EP1576857A1

EP1576857A1 - Chemical synthesis comprising heat treatment by intermittent dielectric heating, combined with a recycling system

Info

Publication number: EP1576857A1
Application number: EP03815414A
Authority: EP
Inventors: Pierre Charlier De Chily; Mikaele Raynard
Original assignee: Aldivia SAS
Current assignee: Aldivia SAS
Priority date: 2002-12-23
Filing date: 2003-12-17
Publication date: 2005-09-21
Also published as: JP2006516008A; FR2849343B1; US8328997B2; JP2013139033A; JP2020006368A; FR2849343A1; JP6646446B2; US20060228088A1; US20100025227A1; US9756687B2; JP2016120491A; EP4084579A1; WO2004066683A1; AU2003300634A1; JP2009226405A; US20150136757A1; JP2018047458A; US20130102804A1

Abstract

The invention concerns the design of a method by intermittent dielectric heating combined with a recycling system. Said method consists in subjecting the reagents to electromagnetic waves selected in the frequencies ranging between 300 GHz and 3 MHz intermittently using a recycling system. Said method enables the treatment of oils which are hardly absorbent and great investments savings. The method enables operation on different scales, whether in laboratories, on a semi-industrial or industrial scale, without forfeiting the advantages of continuous dielectric heating.

Description

Chemical synthesis comprising a heat treatment by intermittent dielectric heating, combined with a recirculation system

Technical sector of the invention and problem posed:

Whatever the complexity of the molecule to be manufactured, the chemist seeks to reduce the reaction times and the number of steps necessary for the synthesis of said molecule in a constant concern for profitability.

Numerous studies have been carried out with the aim of controlling the various parameters that can influence the course of a reaction and its speed. Adjuvants such as solvents and catalysts have been widely used. Although these compounds boost the reaction medium, they are sometimes toxic to humans and the environment and they require economically disadvantageous post-treatments such as neutralization, washing, drying, filtration.

Today, the trend is towards simple, economical manufacturing processes, respectful of man and his environment.

Physical processes have been tested: the use of ultrasound, high frequencies and recently microwaves.

The various tests carried out using dielectric heating, that is to say heating at microwave or high frequency frequencies, have revealed the advantage of this new technology: dielectric heating indeed saves time and considerable energy, combined with a lower investment cost; the reactions no longer require the use of solvent or catalyst; burn-up and unwanted reactions are avoided.

The current high frequency and microwave applicators are numerous but they are all configured so that the reaction medium is permanently exposed to electromagnetic waves in order to be able to benefit from the advantages of this new technology. The quantity of material treated is limited: it indeed depends on the dimensions of the waveguides, themselves standardized.

Summary of the invention:

The applicant has discovered a new heat treatment process involved in chemical synthesis: intermittent dielectric heating combined with a recirculation system. The reagents are subjected to electromagnetic waves intermittently using a recirculation system. The electromagnetic waves are chosen in the frequencies going from 300GHz to 3MHz.

This process is original and economical: it makes it possible to work on different scales, whether on the laboratory, semi-industrial or industrial scale, without losing the advantages of continuous dielectric heating.

Applications:

The invention makes it possible to carry out efficient and rapid heat treatments on different scales, as well on the laboratory, semi-industrial or industrial scale.

The present invention relates to all “thermal applications”, that is to say chemical syntheses involving heat treatment and which involve a single reagent, or a mixture of reagents, in variable proportions, with or without catalysts, with or without "process" gas.

As “thermal applications”, there may be mentioned, by way of nonlimiting examples, the esterification, transesterification, epoxidation, sulfation, phosphitation, hydrogenation, peroxidation, isomerization, dehydration, quaternization, amidification, polymerization, polycondensation reactions. , and all common treatments such as bleaching, deodorization and other volatile compound removal systems. The invention applies in fact very particularly to all the reactions of "iipochemistry".

This innovative technique makes it possible, for example, to manufacture polymers of unsaturated fatty acids, esters of unsaturated fatty acids, unsaturated hydrocarbons or derivatives of these products using intermittent dielectric heating under microwaves. The applicant has filed a patent application FR 98 13770 on this subject and a PCT patent application WO 00/26265 (PCT / FR 99/02646).

Prior art:

The technical sector of the present invention relates to the use of microwave or high frequency electromagnetic waves for any heat treatment.

> MO and HF frequencies

The microwave frequencies MO are between approximately 300 MHz and approximately 30 GHz, preferably at 915 MHz (authorized frequency with a tolerance of 1.4%) or 2.45 GHz (authorized frequency with a tolerance of 2%).

The high HF frequencies are between approximately 3 MHz and approximately 300 MHz, preferably at 13.56 MHz (authorized frequency with a tolerance of 0.05%) or at 27.12 MHz (authorized frequency with a tolerance of 0.6%).

> The absorbed power

The absorbed power Pa is a function of the incident power Pi and the losses of the system. For a product which absorbs little electromagnetic waves and for a given incident power Pi, the absorbed power Pa decreases and the losses increase, in particular those by static electricity.

Indeed, :

Pi = Pa + losses

With:

Pi = incident power in W

Pa = power absorbed in W

Losses = heat losses + static electricity

The power absorbed (in Watt) by a material under HF or MO treatment is given by the following formula:

Pa = kfε "E ² V

With:

Pa: power absorbed in W.

E: electric field created within the material in V / cm.

f: wave frequency

K: constant (MKSA) ≈ 5.56.10 ^"13

V: volume of the material in cm ³ .

ε ". material loss factor = ε'tangδ

ε ': real relative permeability of the material = ε ₀ ^* ε _r

ε _0: vacuum permeability ε _B. dielectric constant

tangδ: angle of losses

ε 'translates the ability of a material to orient itself in the field and tangδ its capacity to release heat.

Note: for air or vacuum, ε '= 1 (the lowest value for ε') and tangδ = 0, or ε "= 0.

> type of energy applicators

The choice of the type of energy applicator depends on the technology used (high frequencies or microwaves), the dimensional characteristics of the product to be treated and its mode of treatment.

For high frequency applicators, it is essentially:

- capacitive type applicators formed by two condenser plates between which the high frequency generator voltage is applied. They are used for the heat treatment of materials whose volume constitutes a parallelepiped, one of the sides of which is sufficiently thick (> 10mm).

- bar applicators for flat materials, consisting of tubular or bar electrodes. They are used for the heat treatment of materials whose volume constitutes a parallelepiped, one of the sides of which is not sufficiently thick (<10mm).

- applicators for filiform materials, formed of loops.

For microwave applicators, we can cite:

- localized field applicators: single-mode cavity

- diffuse field applicators: multimodal cavity - near-field applicators: guide with radiating antennas

Among these microwave applicators, there are on the market for example:

- synthewave 402 and synthewave 1000 which consist of reactors from 1mL to 100ml or 600mL

- Discover with reactors from 1 to 125mL

- Ethos MR with a capacity of less than 400mL

> risk of breakdown or electric arcs

The Applicant has filed a patent application FR No. 0108906 concerning an improved apparatus for the implementation of dielectric heating. In said patent, the invention relates to a new chimney shape or geometry, in particular a conical shape or geometry chimney, which makes it possible to heat any type of product under microwave or high frequencies, static or dynamic with a power density important without risk of electric arcs or "breakdown".

Those skilled in the art can refer to it for more details. For its convenience, here is a summary:

- In the case of poorly absorbent molecules, the choice of applicators is complicated. The applicator must indeed transmit a lot of electromagnetic energy to the product so that it can heat up while avoiding electric arcs.

- Heating under microwave frequencies is preferred to high frequencies for which the risk of breakdown is greater.

- The "single-mode" system (localized field) which is formed of single-mode cavities resonating at the emission frequency according to radiation in the direction of the guide, is preferred to the "multimode" (diffuse field). The single mode system avoids uneven distribution of the electric field and the presence of hot spots. Of similarly, this type of reactor promotes the stability of the exposed products.

- The single-mode applicator provided with usual cylindrical chimneys, the best suited among all the usual applicators with poorly absorbent molecules, does not allow working with a high power density without risk of breakdown.

- Introducing into the reaction medium polar compounds such as water, to play the role of energy transfer intermediary and thus reduce the power density required is however not satisfactory. Unwanted side reactions may take place, additional treatments such as neutralization, washing, drying or filtration may be necessary to purify the product at the end of the reaction.

- An alternative to overcome the problems associated with poorly absorbent compounds, consists in removing static electricity as it is formed on the external wall of the reactor. To evacuate static electricity, you must either promote good ventilation with humid air or another gas comparable in terms of its dielectric constants (example: sulfur hexafluoride SF6 under 1 bar) (1 ^èrΘ solution), or adapt the shapes of the chimneys so as to ventilate them ( ^2nd solution). The first solution does not seem advantageous for reasons of installation complexity, security and cost.

- The Applicant has discovered a new shape or geometry of a chimney, in particular a conical chimney, which makes it possible to heat any type of product under microwave or high frequency frequencies, static or dynamic, with a high power density without risk of 'electric arcs or' breakdown '.

Description of the invention: The applicant has discovered a new heat treatment process which consists in subjecting the reagent, alone or as a mixture, to electromagnetic waves intermittently, using a recirculation system.

The electromagnetic waves are chosen in the frequencies going from 300GHz to 3MHz.

This process retains the advantages of permanent dielectric heating while increasing the production capacity.

> Description of the material

The intermittent heating process is simple and economical. It consists :

- pumps

- reactors subject to the electromagnetic field

- a dielectric system: chimney applicators, generator waveguides, iris, short circuit piston, cooling systems

- buffer reactors

- bins

- a gas circuit, preferably an inert gas such as nitrogen

- condensers

- measuring devices

The pumps

The pump or pumps are of variable flow. It can be a feed metering pump and / or a recirculation pump or a vacuum pump. The flow rate of the recirculation pump influences the time it takes for a molecule to pass under the waves.

The pumps can be chosen as an indication from vane or piston pumps.

Reactors subject to the electromagnetic field

Reactors subjected to the electromagnetic field do not absorb waves (pyrex, quartz ...).

They are traditionally cylindrical in shape.

They are positioned inside the applicators.

Dielectric system: chimney applicators, generator waveguides, iris, short circuit piston, cooling systems

The applicators are formed from single-mode cavities which resonate at the emission frequency according to radiation in the direction of the waveguide.

The chimneys prevent leakage of waves to the outside of the waveguide. They are preferably of conical cylindrical shape, as indicated in the application of FR No. 0108906 of the present Applicant to limit the presence of electric arcs.

The waveguide (s) convey the electromagnetic waves. Each waveguide can be subdivided into two and only two waveguides.

The generators used are microwave or high frequency generators

The microwave frequencies MO are between approximately 300 MHz and approximately 30 GHz, preferably at 915 MHz (authorized frequency with a tolerance of 1.4%) or 2.45 GHz (authorized frequency with a tolerance of 2%). The high HF frequencies are between approximately 3 MHz and approximately 300 MHz, preferably at 13.56 MHz (authorized frequency with a tolerance of 0.05%) or at 27.12 MHz (authorized frequency with a tolerance of 0.6%).

The generators are fitted with a safety device which allows the incident waves to pass and diverts the reflected waves towards a water charge where the waves are absorbed

They also require the use of iris, short circuit piston to attenuate the reflected power and favor the absorption of the power emitted by the generator by the reaction mixture.

The system is equipped with cooling systems to prevent overheating.

Buffer reactors

Buffer reactors allow a larger amount of reaction mixture to be processed.

The bins

The system is equipped with feed tank (s), recipe tank (s), filtration tank (s).

The gas circuits

The heat treatments are carried out under a normal atmosphere or rich in oxygen or preferably inert.

Measuring devices

The system is equipped with measuring devices such as pressure gauges, thermocouples, flow meters. This process can be used in dynamic or continuous.

> Principle of intermittent heating

The entire reaction volume is not permanently exposed to the waves but all the molecules of the reaction mixture are intermittently subjected to the field.

Different configurations can be envisaged for implementing intermittent dielectric heating.

The first is to subject several reactors to electromagnetic waves. See figure 1

The second is to use several energy applicators on the same reactor. See figure n ° 2

The number of applicators depends on the temperature at which one wishes to work, on the quantity of product to be treated, on the time of rise to the reaction temperature, on the dielectric constants of the reagents.

Those skilled in the art will understand that these two configurations are not the only possible ones and that the invention relates to all the other intermediate positions.

In addition, the applicant has found an original system which consists in circulating the reaction mixture in a loop, thus reducing the investment costs with equivalent production capacity. Without this recirculation system, it would indeed be necessary to use a large reactor and a multitude of applicators to manage to heat the same quantity of products and arrive at the desired result, which would entail enormous costs.

See figure n ° 3

Intermittent dielectric heating combined with a recirculation system makes it possible to increase production capacities, limited with the permanent dielectric heating system, shown in Figure 4 or Figure 3 if the applicators cover the entire volume to be treated . This process can be used in dynamic or continuous.

According to this configuration, the entire reaction volume is not permanently exposed to the waves but all the molecules of the reaction mixture are intermittently subjected to the field.

It should be noted that, according to this principle, the invention should logically not have worked, that is to say logically should not have produced good results. Indeed, a molecule will be subjected to electromagnetic waves only during a fraction of its circulation time, for example 1 s every 10 s. Anyone skilled in the art understands that this should have produced results that are either very weak (ineffective process) or zero: however, surprisingly, on the contrary, very good results are obtained, cf. below, and with the important benefits also mentioned here.

> Volume exposed to the electromagnetic field

The volume exposed to the electromagnetic field is calculated according to the formula below:

V (exposed to the field) = Et * R ² * H

With:

R = radius of the reactor exposed to the field

H = height of the reactor exposed to the field.

Parameter H:

The height of the reactor exposed to the field traditionally corresponds to that of the waveguide to allow the maximum amount of material to be treated at once.

Take the case of heat treatments under a single mode microwave, at 2450MHz. The height of the waveguide in TE 0.1 mode (Transverse Electric) is 45mm. The fundamental TE 0.1 excitation mode allows the wave to propagate along a single arch, unlike TE0.2 mode which has two field maxima, implying less homogeneous heating.

Take the case of heat treatments under a single-mode microwave, at 915 Hz. In this case, the height of the waveguide is equal to 124 mm.

Parameter R

The reactor is traditionally of cylindrical shape. Its diameter cannot exceed the width of the waveguide.

In the case of single-mode microwave applicators, under 2450MHz, the width of the waveguide recommended for staying in TE 0.1 (Transverse Electric) mode is between 70 and 100 mm approximately, and more particularly at 90mm.

In the case of single-mode microwave applicators, at 915MHz, the width of the waveguide recommended for staying in TE 0.1 (Transverse Electric) mode is around 250mm.

> Advantages of intermittent dielectric heating

Unlike the usual dielectric systems, the present invention surprisingly makes it possible to heat volumes of materials on an industrial scale while keeping the process economical. To do this, he designed an intermittent dielectric heating process, combined with a recirculation system.

The Applicant demonstrates by this present invention that the reagents benefit from the advantages of electromagnetic wave technology, without being permanently exposed to the field. Indeed, the benefits of dielectric heating are retained: 1 - significantly reduced reaction time;

2- reaction carried out in a single step;

3- no use of solvent;

4- energy saving (because times are significantly shorter);

5- absence of "burn-up" and sub-reactions.

Reagents:

For the present invention, the reagent (s) can be chosen from products that absorb little electromagnetic waves or products that absorb a lot or a mixture of the two, additives or not, of one or more catalysts or adjuvants that absorb little or a lot and or of process gas.

> vegetable oils

As oils of vegetable origin, there may be mentioned, inter alia, rapeseed oil, sunflower oil, peanut oil, olive oil, walnut oil, l corn oil, soybean oil, linseed oil, safflower oil, apricot kernel oil, sweet almond oil, hemp oil, grape seed oil, coconut oil, palm oil, cottonseed oil, babassu oil, jojoba oil, sesame oil, argan oil, thistle oil marie, pumpkin seed oil, raspberry oil, Karanja oil, Neem oil, flaxseed oil, Brazil nut oil, castor oil, castor oil dehydrated, hazelnut oil, wheat germ oil, borage oil, evening primrose oil, Tung oil, tall oil or "tall oil".

> oils or fats of animal origin

As oils or fats of animal origin, there may be mentioned, among others, sperm whale oil, dolphin oil, whale oil, seal oil, sardine oil, herring oil, shark oil, cod liver oil, beef foot oil, beef, pork, horse, mutton fats (tallow) .

> animal or vegetable oil components

One can also use components of animal or vegetable oils such as squalene extracted from unsaponifiables of vegetable oils (olive oil, peanut oil, rapeseed oil, corn germ oil , cottonseed oil, linseed oil, wheat germ oil, rice bran oil) or contained in large quantities in shark oil.

These oils and fats of animal or vegetable origin, as well as their derivatives, can undergo a preliminary treatment aimed at making them more reactive or on the contrary less reactive. The invention relates both to an isolated reagent and to a reaction mixture comprising two or more components. These reaction mixtures can comprise equivalent proportions of each component or certain components can be in the majority.

> hydrocarbons

As unsaturated hydrocarbons, there may be mentioned, alone or as a mixture, and by way of nonlimiting examples, an alkene, for example one or more terpene hydrocarbons, that is to say one or more polymers of isoprene, or one or more polymers of isobutene, styrene, ethylene, butadiene, isoprene, propene, or one or copolymers of these alkenes.

As saturated hydrocarbons, there may be mentioned, inter alia, alkanes, for example ethane, propane.

> saturated and / or unsaturated esters

As esters of saturated and / or unsaturated fatty acids, it is possible to use alone or as a mixture and by way of nonlimiting examples, one or more esters obtained by esterification between a monoalcohol el / or polyol and at least one saturated and or unsaturated fatty acid; waxes; butters, phospholipids; spingolipids; glucolipids.

> saturated and / or unsaturated acids

As unsaturated fatty acids, there may be used, alone or as a mixture, and by way of nonlimiting examples, one or more saturated acids such as caprylic acid, lauric acid, myristic acid, acid palmitic, stearic acid, arachidic acid, behenic acid, lignoceric acid, cerotic acid, one or more monounsaturated fatty acids such as oleic acid, palmitoleic acid, myristic acid, l petroselenic acid, erucic acid; one or more polyunsaturated fatty acids such as for example linoleic acid, alpha and gamma linolenic acids, arachidonic acid; EPA eicosapenten-5c- 8c- 11c-14c-oic acid, DHA dodosahexen-4c-7c-10c-13c-16c-19c-oic acid, one or more acids comprising conjugated dienes or conjugated trienes such as licanic acid, the isomers of linoleic and linolenic acids; one or more acids comprising one or more hydroxyl groups such as ricinoleic acid.

> alcohols

As alcohols, there may be mentioned, inter alia, glycerol, sorbitol, sucrose, mannitol, xylitol, neopentylglycol, pentaerythritol, sucrose, galactose, glucose, maltose, maltotriose, fructose, maltitol, lactitol, lactose, ribose, mellibiose, cellobiose, gentiobiose, altrose, gulose, polyalkyleneglycols, polyglycerols, polyphenols, alkylpolyglucosides, polygiucosides, glycol, pentaerythritol, ethane 1, 2 diol, 1, 4 butanediol, 1, 6 hexanediol, amino alcohols (for example diethanolamine DEA triethanolamine TEA, 3-amino 1, 2 propanediol), epoxy alcohols, saturated or unsaturated fatty alcohols (example: myristyl alcohol, oleyl alcohol, lauryl alcohol), linear or branched alcohols, vitamins (for example tocopherol, ascorbic acid, retinol), sterols (including phytosterols), hemiacetals (for example 1-ethoxy -1-ethanol) , amino alcohols (e.g. ple 2-2'-amino ethoxy ethanol), epoxy alcohols (e.g. 2-3 epoxy-1-propanol), propanol, ethanol, methanol, tetradecyl alcohol and their analogs

The alcohols and their derivatives can undergo a preliminary treatment aimed at making them more reactive or, on the contrary, less reactive, such as, for example, hydrogenation, hydroxylation, epoxidation, phosphitation, lasulfonation.

> epoxies

As epoxides, there may be used alone or as a mixture and by way of nonlimiting examples, vernolic acid, cooronaric acid, 1,2-epoxy-9-decene, 3-4 epoxy-1 -butene , 2-3 epoxy-1 -propanol, fatty esters obtained by esterification between 2-3 epoxy-1 -propanol and a fatty acid (for example Cardura E10 ^® ).

> amino alcohols

As amino alcohols, monoethanolamine MEA, diethanolamine DEA triethanolamine TEA, 3-amino 1, 2 propanediol, 1-amino 2-propanol, 2- can be used alone or as a mixture and by way of nonlimiting examples. 2'- amino ethoxy ethanol.

> amines

As amines, there may be mentioned, inter alia, ammonia, primary, secondary, tertiary alkyl amines (ex: methylamine; dimethylamine; trimethylamine; diethylamine), fatty amines (ex: oleic amines; coconut alkyl amines), amino alcohols ( ex: monoethanolamine MEA; diethanolamine DEA; triethanolamine TEA; 3-amino 1, 2-propanediol; 1 - amino 2-propanol), ethoxylated amines (2-2'-amino ethoxy ethanol; amino 1-methoxy-3-propane) . All these amines can be saturated or not, linear or branched.

> catalysts

Among the catalysts or adjuvants, the following are intended to be non-limiting examples the usual acid catalysts (paratoluenesulfonic acid, sulfuric acid, phosphoric acid, perchloric acid, etc.), the usual basic catalysts (soda, potash, alkali metal alcoholate and of alkaline earth metals, sodium acetate, triethylamines, pyridine derivatives, etc.), acid and or basic resins such as Amberlite ™, Amberlyst ™, Purolite ™, Dowex ™, Lewatit ™, zeolites and enzymes, carbon blacks and activated carbon fibers.

The invention will be better understood on reading the description which follows, and nonlimiting examples below.

EXAMPLES

The examples below highlight the advantage of the invention and will allow the skilled person to easily extrapolate to other dimensions and / or geometries, without departing from the scope of the invention.

The following examples, which are in no way limitative, illustrate the advantage of the invention. They aim to show that the process by intermittent dielectric heating is economical and makes it possible to heat reaction volumes on an industrial scale, while benefiting from the advantages of this technology.

I- Volumes exposed to electromagnetic waves

The tests are carried out on a laboratory and industrial scale using 2 generators: 1 6kW magnetron generator operating at a frequency of 2450MHz for laboratory treatments

1 magnetron of 60kW operating at the frequency of 915MHz for industrial treatments

With:

D = diameter of the cylindrical reactors = 2R H = height of the waveguide

Unit Vexp = volume permanently exposed to waves for a reactor

Vexp total≈ volume permanently exposed to waves for reactors

V (exposed to the field) = π * R ² * H

11- Comparison between conventional heating and intermittent dielectric heating

a- synthesis of polyglycerol

The tests are carried out at 260 ° C, in the presence of 2% sodium acetate so as to obtain a polyglycerol with a viscosity at 50 ° C equal to 3600cP. They refer to patent application FR No. 0108906.

With:

V total glycerol = total volume of glycerol treated

Ratio V = ratio between the volume exposed to the waves and the total volume treated

b- synthesis of polyglycerol esters

Polyglycerol-6 dioletate synthesis

The tests are carried out in the presence of 0.25% sodium acetate at 230 ° C.

They refer to patent application FR No. 0108906.

With:

V total of the mixture = total volume treated

Polyglycerol-2 tristearate synthesis

The tests are carried out in the presence of 0.25% sodium acetate at 260 ° C

They refer to patent application FR No. 0108906.

With:

V total of the mixture = total volume treated

c- Conclusion:

Even if the entire reaction volume is not exposed to electromagnetic waves, the reaction times under intermittent dielectric heating are significantly lower than those obtained by conventional heating.

III- Comparison between intermittent dielectric heating and permanent dielectric heating

a- efficiency of intermittent dielectric heating

The table below shows the efficiency of intermittent dielectric heating compared to permanent dielectric heating, traditionally used.

The tests are carried out under the same conditions (composition of the reaction mixtures, temperatures, catalysts, etc.)

- on a laboratory scale (use of a synthewave 402) which uses permanent dielectric heating,

- at pilot scale using a 2450 MHz generator which uses intermittent dielectric heating

- and on a production scale using a 915 MHz generator which uses intermittent dielectric heating

The synthesis tested consists in manufacturing polymers of unsaturated fatty acids, esters of unsaturated fatty acids, unsaturated hydrocarbons, unsaturated derivatives of these compounds, alone or as a mixture.

With:

Mop = permanent microwave heating

Extrapolated mop = permanent microwave heating in the case of a treatment of 200kg of product.

Me = intermittent microwave heating

Vtreated = reaction volume treated

Ratio V = ratio between the volume exposed to electromagnetic waves and the total reaction volume

t reaction = reaction time

**: processing a large quantity of products requires a reaction time greater than or equal to that corresponding to a lower quantity. The reaction time is 2h15 for 25mL of product. Also, we can say that it will take a reaction time greater than or equal to 2h15 to treat 200kg of the same mixture.

This table shows that the reaction times are unchanged whether working on 25mL, 2kg or 200kg. However in the case of pilot and industrial tests (2kg and 200kg), the entire volume is not subjected to dielectric heating:

- laboratory test (permanent dielectric heating): the entire volume is exposed to electromagnetic waves with Ratio = 1/1

- pilot test (intermittent dielectric heating): only 1/62 of the volume is exposed to the field.

- industrial test (intermittent dielectric heating): only 1/50 of the volume is exposed to the field

b- lower investment costs

If 200 liters of product had to be treated using permanent dielectric heating, the 200 liters would have to be exposed to electromagnetic waves.

When working at the frequency of 2450MHz, the maximum volume exposed per applicator is 32mL. This configuration is not advantageous here. It would indeed require 6250 applicators.

Working at the frequency of 915MHz, the maximum volume exposed per applicator is 1 L. It would therefore require 200 applicators

For the present invention, intermittent dielectric heating makes it possible to use only 4 applicators, ie 50 times less (ratio in accordance with that given in the preceding table) for the same production capacity.

We can compare the investment costs: X = investment cost of a system with intermittent dielectric heating, 4 ways, recirculation

Y ≈ investment cost of a system with permanent dielectric heating, 200 channels, without recirculation

Y = 10 ^* X

The investment cost would therefore be 10 times higher in the case of permanent dielectric heating compared to intermittent dielectric heating. This mainly comes from the cost of the applicators, which is significantly higher than the rest of the installation (buffer reactor, pump ...)

Claims

1 Heat treatment process involved in chemical synthesis, of the dielectric type, characterized in that said dielectric heating is carried out intermittently, that is to say that the reagent (s) are subjected to electromagnetic waves intermittently , in combination with a recirculation system.

2 Method according to claim 1 characterized in that the electromagnetic waves are chosen in the frequencies ranging from 300GHz to 3MHz.

3 Method according to claim 2 characterized in that the frequencies are chosen from:

> MO and HF frequencies

- MO microwave frequencies which are between approximately 300

MHz and around 30 GHz, preferably at 915 MHz (authorized frequency with a tolerance of 1.4%) or 2.45 GHz (authorized frequency with a tolerance of 2%).

the high frequencies H F which are between approximately 3 MHz and approximately 300 MHz, preferably at 13.56 MHz (authorized frequency with a tolerance of 0.05%) or at 27.12 MHz (authorized frequency with a tolerance of 0.6%).

4 Method according to any one of claims 1 to 3 characterized in that the entire reaction volume is not permanently exposed to dielectric waves but that all the molecules of the reaction mixture are intermittently subjected to the field. 5 Method according to any one of claims 1 to 4 characterized in that the reagent or reagents can be chosen from products absorbing little electromagnetic waves or products absorbing a lot or a mixture of the two, additive or not of one or several catalysts or adjuvants absorbing little or a lot and / or process gas.

6 Method according to claim 5 characterized in that the reagent (s) are chosen from:

> vegetable oils

rapeseed oil, sunflower oil, peanut oil, olive oil, walnut oil, corn oil, soybean oil, flaxseed oil, safflower oil, apricot kernel oil, sweet almond oil, hemp oil, grape seed oil, coconut oil, palm oil, seed oil cotton, babassu oil, jojoba oil, sesame oil, argan oil, milk thistle oil, squash seed oil, raspberry oil, Karanja oil , Neem oil, flaxseed oil, Brazil nut oil, castor oil, dehydrated castor oil, hazelnut oil, wheat germ oil, l borage oil, evening primrose oil, Tung oil, tall oil or "tall oil".

> oils or fats of animal origin

sperm whale oil, dolphin oil, whale oil, seal oil, sardine oil, herring oil, shark oil, cod liver oil, beef foot oil, fat from beef, pork, horse, sheep (tallow).

> animal or vegetable oil components

squalene extracts unsaponifiables from vegetable oils (olive oil, peanut oil, rapeseed oil, corn germ oil, cottonseed oil, linseed oil, l wheat germ oil, rice bran oil) or contained in large quantities in shark oil. > hydrocarbons

unsaturated: alone or as a mixture, an alkene, for example one or more terpene hydrocarbons, that is to say one or more polymers of isoprene, or one or more polymers of isobutene, styrene, ethylene, butadiene , isoprene, propene, or one or more copolymers of these alkenes.

saturated alkanes, for example ethane, propane.

> saturated and / or unsaturated esters

alone or as a mixture, one or more esters obtained by esterification between a monoalcohol and or polyol and at least one saturated and / or unsaturated fatty acid; waxes; butters, phospholipids; spingolipids; glucolipids.

> saturated and / or unsaturated acids

alone or as a mixture one or more saturated acids such as caprylic acid, lauric acid, myristic acid, palmitic acid, stearic acid, arachidic acid, behenic acid, lignoceric acid, cerotic acid, one or more monounsaturated fatty acids such as oleic acid, palmitoleic acid, myristic acid, petroselenic acid, erucic acid; one or more polyunsaturated fatty acids such as for example linoleic acid, alpha and gamma linolenic acids, arachidonic acid; EPA eicosapenten-5c- 8c- 11c-14c-oic acid, DHA dodosahexen-4c-7c-10c-13c-16c-19c-oic acid, one or more acids comprising conjugated dienes or conjugated trienes such as licanic acid, the isomers of linoleic and linolenic acids; one or more acids comprising one or more hydroxyl groups such as ricinoleic acid. > alcohols

glycerol, sorbitol, sucrose, mannitol, xylitol, neopentylglycol, pentaerythritol, sucrose, galactose, glucose, maltose, maltotriose, fructose, maltitol, lactitol, lactose, ribose , mellibiose, cellobiose, gentiobiose, altrose, gulose, polyalkyleneglycols, polyglycerols, polyphenols, alkylpolyglucosides, polyglucosides, glycol, pentaerythritol, ethane 1, 2 diol, 1, 4 butanediol, 1, 6 hexanediol, amino alcohols (for example diethanolamine DEA triethanolamine TEA, 3-amino 1,2 propanediol), epoxy alcohols, saturated or unsaturated fatty alcohols (example: myristyl alcohol, oleyl alcohol, lauryl alcohol), linear or branched alcohols, vitamins (for example tocopherol, ascorbic acid, retinol), sterols (including phytosterols), hemiacetals (for example 1-ethoxy -1 -ethanol), amino alcohols (for example 2-2 ' -amino ethoxy ethanol), epoxyalco ols (e.g. 2-3 epoxy-1 -propanol), propanol, ethanol, methanol, tetradecyl alcohol and their analogs

> epoxies

alone or as a mixture of vernolic acid, cooronaric acid, 1, 2-epoxy-9-decene, 3-4 epoxy-1 -butene, 2-3 epoxy-1 -propanol, fatty esters obtained by esterification between 2 -3 epoxy-1 -propanol and a fatty acid (for example Cardura E10 ^® ).

> amino alcohols

alone or as a mixture, monoethanolamine MEA, diethanolamine DEA triethanolamine TEA, 3-amino 1, 2 propanediol, 1-amino 2-propanol, 2-2'-amino ethoxy ethanol.

> amines

ammonia, primary, secondary and tertiary alkyl amines (e.g. methylamine; dimethylamine; trimethylamine; diethylamine), amines fatty (e.g. oleic amines; coconut alkylamines), amino alcohols (e.g. monoethanolamine MEA; diethanolamine DEA; triethanolamine TEA; 3- amino 1, 2-propanediol; 1-amino 2-propanol), ethoxylated amines (2- 2'- amino ethoxy ethanol; amino 1-methoxy-3-propane), these amines can be saturated or not, linear or branched.

7 Method according to claim 6 characterized in that oils and fats of animal or vegetable origin, as well as their derivatives, can undergo a preliminary treatment aimed at making them more reactive or on the contrary less reactive (both an isolated reagent and a reaction mixture comprising two or more components, these reaction mixtures being able to comprise equivalent proportions of each component or certain components being able to be majority).

8 Method according to claim 6 or 7 characterized in that the alcohols and their derivatives can undergo a preliminary treatment aimed at making them more reactive or on the contrary less reactive such as for example hydrogenation, hydroxylation, epoxidation, phosphitation, lasulfonation.

9 Method according to any one of claims 1 to 8 characterized in that it uses as catalysts or adjuvants:

> catalysts

the usual acid catalysts (paratoluenesulfonic acid, sulfuric acid, phosphoric acid, perchloric acid ...), the usual basic catalysts (sodium hydroxide, potassium hydroxide, alkali metal and alkaline earth metal alcoholate, sodium acetate, triethylamines, pyridine derivatives ...), acid and or basic resins such as Amberlite ™, Amberlyst ™, Purolite ™, Dowex ™, Lewatit ™, zeolites and enzymes, carbon blacks and activated carbon fibers.

10 Method according to any one of claims 1 to 9 characterized in that the volume exposed to the electromagnetic waves is:

with 1 6kW magnetron generator operating at a frequency of 2450MHz for laboratory treatments

With:

D = diameter of the cylindrical reactors = 2R

H = height of the waveguide

Unit Vexp = volume permanently exposed to waves for a reactor

Vexp total≈ volume permanently exposed to waves for reactors

V (exposed to the field) = π * R ² * H

1 1 Device for implementing the method according to any one of claims 1 to 10 characterized in that it comprises or consists of:

AT

of pumps

of reactors subject to the electromagnetic field - a dielectric system: chimney applicators, generator waveguides, iris, short circuit piston, cooling systems

- buffer reactors

- bins

- a gas circuit, preferably an inert gas such as nitrogen

- condensers

- measuring devices

-and in particular B

- pumps

The pump or pumps are of variable flow.

It can be a feed metering pump and / or a recirculation pump and / or a vacuum pump. The flow rate of the recirculation pump influences the time it takes for a molecule to pass under the waves.

The pumps can be chosen as an indication from vane or piston pumps.

-one or more reactors subjected to electromagnetic waves

a) Reactors subjected to the electromagnetic field do not absorb waves (pyrex, quartz ...).

b) They are traditionally cylindrical in shape.

c) They are positioned inside the applicators.

- a dielectric system: energy applicators, chimneys, waveguides, generator, iris, short circuit piston, cooling systems.

a) The applicators are formed from single-mode cavities which resonate at the emission frequency according to radiation in the direction of the waveguide. b) Chimneys prevent leakage of waves to the outside of the waveguide. They are preferably of conical cylindrical shape, as indicated in patent application FR No. 0108906 of the present Applicant to limit the presence of electric arcs.

c) The waveguide (s) convey the electromagnetic waves. Each waveguide can be subdivided into two and only two waveguides.

d) The generators used are microwave or high frequency generators

e) The MO microwave frequencies are between approximately 300 MHz and approximately 30 GHz, preferably at 915 MHz (authorized frequency with a tolerance of 1.4%) or 2.45 GHz (authorized frequency with a tolerance of 2%).

f) The high HF frequencies are between approximately 3 MHz and approximately 300 MHz, preferably at 13.56 MHz (authorized frequency with a tolerance of 0.05%) or at 27.12 MHz (authorized frequency with a tolerance of 0.6%).

g) The generators are fitted with a safety device which lets the incident waves pass and diverted the reflected waves towards a water charge where the waves are absorbed

h) They also require the use of iris, short circuit piston to attenuate the reflected power and favor the absorption of the power emitted by the generator by the reaction mixture.

i) The system is equipped with cooling systems to prevent overheating.

- buffer reactors

Buffer reactors allow a larger amount of reaction mixture to be processed.

-bins The system is equipped with feed tank (s), recipe tank (s), filtration tank (s).

- gas circuits

- measuring devices

The system is equipped with measuring devices such as pressure gauges, thermocouples, flow meters.

12 Device according to claim 11 characterized in that the method can be used in dynamic or continuous.

13 Device according to claim 11 or 12 characterized in that it uses as an energy applicator

> type of energy applicators

- For high frequency applicators, these are essentially:

- bar applicators for flat materials, consisting of tubular or bar electrodes. They are used for the heat treatment of materials whose volume constitutes a parallelepiped, one of the sides of which is not sufficiently thick (<10mm). applicators for filiform materials, formed of loops.

For microwave applicators, we can cite:

- localized field applicators: single-mode cavity - diffuse field applicators: multimodal cavity

- near-field applicators: guide with radiating antennas,

14 Device according to any one of claims 1 1 to 13 characterized in that

- The “single-mode” system (localized field) which is formed of single-mode cavities resonating at the emission frequency according to radiation in the direction of the guide, is preferred to the “multimode” (diffuse field).

- The applicator is fitted with standard cylindrical chimneys.

- The device includes good ventilation by humid air or by another gas comparable in terms of its dielectric constants (example: sulfur hexafluoride SF6 under 1 bar) or forms of chimneys adapted to evacuate static electricity which forms on the outer wall of the reactor.

15 Device according to any one of claims 11 to 14, characterized in that one uses a geometry of chimney, in particular conical chimney.

16 Device according to any one of claims 11 to 15 characterized in that the reactor is traditionally of cylindrical shape, its diameter not being able to exceed the width of the waveguide.

17 Device according to any one of claims 11 to 16 characterized in that in the case of single-mode microwave applicators, under 2450MHz, the width of the waveguide recommended to remain in TE 0.1 (Transverse Electric) mode is between 70 and 100 mm approximately, and more particularly at 90mm.

18 Device according to any one of claims 11 to 16 characterized in that in the case of single-mode microwave applicators, under 915MHz, the width of the waveguide recommended to remain in TE 0.1 (Transverse Electric) mode is located towards 250mm. 19 Device according to any one of claims 1 1 to 18 characterized in that the dielectric system comprises applicators, chimneys, waveguides, generator, iris, short circuit piston, cooling systems, as follows:

- The applicators are formed from single-mode cavities which resonate at the emission frequency according to radiation in the direction of the waveguide.

The chimneys prevent leakage of waves to the outside of the waveguide. They are preferably of conical cylindrical shape, as indicated in patent application FR No. 0108906 of the present Applicant to limit the presence of electric arcs.

we also make use of iris, short circuit piston to attenuate the reflected power and favor the absorption of the power emitted by the generator by the reaction mixture.

20 Method and Device according to any one of claims 1 to 19 characterized in that the heat treatments are carried out under a normal atmosphere or rich in oxygen or preferably inert.

21 Applications of the method according to any one of Claims 1 to 10 and 20 and of the device according to any one of Claims 11 to 19 in all "thermal applications", that is to say chemical syntheses involving heat treatment and which involve a single reagent, or a mixture of reagents, in variable proportions, with or without catalysts, with or without "process" gas.

22 Applications according to claim 21 characterized in that as "thermal applications", there may be mentioned, by way of nonlimiting examples, the esterification reactions, transesterification, epoxidation, sulfation, phosphitation, hydrogenation, peroxidation, isomerization , dehydration, quaternization, amidification, polymerization, polycondensation, and all the usual treatments such as discoloration, deodorization and other volatile compound removal systems.

23 Applications of the method according to any one of claims 1 to 10 and 21 and of the device according to any one of claims 11 to 19 to all the reactions of "lipochemistry".

24 Applications of the method according to any one of claims 1 to 10 and 21 and of the device according to any one of claims 11 to 19 for manufacturing polymers of unsaturated fatty acids, esters of unsaturated fatty acids, unsaturated hydrocarbons or derivatives of these products using intermittent dielectric heating in the microwave.

25 Specific applications of the method according to any one of claims 1 to 10 and 21 and of the device according to any one of claims 11 to 19 to the synthesis of:

polyglycerol

polyglycerol esters

polyglycerol-6 dioletate

polyglycerol-2 tristearate