suitable aqueou~ or non-aqueous liquids, and also bitumen or oil based emulsions, may be used for this purpose. ~or this reason it is found to be expedient to wet the straw with a liquid as described above because water alone has relatively little effect because of its poor wetting capacity. ~he use of proper wetting agents, e.g. surface active agents, detergents and electrolytes, which are chemical compounds which dissociate in aqueous solutions, is therefore recommended. The adhesion capacity increased in this manner allows the straw on pressing to come into intimate contact and thus leads to exceptionally favourable air extraction. ~he better the adhesion of the straw, the less can air remain between the straw during manufacture cf the briquettes. To effect air extraction, presses may be used which are fitted with at least one air extraction line, opening in the pressing chamber, or presses with localised air penetration zones formed in the pressing chamber. The base, press ram or piston and/or the side walls of the pressing chamber are usually considered for such localised ~03635~
zones.
It has been found particularly desirable firstly to wet the straw after its size reduction and then to pre-compress at comparatively low pressure. Through such a pre-compression of the straw, the straw blades comes into the de~ired intimate contact which makes the straw most suitable for proceRsing into briquettes in a high pres~ure press with an optimum low air content.
Completely dry straw may be processed into briquettes only with difficulty and very high energy expenditure, and the energy consumption for producing such briquettes may be considerabl~ reduced if the surface between the straw and press chamber wall is treated with a friction-reducing liquid. Either the straw or the wa~l of the press may be wetted with a suitable substance for reducing friction, before or during the pres~ing, A lubricant, e.g. based on ¢arbon, h~drocarbon or ~ynthetically based, for example graphite, a mineral oil, an organic oil, a tar oil or silicon, may be optionally added to the straw either before or during the pressing in addition to the use of such a friction-reducing liquid.
The addition of such a lubricant may be conveniently combined with the addition of an adhesion increasing li~uid, a wetti~ agent or the like. The wetti~g agents and lubricants in practice may be identical.
By adding such a lubricant, the power required for pressing the straw is reduced to a minimu~. All mineral ~0363S6 and organic oils are especially useful as lubricants, and such substances are also the easiest for ~eeding to the pressing chamber of a press.
A binding agent, e.g. bitumen, a synthetic resin adhesive or a glue, may be added to the straw either before or during the pressing for solidifying a~d improvin~ the shape stabiiity of the briquettes, as for example is done in the production of coal briquettes.
Such binding agents may in practice also function as lubricants.
~he storage stability of the straw briquettes may be improved by adding a moisture repellent, e.g. a~
impregnating compound based o~ a hydrocarbon or on a synthetic resin,to the straw before or during the pressing.
Such impregnated briquettes are rot proof and may be stored in the open or in d~mp spaces. Similarly a decay prevention agent, e.g. a disinfectant, may be added to the straw briquettes either before or during the pressing.
If the straw briquettes are intended for a chemical or microbiological use, a substance which favours or at least is not detrimental to the intended use of the briquettes may be added either before or during the pressing, e.g. a catalyst for producing chemical products from the briquettes, or a substance inert to the chemical or micro-biological utilisation of the briquette which may later form a co~ponent of the product obtained from utilising the briquette.
~0363s6 h liquid may be added by any desired ~ethod which gives ~ood mixing of the liquid with the straw.
Advantageously, the liquid added to the straw contains additives in the form of an emuslion, a dispersion, a solution or a colloidal solution. These additives may however, be first miXed dry with the straw and then a liqui~ added, in which the additives become suspended, dispersed or dissolved.
~he results described below illustrate the advantages of adding a liquid or such additives.
Disregarding the no-load losses of a straw pressin~
plant, at an output of approximately 140 kg/h of straw briquettes with the addition only of water as added liquid, the measured current consumption was 24-25 A. When from 0 4 to 0.5 percent by volume of a wetting agent, e.g. a ~urface active agent, was ~dded to the water, the current oonsumption dropped to approximately 14 A. When, however, approximately 0.15 percent by volume of a wetting agent plus approximately 1 percent by volume of oil or bitumen were added to the water, the current consumption dropped to 7-8 A.
Although it is advantageous to add the liquid to the straw before the compression, in order to facilitate the processing of the straw and production of the briquettes, there may be subsequently carried out a water repellent treatment or treatment to improve the storage stability of the briquettes (e.g~ protectio~ against rotting or swelling), by spraying or immersing or impregnating the finished briquettes, possibly as an additional operation.
Impregnation substances based on hydrocarbons7 e;g. tar oil, are especially suitable for such after- -treatment of the finished briquettes.
~he straw to be pressed should be reduced, at least before the last pres~ing operation which determines the final density, into adaptable portio~s which are neither bulky nor unduly elongate, but which join together well in the briquettes, 80 that the straw a~ready has its highest possible bulk density before pressing.
~n extensive destruction of the straw structure takes place as a result of the high pressure used for the final compression, additional to the previous reduction in size of the straw blades before pressing. The briquettes obtained by high compression of the straw may be reduced i~ size before or durin6 their utilisation ~nto a for example granular or powdered material. ~he briquettes are then fed in granular or powder form, preferably dispersed in a gas or liquid, for their utilisation or further processi~g. ~he straw briquettes may thereby be reduced in size to particles of basically any desired size, according to the intended purpose for which the particles are to be used, such as grinding the briquettes for firing as powdered fuel or suspending the particles in a reaction liquid.
~he granular or pulverised straw may also be mixed or used mixed with materials which are of assistance to its thermal or chemical-microbiological use, such as, in the case of thermal use, with other combustion materials, or, in the case of chemical use, with substances which are components or catalysts for the actual chemical raw material to be produced. In the case of microbiolo~ical utilisation of the straw, the mixed mass with the granular or pulverised straw may for example be used as the secondary component or basic substance of a suitable nutrient medium for the small organisms to be used.
~he extent of the compression is determined in relation to technical and economical considerations, and consequently the optimum extent is determined by ta~ing into consideration the cost of the portable and/or stationary straw presses and the transport costs for the pelletised straw units. ~he e~tent of the precompression may be ¢hosen to be any desired fra¢tion, for e~ample? one half, of the final density.
'~he straw to be utilised which is still in the field is suitably firstly cut with a harvester thresher, is threshed and then distributed on the cut field. This distributed straw is received, reduced in size and compressed into briquette-like blocks having a bulk density of from 200 to 300 kg/m3 by means of known portable machines previously used only for bri~uetting hay. During this operation the straw may also be subvectad to air removal and/or reduction in the skin friction in the compression ~036356 cylinder arld/or improvement in adhesion by wetting and/or reduction in the electrostatic charge on the straw - particles.
'rhese briquette-like blocks, still of comparatively low density, are then fed to presses which permit the predetermined final density to be obtained. Ih~se presses may be stationary or, at least between the individual pressing stages, transportable. In the latter case a stationary press is, however, recommended at least during the compression process.
Before the final compressio~ into briquettes having a bulk density of from 500 to 1000 kg/m3 or ~ore, the blocks are reduced in size, wetted with a liquid as described above, subjected if required to compression in order to remove air, and finally compressed to the final bulk density.
If subjected to water repellent treatment, these briquettes may be stored in the open air and supplied at any required time for their desired use, e.g. burning in a furnace. If no water repellent treatment is provided, it is recommended that the briquettes are stored under a lean-to-roof. By adding a suitable liquid, the briquettes may be fed to a~enzymatic or acid hydrolysis cellulose production process, by which the cellulose is decomposed to d-glucose, which as such may be used for example as fodder or may be con~erted by adding suitable micro-organisms to proteins or other products, e.g. ethyl alcohol.
The straw, in the form of such highly compressed ~0363S6 briquet~es, which may be handled as loose lump material, may be rationally supplied to the desired utilisation and processing facility, e.g. to a thermal power station or a chemical factory. ~he briquettes may be transported by any suitable means for conveying loose material, for ex~nple containers, car5 and conveyors.
In producing the briguettes extensive destruction of the blades of the straw taXes place and because of the exceptionally low air content of the briquettes they may be considered as a homogeneous material, or even to a certain extent as pure straw, a~ are accordingly much more suitable for utilisation than straw pressed i~to bales even if such bales are highly compressed. Due to the extensive destruction of the blades of the straw in the briquettes, the briguettes may either before or during their utilisation be divided or disintegrated without difficulty, e.~. crumbled, pulverised or ground, and in the latter case further handled as granuled or pulverised loose material.
~o limits are imp~sed on the possible thermal, industrial, chemical or microbiological utilisation of such a homogeneous, compact, lump granular or ground straw briquette. It is however essential that the briquettes have a very high briquette density. Although a density of 5 kg/m3 is sufficient for most uses, it is expedient because of smaller space requirements to produce briquettes with a density of at l0ast 1000 Xg/m3. Suitable high pressure presses are readily available for such compression and are already used for producing hay and straw briquettes intended for fodder, i.e. for feeding domestic animals. ~o this end, the straw is digested with soda lye and/or mixed with molasses before pressing.
Such briquettes have not previously been considered for thermal o~ industrial utilisation.
It is particularly expedient to at least partially extract the air contained in the straw to be pressed, before and/or during the pressing operation. ~en pressing the straw to the above-mentioned minimum density,the accompanying pressing of too much air contained in the straw should be avoided, because the compressing or accompanying air considerably lowers the strength of the produced bri~uettes, and under certain circumstances the briquettes can be shattered after their production by expansion. This can be prevented only by very high pressing pressure, which causes such a compression of the straw that the expansion of the air contained in the briquettes is prevented.
On ths other hand, if the air content is largely extracted from the straw before or during pressing, briquettes can be produced having a density approaching the specific gravity of pure air-free straw.
~ Air extraction may be carried out by various methods, whether the air contained in the straw is extracted by suction or by pressure. Ihis suction or pressure ex-traction of the air may be carried out either before the actual pressing operation or advantageously simultaneously with the pressing operation~
It is also found to be extremely advantageous to treat the straw before pressing with one or more liquids, which because of their low surface tension have good wetting capacity for straw, and/or which because of their electrical conductivity reduce the static electricity charge on the straw and/or improve adhesion of the straw.
Suitable aqueou~ or non-aqueous liquids, and also bitumen or oil based emulsions, may be used for this purpose. ~or this reason it is found to be expedient to wet the straw with a liquid as described above because water alone has relatively little effect because of its poor wetting capacity. ~he use of proper wetting agents, e.g. surface active agents, detergents and electrolytes, which are chemical compounds which dissociate in aqueous solutions, is therefore recommended. The adhesion capacity increased in this manner allows the straw on pressing to come into intimate contact and thus leads to exceptionally favourable air extraction. ~he better the adhesion of the straw, the less can air remain between the straw during manufacture cf the briquettes. To effect air extraction, presses may be used which are fitted with at least one air extraction line, opening in the pressing chamber, or presses with localised air penetration zones formed in the pressing chamber. The base, press ram or piston and/or the side walls of the pressing chamber are usually considered for such localised ~03635~
zones.
It has been found particularly desirable firstly to wet the straw after its size reduction and then to pre-compress at comparatively low pressure. Through such a pre-compression of the straw, the straw blades comes into the de~ired intimate contact which makes the straw most suitable for proceRsing into briquettes in a high pres~ure press with an optimum low air content.
Completely dry straw may be processed into briquettes only with difficulty and very high energy expenditure, and the energy consumption for producing such briquettes may be considerabl~ reduced if the surface between the straw and press chamber wall is treated with a friction-reducing liquid. Either the straw or the wa~l of the press may be wetted with a suitable substance for reducing friction, before or during the pres~ing, A lubricant, e.g. based on ¢arbon, h~drocarbon or ~ynthetically based, for example graphite, a mineral oil, an organic oil, a tar oil or silicon, may be optionally added to the straw either before or during the pressing in addition to the use of such a friction-reducing liquid.
The addition of such a lubricant may be conveniently combined with the addition of an adhesion increasing li~uid, a wetti~ agent or the like. The wetti~g agents and lubricants in practice may be identical.
By adding such a lubricant, the power required for pressing the straw is reduced to a minimu~. All mineral ~0363S6 and organic oils are especially useful as lubricants, and such substances are also the easiest for ~eeding to the pressing chamber of a press.
A binding agent, e.g. bitumen, a synthetic resin adhesive or a glue, may be added to the straw either before or during the pressing for solidifying a~d improvin~ the shape stabiiity of the briquettes, as for example is done in the production of coal briquettes.
Such binding agents may in practice also function as lubricants.
~he storage stability of the straw briquettes may be improved by adding a moisture repellent, e.g. a~
impregnating compound based o~ a hydrocarbon or on a synthetic resin,to the straw before or during the pressing.
Such impregnated briquettes are rot proof and may be stored in the open or in d~mp spaces. Similarly a decay prevention agent, e.g. a disinfectant, may be added to the straw briquettes either before or during the pressing.
If the straw briquettes are intended for a chemical or microbiological use, a substance which favours or at least is not detrimental to the intended use of the briquettes may be added either before or during the pressing, e.g. a catalyst for producing chemical products from the briquettes, or a substance inert to the chemical or micro-biological utilisation of the briquette which may later form a co~ponent of the product obtained from utilising the briquette.
~0363s6 h liquid may be added by any desired ~ethod which gives ~ood mixing of the liquid with the straw.
Advantageously, the liquid added to the straw contains additives in the form of an emuslion, a dispersion, a solution or a colloidal solution. These additives may however, be first miXed dry with the straw and then a liqui~ added, in which the additives become suspended, dispersed or dissolved.
~he results described below illustrate the advantages of adding a liquid or such additives.
Disregarding the no-load losses of a straw pressin~
plant, at an output of approximately 140 kg/h of straw briquettes with the addition only of water as added liquid, the measured current consumption was 24-25 A. When from 0 4 to 0.5 percent by volume of a wetting agent, e.g. a ~urface active agent, was ~dded to the water, the current oonsumption dropped to approximately 14 A. When, however, approximately 0.15 percent by volume of a wetting agent plus approximately 1 percent by volume of oil or bitumen were added to the water, the current consumption dropped to 7-8 A.
Although it is advantageous to add the liquid to the straw before the compression, in order to facilitate the processing of the straw and production of the briquettes, there may be subsequently carried out a water repellent treatment or treatment to improve the storage stability of the briquettes (e.g~ protectio~ against rotting or swelling), by spraying or immersing or impregnating the finished briquettes, possibly as an additional operation.
Impregnation substances based on hydrocarbons7 e;g. tar oil, are especially suitable for such after- -treatment of the finished briquettes.
~he straw to be pressed should be reduced, at least before the last pres~ing operation which determines the final density, into adaptable portio~s which are neither bulky nor unduly elongate, but which join together well in the briquettes, 80 that the straw a~ready has its highest possible bulk density before pressing.
~n extensive destruction of the straw structure takes place as a result of the high pressure used for the final compression, additional to the previous reduction in size of the straw blades before pressing. The briquettes obtained by high compression of the straw may be reduced i~ size before or durin6 their utilisation ~nto a for example granular or powdered material. ~he briquettes are then fed in granular or powder form, preferably dispersed in a gas or liquid, for their utilisation or further processi~g. ~he straw briquettes may thereby be reduced in size to particles of basically any desired size, according to the intended purpose for which the particles are to be used, such as grinding the briquettes for firing as powdered fuel or suspending the particles in a reaction liquid.
~he granular or pulverised straw may also be mixed or used mixed with materials which are of assistance to its thermal or chemical-microbiological use, such as, in the case of thermal use, with other combustion materials, or, in the case of chemical use, with substances which are components or catalysts for the actual chemical raw material to be produced. In the case of microbiolo~ical utilisation of the straw, the mixed mass with the granular or pulverised straw may for example be used as the secondary component or basic substance of a suitable nutrient medium for the small organisms to be used.
~he extent of the compression is determined in relation to technical and economical considerations, and consequently the optimum extent is determined by ta~ing into consideration the cost of the portable and/or stationary straw presses and the transport costs for the pelletised straw units. ~he e~tent of the precompression may be ¢hosen to be any desired fra¢tion, for e~ample? one half, of the final density.
'~he straw to be utilised which is still in the field is suitably firstly cut with a harvester thresher, is threshed and then distributed on the cut field. This distributed straw is received, reduced in size and compressed into briquette-like blocks having a bulk density of from 200 to 300 kg/m3 by means of known portable machines previously used only for bri~uetting hay. During this operation the straw may also be subvectad to air removal and/or reduction in the skin friction in the compression ~036356 cylinder arld/or improvement in adhesion by wetting and/or reduction in the electrostatic charge on the straw - particles.
'rhese briquette-like blocks, still of comparatively low density, are then fed to presses which permit the predetermined final density to be obtained. Ih~se presses may be stationary or, at least between the individual pressing stages, transportable. In the latter case a stationary press is, however, recommended at least during the compression process.
Before the final compressio~ into briquettes having a bulk density of from 500 to 1000 kg/m3 or ~ore, the blocks are reduced in size, wetted with a liquid as described above, subjected if required to compression in order to remove air, and finally compressed to the final bulk density.
If subjected to water repellent treatment, these briquettes may be stored in the open air and supplied at any required time for their desired use, e.g. burning in a furnace. If no water repellent treatment is provided, it is recommended that the briquettes are stored under a lean-to-roof. By adding a suitable liquid, the briquettes may be fed to a~enzymatic or acid hydrolysis cellulose production process, by which the cellulose is decomposed to d-glucose, which as such may be used for example as fodder or may be con~erted by adding suitable micro-organisms to proteins or other products, e.g. ethyl alcohol.
Claims (6)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A process for utilizing straw comprising the steps of grinding dry straw to produce ground dry straw particles;
wetting the ground dry straw particles with a liquid containing additives for lowering the surface tension, increasing electrical conductivity and improving the cohesion thereof; pre-pressing the wetted, ground straw particles to substantially rework the air contained therebetween by pressing the elastic straw particles tightly against one another, whereby the straw particles remain tightly against one another due to the lowered surface tension, the increased electrical conductivity and the improved cohesion; and final pressing of the substantially air freed straw particles by application of a high pressure to produce bulk density of at least 500 kg/m3.
wetting the ground dry straw particles with a liquid containing additives for lowering the surface tension, increasing electrical conductivity and improving the cohesion thereof; pre-pressing the wetted, ground straw particles to substantially rework the air contained therebetween by pressing the elastic straw particles tightly against one another, whereby the straw particles remain tightly against one another due to the lowered surface tension, the increased electrical conductivity and the improved cohesion; and final pressing of the substantially air freed straw particles by application of a high pressure to produce bulk density of at least 500 kg/m3.
2. A process as claimed in Claim 1 comprising effecting the said final pressing to produce bulk density of at least 1000 kg/m3.
3. A process as claimed in Claim 1 or 2 comprising adding a lubricant to the straw.
4. A process as claimed in Claim 1 or 2 comprising adding a binding agent to the straw.
5. A process as claimed in Claim 1 or 2 comprising adding a moisture repellent to the straw.
6. A process as claimed in Claim 1 or 2 comprising adding a decay prevention agent to the straw.
Applications Claiming Priority (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| AT951073 | 1973-11-12 | ||
| AT1032273A AT355289B (en) | 1973-12-10 | 1973-12-10 | METHOD FOR TREATING STRAW |
| AT761074A AT357335B (en) | 1974-09-23 | 1974-09-23 | METHOD FOR RECYCLING STRAW |
| AT806674A AT353469B (en) | 1974-10-08 | 1974-10-08 | METHOD OF RECYCLING STRAW |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1036356A true CA1036356A (en) | 1978-08-15 |
Family
ID=27422220
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA213,506A Expired CA1036356A (en) | 1973-11-12 | 1974-11-12 | Process for utilising straw |
Country Status (3)
| Country | Link |
|---|---|
| CA (1) | CA1036356A (en) |
| DE (1) | DE2452891C2 (en) |
| FR (1) | FR2256010A1 (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1899125A1 (en) * | 2004-06-23 | 2008-03-19 | New Zealand Forest Research Institute Limited | Method for producing wood fibre pellets |
| AU2013101732B4 (en) * | 2013-08-28 | 2016-07-28 | Seven Horses Australia Pty Ltd | Improvements in packing organic matter |
| US9511508B2 (en) | 2004-06-23 | 2016-12-06 | New Zealand Forest Research Institute Limited | Method for producing wood fibre pellets |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2551624B1 (en) * | 1983-09-14 | 1986-05-16 | Lasne Jean Claude | PROCESS AND DEVICE FOR PACKAGING PLANT PRODUCTS AND PRODUCTS THUS OBTAINED |
| CN105397891A (en) * | 2015-11-25 | 2016-03-16 | 阜南县胜天新能源开发有限公司 | Soaking solution for straw processing |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2486266A (en) * | 1945-05-03 | 1949-10-25 | Duggan Alejandro Heriberto | Method and apparatus for manufacturing blocks from various materials |
-
1974
- 1974-11-07 DE DE2452891A patent/DE2452891C2/en not_active Expired
- 1974-11-12 FR FR7437344A patent/FR2256010A1/en active Granted
- 1974-11-12 CA CA213,506A patent/CA1036356A/en not_active Expired
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1899125A1 (en) * | 2004-06-23 | 2008-03-19 | New Zealand Forest Research Institute Limited | Method for producing wood fibre pellets |
| EP1899125A4 (en) * | 2004-06-23 | 2013-05-29 | Nz Forest Research Inst Ltd | Method for producing wood fibre pellets |
| US9511508B2 (en) | 2004-06-23 | 2016-12-06 | New Zealand Forest Research Institute Limited | Method for producing wood fibre pellets |
| US10150227B2 (en) | 2004-06-23 | 2018-12-11 | New Zealand Forest Research Institute Limited | Method for producing wood fibre pellets |
| AU2013101732B4 (en) * | 2013-08-28 | 2016-07-28 | Seven Horses Australia Pty Ltd | Improvements in packing organic matter |
Also Published As
| Publication number | Publication date |
|---|---|
| DE2452891A1 (en) | 1975-07-17 |
| FR2256010A1 (en) | 1975-07-25 |
| DE2452891C2 (en) | 1983-04-14 |
| FR2256010B1 (en) | 1978-12-29 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Rominiyi et al. | Potential utilization of sawdust in energy, manufacturing and agricultural industry; waste to wealth | |
| WO2021004103A1 (en) | Device and method for cooperatively processing straw and sludge | |
| US3946660A (en) | Process for utilising straw | |
| EP2160458B1 (en) | Biogas plant and process for the production of biogas from straw with fermentation residue pelleting | |
| CN105542893B (en) | A kind of biomass granule fuel and preparation method thereof | |
| US8444722B2 (en) | Organic fuel brick | |
| CN107858386A (en) | For the method for the biomass for processing lignocellulose-containing | |
| CA1072331A (en) | Process for manufacturing combustible bricks from plant materials | |
| DE112005001721T5 (en) | Method and system for drying and heat treating materials | |
| WO1989009809A1 (en) | Method and apparatus for refinement of organic material | |
| CN101899349A (en) | Method for preparing solid renewable clean fuel from agricultural and forestry waste/domestic garbage | |
| CA1036356A (en) | Process for utilising straw | |
| EP0148871A1 (en) | A process and an apparatus for chemical treatment of bulky organic materials, such as straw and other biomass, with volatile chemicals | |
| KR880009856A (en) | Method and apparatus for manufacturing compact from moisture containing waste | |
| US9255235B2 (en) | Organic fuel products and fire starters | |
| SE441601B (en) | PROCEDURE FOR MANUFACTURING FUEL BRICKETS | |
| CN108848961A (en) | One kind being used for corn straw smashing clamp dog device | |
| US4609624A (en) | Process for producing isopropyl alcohol from cellulosic substrates | |
| CN105271219A (en) | Preparation process for straw active carbon | |
| CN110577848B (en) | Method for preparing high-quality bio-oil by taking pig manure as raw material | |
| EP0108111B1 (en) | A method of manufacturing briquettes of straw or similar material | |
| DE60210072T2 (en) | PROCESS FOR THE PRODUCTION OF SOLID FUEL FROM BIOMASS | |
| WO2001019942A2 (en) | Procedure for processing of fresh biomass in ecological briquettes as fuel and fodder, conveying assembly with tool for application of the procedure and ecological briquettes as fuel and fodder, as the products resulted from the procedure | |
| CN208480320U (en) | One kind being used for corn straw smashing clamp dog device | |
| RU2155238C2 (en) | Method for agglomeration of vanadium-containing sludges from heat and power stations |