OA18764A - Banana biomass renewable energy (ERBB). - Google Patents

Abstract

The invention relates to two aspects: - (1) fragmentation or fraction of the banana to become a useful banana biomass - (2) treatment of said fragmented banana biomass for renewable energies and other banana by-products. The process of fractionation by dry or wet route of lignocellulosic biomass comprising at least 50%, by mass, of lignins, cellulose and hemicelluloses, comprising: - (i) a step of fragmentation of the banana tree to obtain a coarsely ground pulp - (ii) a banana fragmentation step by dry process to obtain an ultrafine powder. The invention relates to a method for fragmenting wet or dry bananas and for treating this lignocellulosic biomass of bananas fractionated into pulp, powder, flour and pellet, including the gasification of a powdery wood residue. The woody residue comes from a process for the biochemical treatment of lignocellulosic biomass of banana which comprises a wet pretreatment step, by heating under acid conditions and / or self-hydrolysis to produce a pretreated banana substrate. Said banana substrate, optionally separated from a liquid fraction, is subjected to an enzymatic hydrolysis and is optionally subjected to a fermentation which is separate or concomitant with hydrolysis, said fermentation being followed by distillation. The woody banana residue is separated downstream of the hydrolysis. It is dried and conditioned to obtain the woody powder residue with a particle size between 15 and 900µµ, a water content of less than 12% wt, a grain density of between 500 and 900 kg / m 3 and a minimum speed. fluidization is greater than zero and less than 0.15m / s. The powder is introduced into a fluidization gas at a speed greater than or equal to the minimum fluidization speed. The invention is particularly suitable for the production of biofuels from synthesis gas, and in general in a banana fragmentation process for several processes for producing renewable and other energies, based on banana.

Description

Advantage:

The present invention highlights the energy potential of the waste (biomass) of the banana produced and not upgraded, as in all the countries producing bananas and plantains in Africa in particular and in the world in general.

The present invention aims to remedy these drawbacks. More particularly, the present invention aims to provide a device which would make it possible to enhance the economic value of the banana tree at 100%. And promote the inclusion of bioenergy specific to our environment.

Disadvantages:

Fuelwood, overexploited and considered a source of energy for the poor, has long been forgotten in national energy accounts. Electricity remains a luxury that cannot be accessed by underprivileged populations in rural areas in Africa, whose poverty level is around 70%. According to the Rural Electrification Agency (AER) cited by Wandji (2007), Example: only 2,010 Cameroonian rural localities out of a total of around 7,500 with a population of over 200 inhabitants, benefited from electricity in 2003.

These statistics show that a large segment of the population does not have sufficient income to pay their electricity bill, despite multiple supply problems and untimely power cuts. This results in a strong use of wood energy and kerosene. Rural areas are thus characterized by a low penetration of modern energies (in the form of kerosene and rarely electricity). These are mainly used for lighting, other energy needs being served by wood energy.

Λ / g: And the invention comes to solve these problems which did not have solutions yet.

THE PURPOSE OF THE INVENTION

The present invention aims to remedy all or part of these drawbacks, which is the non-use of banana biomass.

“Θ To this end, according to a first aspect, the present invention relates to a process for the wet or dry fractionation of lignocellulosic banana biomass comprising at least 50%, by mass, of lignins, cellulose and hemicelluloses, which process comprises :

- a step of fragmentation of wet or dry banana to obtain a biomass in paw or ultrafine powder and at least one step of separation of a fraction enriched in cellulose, on the one hand, from a fraction enriched in lignin and in hemicelluloses on the other hand, by electrostatic sorting of the ultrafine particles.

Subsequent operations of aerodynamic sorting (based on particle density) and dimensional sorting (based on particle size) can be applied to the previously separated fractions, to increase their purity.

- The process that is the subject of the present invention makes it possible to concentrate the lignins, minerals and polysaccharides without solvent, without chemical reagent and without recycling and treatment of waste. This process thus makes it possible to very effectively valorize these different fractions into biomolecules and bio-sourced materials.

A bio-based product is a non-food product, partially or totally derived from biomass. The 30 bio-based products include high value products such as those from fine chemicals (pharmaceuticals, perfumes, food additives, etc.), as well as specialty products (lubricants, detergents, etc.), or again commodity products (polymers, chemical intermediates, etc.). The concept excludes traditional bio-based products, such as those derived from pulp and paper, wood and biomass, used as an energy source.

We are betting on a bio-based product for a wide range of applications, and on bio-based material more specifically in the field of eco-construction.

By “ultra-fine powder” is meant here a set of particles whose median diameter (d50) is less than 200 μm (50% of the total volume of the particles correspond to the volume of particles with diameters less than d50). The homogeneity of the composition of the particles resulting from the grinding of plants increases when their size decreases. Thus, certain ultrafine particles have a high content of lignins, cellulose and / or hemtcefluloses. It is noted that these lignins, celluloses and hemicelluloses are present in the walls of plants.

The combination of the stages of ultra-fine grinding (particles of d50 less than 200 μm) of lignocelluloses (wood and co-products from the sector, agricultural and agro-food co-products, dedicated plants, municipal and industrial waste) and sorting in a strict dry environment (sorting electrostatic, three-dimensional, aerodynamic sorting) makes it possible to isolate fractions enriched in cellulose, hemicelluloses, lignins and / or minerals, without chemical modification, unlike chemical fractionation processes developed until now.

In some embodiments, the step of sorting the ultrafine particles comprises:

A step of tribo-electrostatic charge of ultrafine particles and at least one step of deviation of the trajectory in the electric field of the charged particles to sort the particles.

We have found this type of sorting to be particularly effective. In some embodiments, the method that is the subject of the present invention further comprises a step of scraping the electrode of an electrostatic sorting means implemented during the deflection step, to collect the particles fixed on a electrode after Particle deviation retape. These embodiments make it possible to collect the particles fixed on the electrode, the electric charge of which is strong, which means that their constitution is particularly homogeneous.

In some embodiments, the method that is the subject of the present invention further comprises a step of cyclic inversion of the polarity of each electrode of an electrostatic sorting means implemented during the deflection step. These embodiments make it possible to take off and collect the particles attached to the electrodes, the constitutions of which are particularly homogeneous, and to collect the particles attached to each electrode without mechanical action such as scraping.

In some embodiments, the method that is the subject of the present invention comprises, downstream of the deflection step, at least one secondary deflection step. The separation of the components resulting from the plurality of successive sorts carried out by the method is then more precise.

In some embodiments, the less charged particles obtained after a first deflection step are recycled in the tribo-electric separator. The advantage of these embodiments is that they allow the particles whose electric charge is undetermined after two electrostatic sorting to follow a new implementation of the method that is the subject of the present invention.

In some embodiments, the method that is the subject of the present invention comprises, downstream of at least one deflection step, a step of comparing the dimensions of particles with respect to a predetermined limit value and a step of feeding a means for crushing into particles whose dimensions are greater than the predetermined limit.

Thanks to these arrangements, particles too large to be sorted efficiently are ground again so as to optimize their sorting. On the other hand, particles whose dimensions are nominal can be re-removed without undergoing additional grinding. In some embodiments, during the charging step, a dynamic fluidized air bed is used. The use of a fluidized air bed allows both the formation of electrostatic charges on the moving particles and their separation with a view to sorting them.

In some embodiments, during the step of fragmentation of the biomass, a grinding of the biomass is carried out.

In some embodiments, during the biomass fragmentation step, a vibrating or rotary ball mill is used.

In some embodiments, the method that is the subject of the present invention comprises, upstream or during the step of fragmentation of the biomass, a step of pre-treatment of the biomass. This pretreatment makes it possible to promote the deconstruction of the biomass during grinding.

In some embodiments, during the pre-treatment step, a chemical treatment of the biomass is carried out by contact with an oxidizing gas or aerosol. For example, an oxidizing gas comprising oxygen or ozone can be used. Oxidants are known to cause the degradation of the phenolic constituents of the plant wall and thus promote rupture under mechanical stress.

H • Starchy parts in which the starch is hydrolyzed into glucose, fermentable sugar: process of fragmentation and grinding of the green dry banana fruit into flour.

• Lignocellulosic parts, the cellulose of which can be broken down into fermentable sugars, process of fragmentation of false trunks, leaves and shoots of banana in dry powder or wet paste.

2) Second major level of process with the already fragmented BANANA TREE

In banana biomass which can be used directly for processing to obtain renewable energies in this invention there are three main methods of treating this biomass which is as follows:

v The biochemical treatment process ··· The thermochemical treatment process ❖ The biological treatment process

FIRST OF ALL:

We start with the various methods of fragmentation of the banana tree (wet A and dry B), that is to say with the stem and the leaves on the one hand and the fruit on the other hand in banana biomass as the first aspect of this invention.

A- Wet or fresh use of the banana tree object of this invention

- ° ^C t ^J , ^é _k ^al · .fragmentatton of moist banana (false throne, reamed leaf and suckers) by hammer milling in order to result in fresh lignocellulose biomass of banana in pulp.

^E r ^ ^{2 yielded: fra} g ^ment "fresh banana ion (wet fruit) by throwing hammer to get a starched paste biomass banana.

- ^CédéA ] ^: fr ^a S ^rnen tation of fresh bananas (wet fruits) by hammer milling in order to obtain the moist banana biomass chips.

B- Dry or dry use of the banana tree object of this invention:

^ □ çidé ^ l: fragmentation of dried banana (false trunk, stem leaf and dry suckers) by grinding in order to obtain the dry lignocellulose biomass of powdered banana.

Process B2: fragmentation of dry bananas (dried fruits) by milling in order to obtain a starched flour of banana biomass.

g ^ ^edeB3: fragmentation of dry banana chips (dry fruits and peels) by grinding in order to obtain a flour of dried banana biomass chips.

^P ^ ^cede fractionation by wet or dry lignocellulosic biomass comprising at least banished ^{l, gn, NE5} '/ ^{el, ulose and} hemicellulose, _comprising: (i) a banana fragmentation step to obtain a coarsely crushed pulp (ii ) a step of dry fragmentation of the banana to obtain an ultra-fine powder.

The invention relates to a method of comminuting wet or dry banana and treating this fractionated hgnocellulosic biomass of banana into paste, powder, flour and pellet, including gasification of a powdered wood residue. The woody residue comes from a process of biochemical treatment of the hgnocellulosic biomass of banana which comprises a stage of pretreatment in the wet process, by cuffing in acidic conditions and / or self-hydrolysis to produce a substrate of pre-treated banana. Said banana substrate, optionally separated from a liquid fraction, is subjected to an enzymatic hydrolysis is optionally subjected to a separate fermentation or concomitant with the hydrolysis, said fermentation being followed by a distillation. The woody banana residue is separated downstream of the hydrolysis. It is dried and conditioned to obtain the powdered woody residue with a particle size between 15 and 900 μm, the water content less than 12% by weight, a grain density of between 500 and 900 kg / m ³ and a minimum speed. fluidization is greater than zero and less than 0.15 m / s. The powder, alone or as a mixture, is introduced into a fluidization gas at a speed greater than or equal to the minimum fluidization speed. The invention is particularly suitable for the production of biofuels from synthesis gas, and in general in a banana fragmentation process for several processes for the production of renewable energies based on banana. ^E

The embodiments of biomass semolina according to the invention are indicated below.

The characteristics of the dried banana powder, from which these examples of semolina are obtained by wet granulation, are shown in Table 1 below.

Table 1

Diameters (microns) dlO 14.6 d50 ____ 37.7 d95 104.1) 1 Spread of the particle size distribution (d9O-dlO) / d5O -------- 1 2 Aerated density (Kg / m ³ ) 206 Other characteristics Avalanche angle 9 (°) 72 1 I ____ Cohesion at 3 kPa (KPa) 0.99

The characteristics of this dry banana powder make it a powder which flows with difficulty compared to non-cohesive powders such as semolina and powdered sugar, whose cohesions at 3kPa are: d approximately 0.01 and 0.05 kPa respectively, and their avalanche angle around 40 ° C.

A number of studies are devoted to the fine grinding of banana biomass particles, in particular platelets, to achieve particle sizes from millimeter to micron depending on the case. In these studies, the effects of the nature of the banana biomass, the type of crusher (s) used, the desired particle size were characterized on the energy cost of the actual fine grinding operation, and / or the properties of the powder obtained (particle size distribution, shape of the particles).

The present description is given without limitation. We note, from now on, that the figures are not in ecelle.

The term “ultrafine” is used to refer to a dough, flour, or a powder whose particles have a median diameter of less than 200 micrometers, preferably between 10 micrometers and 200 micrometers.

According to another definition, the term “ultrafine” is used to refer to a powder of which half (50%) by volume of the particles has a dimension less than 200 micrometers (dSO <200 μm), preferably less than 100 micrometers more preferably less than 50 micrometers. To measure the particles, a laser granulometer can be used.

With reference to FIG. 1 / XV, the device according to the invention comprises the circuit for collecting the false trunk has fragmentation in powder or pulp from the banana biomass.

-As shown in the figures, the device comprises an element (l) which is essential the banana tree that is to say (the stem, the leaves and the fruits) in the wet or dry state. (Figure l / XV)

-In the mode of operation of figure JV / XV, the element (figure ll / XV) presents the complete chain of fragmentation of the banana tree in order to make its biomass useful for the manufacture of renewable energies and other products such as organic fertilizers and pulp for cardboard and cardboard folders.

- The harvested banana is first fragmented, shredded into chips or pellets and ground into wet pulp or dry powder in order to produce the various useful biomasses according to our various transformation processes into renewable energies such as:

Biofuels, bioelectricity and pulp.

The purpose of the dry plant refinery is to make biomass, and lignocellulosic biomass in particular, more suitable for a given end use. This type of process has the particularity of not generating polluting effluents, unlike the liquid refinery.

L2i_ Ultrafine particles resulting from grinding have the advantage of having a very homogeneous chemical composition. The tribo-electrostatic charging means 110 allows the particles to charge or discharge electrons depending on their main chemical component. The main electrostatic sorting means 120 thus separate the particles whose main components are different. The device 100 thus separates the fractions enriched in different components.

A second particular embodiment of the device 200 which is the subject of the present invention is observed in FIG. IV / XV. This device includes:

A means 240 for grinding the biomass into powder of ultrafine particles comprising:

a means 245 for configuring the fineness of grinding produced by the grinding means 240

a means 275 for configuring the temperature of the grinding means 240;

> an inlet 205 for ultrafine particles resulting from grinding,> a means 210 for tribo-electrostatic charging of the particles received,> a means 220 for the main electrostatic sorting of the transmitted particles which comprising:

two electrodes 225;

- a means 280 for scraping the electrode from the main electrostatic sorting means 220 and

a means 285 for inverting the polarity of an electrode 225 of the main electrostatic sorting means 220;

r two secondary electrostatic sorting means 250 each comprising two electrodes 255 and two means 270 for comparing the dimensions of particles opposite a _{¥ 9} | _e ur bmm ”predetermined.

The means 240 for grinding the biomass to ultrafine particle powder is, for example, a centrifugal mill configured to grind biomass to ultrafine particles. This grinding means 240 comprises a means 245 for configuring the fineness of the grinding carried out by the grinding means 240. This means 245 for configuring the fineness of the grinding is, for example, a touch screen on which a computer program has displayed the current fineness of grinding, an interactive zone allowing a user to increase the fineness of grinding and an interactive zone allowing the user to reduce the fineness of grinding Depending on the fineness of grinding configured, the grinding means 240 is configured to grind the biomass into powder of particles whose diameter has been defined by the configuration means 245. This grinding means 240 also comprises a means 275 for configuring the temperature of the grinding means 240 This means 275 for configuring the temperature is, for example, a touch screen on which a computer program appears the temperature of the grinding means 240. current, an interactive zone allowing a user to increase said temperature and an interactive zone allowing the user to reduce said temperature.

^{205 P} r ^{ultrafine ticles from a br} ° ^are e ^e is, for example, a conduit connecting the grinding means 240 and 210 of tribo-electrostatic charge means of the received particles. The means 210 for triboelectrostatic charging of the particles received is, for example, an interior surface of a pipe, at least a part of which is made of glass, Teflon, PVC or steel. The particles passing through the conduit become charged on contact with the charging means 210. In particular, cellulose is charged with positive charges. The particles move in the charging means 210 by using a dynamic fluidized air bed set in motion by a turbine, for example. The main electrostatic sorting means 220 for the transmitted particles is, for example, a cylindrical conduit on the inner surface of which are placed two diametrically opposed electrodes 225. One of these electrodes 225 is positively polarized, and the other electrode 225 is negatively polarized. Near each of these electrodes 225 and downstream of the sorting means 220 are positioned two conduits configured to allow the passage of particles being attracted by one or other of the electrodes 225. The particles negatively charged by the charging means 210 are attracted to positively charged electrode225. Particles positively charged by the charging means 210 are attracted to the negatively charged electrode 225.

This main electrostatic sorting means 220 further comprises a means 280 for scraping the electrode from the main electrostatic sorting means 220. This scraping means 280 is, for example, a flexible plastic shape configured to conform to the shapes of the electrode 225 on which the shape is placed. This form is set in motion by a mechanical motor when the device is stopped.

This scraping means 280 is configured to collect the particles thus scraped off. The scraped particles have the particularity of comprising a large number of fractions attracted by the electrode 225, to the point that these particles are attached to the electrode 225. For example, in the case of a negatively charged electrode 225, the particles collected by the scraping means 280 mainly comprise fractions comprising cellulose. This main electrostatic sorting means 220 further comprises a means 285 for reversing the polarity of an electrode 225 of the main electrostatic sorting means 220. This means of the polarity inversion is for example an electronic circuit, implementing a tenth of a second every minute, configured to reverse the polarity of the PADS _e 225. The polarity reversal allows to take off and collect the particles attached to said electrode 225.

In variants, the main electrostatic sorting means 220 comprises a scraping means 280 and a polarity reversal means 285 for each electrode 225 of the sorting means 220. At the end of each of the conduits of the main electrostatic sorting means 220, a secondary electrostatic sorting means 250 are positioned. Each of these secondary electrostatic sorting means 250 comprises a positively or negatively polarized electrode. The electrode of the secondary sorting means 250 is polarized similarly to the electrode near the conduit to which said secondary sorting means 250 is attached.

In variants. The electrode of the secondary sorting means 250 is reverse biased to the electrode near the conduit to which said secondary sorting means 250 is attached.

In variants, at least one secondary electrostatic sorting means 250 comprises two oppositely polarized electrodes located on either side of said secondary sorting means 250. In this way, particles comprising a majority of fractions comprising hgna-cellulose are attracted to one of the electrodes. Each secondary electrostatic sorting means 250 thus makes it possible to sort, on the one hand, the particles comprising a majority of cellulose and, on the other hand, a majority of lignine-hem.ee luloses and minerals. At the output of each secondary sorting means 250 are positioned two conduits. A first conduit corresponds to a similar sorting result, called “convergent”, by the first sorting means 220 and the secondary sorting means 250 at the outlet of which this conduit is positioned. For example, a particle having a large proportion of cellulose is positively charged, then attracted by negatively charged electro e in sorting means 220, and then finally attracted by the negatively charged electrode in secondary sorting means 250. In the case where the result of sorting a particle by the ri means 220 and the secondary sorting means 250 is different, the result of the sort is said to "diverge". In the case where the result of the sorting by the sorting means 220 and the secondary sorting means 250 diverges, the particle enters the second duct at the outlet of said secondary sorting means 250.

In variants, at least one secondary sorting means 250 comprises at least one scraping means 280 and / or a polarity inversion means 285 similar to those configured for the main electrostatic sorting means 220. Each duct configured to receive the particles whose result of sorting by the sorting means 220 and the secondary sorting means 250 diverges includes a means 270 for comparing the dimensions of the particles with respect to a predetermined limit value. This comparison means 270 is, for example, a sorter of the cyclone type. In variants, this comparison means 270 is a filter configured to retain particles whose dimensions are greater than the predetermined limit value. The particles whose dimensions are larger than the predetermined limit value are passed to the grinding means 240 to be ground again. The particles whose dimensions are smaller than the predetermined limit value are transmitted again to the charging means 210 in order to be removed.

The ultrafine particles resulting from grinding have the advantage of having a very homogeneous chemical composition. The tribo-electrostatic charging means 210 allows the particles to charge or discharge electrons depending on their main component. The main electrostatic sorting means 220 thus separates the particles whose main components are different.

The device 200 thus separates the fractions of the biomass enriched in different components, these components having different properties and industrial applications. In addition, the separation of the components resulting from the plurality of successive sorts carried out by the main sorting means 220 and the two secondary means 250 for sorting device 200 is then more precise than if the device 200 had a single means 220 for main electrostatic sorting. , as in the device 100 illustrated in FIG. 5. This device 200 concentrates the grinding means 240, the receiving means 205, the discharged means 210 and each sorting means 220, 250. Thus, the device 200 is more compact. In addition, the powder does not have time to aggregate, to take on moisture, to oxidize or, more generally, to change state, between grinding and sorting. The operation of the device is improved. The average diameter of the particles at the outlet of the grinding means 240 of the device 200 makes it possible to obtain particles which have a homogeneous chemical composition and, once charged, remain mobile as a function of their charge in the presence of the electrodes. By means of the comparison means 270 of the device 200, the particles which are too large to be sorted efficiently are ground again so as to optimize the sorting of these particles. On the other hand, the particles whose dimensions are nominal can be re-sorted without further grinding. The means 275 for configuring the temperature of the grinding means 240 configured so that the biomass reaches a temperature at which at least one component of the biomass becomes brittle allows the grinding means 240 to more easily grind the biomass into ultrafine particles. The use of a fluidized air bed allows both the constitution of electrostatic charges on the moving particles and their separation for sorting. The electrode scraping means 280 of the main electrostatic sorting means 220 collects the particles fixed on the electrode 225), the electric charge of which is strong, which means that their constitution is particularly homogeneous.

The means 285 for cyclic reversal of the polarity of each electrode 225 of the main electrostatic sorting means 220 makes it possible to take off the particles fixed to the electrodes 225), the constitutions of which are particularly homogeneous and to collect the particles fixed on each electrode without mechanical action. such as scraping.

We observe, in figure VII / XV, two cyclonic separation units 305 and 310 connected to the same single suction means 315. It is recalled that a cyclonic separation unit is a technological unit requiring rapid rotation of a gas in order to separating, by centrifugation, the fine solid particles which are mixed therein. The inlets of the cyclonic separation units 305 and 310 respectively constitute the containers 130 or 230, on the one hand, and 135 or 235, on the other hand. When a single stage is used, Fl A- represents the fraction obtained on the negatively charged electrode when a single stage is used, F2B + represents the fraction obtained on the positively charged electrode when, at the input of a second stage, the sample is the fraction Fl B +, F2A- represents the fraction obtained on the negatively charged electrode when, at the input of a second stage, the sample is the fraction Fl A- and the end of the name of the fraction in "e" means that your fraction was obtained by scraping the electrode.

Example 1 Application of the method which is the subject of the present invention to the banana leaf.

Regarding the method of preparation, a raw leaf sample underwent the following refinery operations:

• impregnation (without treatment), • no drying operation and • grinding.

The banana leaf was ground without prior treatment with a moisture content of less than 20% (by mass). The mill used is an impact mill for particle sizes less than 200 µm. The substrates are first ground in a knife mill and then in a centrifugal mill.

The various ground materials or powders obtained were separated by electrostatic sorting under the following conditions:

the power supply is 0.5 to 1 kg / h and • the voltage is 5 to 20 Kv.

The different fractions obtained are characterized, and an example of characterization is presented in Table 2 (the tribo-electrostatic sorting is carried out with electrodes having a potential difference of 15 kVolts, at a distance between them, of 3 cm. And measuring 30 cm high and 10 cm wide). Table 2: Example of the banana leaf - Composition of the fractions, by weight.

Fractions recovered rate ash lignin hemicelluloses cellulose FO 81.9 4.43 20.5 28.3 44.2 FIA- 25 81.2 5.14 22.4 32.5 41.8 F1B + 46 52.2 3.67 18.1 22.6 54.7 FlA-e _4____________ 42.2 15.2 ________ 16.6 30.1 37.3

I ------- ^F1B * ^e I ⁵ I 44.8 I 2.94 I 16.6 | 22.4 | 57 ^ --------- 1

The rate recovered (second column) is given as a percentage by mass.

It is observed that the combination of the operations of crushing the banana leaf and of electrostatic sorting in a strict dry environment, made it possible to isolate:

on the one hand, fractions enriched in cellulose (up to 57.8% compared to 44.2% in the raw banana leaf) and depleted in hemicelluloses up to 22.4%, compared to 28.3% in the raw leaf) and -on the other hand, fractions enriched in lignin (up to 22.4%, compared to 20.5% in the raw leaf), hemicelluloses (up to 32.5%, compared to 28.3% in the raw leaf) or lignin-hemicellulose complexes.

On the electrodes, we also obtained fractions very rich in minerals (up to 15.2% for the fraction -, compared to 4.4% in the raw banana leaf), without chemical modifications.

It is observed, in view of this Table 2 that the fractions Fl B + and Fl B + e contain more cellulose in comparison with the other fractions. This cellulose can be used as a source of bioenergy after hydrolysis to glucose and fermentation (bioethanol and biogas). On the other hand, the Fl A- and Fl Ae fractions are enriched in hgnme-hemicelluloses, which can be intended for the synthesis of bio-sourced materials. Thus the bioaccessibility and the transformation of cellulose into glucose have been improved (with a doubled rate compared to with raw straw), without resorting to chemical pretreatments. Fractions enriched with lignin-hemicellulose complexes and minerals which can be used for the synthesis of bio-source materials were concentrated.

Figure VI / XV illustrates the transformation by enzymatic hydrolysis of wheat straw fractions, as decnt in the publication Barakat et al, “Eco-friendly drychemo-mechanical pretratments of lignocellulosic biomass: impact on energy and yield of the enzymatic hydrolysys” Applied Energy 2014 113 (2014) 97-105, incorporated herein by reference which details the methods used herein to analyze sugars, lignin, and enzymatic purification.

The vertical white bars represent, in mg / g, glucose (cellulose). The black vertical bars represent xylose (hemicelluloses) in mg / g. This figure VI / XV shows the enrichment in hydrolyzable cellulose in the “+” fractions. The glucose resulting from the enzymatic hydrolysis of cellulose can be used as a source of fermentation for the production of bioethanol or other molecules intended for green chemistry, depending on the fermentation microorganisms used.

Example 2: banana shoot

- In the case of offspring, a sample of raw biomass has undergone the following operations:

knife grinding, paddle grinding, drying to a water content of less than 10%,. . . ^br ° y ^{aee with rotary balls} and a fraction enriched in minerals and in particular in silica and a fraction enriched in lignin and cellulose and depleted in minerals.

Example 3: banana leaf

Figures VII / XV and IX / XV represent, respectively, the cellulose and lignin contents of different fractions obtained by the implementation of the process object of the present invention on a biomass consisting of banana. It is observed that this process makes it possible to obtain, on the one hand, fractions enriched in cellulose (Fl B + and F2B +) and on the other hand, fractions enriched in lignin (Fl A- and F2A-).

Example 4: banana shoot

The grinding step having the highest energy cost is the last one bringing the particle size into the range of I ultra-fine (from around one hundred to around ten micrometers). It is therefore on this that the efforts to reduce I grinding energy are to be provided. The following example is given on wheat straw, with a rotating laboratory ball mill. The temperature inside the grinding jar (Marne 0 ball mill from Faure Instruments) can reach 40 ° C. when the grinding is carried out at room temperature, which has an effect on the elasticity / rigidity of the straw fibers. To limit this effect of loss of rigidity, the ^b ° Î? ^S ? ^{It was used in a cold room} at 5 ° C (the inside of the mill then rises to 20 ° C in stabilized operation).

Figure 10 shows the evolution of the grinding time as a function of temperature:

-the total grinding time to reach a d50 of 20 prn is 120 hours at 40 ° C (top line) against 70 hours at 20 ^° C (lower curve).

The fragmentability of the biomass is improved by the use of low temperatures: it is necessary to control the clutch temperature in order to maintain it in the plants in their rigidity range, ie below 40 C for the materials considered. Strongly negative temperatures do not bring any real advantage (high cost, re-agglomeration and absorption of humidity by condensation when returning to ambient temperature).

Example 5: banana leaf

For observing an effect of the milling atmosphere on the grindability and / pu on the reactivity of wheat straw, ^s tests were conducted in an oxidizing atmosphere (air) and neutral (argon) in a model Faure Marne ball mill O fitted with an 8 liter ceramic jar. The presence of argon during grinding does not affect the fragmentation of the wheat straw. The time required to obtain a 20 micron powder is the same. On the other hand, the reactivity, for example the capacity to release thermal energy, is modified.

Example 6: banana leaf

We describe, below. a combination of electrostatic separation and chemical pre-treatment and enzymatic treatment after separation. As illustrated in Figure 11, during a step 605, the wheat straw is crushed, for example using a knife mill with a two mm grid. uis, the crushed straw is impregnated with soda during a step 610. For example, this step 610 is carried out according to the method described by Barakat et al. 2014, in the publication referenced above. After drying at 40 ° C until the humidity level reaches a value between 7% and 10%, the biomass is crushed again with an impact mill (UPZ, already described in detail with regard to Figures 1 to 9 ), during a step 615. The ground material is then fractionated by electrostatic separation according to the same method and under the conditions described with reference to FIGS. 1 to 9, during a step 620.

During a step 625, at least one of the enriched fractions thus obtained is functionalized by treatment with enzymes (Barakat et al. 2014). The results obtained are presented in FIG. 12. The ordinate y represents the rate of reducing sugars (glucose), in milligrams per gram. On the left, we represent the unseparated straw. In the center, the positive fractions Fl B + are shown after one passage through the separator On the right, the positive F2B + fractions are shown after two passages through the separator The solid black rectangles represent the results obtained in the absence of impregnation with soda The Hatched rectangles represent the results obtained with a soda impregnation step.

In general, the coupling of the chemical treatment, grinding and electrostatic separation processes has a very significant effect on the accessibility of cellulose by enzymes (cellulases) and the production of glucose (precursor to produce ethanol) which achieves a yield of 95% for the positively charged fractions. ^&

Referring to Figure l / XV, the device according to the invention comprises, the circuit of the collection of the false trunk to the fragmentation into powder or pulp of the banana biomass.

As shown in the figures, the device comprises an element which is essential the banana tree that is to say (the stem, the leaves and the fruits) in the wet or dry state.

In the mode of operation one of the figures, the element presents the complete chain of fragmentation of the banana tree in order to make its biomass useful for the manufacture of renewable energies and other products such as organic fertilizers and pulp for cardboard. and cardboard folders.

The harvested banana is first fragmented, shredded into chips or pellet and ground into wet pulp or dry powder in order to produce the various useful biomasses according to our various transformation processes into renewable energies such as: biofuels , bioelectricity, organic fertilizer and pulp.

θ quantity in various forms: false trunk, leaves, bulbs and fruits of bananas and plantains etc. One of its main advantages is that it does not compete with food uses and that the potential deposit is much greater.

Three paths are mainly developed in this invention:

1- biochemical conversion

2- thermochemical conversion.

3- And biologically by alcoholic fermentation

Renewable energy process C1: process for biochemical transformation of segmented fresh or wet banana biomass, for treatment in 2nd generation bioethanol.

BIOCHEMICAL TREATMENT PROCESS:

Biochemical conversion makes it possible to transform banana biomass into ethanol, or even into other alcohols. The research work of Pastor Abanda Ndouma Jules, with regard to New Energies in Cameroon, focuses on the stages related to the specific processes of the ^1st and ^2nd generation:

a) ^1st step: pretreatment to release complex sugars,

b) 2i ^me step: enzymatic hydrolysis to convert the complex sugars into simple sugars easily fermentable.

The processes for producing ethanol from lignocellulosic biomass incorporate several basic considerations:

• lignin cannot be fermented into ethanol, • the lignocellulosic matrix must be pretreated to make cellulose and hemicellulose hydrolyzable, • cellulose and hemi cellulose fractions are potential sources of fermentable sugars.

6-step banana cellulosic ethanol manufacturing process:

The process of making ethanol from cellulose is much more complex than that of starch or sucrose. Cellulose must first be broken down into fermentable molecules. However, the long chains of glucose molecules that make up cellulose are encapsulated by lignin, a very resistant material that is difficult to break down.

Several processes have been developed to produce cellulosic ethanol:

Acid hydrolysis, enzymatic hydrolysis and thermochemical process (gasification). Although these so-called "second generation" processes are all technically feasible, to date the enzymatic hydrolysis process is the only process used on an industrial scale in Canada which uses biomass of agricultural origin as raw material.

The steps of the enzymatic hydrolysis process are similar to those of the grain ethanol manufacturing process. However, the techniques and microorganisms involved are very different.

The main steps in the production of cellulosic ethanol by enzymatic hydrolysis are as follows:

1. Pretreatment

3Q The raw material (fibers) is first of all pretreated by a vapor explosion defibration process. This step makes it possible to increase the specific surface area in order to increase the accessibility of the fibers to the enzymes used in the following steps of the process.The efficiency of this pretreatment is essential to limit the duration of the hydrolysis step and therefore, the costs of the entire process.

2. Enzymatic hydrolysis

The hydrolysis of cellulose is carried out using cellulases, a set of enzymes which, when brought into contact with the raw material, break it down in order to produce units of elementary sugars. In the natural environment, cellulases are produced by symbiotic bacteria present in the stomachs of ruminants and termites. It is these enzymes, moreover, that allow ruminants to use a large part of the energy contained in plants. The cellulases used in the cellulose hydrolysis process must meet specific criteria in order to optimize the rate of conversion of cellulose into elementary sugars. At present, this stage is the most expensive since several days are necessary

Ξ to complete this decomposition. Several research are currently underway to increase! effectiveness of these enzymes. The hydrolysis of cellulose requires up to 100 times more enzymes than that of starch.

3. Separation

After enzymatic hydrolysis, the lignin, which has remained intact, is separated from the liquor and then dehydrated. It can be used directly to produce thermal energy or electrical energy, litter, absorbents, etc.

4. Fermentation

The liquor obtained after the separation contains the sugars resulting from the enzymatic hydrolysis. These sugars are fermented by microorganisms. At this stage, the search for bacteria to replace yeasts] Q would speed up the process and improve biomass yield.

5. Distillation

The fermented liquor contains about 5-6% ethanol. The ethanol is separated from the liquor by a multi-column distillation system which will provide 96% pure alcohol.

6. Dehydration

For marketing purposes, ethanol is dehydrated by a molecular sieve.

The ethanol is then said to be “anhydrous”. A denaturant is added to it in small quantities (2 to 5%) in order to prevent it from being sold on the human food market.

] 5 Up to ^75% of the cellulose and hemicellulose contained in the plant raw material can be partially converted into ethanol. The efficiency of this transformation depends in particular on the rate of recovery of cellulose and hemicellulose, on the efficiency of their conversion into fermentable sugars as well as on the efficiency of the fermentation of glucose into ethanol.

Two co-products are generated by the manufacture of cellulosic ethanol:

Lignin and carbon dioxide (CO2) produced during fermentation. The amount of lignin produced depends greatly on the raw material. It is minimum for the transformation of energy crops into ethanol and maximum for the transformation of forest residues of conifers. Once harvested, cleaned of impurities (residual alcohol) and then compressed, carbon dioxide finds an outlet in the manufacture of soft drinks and dry ice or in the rapid cooling of food processes. In total, one ton of biomass, based on dry matter, would currently produce between 200 and 230 liters of ethanol. Optimization of the cellulose and hemicellulose conversion processes and fermentation could increase this yield to nearly 400 liters.

Therefore, the generic scheme of the process includes the following main unit operations: the pretreatment of the raw material, the hydrolysis, the ethanolic fermentation and the separation of the ethanol ^{from the} fermentation ^wort .

Hydrolysis

BLC — Pretreatment - *

Elhanol

the physical crossroads Crushed intense mechanics (fragments <2mm) T hernwlyse (heating at T <300 ° C suis-i of acid hydrolysis) Physico-chemical processes 1 hydrolyzed henno (cooking under pressure tofle for a period of (5 to 60 minutes allowing the solubilization of the hemicellulose and the binding of a) Steam explosion (injection of steam at high pressure for a few seconds followed by a sudden release at atmospheric pressure) Steam explosion under acidic conditions (identical to the previous one but in acidic medium) Proceda AFEX (Ammonia Fiber Explosion) Explosion at CO, Chemical processes Hot dilute acid pretreatment Pretreatment in an alkaline medium (which lead to an almost total solubilization of the lignin and of part of the hem celluloses and a swelling of the cellulose fibers which are much more accessible to the enzymes) loses in an oranic solvent Chemical oxidation processes including ozonolysis or wet oxidation Biological processes; using peroxidase-type enzymes or ligno lytic fungi___

^S ° ^U ^ ^e .: ^{State of l, them} 'P ^ers P ^sc dves and development issues - Daniel BALLERINI, with the collaboration of Nathalie ALAZARD-TOUX.

The universal and ideal pretreatment process does not exist. The most attractive technologies a priori are thermohydrolysis, dilute acid pretreatment and steam explosion. They depend on the material to be processed from the banana tree.

Pretreatment

This is not the conditioning of the plant itself, which generally consists of grinding / cutting the fibrous materials, but the treatment necessary to make the cellulose accessible to hydrolysis.

The main pre-treatment processes aim to:

• to lower the lignin and hemicellulose content of the solid substrate to be treated, • to increase the porosity of the matrix, by reducing the crystallinity of the cellulose or by increasing its specific surface, • to combine the two principles.

Steam explosion of powdered banana biomass

Steam explosion is a two-step treatment that not only hydrolyzes and extracts sacchandes, but also destroys banana biomass.

Î! _n ^P æ ^{Mière phase is' e is} P ° ^crac luage during which steam under high pressure (up to 40 bars 250 C) penetrated fragments banana. These conditions lead to the hydrolysis of the polysaccharides. After a few minutes, a sudden decompression is applied, destroying the banana biomass. The reaction can be catalyzed by sulfur dioxide (SO2) or sulfuric acid. A treatment carried out at ⁵ ° ^on D ^{02 for 7-5 min on} Douglas-fir made it possible to extract 70% of the hemicelluloses or 86% of the hexoses, the immense majority in monomeric form. In addition, HMF and furfural concentrations do not exceed 0.5 g / L.

The second phase: A more severe treatment (215 ° C, 6.6 min, 2.38% SO2) leads to a strong degradation of the sacchandes. The amount of hemicelluloses in the hydrolyzate drops to 37.5% Extraction of hemicelluloses is very effective by this treatment. However, decompression degrades the fibers enormously. It is therefore impossible to make pulp of good quality from it, but this constitutes an interesting pretreatment before an enzymatic hydrolysis of the cellulose. Thus the steam explosion is mainly used to make

I cellulosic ethanol (from hemicelluloses and banana cellulose).

Hydrolysis

Due to the structure of cellulose, its crystallinity and its association with lignin and hemicelluloses still present, even after the pretreatment step, its hydrolysis into fermentable monomers (glucose) is a difficult operation which can be carried out by two methods: chemical hydrolysis catalyzed by an acid or enzymatic hydrolysis.

Chemical hydrolysis: takes place in two stages. The first is similar to the dilute acid pretreatment and allows to _lg-operate hemicellulose and dissolve the sugars derived from them. After separation, the solid fraction containing the cellulose is subjected to a further hydrolysis.

enzymatic drolysis: hydrolysis of cellulose by enzymes is often the recommended route for

I obtained fermentable sugars for the following reasons:

• it is more economical, • it generates little effluents to be treated, • it presents much greater prospects for improvement than chemical hydrolysis, which has been the subject of work for several decades.

Among the cellulosic bacteria are bacteria belonging to the genera Ruminococcus, Clostridium, Ce ulomonas, Thermonospora, Streptomyces. Although some bacteria such as Clostridium thermocellum produce cellulases with high specific activity, their production capacities and growth rates are too low to consider their use at the industrial stage. Cellulolytic fungi belong to different genera: Aspergillus, Schizophyllum, Penicillium, Trichoderma ...

Among these, Trichoderma reesei is capable of secreting high concentrations of very active cellulases and has been the object of industrial use.

Cellulolytic systems are multienzymatic systems possessing three types of action which are capable of totally degrading cellulose. Current efforts are aimed at reducing the cost of producing cellulases and increasing their specific activity.

Enzymatic hydrolysis:

Enzymatic hydrolysis has become essential for the production of ethanol from starch. However, it is still far from being effective for second generation ethanol.

FUTUROL) ' ^{, iSée the pilot scale for} the hydrolysis of cellulose (see for example the NILE projects and

Three different classes of enzymes are then necessary. The exo-1,4-Pd-glucanases produce cellobiose starting from the ends of the cellulose, the endo-1,4-Pd-glucans hydrolyze the internal glycosidic bonds in the cellulose, to create new reducing ends, and finally the 1,4-P-dglucosidases convert cellobiose into glucose. With regard to hemiceiluloses, the necessary cocktail of enzymes is even more important, knowing that each enzyme admits as a substrate a _J5 type of specific binding. If only for GGMs, it is essential to have endo-1,4-pmannanases, p-mannosidases, β-glucosidases, α-galactosidases as well as acetylmannaneesterases if the acetyl groups are to be released. These enzymes can be produced from microorganisms, such as Trichoderma reesei or even pure Penicillium purogenum.

The effectiveness of enzymes is reduced by their inhibition to their product, their own substrate, as well as by phenolic compounds. However, this process remains attractive for secondary hydrolysis after autohydrolysis or alkaline extraction. Indeed, it would limit the degradation of monosaccharides and could reduce the release of acetyl groups, inhibitors for fermentation (see part C.2.2 of this chapter). 2q This process would facilitate fermentation, but would decrease the fermentable raw material, as hexose linked to an acetyl group cannot be converted into ethanol. The hemicelluloses being solubilized, the action of the enzymes is facilitated. However, to achieve efficient and cost-effective enzymatic hydrolysis, microorganisms must be improved, genetic manipulation seeming to be the most promising route.

Fermentation

Ethanolic fermentation

Once the cellulose is hydrolyzed to glucose, this is fermented in the same way as glucose from banana starch. There remain specific problems with the use of lignocellulosic materials as an initial substrate, such as:

• fermentation of pentoses in ethanol (xylose obtained from banana hemicelluloses), • the presence of toxic and inhibitory compounds resulting from hemicelluloses and lignin, • the possibility of carrying out enzymatic hydrolysis and fermentation in a single step.

Fermentation with yeasts

While Saccharomyces cerevisiae, some strains of which are used industrially for alcoholic fermentation, cannot use xylose as a carbon source, other yeast species can convert xylose into ethanol (Pichia stipitis, Candida shehatae, Pachysolen tannophilus). However, these yeasts have many weak points: fermentation performance significantly lower than that of S. cerevisiae on glucose, inhibition by ethanol from concentrations of the order of 3 to 5%, high sensitivity to inhibitors present in hydrolysates such as acetic acid.

Studies are being carried out to modify the genome of Saccharomyces cerevisiae so as to make it capable of transforming xylose.

Fermentation by bacteria

Xylose is convertible into ethanol by several species of thermophilic bacteria such as Thermoanaerobacter ethanolicus, Clostridrium thermohydrosulfuricum or by modified strains of Bacillus stearothermophilus. Mesophilic bacteria such as Escherichia coli and Klebsiella oxytoca or K. plantico la are also able to ferment pentoses.

Good ethanol productions have been obtained with strains of E. Coli in which significant improvements were obtained: strong expression of certain genes (pdc and adh) to direct the carbon flow towards the production of ethanol, obtaining mutants resistant to ethanol, deletion of the fumarate reductase gene at the origin of the formation of succinate.

Distillation

The stages for recovering ethanol by distillation / rectification / dehydration are identical to those of the already proven processes for the production of ^1st generation ethanol.

THERMOCHEMICAL TREATMENT BTL (Biomass To Liquid)

Thermochemical conversion

The second path studied by Pastor Abanda NJ. is the thermochemical sector. It makes it possible in particular to produce biodiesel and biokerosene and uses two technologies in particular: gasification and pyrolysis.

In the gasification or BtL (Biomass to Liquids) route, it involves conditioning the banana and plantain biomass, gasifying it, purifying the synthesis gas obtained, then carrying out a FischerTropsch synthesis to transform the gas. of synthesis in biodiesel and biokerosene of very high quality.

Pyrolysis is another thermochemical process used to obtain diesel, gasoline or kerosene. It consists in liquefying the biomass, then treating the liquefied material to make fuels. Pastor Abanda NJ. has invested in developing pyrolysis technology to develop a process for treating liquefies.

And beyond...

Beyond the biochemical and thermochemical pathways, other more exploratory avenues for the production of 2nd generation biofuels are being studied, such as the production of higher alcohols from banana biomass by biological means. The process follows the same steps as those for cellulosic ethanol production.

A 4-step process

The biomass is first processed and ground into powder. The project partners chose roasting (as for coffee), in order to obtain a powder fine enough to be inserted in a gasifier with ultimately lower energy consumption. The powder is then transformed into synthesis gas at very high temperature (between 1200 and 1600 ’C) and in the presence of oxygen. The transformation is completed in less than two seconds, with a conversion level of over 99%. Before being used as a liquid fuel, the synthesis gas must be of high purity and have the correct composition. This operation involves the use of specific catalysts. The final conversion then involves a technology well known as the Fischer-Tropsch process.

Synthetic diesel or BTL (Biomass To Liquid)

The term BtL is applied to synthetic fuels produced from biomass thermochemically. The aim is to produce fuels similar to those currently produced from fossil fuels and which can therefore be used in existing fuel distribution systems and with standard engines.

Synthetic biofuels such as Fischer-Tropsch diesel (FT-diesel), dimethyl ether (DM E) I hydrogen (H2) and, to a lesser extent, bio methanol, are among the most popular liquid biofuels channels. promising in the medium to long term. However, these so-called synthetic sectors have not yet passed the pilot stage, or even research and development (R&D), and it will certainly take several years before they establish themselves in the biofuels market. However, several large-scale projects are currently underway aimed at the commercial development of the first production plants. Among the most ambitious projects, let us note the RENEW project (of which Volkswagen, BP and Total are partners). One of the production processes evaluated as part of this project is the Carbo-V 'process from the company Choren,

The Carbo-V ^{e process} (as described by Choren) is a three-step gasification process involving the succession of the following sub-processes:

• low temperature gasification;

• high temperature gasification;

• entrained bed endothermic gasification.

Biomass is first continuously carbonized by partial oxidation (low temperature pyrolysis) with air or low temperature oxygen of the order of 400-500 ° C. The biomass is thus broken down into a gas containing tars (volatile elements) and carbonaceous residues (banana charcoal).

The tar-containing gas is then post-oxidized with air and / or oxygen in a combustion chamber operating above the melting point of the fuel ash to transform it into a high temperature gasification medium. .

The banana charcoal is ground into pulverized fuel and then injected into the high temperature gasification medium. The pulverized fuel and the gasification medium react endothermically in the gasification reactor at over 1000 ° C where they are converted to a crude synthesis gas consisting of carbon monoxide (CO) and hydrogen (H2). Catalyzed in which carbon monoxide and hydrogen are converted to liquid hydrocarbons.

(2n + l) H 2 + n (CO) CnH2n + 2 + nH 20

3TL (blortiAss Iiquld) or synthetic fuel j - ij'ntncic

USE OF OUR INVENTION FOR THE PRODUCTION OF BIODIESEL

Can be associated with 2nd generation biofuels, banana crops whose technologies used to obtain the biofuel are the same as those of the ^1st generation, but which do not compete with human or animal food. .

Once this reaction is properly carried out, the synthesis gas can be used for the production of Fischer-Tropsch - Diesel. The Fischer-Tropsch process is a chemical reaction.

The invention advantageously applies to the gasification of banana biomass for the production of biofuels from synthesis gas widely known under the name "Syngaz". By banana lignocellulosic biomass refinery processes which participate in the supply of bioenergy in the form of powder and ethanol, bio-sourced materials, in particular to load matrices and biomolecules with high added value, for example phenols, fatty acids and minerals.

The actual gasification step is carried out continuously from banana biomass of different nature and particle size, usually stored at atmospheric pressure.

Thus, the gasification processes of banana lignocellulosic biomass make it possible to generate synthesis gas which makes it possible to produce downstream either liquid fuels or other organic products. This gasification typically takes place in the presence of water vapor around 1400-1600 ° C for entrained flow reactors. Conventionally, these processes convert the carbon in banana biomass with a gas

The invention is particularly advantageous to implement in an installation comprising an entrained flow reactor (RFE), with a device consisting of a rotating plate granulator or a mixing granulator with high shear rate, the reactor being a reactor of the high shear type. entrained flow.

Thus the invention essentially consists in introducing a step of wet granulation of the dried biomass powder before the step of injection into the gasification reactor.

Due to the change in shape and increase in size induced by granulation, semolina-forming biomass granules have greatly improved flow properties compared to dried biomass powder.

The conveying of the banana biomass is thus greatly improved, which makes it possible to obtain easy and continuous injection into the gasification reactor, with a fine, precise, stable and reproducible dosage.

The syngas production process

The production of "syngas", in particular by a BTL route, and in particular in a gasifier with entrained flow, comprises, in a first step, a pretreatment of the native lignocellulosic biomass to reduce the charge to the state of a finely ground powder. (between 50 and 200μμ) and easily fluidizable so as to allow the pneumatic transport and injection of the biomass feed into the gasification unit, the operating conditions of which are typically a pressure P between 20 and 45 bars (1 bar = 0.1 MPa) and a temperature T between 1200 ° C and 1600 ° C.

In the second stage of gasification, the carbonaceous material is partially oxidized in the presence of oxygen and water vapor in the gasification unit or gasifier.

The present invention relates to the first step of pretreatment of the lignocellulosic biomass of banana.

As the gasification unit needs to be finely regulated and supplied with a homogeneous solid feed rate, the pre-treatment of the biomass is an essential phase to allow the proper functioning of the subsequent fluidization and gasification stages.

The gasification can be carried out in a dry injection entrained bed or flow gasifier, that is to say a gasifier intended for the production at high T and P of "syngas" by the dry process.

The principle of this technology, which is proven for fossil feeds such as coal, is based on the pneumatic transport of a pulverized feed to the inlet of a burner which is also supplied with oxygen and / or steam. water. When this technology is applied to lignocellulosic feeds, the main technical obstacle is the pneumatic feed and transport system upstream of the gasifier.

This system is essentially a fluidized bed which operates in the homogeneous fluidization regime, with an inert gas, typically N ₂ or CO ₂ . The pressure difference between this fluidized bed and the entrained flow gasifier allows the pneumatic transport of the solid particles to the latter. Once in the gasifier (P - 20-45 bars) the pulverized feed is gasified very quickly (residence time less than 2s) to produce a syngas (mixture in particular of H ₂ + CO) which can then be upgraded by several different routes. (Fischer-Tropsch synthesis, methanisions, hydrogen production ...).

Other processes incorporate this technology for the gasification of banana biomass feeds. This is the case of the BTL (Biomass To Liquid) chain, which generally considers a thermal and mechanical pre-treatment of lignocellulosic banana biomass (roasting + grinding) before gasification.

Homogeneous fluidization involves an expanded bed but without creating bubbles in order to allow a continuous and stable supply to the gasifier burner. Furthermore, it is also desired to minimize the fluidization speed in order to limit the flow rate of inert gas which will be injected into the gasifier. The fluidization speed is understood as the superficial speed of the fluid, i.e. the ratio between the volume flow rate of gas and the section of the equipment in which the fluidization takes place, without taking into account the presence of the solid to be fluidized. The minimum fluidization speed is a characteristic specific to the solid powder which corresponds to the minimum gas flow rate necessary for the fluidization of the powder. The minimum fluidization speed is measured according to ASTM D7743-1 “Standard Test Method for Measuring the Minimum Fluidization Velocities of Free Flowing Powders”.

The homogeneous fluidization regime corresponds to type A particles according to the Geldart Classification (Ref: “Types of Gas Fluidization”, D. Geldart, Podwer

Claims (10)

1. Process for the fractionation of bananas by wet vote of lignocellulosic biomass comprising at least 50%, by mass, of lignins, cellulose and hemicelluloses, according to (Figure ll / XV) characterized in that it comprises: - a banana fragmentation step in order to obtain a wet cake of hard biomass, - a step of pressing the banana fragments in order to obtain dried biomass granules, - a stage of fragmentation of the wet banana in order to obtain a pasty wet biomass, - a step of fragmentation of the fresh green or ripe banana fruit in a pod in order to obtain a wet or dried cosette biomass, - a step of fragmentation of the ripe fresh banana fruit in order to obtain a sucked biomass paste, - a step of fragmentation of the banana cosette in order to obtain a biomass of dried flour. 2. Process for the dry fractionation of lignocellulosic biomass comprising at least 50%, by mass, of lignins, cellulose and hemicelluloses, according to (Figure ll / XV) characterized in that it comprises. - a step of fragmentation of the biomass to obtain an ultrafine powder and - a step of separating a fraction enriched in cellulose, on the one hand, from a fraction enriched in lignin, hemicelluloses and minerals on the other hand, by electrostatic sorting of the ultrafine particles. 3. Method according to claim 2, in which the step of separation of the fractions according to (Figure III / XV) comprises: - a tribo-electrostatic charge step for ultrafine particles, a step of deviation of the trajectory in the electric field of the charged particles to sort the particles. 4. Method according to the preceding claims, in which, during the step of various fragments of the banana tree into useful biomass, a grinding of the biomass is carried out and which also comprises: an electrode scraping step of an electrostatic sorting means implemented during the deflection step, to collect the particles fixed on an electrode after the particle deflection step, - a step of cyclic inversion of the polarity of each electrode of an electrostatic sorting means implemented during the deflection step, - downstream of the deviation step, at least one secondary deviation step, - downstream of at least one deviation step, a step of comparing the dimensions of particles with respect to a predetermined limit value and a step of feeding a grinding means into particles whose dimensions are greater than the limit predetermined and in which, during the charging step, a dynamic fluidized air bed is used. 5. Method according to the preceding claims, in which, during the biomass fragmentation step, a vibrating or rotary ball mill is used, and which comprises, upstream or during the fragmentation step of biomass, a step of pretreatment of the fragmented banana biomass, during which a chemical treatment of the biomass is carried out by contact either with a gas or an oxidizing aerosol, or with a reducing gas or aerosol and either with a inert gas; it includes, downstream of the separation step, a functionalization step of at least one enriched fraction, during which a roasting and enzymatic hydrolysis of the enriched fraction are carried out; the fractions enriched either in cellulose, in hemi-celluloses-lignin or in minerals being used for the generation of biofuel and for the production of bio-sourced materials. 6. Process for the treatment of lignocellulosic biomass of banana according to (Figure VIII to XV / XV) comprising: a) -a step for preparing a banana powder whose particle size is between 15 and 900μμ, preferably between 20-500μμ, having a water content of less than 15% by weight, a grain density between 500 and 900 kg / m, and a minimum fluidization speed greater than zero and less than 0.15 m / s, preferably less than 0.1 m / s, b) a step of fluidizing at least part of said banana powder, alone or as a mixture, by injecting a fluidizing gas at a speed greater than or equal to the minimum fluidization speed 5 of said powder, c) a step of injecting said fluidized medium into a gasification step to produce a synthesis gas containing CO and H2, and said step a) of powder preparation comprises a biochemical treatment (steps A to D) with obtaining a woody residue and the treatment of the woody residue (step E) to obtain a powder: A) -a step of pretreatment of lignocellulosic biomass of banana carried out wet, by heating under acidic conditions and / or self-hydrolysis, step which generates a substrate of pretreated banana; preferably said pretreatment is a vapor explosion under acidic conditions, Ιθ B) -an optional step of liquid / solid separation of all or part of the pretreated substrate resulting from step (A) with obtaining a liquid and a pretreated substrate containing the solid, C) -a step of enzymatic hydrolysis of the pretreated substrate from step (A) and / or from the optional step (B), carried out in the presence of cellulolytic or hemicellulolytic enzymes, CI / C2) -optionally a fermentation step (Cl), the hydrolysis and fermentation taking place simultaneously or separately, and the fermentation being followed or not by a separation step (C2). I5 D) -a solid / liquid separation step after enzymatic hydrolysis and / or, when they exist after fermentation or separation, obtaining a woody banana residue E) - a drying step so that its water content is less than 15% by weight, and packaging of said woody powder residue devoid of the fibrous nature and whose particle size is between 15 and 900 μμ. 7. Method according to the preceding claims, characterized in that: 9θ - the woody residue in banana powder also has a grain density between 500 and 900 kg / m3, a loading density between 200 and 400 kg / m3, - drying takes place at a temperature of 80-150 ^e C, preferably 12O-125 ° C, - conditioning is a physical operation to separate the agglomerated particles, for example by stripping and / or unclogging and / or homogenization and / or grinding and / or pelletizing-grinding so as to obtain a banana powder whose particle size is between 15 and 900μμ, preferably between 20-500μμ having a water content of less than 15% by weight, and a grain density of between 500 and 900 kg / m, Step A) is carried out at a temperature of 120-250 ° C. and with a water content of the reaction medium of at least 35% by weight, - where it exists, step B) optionally includes washing of the solid and / or neutralization, - step C) is carried out at a temperature of 35-50 ° C, at a pH between 4 and 6, in the presence of enzymes from a strain selected from the group formed by Trichoderma, Aspergilius, Penicillium or Schizophyllum , Clostridium, preferably the strain is Trichoderma reesei, one of the preceding claims in which step D) is carried out: OJ - in the case where there is no fermentation or other treatment: immediately after enzymatic hydrolysis (step C) the fermentation (Cl) (alcoholic fermentation, preferably ethanolic) is carried out at a temperature of 25-40 ° C , in the presence of a yeast Saccharomyces cerevisiae, one of the preceding claims in which the woody powder residue is prepared without roasting. 8, Method according to one of the preceding claims, in which the woody residue from step D) of the process does not undergo chemical treatment before step E) characterized in that: - the gasification step is carried out in a dry flow gasifier with dry injection, with a driven bed, at a pressure of 20-80 bars and a temperature of 1200-1600 ”C; - the woody banana powder residue is fluidized in a mixture either with at least one other powder of lignocellulosic biomass origin of banana or plantain, or with at least one other powder of fossil origin; - the woody banana powder residue from step E) is packaged in the form of pellets or extruded, and, before being fluidized, it is ground to obtain said powder residue; gasification produces a syngas subsequently treated for the production of biofuels or other chemicals, or for energy use in combined cycle plants (example: banana biomass plants or cogeneration plants). 9. Process for the treatment of banana biomass by bio-chemical route according to the figure (XII / XV) comprising: a) -a step of biochemical treatment of wet biomass in hard cake, in order to obtain bioethanol; b) a step of biochemical treatment of the wet biomass in hard cake, in order to obtain biogas or bimane; c) -a step of processing dry banana biomass granules, in order to obtain bioelectricity by cogeneration; d) - a step of processing the banana biomass digestate, in order to obtain solid or liquid organic fertilizers; e) - a step of processing the hard cake of wet banana biomass, in order to obtain paper pulp. 10. Process for the treatment of banana biomass thermochemically according to the figure (XV / XV) comprising a step of treatment of dry powdered biomass, in order to obtain the biofuels (biodiesel, biokerozene and ..).