Classifications

• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10L—FUELS NOT OTHERWISE PROVIDED FOR; NATURAL GAS; SYNTHETIC NATURAL GAS OBTAINED BY PROCESSES NOT COVERED BY SUBCLASSES C10G, C10K; LIQUEFIED PETROLEUM GAS; ADDING MATERIALS TO FUELS OR FIRES TO REDUCE SMOKE OR UNDESIRABLE DEPOSITS OR TO FACILITATE SOOT REMOVAL; FIRELIGHTERS
  • C10L5/00—Solid fuels
  • C10L5/40—Solid fuels essentially based on materials of non-mineral origin
  • C10L5/44—Solid fuels essentially based on materials of non-mineral origin on vegetable substances
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10L—FUELS NOT OTHERWISE PROVIDED FOR; NATURAL GAS; SYNTHETIC NATURAL GAS OBTAINED BY PROCESSES NOT COVERED BY SUBCLASSES C10G, C10K; LIQUEFIED PETROLEUM GAS; ADDING MATERIALS TO FUELS OR FIRES TO REDUCE SMOKE OR UNDESIRABLE DEPOSITS OR TO FACILITATE SOOT REMOVAL; FIRELIGHTERS
  • C10L2250/00—Structural features of fuel components or fuel compositions, either in solid, liquid or gaseous state
  • C10L2250/06—Particle, bubble or droplet size
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10L—FUELS NOT OTHERWISE PROVIDED FOR; NATURAL GAS; SYNTHETIC NATURAL GAS OBTAINED BY PROCESSES NOT COVERED BY SUBCLASSES C10G, C10K; LIQUEFIED PETROLEUM GAS; ADDING MATERIALS TO FUELS OR FIRES TO REDUCE SMOKE OR UNDESIRABLE DEPOSITS OR TO FACILITATE SOOT REMOVAL; FIRELIGHTERS
  • C10L2270/00—Specifically adapted fuels
  • C10L2270/04—Specifically adapted fuels for turbines, planes, power generation
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10L—FUELS NOT OTHERWISE PROVIDED FOR; NATURAL GAS; SYNTHETIC NATURAL GAS OBTAINED BY PROCESSES NOT COVERED BY SUBCLASSES C10G, C10K; LIQUEFIED PETROLEUM GAS; ADDING MATERIALS TO FUELS OR FIRES TO REDUCE SMOKE OR UNDESIRABLE DEPOSITS OR TO FACILITATE SOOT REMOVAL; FIRELIGHTERS
  • C10L2290/00—Fuel preparation or upgrading, processes or apparatus therefore, comprising specific process steps or apparatus units
  • C10L2290/08—Drying or removing water
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10L—FUELS NOT OTHERWISE PROVIDED FOR; NATURAL GAS; SYNTHETIC NATURAL GAS OBTAINED BY PROCESSES NOT COVERED BY SUBCLASSES C10G, C10K; LIQUEFIED PETROLEUM GAS; ADDING MATERIALS TO FUELS OR FIRES TO REDUCE SMOKE OR UNDESIRABLE DEPOSITS OR TO FACILITATE SOOT REMOVAL; FIRELIGHTERS
  • C10L2290/00—Fuel preparation or upgrading, processes or apparatus therefore, comprising specific process steps or apparatus units
  • C10L2290/28—Cutting, disintegrating, shredding or grinding
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
  • Y02E50/00—Technologies for the production of fuel of non-fossil origin
  • Y02E50/10—Biofuels, e.g. bio-diesel
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
  • Y02E50/00—Technologies for the production of fuel of non-fossil origin
  • Y02E50/30—Fuel from waste, e.g. synthetic alcohol or diesel

Definitions

• the present invention relates to a solid fuel, in the form of a powder, comprising at least one lignocellulosic constituent in the form of a powder.
• the present invention also relates to the process for the preparation of said lignocellulosic constituent in the form of a powder, as well as its use for the manufacture of a solid fuel intended for an internal combustion engine or a burner.
• the invention further relates to a method of producing energy using the solid fuel according to the invention.
• cellulosic materials would, in particular, reduce the wear of the engine and increase the speed and quality of combustion.
• WO 01/98438 discloses a solid fuel containing predominantly at least one constituent, which contains mainly at least one compound selected from the group consisting of starch, lactose, cellulose and at least 15% by weight of carbohydrates by weight total component (s) being in the form of a powder whose mean diameter and the median diameter of the particles are greater than or equal to 150 pm, preferably between 150 and 500 ⁇ .
• the exemplified powders are dehydrated chocolate powder, dehydrated milk powder, and the remolding fraction of a wheat flour.
• the powders described in this application have the disadvantage of competing with the food chain. Moreover, being unable to operate in the conditions of self ignition, the powders described in this application can not be a suitable solution for many engine applications.
• WO 2008/063549 discloses fuels, in the form of a biomass powder having a relatively heterogeneous particle size distribution, namely, less than 5% by weight of the particles have a size greater than or equal to 74 ⁇ and at least 25% by weight , a size less than 44 ⁇ .
• the particle size distribution of the powders in this document varies according to the origin of the biomass. For example, in the case of wood particles, less than 5% by weight of the particles have a size greater than or equal to 177 ⁇ m and at least 30% by weight, a size of less than 74 ⁇ m.
• WO 2009/158709 describes methods for preparing lignocellulosic biomass powders for use in combustion.
• the powders have more or less heterogeneous particle size distributions.
• 5% by weight of the particles have a size greater than or equal to 177 ⁇ and 15% by weight of the particles have a size of less than 74 ⁇ m.
• 5% of the particles have a size greater than or equal to 74 ⁇ and at least 25% by weight, a size of less than 44 ⁇ .
• the fine lignocellulosic biomass powders are not suitable for use in an internal combustion engine. Indeed, when the particles are too fine, they tend to assemble to form agglomerates that affect the quality of the combustion of these powders (incomplete combustion and / or slower, more difficult routing in the combustion chamber, etc.).
• the present invention is specifically intended to meet these needs by providing a solid fuel, in the form of a powder, characterized in that it comprises at least one lignocellulosic constituent in the form of a powder (P) of which:
• the mean diameter and the median diameter (d 50 ) of the particles are less than or equal to 35 ⁇ , preferably between 10 and 30 ⁇ , more preferably between 10 and 20 ⁇ , limits included, and
• the moisture content of the particles of the powder (P) is at most 15% by weight, preferably at most 10% by weight, more preferably less than or equal to 5% by weight, even more preferably lower, or equal to 2% by weight of water, relative to the total mass of the powder (P).
• the combustion rate of the fuel according to the invention is high, comparable to that of diesel fuel for example, causing a production of energy and / or a release of heat also high and comparable to that of diesel.
• Solid fuels according to the invention thus allow operation at high speed of rotation of the engines.
• the improved rheological characteristics of the powder (P) make it easier to convey the powdery solid fuel according to the invention to the combustion chamber and a better homogeneity of the explosive cloud formed in the combustion chamber.
• the characteristics of the powders (P), in particular of size (average diameter and median diameter) and of composition, in particular moisture, allow a large compaction of the pulverulent solid fuel according to the invention making it possible to reduce the space required. storage of it.
• lignocellulose as a motor fuel has the advantage that the C0 2 produced does not constitute an environmental surplus, unlike that which is rejected by the use of fossil fuels.
• the process for manufacturing the powder (P) according to the invention makes it possible to remain in a "dry route" stream, thus having the advantage of not generating effluents.
• lignocellulosic constituent is a biomass of plant origin, composed of lignin, hemicellulose and cellulose in varying proportions.
• plant origin includes all compounds produced by living plant organisms.
• the lignocellulosic constituent of the invention that can be used in the context of the invention can come from herbaceous plants, algae, microalgae, cereal straws, wood, wood from culture for energy purposes, wood from waste ( carpentry, construction, etc.), other waste of agricultural origin (olive stones, rice husks, etc.), stationery waste, wood and cardboard packaging waste.
• the lignocellulosic component of the invention is derived from cereal straws, in particular wheat straw, barley straw, oat straw, rye straw, straw rice, and any other straw.
• cereal straws in particular wheat straw, barley straw, oat straw, rye straw, straw rice, and any other straw.
• the fuel according to the invention comprises at least one lignocellulosic constituent which contains:
• Cellulose can be in its various forms: microcrystalline and / or amorphous.
• the average and median diameters ( ⁇ $ ⁇ ) of the lignocellulosic constituents of the invention were measured by the laser particle size measurement method with a Mastersizer 2000 apparatus from Malvern.
• the mean diameter is the diameter calculated by the device software and is representative of the diameter that particles, whose size is measured, have, on average.
• the median diameter (d 50 ) corresponds to the particle size at which 50% by mass of the particles constituting the powder (P) and whose size is measured, have a smaller size, and 50% by mass of the particles constituting the powder ( P) and whose size is measured, have a larger size.
• the particle size distribution of the powder (P) constituting the fuel of the invention is also an important criterion.
• the particle size distribution of the particle size of the powder (P) is narrow, that is to say that the fuel according to the invention contains the least possible of different particle size populations.
• the fuel according to the invention more than 70% by weight, preferably 80% by weight, more preferably 90% by weight of the powder (P) consists of particles having a mean diameter and a median diameter. (d 5 o) less than or equal to 35 pm, preferably between 10 and 30 ⁇ , more preferably between 10 and 20 ⁇ .
• the moisture content is another important characteristic of the powder (P).
• moisture content means the quantity of water expressed as a percentage by weight of water present in the particles of the powder (P). It is determined by the standard AFNO XP CEN / TS 14774-3.
• the moisture content of the particles of the powder (P) is at most 15% by weight, preferably at most 10% by weight, more preferably less than or equal to 5% by weight, still more preferably less than or equal to 2% by weight of water, relative to the total mass of the powder (P).
• the solid fuel according to the invention is characterized in that the lignocellulosic constituent in powder form (P) produces, after combustion, at most 10% by weight of ash, preferably between 0 and 10% by mass of ash. more preferably between 0 and 5% by weight, more preferably between 0 and 1% by weight, inclusive, with respect to the total mass of the powder (P).
• ash means the inorganic basic residues obtained by complete combustion of the solid fuel according to the invention.
• the composition of ash varies according to many parameters, which depend mainly on the plant species burned, parts of plants (bark, trunk, or young branches for example), the nature of the soil, as well as the time of the year during which these plants were harvested.
• the ashes comprise mainly, for example, calcium oxide, potassium hydroxide, sodium hydroxide, magnesium oxide, silica, alumina, iron oxide, manganese oxide.
• silica and alumina are the most abrasive compounds.
• the solid fuel according to the invention is characterized in that the lignocellulosic constituent in powder form (P) contains, after combustion, at most 3% by weight of alumina, more preferably between 0 and 3% by weight. more preferably between 0 and 1% by weight, relative to the total initial mass of the powder (P).
• the lignocellulosic constituent in the form of powder (P) contains, after combustion, at most 3% by weight of silica, preferably between 0 and 3% by weight, more preferably between 0 and 1% by weight, relative to the total initial mass of the powder (P ).
• the ash results from the combustion of the lignocellulosic component of the invention, leading to the oxidation of the mineral elements contained in the lignocellulosic compounds s. Their rate is determined by the standard AFNOR XP CEN / TS 14775.
• the low ash content especially silica and alumina, reduces the wear of feed equipment (pump, injector) and moving parts in contact with the fuel or with its combustion residues; it also allows better control of the risks associated with the high explosiveness of these powders. This leads to a satisfactory combustion of the fuel, adapted to the operation of an internal combustion engine and / or a burner.
• One of the advantageous characteristics of the solid fuel of the invention is the high content of volatile matter emitted by the fuel at the start of combustion.
• volatile materials means gaseous compounds, condensable or not, which are emitted by the lignocellulosic component of the powder (P) during its combustion, in particular at the beginning of its combustion. .
• the onset of combustion is usually indicated by the first measurable heat release.
• Volatiles are most often hydrocarbons, hydrogen, carbon monoxide, carbon dioxide, nitrogen oxides, etc.
• the level of volatiles evolved can vary.
• the evolution of the volatiles can begin at different temperatures. The lower this temperature, the sooner the combustion starts.
• the fuel according to the invention is characterized in that the lignocellulosic constituent in powder form (P) emits, in the form of volatiles, at least 50% by weight, preferably between 50 and 70% by weight, more preferably between 70 and 80% by weight, more preferably between 80 and 100% by weight of volatiles, relative to the total mass of the powder (P).
• the level of volatiles generated is, in general, determined by the volatiles index. This index refers to the volatile organic matter fraction according to the AFNOR XP CEN / TS 15148 standard.
• the high rate of volatile matter makes it possible to improve the quality and the progress of the combustion.
• the higher the rate of volatiles the higher the share of the original fuel that can burn rapidly.
• the subject of the invention is also a process for preparing a lignocellulosic constituent in the form of a powder (P) of which:
• the mean diameter and the median diameter (d 50 ) of the particles are less than or equal to 35 ⁇ , preferably between 10 and 30 ⁇ , more preferably between 10 and 20 ⁇ , limits included, and
• the moisture content of the particles is at most 15% by weight, preferably at most 10% by mass, more preferably less than or equal to 5% by mass, even more preferably less than or equal to 2% by weight; water mass, relative to the total mass of the powder (P),
• cereal straws comprising at least one step of grinding cereal straw and optionally at least one drying step.
• the number of grinding stages will depend, for example, on the nature of the lignocellulosic constituent to be ground, on the particle size of the powder (P) that one wishes to obtain, on the type of grinder used and therefore on the grinding efficiency. .
• the process for preparing a lignocellulosic constituent in the form of a powder (P) comprises the following steps:
• step (I) a first step of grinding cereal straw to obtain a powder (A) whose mean diameter and the median diameter (dso) of the particles are greater than 0 and go up to 3000 ⁇ , preferably between 200 and 3000 ⁇ , more preferably between 200 and 2000 ⁇ ;
• a second step of grinding the powder (A) making it possible to obtain a powder (B) whose mean diameter and median diameter (dso) of the particles are less than or equal to 150 ⁇ , preferably less than or equal to at 135 ⁇ ;
• step (iii) a third step of grinding the powder (B) resulting from step (ii) making it possible to obtain a powder (P) whose mean diameter and the median diameter (d 50 ) of the particles are less than or equal to 35 ⁇ , preferably between 10 and 30 ⁇ , more preferably lement-between 10 and 20 ⁇ ;
• a drying step being implemented before step (iii), after the step
• the raw cereal straw can be milled by any type of mill to reduce to a particle size greater than 0 and up to 3000 ⁇ , preferably between 200 and 3000 ⁇ more preferably between 200 and 2000 ⁇ , such as, for example, a knife or hammer mill.
• the knife mill may be of the brand RETSCH ® .
• step (i) The powder (A) resulting from step (i) may be subjected directly to a second grinding step (step (ii)).
• the particles whose average diameter and the median diameter (dso) are less than 200 ⁇ are removed from the powder (A).
• the removal of these particles can be carried out by any means of separation, for example, by sieving and / or by a sorting process such as for example an electrostatic sorting method (making it possible to sort the particles according to their chemical nature), a process sorting by turboseparation (making it possible to separate the particles by means of a flow of air).
• the fraction whose average diameter and the median diameter (d 50 ) are less than 200 ⁇ corresponds to the external part of the stem which is, in general, more easily reduced because it is richer in minerals. Its elimination reduces, for example, the ash rate.
• the powder (A) directly from step (i), or after the separation step, is subjected to a second milling step (ii) .
• This step can be carried out using a pallet mill. for example, like that of the brand HOSOKAWA model Alpine 100 UPZ rotating at 18,000 revolutions / minute and with a straw introduction rate from step (i) of 1 kg / h.
• This step makes it possible to obtain a powder (B) whose average diameter and the median diameter (d 5 o) of the particles are less than or equal to 150 ⁇ , preferably less than or equal to 135 ⁇ .
• the particles whose average diameter and the median diameter (d 5 o) are less than 20 ⁇ can optionally be removed from the powder (B ).
• the removal of these particles can be carried out by any means of separation, for example, by sieving and / or by a sorting process as described above.
• the powder (B) may optionally be sorted in order to obtain a fraction more or less rich in lignin and / or cellulose.
• the powder (B) from step (ii) can then be dried at a temperature between 30 and 120 ° C, preferably between 50 and 100 ° C.
• the drying time can be from 2 to 72 hours, preferably from 4 to 48 hours.
• the powder (B) has a moisture content of less than 10% by weight, preferably less than 5% by weight, even more preferably less than or equal to 2% by weight of water, relative to the total mass of the powder.
• the powder (B) is then subjected to a third grinding step (step (iii)) to obtain a powder (P) whose mean diameter and the median diameter (d 50 ) of the particles are less than or equal to 35 ⁇ , of preferably between 10 and 30 ⁇ , more preferably between 10 and 20 ⁇ .
• This step can be carried out by a slow grinding technique, for example, by means of a ball mill as shown in FIG. 1, or by a rapid grinding technique, for example, by means of a jet mill. air as shown in Figure 2.
• the ball mill comprises a jar 1 containing ceramic balls 2 and the product to be ground 3.
• the jar 1 is rotated in the direction of the arrow.
• the shocks caused by the balls 2 cause the particle size reduction of the product 3.
• the addition of the dotted line represents the trajectory of the balls.
• the air jet mill projects at very high speed and against each other, the particles to grind 3.
• the collisions between the particles are represented by the arrow 9.
• the compressed air is injected in the grinding chamber 5 via the nozzles 6.
• the grinding particles 3 are introduced by means of the supply line 4.
• the particles 3 are fluidized. Then the accelerated particles mix at the point of convergence where many jets of air also mingle with each other. Inter-particle collisions generate ultrafine particles.
• the duration of this grinding operation can be adapted to the desired final grain size.
• the duration of the grinding step (iii) can be between 1 to 240 hours, preferably between 12 and 216 hours, and even more preferably between 48 and 216 hours.
• the grinding temperature at this stage is advantageously less than or equal to 25 ° C, preferably between -10 and 15 ° C. These temperature ranges favor the grinding of the powder (B) because at these temperatures, the lignocellulosic fibers are rigid and therefore more fragile.
• the grinding of the powder (B) may be further promoted by grinding in the presence of compounds which weaken said powder. Still with the aim of promoting the grinding of the powder (B), said powder may be subjected to acidic or basic treatment prior to grinding or during grinding.
• the third grinding step (iii) can be carried out, preferably under an inert atmosphere, by example under argon, nitrogen and / or C0 2 .
• a drying step is carried out before step (iii), after step (iii), or before and after step (iii).
• the drying which takes place before and / or after step (iii), is carried out at a temperature of between 30 and 120 ° C., preferably between 50 and 100 ° C.
• the drying can be carried out for 2 to 72 hours, preferably for 4 to 48 hours.
• the method of the invention satisfies at least one of the following conditions:
• step (iii) is carried out at a temperature of between 30 and 120 ° C, preferably between 50 and 100 ° C,
• step (iii) is carried out for from 2 to 72 hours, preferably from 4 to 48 hours,
• the powder (B) after drying before step (iii), has a moisture content of less than 10% by weight, preferably less than 5% by weight, more preferably less than 2% by weight, relative to the total weight of the powder,
• the duration of the third grinding stage (iii) is between 1 to 240 hours, preferably between 12 and 216 hours, and more preferably between 48 and 216 hours,
• the third grinding step (iii) is carried out at a temperature of less than or equal to 25 ° C, preferably between -10 and 15 ° C,
• the third grinding step (iii) is carried out under an inert atmosphere which may be argon, nitrogen and / or C0 2 ,
• the particles whose average diameter and the median diameter (dso) are less than 200 ⁇ are removed from the powder (A) by sieving and / or by a sorting method as described above, before step (iii), the particles whose average diameter and the median diameter (dso) are less than 20 ⁇ may optionally be removed from the powder (B) by sieving and / or by a sorting method as described previously.
• a selective sorting of the particles from step (iii) can be carried out by a sorting process as described above, in order to obtain different populations of powders in order to improve their qualities as a motor fuel. .
• a population of sorted particles having a higher lignin content and thus a higher calorific value can be selected.
• the process according to the invention is simple and economical.
• the powder (P) obtained according to the process of the invention can be used directly, without further processing or treatment, as a fuel.
• the invention also relates to the use of a lignocellulosic constituent in the form of a powder (P) whose mean diameter and the median diameter (d 50 ) of the particles are less than or equal to 35 ⁇ , preferably included between 10 and 30 ⁇ , more preferably between 10 and 20 ⁇ , obtained according to the process of the invention, for the manufacture of a solid fuel intended for an internal combustion engine.
• the fuel according to the invention can be used alone or mixed with other fuels. It can be used, for example, for the operation of internal combustion engines whether spark ignition or diesel, for the operation of turbines, boilers, industrial furnaces involving burners.
• the fuel of the invention is to be used alone, optionally in suspension, for example in air to produce a fuel mixture.
• the proportion of the fuel of the invention in a liter of air can then be, for example, 200 mg of fuel in one liter of air.
• This value is the minimum ignition concentration, and may vary depending on the fuel composition considered. It corresponds to the stoichiometric value leading to complete combustion.
• the discharges produced during the combustion of the fuel according to the invention do not contain lead.
• the quantities of sulfur released by the combustion of a lignocellulosic powder are considerably limited compared to a fossil fuel. On average, they can be less than a factor of 10.
• the fuel according to the invention can be used without major modification of the current internal combustion engines.
• the fuel of the invention still has many advantages. It is economically more advantageous than refined petroleum products and liquefied gases, it is available in abundance, it is an indefinitely renewable source of energy. It is biodegradable, neutral for the greenhouse effect and easily storable.
• composition of the fuel combustion waste of the invention includes C0 2 as liquid hydrocarbons
• combustion of the fuel of the invention only restores the C0 2 absorbed during the growth of the fuel.
• cereals whose lignocellulosic component of said fuel is derived unlike products of fossil origin that massively move the carbon reserves of the subsoil to the atmosphere.
• the energy produced by this process is advantageously thermal energy that can lend itself to any conversion mode.
• the proportion of the solid fuel with respect to the oxidizing gas in the suspension may be, for example, 1 part of solid fuel for 7 parts of gas, by mass.
• controlled flow means the flow of solid fuel in powder form. By modulating the flow of solid fuel, energy production can be modulated.
• FIG. 1 shows a schematic diagram of the ball mill. This type of grinding consists in rotating a jar 1 containing ceramic balls 2 and the product to be ground 3. Shocks caused by the balls cause the particle size reduction of the product.
• - Figure 2 shows a schematic diagram of the air jet mill. This type of grinding consists in projecting at very high speed and against each other, the particles to grind.
• FIG. 3 represents the progress of the various steps of the variant of the method according to the invention, as described in Example 1.
• FIG. 4 represents the comparative pressures of the straw according to the invention, diesel fuel and those obtained in the absence of fuel, measured in the engine cylinder during the operating cycle, at 790 rpm, 13 Nm ( in Joules / DV).
• the pressure, expressed in bar, is represented on the ordinate and the displacement of the piston, expressed in degrees crankshaft (DV), is represented on the abscissa.
• FIG. 5 shows the rate of heat release (ordinate and expressed in Joules / DV) calculated on the basis of pressure cycles obtained in the absence of fuel, with diesel injection and with feeding by the admission of powder of straw only, the displacement of the piston, expressed in degrees crankshaft (DV), is represented in abscissa.
• Wheat straw has been identified as a valuable source of dry biomass because of its high availability and residual character.
• the speed of combustion being controlled by the fineness of the material, it was a question of grinding up to the micron scale a lot of straw originating from the region of Tarn (81430 Le Fraysse).
• the grinding operations of the wheat straw took place in several stages as represented in FIG. 3, starting from the original boot.
• the straw was first milled with a knife mill (RETSCH SM 100). This operation allowed to reduce the particle size and to obtain particles whose average diameter and median diameter (d 50 ) are greater than 0 and go up to 2000 microns.
• the ash content was reduced by sieving, eliminating the fraction less than 200 microns, which corresponds to the outer part of the stem, more easily reduced because richer in minerals.
• the straw was fed into a HOSOKAWA Alpine 100 UPZ pallet mill at room temperature (about 20 ° C). This operation made it possible to reduce the particle size up to a hundred microns (the average diameter and the median diameter (d 5 o)).
• This type of grinding shown schematically in FIG. 1, consists of rotating a jar 1 containing ceramic balls 2 and the grinding product 3. The shocks caused by the balls 2 cause the particle size reduction of the product.
• the ball mill used is the model Marne 0 No. 55 distributed by the company FAURE.
• the operations took place in a cold room, maintained at 5 ° C.
• the jar containing 1/3 powder B, 1/3 alumina balls and 1/3 air by volume was rotated 1 turn / second in 24 hour increments, after which a sample was taken.
• the air was replaced by argon; the other effect being to control the oxidation of the product.
• the grinding operation is as follows: 1 kilogram of straw powder (B) is inserted in an 8 liter ceramic jar in the presence of 4 kilograms of alumina balls of 17 mm diameter and 4 kilograms of pellets. diameter 25 mm. After 48 hours, the balls are changed to 4 kilograms of 9 mm diameter balls and 4 kilograms of 7 mm diameter balls. This has the effect of optimizing grinding by reducing the space between the balls and thus increasing shocks causing grinding.
• This type of grinding shown schematically in FIG. 2, consists in projecting the particles to be grinded at a very high speed and against each other. This technology offers the advantage of not affecting the chemical characteristics of the material.
• the air jet mill used is the 100 AFG model from HOSO AWA Alpine.
• Particles having a mean diameter and a median diameter (d 50 ) of 20 microns were obtained with a feed rate of approximately 700 g / hour (ie 20 rpm for the hopper) and a speed of rotation of the selector. 6000 rpm.
• Particles having a mean diameter and a median diameter (d 50 ) of 10 microns were obtained at about 200 g / hour (ie 6 rpm for the hopper) and the selector set at 12000 rpm. Characterization of powders
• the straw powders obtained at the end of the second grinding step (vane crusher) and at the end of the third grinding step with a ball mill (straw-balls and straw-balls 20) and with a air jet mill (air-straw-10 and air-jet straw-20) were characterized, compared with each other and compared with the following commercial plant powders: microcrystalline cellulose (Serva-Electrophoresis), crystalline parts of the cellulosic portion of plant fibers, median diameter 23 microns (d 5 o) and poorly dispersed;
• alpha-cellulose Sigma-Aldrich
• amorphous part of the cellulosic part of the plant fibers interconnecting the crystalline zones, median diameter 65 microns (d 5 o);
• lignin (Sigma-Aldrich), obtained by kraft process, with a high sodium content and about 3% sulfur, median diameter 100 microns (d 5 o);
• wheat starch Prolabo
• d 50 diameter 23 microns
• corn starch (Maizena), spherical grains, median diameter 20 microns (d 50 ).
• Non-commercial powder was also used:
• Ultracarbofluid dry residue of vegetable charcoal used in slurry
• bimodal particle size distribution probable agglomeration of particles of median diameter (d 50 ) 18 microns in clusters of 350 microns.
• the fuel powders according to the invention do not compete with the food chain in terms of agricultural land use.
• the fuel powders according to the invention cause a lower wear of the systems used for their conversion into energy, unlike the coal powders used in the past.
• the fuel powders according to the invention allow better control of the risks associated with their handling thanks to their particular rheological properties.
• the fuel powders according to the invention allow optimized storage thanks to their particle size properties (low dispersion and micron size), allowing their compaction.
• the fuel powders according to the invention do not require advanced storage conditions.
• the production of the fuel powders according to the invention is therefore possible at a lower cost, and in a simple way, which extends the scope of their use to developing countries and to isolated areas whatever they are, unlike the fossil fuels of any kind, including coal powders.
• the production by simple grinding in the dry process of the fuel powders according to the invention does not generate liquid or gaseous effluents, impacting the environment.
• the energy conversion of the fuel powders according to the invention does not add C0 2 to the environmental balance, unlike any fossil fuels, including coal powders.
• the conversion into energy of the fuel powders according to the invention generates no or few sulfur compounds, unlike any fossil fuels, and in particular coal powders.
• the conversion into energy of the fuel powders according to the invention in an internal combustion engine extends to high-speed applications and especially transport, unlike coal powders.
• the conversion into energy of the fuel powders according to the invention in an internal combustion engine can extend to high power applications, unlike coal powders, especially in suspension.
• the engine on the test stand is a four-stroke diesel model Hatz
• An injection pressure sensor (Kistler 4067B2000) is mounted on the supply line of the injector.
• the injection pressure is not a paramount parameter, it is reported for the sole purpose of indicating the presence or absence of diesel.
• An angular encoder (Kistler 2614A) is mounted on the motor shaft. It returns one lap per lap, which is positioned in top dead center (TDC) and one top per half-degree crankshaft, which is used to clock the acquisition.
• the LabView 2010 software is used for data acquisition. The pressures and temperatures as well as the speed and torque are recorded and displayed according to the acquisition point.
• Figure 5 shows the heat release calculated on the basis of the pressure cycles obtained in the absence of fuel, with diesel fuel injection and fed by the intake of straw powder only.
• the release of heat postpones the amount of heat emitted by the combustion of the straw according to the invention and diesel in joules / DV, and as a function of time. In order to be able to locate the different phases of this clearance in the motor rotation cycle, this time is reported in crankshaft degree (DV).
• crankshaft degree (DV) crankshaft degree
• the product of the devolatilization of the straw particle is coal, which burns more slowly (the diffusion of oxygen in its pores controls combustion). This explains the prolongation of the release of heat over time.
• the burning speed of the straw powder does not limit the engine speed at least up to 3200 revolutions / minute.
• the engine rises to 34 Nm, or more than 90% of the maximum allowed diesel torque.
• Example 3 Comparative Test Between Powder and Powdered Chocolate A comparative test was carried out with the engine described in Example 2. Wheat straw milled to 20 microns (powder (P) according to the invention ) has been compared to commercial chocolate powder, whose particle size distribution is similar to that used in application WO 01/98438 (see Table 1).
• test conditions were as follows: the engine was started on diesel, and stabilized at 1000 rpm at zero load, the powder was fed through the intake pipe at a rate of 4 kg / h, and the feed diesel is cut.
• the fuel powders according to the invention do not compete with the food industry.
• the fuel powders according to the invention are suitable for use in any type of internal combustion engine for their conversion into energy, unlike the chocolate powders used in the application WO 01/98438.

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• Organic Chemistry (AREA)
• Solid Fuels And Fuel-Associated Substances (AREA)

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• 2012
  • 2012-01-18 FR FR1250511A patent/FR2985735B1/fr not_active Expired - Fee Related
• 2013
  • 2013-01-15 WO PCT/IB2013/050364 patent/WO2013108177A1/fr active Application Filing
  • 2013-01-15 CA CA2861243A patent/CA2861243A1/fr not_active Abandoned
  • 2013-01-15 US US14/372,915 patent/US20150007492A1/en not_active Abandoned
  • 2013-01-15 EP EP13705589.3A patent/EP2804932A1/fr not_active Withdrawn
  • 2013-01-15 IN IN5941DEN2014 patent/IN2014DN05941A/en unknown
  • 2013-01-15 BR BR112014017727A patent/BR112014017727A8/pt not_active Application Discontinuation
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