Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D11/00—Solvent extraction
  • B01D11/02—Solvent extraction of solids
  • B01D11/028—Flow sheets
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08B—POLYSACCHARIDES; DERIVATIVES THEREOF
  • C08B37/00—Preparation of polysaccharides not provided for in groups C08B1/00 - C08B35/00; Derivatives thereof
  • C08B37/0006—Homoglycans, i.e. polysaccharides having a main chain consisting of one single sugar, e.g. colominic acid
  • C08B37/0036—Galactans; Derivatives thereof
  • C08B37/0039—Agar; Agarose, i.e. D-galactose, 3,6-anhydro-D-galactose, methylated, sulfated, e.g. from the red algae Gelidium and Gracilaria; Agaropectin; Derivatives thereof, e.g. Sepharose, i.e. crosslinked agarose
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08B—POLYSACCHARIDES; DERIVATIVES THEREOF
  • C08B37/00—Preparation of polysaccharides not provided for in groups C08B1/00 - C08B35/00; Derivatives thereof
  • C08B37/0006—Homoglycans, i.e. polysaccharides having a main chain consisting of one single sugar, e.g. colominic acid
  • C08B37/0036—Galactans; Derivatives thereof
  • C08B37/0042—Carragenan or carragen, i.e. D-galactose and 3,6-anhydro-D-galactose, both partially sulfated, e.g. from red algae Chondrus crispus or Gigantia stellata; kappa-Carragenan; iota-Carragenan; lambda-Carragenan; Derivatives thereof

Definitions

• the subject of the present invention is a process for extracting and producing hydrocolloid polymers from plant or animal material.
• the invention may relate to various technical sectors, both in the context of the implementation and of the applications of the actual extraction process and of the production, which comprises various stages, from the grinding of the raw material itself up to to the drying of the product obtained through different specific steps as described below.
• agar or agar it is a phycocolloid located in the cell wall of red algae of the genus Gracilaria, Gelidium and / or Pterocladia for the most part;
• Agar-Agar designates a substance which gives up boiling water a mucilage which becomes jelly while cooling: one thus obtains a gel in cold solution below 40 ° C which can only reform a solution once brought back to the boil.
• Such a characteristic is used in various fields such as for the solidification of bacteriological culture media, in foodstuffs to prepare jams, express creams, sauces, etc. the paper industry, in that of fabrics for making finishes, in pharmacies as an emulsifying agent or as a laxative.
• this colloid having a melting point distant from its gelling point which is called hysteresis
• hysteresis is also used to carry out its extraction of algal tissues in water brought to the boil at least in a tank or in a tank. ; to then obtain a dry extract, the cooled solution solidifying, use to date prior to drying, different techniques which range from pressing to freezing / thawing through centrifugation in order to reduce the amounts of water to be evaporated.
• Fluidized bed drying is then carried out and the yields generally observed are in the range of 16 to 20% of the quantity of agar extracts recovered relative to the quantity of dry algae used during the treatment.
• KOGIMA et al in 1960, and GUISELEY in 1968 used a higher temperature and pressure in autoclaving to reduce the heating time; MATSUHASHI in 1971 added phosphates to improve extraction; SAINT MARTIN et al in 1988 describes the effect of cellulase to improve extraction yields; and VERDUGO in CHILE in 1993 recommends a pre-treatment of swelling to reach the announced but unverified yields of 50 to 75%.
• the most generally used extraction and production process to date combines different stages which are, with regard to the actual extraction phase, autoclave and steam systems and then with regard to the concentration of freezing / thawing systems and for drying fluidized bed devices; the different variants depending on the type of algae used, relate to the extraction aids, such as acids, bases, bleaches, etc.
• the tanks can be agitated, but despite this, the heat transfer which takes place either through a double jacket or using coils immersed in the tank, never allows temperature uniformity throughout the mass thereof, the temperature being of course higher near the exchange walls and much lower in the center of the tank for example.
• the problem is therefore to be able to extract and produce hydrocolloid polymers from plant or animal materials, such as water-soluble polysaccharides including carrageenans and / or Agar-Agar, by optimizing in particular the two extraction parameters that are the temperature and the quantity of water to improve both the yield of the quantity of product extracted compared to the quantity of dry algae used during the treatment as well as the economic balance of this extraction then of the production including in particular the energy balance; moreover, this must make it possible to reduce the volume, the importance and the maintenance of the equipment necessary for such an extraction and to facilitate their implementation and their control.
• plant or animal materials such as water-soluble polysaccharides including carrageenans and / or Agar-Agar
• the raw material, mixed with water and sodium carbonate is introduced into a reaction chamber which, instead of being formed by a conventional container, is in the form of a tube about two hundred millimeters in diameter and one hundred and twenty meters in length, bent several times at an angle of one hundred and eighty degrees.
• the mixture which is introduced into this chamber under the control of a simple valve, is brought to the treatment temperature, of the order of one hundred and thirty five degrees Celsius, over at most the first six hundred millimeters of its long course. of the tube.
• the high viscosity of the mixture during treatment causes pressure drops.
• the mixture is cooled to a temperature of the order of one hundred and fifteen degrees Celsius, from which there is still a risk of vaporization.
• a solution to the problem posed is a method and a device making it possible to implement this method as shown diagrammatically in the attached single figure, for extracting hydrocolloid polymers from plant or animal material 4, such as:
• said vegetable or animal material is ground 2 according to a particle size given as a function of this material, in order to obtain an exchange surface of the latter, in the following stages of the process, which is as high as possible and, preferably, above a minimum value which is at least of the order of that accepted in the processes used to date,
• the said material thus ground is diluted 5 in water, at a rate which also depends on this material,
• the residues 10 of material are then separated 9 from the juice containing the said polymers which are concentrated 13, 14 by any means, until a given rate is obtained for a desired final product 15.
• any plant material containing water-soluble polysaccharides is selected which is ground to obtain particles of 0.1 to 5 millimeters; these particles are mixed with water in a proportion of 1 / 15th to 1 / 25th and the said mixture is circulated in the said heating tubes which bring it to a temperature of 90 ° C to 145 ° C for 10 to 40 minutes .
• algae containing Agar-Agar are selected as said plant materials.
• each piece of equipment in which a treatment is thus carried out continuously according to a step of the method according to the invention is supplied by fluid pipes; this is the juice produced by the upstream equipment, in which another specific treatment, corresponding to the previous stage of the process, was carried out; the juice is then supplied after treatment to the downstream equipment, corresponding to the next step of the process according to the invention; and so on until the treatment and the final equipment such as for example drying 14, possibly followed by cooling 18.
• the juice can be used at the outlet of any equipment located after that allowing of course the extraction by dilution and heating, without going to treatment with the following equipment (s), or by using d other types of treatment and / or equipment.
• the process according to the invention firstly presents all the recognized advantages of a continuous process, namely flexibility of use, simple and immediate adjustment of the operating conditions, such as the flow rate and therefore the time of stay of the material in the heating tubes as well as the heating temperature itself, the limitation of production stoppages by the existence for example of one or more launching tanks upstream of the heating pipes, allowing a permanent supply, etc. ...
• Another important advantage of the process according to the invention is the homogeneity of the treatment undergone by the product since in the said heating tubes, the temperature within the product which circulates therein, is identical in all points of this product, insofar as the internal dimension of section of the pipes is sufficiently small, such as for example of the order of 20 millimeters; such a weakness of dimensions also allows a good regulation of the temperature which can be maintained for example to within 1 degree compared to the desired temperature thanks to the arrangement of the various systems of probes preferably external to the passage section, for example, whereas in the tank systems known to date, such temperature control and regulation, in addition to the problems of homogeneity, is very difficult to obtain; However, if we increase the temperature too much above a given temperature, we risk destroying the product that we want to extract and if, on the contrary, the temperature is too low, we no longer extract it enough which explains without partly doubts the low yield obtained to date in known installations.
• the homogeneity of the dissolved product as well as of the treatment is also reinforced by the presence of numerous bends or changes of direction of the pipes that can be produced in the installation, playing in a way a role of product mixer and homogenizer. of temperature.
• Such heating tubes can be made of piping elements, arranged in series and / or in parallel and heated by any means such as for example electrical resistances then avoiding the presence of a boiler and a heat transfer fluid, thus reducing the consumption costs and the problems inherent in the use of steam for example.
• electrical resistors which can be of the Joule effect type or according to any other type of assembly, allows production to be stopped and resumed easily, as well as very good regulation of the process, with respect to a fluid. heat carrier, as well as a rapid rise in temperature of the order of a few minutes.
• the energy consumed is, for the extraction phase proper, the sum of that corresponding to the pumping power and that necessary for heating the tubes, with possibly that of cooling necessary to bring the product below 100 ° C at the outlet of these heating tubes, for the following treatments , but it is also possible according to the present invention, to do without such a cooler.
• the heat losses are moreover negligible and the residence time of the product in the heating tubes is short, and in any case less than the conventional systems used to date which are one to two hours.
• the said algae used in the process according to the invention are preferably washed beforehand 3, then crushed 2 to obtain particles with a size varying from 0.1 to 5 millimeters, but preferably rather greater than 1 millimeter to then allow their decantation, facilitating the liquid and solid separation operations; the above particle size obtained by grinding 2, must however allow a sufficient exchange surface to allow the dilution of the Agar-Agar according to the process of the invention.
• a volumetric pump 63 can be used, ensuring the admission of algae from a first launch tank 8 and another 64, for the entry of water, so that the mixture either entrained either directly without risk of settling for the process according to the invention in the chosen ratio, such as 1/20, and at the desired flow rate according to the size of the installation and the desired production, or after a tank of dilution 5 of low buffer volume with a 7 T stirring system.
• the size of the particles mentioned above and the ratio of dry algae to the volume of water makes it possible to optimize the release of the colloid in the water during its extraction in order to dissolve a maximum of it in a minimum of 'water.
• algae having a relatively high density compared to that of water tend to have a low flow rate to line the bottom of the tubes 16 and not to travel through the entire installation 1: this can be avoided with high speeds.
• sufficiently high traffic such as in particular with a high flow in small diameter pipes, which is generally the case for industrial installations and ensuring a speed of the order of at least one meter per second.
• the extractor 1 of Agar-Agar by heating allowing its dilution is therefore a tubular system 16, that is to say a set of heating pipes arranged in parallel and in series, such as by effect joule or by electrical resistance, likely to bring the reaction mixture between 90 "C and 145 ° C and preferably at 135 ° C for 10 to 40 minutes and preferably 20 minutes.
• each suspended algae particle undergoes exactly the desired treatment, authorizes a maximum extraction of 50% of Agar-Agar yield relative to the weight of the initial dry algae, while the tank systems used to date do not allow a contact time under ideal conditions and therefore such optimization, both of the yield relative to the initial weight of algae and of the energy total consumed.
• pipe diameter must also be optimal, on the one hand, do not create too great a pressure drop and risk blockage and on the other hand, keep a sufficiently high flow speed for the reasons mentioned above -above.
• a diameter of the order of 15 to 40 millimeters can be a good compromise, such as 18 millimeters then ensuring for a flow rate of 1 cubic meter per hour, a circulation speed of the order of 1 meter per second.
• the pressure in the installation must therefore be sufficient so that there is no risk of vaporization; for this, it is therefore necessary that the overpressure both at the inlet and at the outlet of the installation is higher than that of the vaporization pressure, or for 120 ° C, 0.194 MPa and at 130 ° C, 0.268 MPa. To therefore have a certain safety margin, it is necessary to maintain in the installation 1 an always higher pressure and of the order of 3 bar, which can be created naturally by a flow of the fluid in pipes of length and diameter chosen, to obtain a pressure drop equal to 0.3 MPa.
• a necessary length of pipe of 469 meters is required, or for a diameter of 15 millimeters, a length of 346 meters, or for a diameter of 12 millimeters a length of 267 meters.
• another constraint to be observed in the process according to the invention is the residence time of the diluted algae particles in the heated part which must be of the order of approximately 20 minutes, which for a flow rate of 1000 liters per hour, requires a total volume of tubular chamber of 335 liters.
• a pipe 469 meters in diameter in 18 millimeters represents only 119 liters; it is therefore necessary to have both the sufficient back pressure and the desired volume, to have a first tubular assembly of larger diameter satisfying the requirements of the volume, followed by a tubular assembly of smaller diameter to create the minimum desired pressure drop defined above, such as for example 322 meters from a 36-millimeter tube, followed by 267 meters from a 12-millimeter tube or even 166 meters from a 48-millimeter tube, followed by 346 meters of a 15 millimeter tube.
• said heating tubular assembly 1 which can be defined as comprising a first stage which can be qualify as a Joule effect driver to raise the product to the optimum temperature desired, followed by a second stage, known as a chamberer, with a large diameter and maintaining the product at the desired temperature for the minimum duration desired, and finally a third stage known as restrictor of smaller diameter conduits, ensuring sufficient back pressure, the whole solution then passes through a means of separation 9 of the residues in order to recover the juice containing the hydrocolloid polymers such as Agar-Agar, such as in a centrifugal wringer 9 continuously self-cleaning, dimensioned in proportion to the preceding reactor 1, the precipitated residues 10 having a final mass equal to three times that initial.
• a means of separation 9 of the residues in order to recover the juice containing the hydrocolloid polymers such as Agar-Agar, such as in a centrifugal wringer 9 continuously self-cleaning, dimensioned in proportion to the preceding reactor 1, the precipitated residues 10 having
• the centrifugal gravity force applied to the particles is sufficient, such as that created by a rotation speed of the order of 7000 rpm, the clarification of the juice is excellent and allows continuous operation, as in the reactor extractor 1 previous.
• the solution obtained then containing agar of 1.5 to 2.5% approximately of dilution, can be conveyed for example towards a tank 12, of agitated storage l ⁇ -, to avoid solidification of the total volume and serving as a buffer before the following steps.
• filtration 11 on a candle filter can then be recommended after the centrifugal wringer 9, in particular for uses in biology.
• Bleaching can also be recommended in particular embodiments, such as on cationic ion exchange resins 17, in the form for example NH4 + , allowing demineralization of the extraction juice and anionic, in the form for example Co3-, allowing actual discoloration; the said resins being in a weight ratio relative to the volume of the colloid solution, 1/6 and the flow being upward.
• ammonium and carbonate ions is that they are vaporizable during drying, the resulting Agar being then desalted.
• the juice thus obtained can then be concentrated such as in an evaporator 13 under vacuum, to bring its titration which is of the order of 1.5 to 2.5% as indicated above, ie for example 2%, up to at least 10%, preferably around 20% by weight-volume ratio.
• conditionable powder such as in an atomization tower 14 or other means making it possible to reduce the humidity of the powder. obtained up to a rate of the order of 5 to 10%.
• phases of separation of residues and of concentration until the drying possibly necessary according to the application and according to the process of the invention are preferably those indicated above, although other means can be retained; those preferentially described and represented in the single attached figure allow to remain in production and in continuous treatment, always in the form of liquid, following the extraction phase proper by dilution 5 then heating 1 for the extraction of the Agar- Agar, from crushed algae 2, even if these process steps have a lower energy balance than in other methods, such as concentration by freezing / thawing but which does not allow a continuous process.
• the process of the present invention can also be applied to algae residues which have already been used during a first extraction according to a known process, in order to further extract therefrom what would remain in said algae, and thus supplement the yield of production; tests according to the method described above were carried out on Gelidium algae residues which have therefore already been treated for the extraction of Agar in a factory of a European industrial group; 5 kilos of such residues after circulation then according to the method of the invention in the tubular reactor with a volume of 100 liters of water, after a treatment of 20 minutes at 135 ° C., made it possible to recover a further 0.650 grams of Agar , or approximately 13% of the dry weight of starting residues.
• a vacuum progressively produced around -0.04 MPa allows a boiling temperature around 75 ° C of the solution, and the temperature of the inlet vapor is limited to 105 ° C.
• the condensation rate recovered at the end of the experiment is measured at 262.5 liters, ie a final concentration of the initial solution brought to 20%.
• This solution kept permanently at 'more than 70 ° C remains sufficiently fluid to be then injected into an atomizer 14, by a nozzle spraying the solution at the top of the device.
• the incoming air is set at 135 ° C and the outlet temperature is 85 ° C; a very fine colorless powder, titrating
• the process of the invention does not use a sufficient viscosity of the mixture during processing, but on the contrary its fluidity and a tuburlent regime favorable to mass transfers.
• Heating takes place over the entire length of the treatment path, resulting in optimum efficiency.
• calculation software is provided to regulate the installation.
• the back pressure which is obtained makes it possible to avoid vaporizations in the tube.
• the back pressure pipe is replaced by a pneumatic valve.
• the butterfly valves or the like are to be excluded because they can induce clogging. lo
• the outlet temperature is kept below one hundred degrees Celsius which eliminates the risk of vaporization.

Landscapes

• Chemical & Material Sciences (AREA)
• Life Sciences & Earth Sciences (AREA)
• Health & Medical Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Biochemistry (AREA)
• Engineering & Computer Science (AREA)
• Molecular Biology (AREA)
• Materials Engineering (AREA)
• General Health & Medical Sciences (AREA)
• Medicinal Chemistry (AREA)
• Polymers & Plastics (AREA)
• Organic Chemistry (AREA)
• Polysaccharides And Polysaccharide Derivatives (AREA)
• Extraction Or Liquid Replacement (AREA)

Applications Claiming Priority (3)

Publications (1)

Family

ID=9479633

Family Applications (1)

Country Status (4)

Family Cites Families (2)

• 1995
  • 1995-05-24 FR FR9506611A patent/FR2734569B1/fr not_active Expired - Fee Related
• 1996
  • 1996-05-22 MA MA24249A patent/MA23881A1/fr unknown
  • 1996-05-23 WO PCT/FR1996/000772 patent/WO1996037518A1/fr not_active Application Discontinuation
  • 1996-05-23 EP EP96917537A patent/EP0772635A1/de not_active Withdrawn

Non-Patent Citations (1)

Also Published As

Similar Documents

Legal Events