MXPA99007643A

MXPA99007643A - A continuous process for effecting gas liquid reactions

Info

Publication number: MXPA99007643A
Application number: MXPA/A/1999/007643A
Authority: MX
Inventors: Fanelli Pasquale
Original assignee: Cp Tech Srl
Priority date: 1997-02-25
Filing date: 1999-08-18
Publication date: 2000-01-01

Abstract

The present invention relates to a continuous process for the production of polyadducts of alkylene oxide on a chain initiator with at least one active hydrogen. The process is characterised in that it comprises the step of:(a) providing n reaction units constituted by a tubular reactor (11), and a heat exchanger (14) downstream of the tubular reactor (11);(b) supplying the preheated chain initiator and the alkylene oxide to the reactor of the first reaction unit;(c) reacting the chain initiator with the alkylene oxide to obtain a first mixture;(d) cooling the first mixture by means of the heat exchanger (14);(e) supplying the reactor of the following reaction unit with the cooled mixture and with alkylene oxide;(f) repeating the procedure until the last reaction unit and then discharging the last mixture containing the desired product.

Description

A CONTINUOUS PROCESS TO PERFORM GAS-LIQUID REACTIONS Description of the invention The present invention relates to a process for effecting gas-liquid reactions which occur with a liquid dispersion mechanism in gas. In particular, the present invention relates to a continuous process for the production of alkylene oxide polyadducts, by means of a polyaddition reaction on a chain initiator having at least one active hydrogen. These products, particularly the polyethylene oxides of ethylene and propylene, are mainly used as nonionic surfactants and polyether polyols. Nonionic surfactants are very widely used as wetting agents, dispersants, stabilizers, emulsifying agents and anti-emulsifiers, antifoaming and foaming agents and, in general, as auxiliary chemicals and functional fluids in the textile, paper, cellulose and pharmaceutical industries. , from REF .: 31090 foods, cosmetics, paints, resins, extraction and processing of minerals, advanced recovery and extraction of oil industries etc. In particular, the use of non-ionic surfactants based on natural or synthetic fatty alcohols, as primary components in the formulation of household and industrial detergents, and also of polyether polyols as the main intermediates in the production of polyurethanes (rigid foams) should be mentioned. , semi-rigid, flexible, elastomers, adhesives, sealants, etc.). Italian patent No. 1 226 405 discloses a method for the production of alkylene oxide polymerization products starting from alkylene oxides, ethylene and / or propylene oxides which are most commonly used, and compounds having an active or mobile hydrogen with suitable catalysts. The method of this patent uses a two-section reactor of which the upper part is called the gas-liquid reactor and the lower part is an accumulation tank, placed essentially horizontally. The gas-liquid reaction takes place in the upper section, the chain initiator is supplied from a plurality of spray or spray heads over a central distributor while the lower body acts as a receiver and for recycling through a pump and an external heat exchanger, the reaction product arriving from the upper section is re-fed to the latter to continue the polymerization reaction. The process described in the aforementioned patent, however, has several disadvantages. First of all, since this has to do with a semicontinuous process, the productivity per unit of time is considerably restricted by the need to discharge the contents of the reactor periodically. Since internal distributors are provided, the surface-volume ratio of the reactor used in this process is very high, thereby increasing the likelihood of side reactions. The presence of internal distributors also creates dead spaces inside the reactor, which makes it more difficult to drain and clean the reactor, thus increasing the problems in the production change.

It should also be mentioned that the flow under gravity of the reaction product that is collected in the upper horizontal section and is then conducted downward to the lower part, induces backscattering and overexposure to the oxidizing atmosphere. The North American patent no. No. 4261922 describes a continuous process for obtaining polymerization products of alkylene oxides, starting from 1,2-alkylene oxides and a hydroxyl group-containing compound selected from the group comprising water and mono-, di-, tri- and polyaliphatics This process is carried out with the use of a coil reactor having a length of at least 1.2 m submerged in a suitable heat exchange fluid. A mixture of the hydroxyl compound and an alkaline catalyst is introduced continuously into the reactor and is brought into contact with the oxide., 2-alkyl dosed from a plurality of devices located along the entire length of the reactor. In order to optimize the reaction kinetics, the dosing devices are located at intervals such as to ensure the optimum concentration of the unreacted oxide, at each point. The processes carried out in such a reactor, however, have the major disadvantage of being extremely rigid, since they do not allow absolutely variations in the reaction parameters, such as, the temperature, the type of chain initiator, etc. Whenever there is in fact a variation, it is necessary to readjust the positions of the dosing devices along the entire coil, as a result of the change in the concentration of the unreacted oxide, which occurs exactly due to this variation. It should also be mentioned that, as long as the speed of the polymerization reaction in the starting phase differs from that during the propagation phase, the dosing devices can not be placed at regular intervals along the reactor; a change in the parameters of the process thus requires the separate readjustment of each of them. The problem in the base of the invention is thus to provide a process for the production of alkylene oxide polyadducts, which can be used with any chain initiator, catalyst and alkylene oxide, and which is also capable of overcoming the problems mentioned above. The problem is solved according to the invention by a continuous process for the production of alkylene oxide polyadducts on a chain initiator which has at least one active hydrogen, characterized in that it comprises the steps of: a) the provision of n units of reaction, wherein n is an integer from 2 to 100, each constituted by a tubular reactor that is substantially vertical and has an upper part and a lower part, and a heat exchanger downstream of the tubular reactor, having the tubular reactor at least a first supply device, for supplying the alkylene oxide, at least a second delivery device and an exit opening, the devices being located on the internal surface of the upper part of the tubular reactor. b) supplying the reactor of a first of the n reaction units with the chain initiator, preheated to a predetermined temperature, through at least one second delivery device and with the alkylene oxide through at least one first supply device; c) reacting the chain initiator with the alkylene oxide to obtain a first liquid mixture containing an intermediate product; d) cooling the first liquid mixture by means of the heat exchanger; e) supply to the reactor of a second of the n reaction units with the first liquid mixture by means of at least one second supply device and with the alkylene oxide, by means of at least one first delivery device; f) the reaction of the first liquid mixture with the oxide to obtain a second liquid mixture; g) the repetition of steps d), e) and f) in each of the n-2 remaining reaction units, to obtain an nth liquid mixture containing the desired product; i) cooling and discharging the nth liquid mixture containing the desired product. The expression "tubular" is intended to include any type of elongated body with a section of any shape and dimensions, which also includes reactors with two different diameters, with a conical end and mushroom type reactors. used by the process of the present invention are compounds having at least one active hydrogen, according to the final product desired, examples of such chain initiators can be found among alkylphenols, such as octylphenol, nonylphenol, dodecylphenol dinonyl phenol, tristyrylphenol, natural and synthetic fatty alcohols and mixtures thereof, such as decyl alcohol, tridecyl alcohol, oleyl alcohol, oleyl alcohol, cetylstearyl alcohol, lanolin, cholesterol, acetylenediol, fatty amines and hydrogenated amines, such as laurylamine. , oleyl ina, cocoamine, tallow amine and soy amine, sebo-iminopropi lenam ina, abiethylamine, fatty amides, such as laurylamide, stearylamide, fatty amides derived from coconut oil, soy and tallow; fatty acids such as coconut, lauric, tallow, stearic, palmitic, oleic, myristic, linoleic, abietic and naphthenic acids; sorbitan esters, such as onolaurate, monopalmitate, monostearate, mono-oleate, monoabierant, dilaurate, tristearate, trioleate, pentalaurate, hexaoleate, hexaes thearate; monoglycerides and monoes therates of, for example, coconut and glycerol; esters of pentaeri tri tol, such as monolaurate, mono-oleate and lanolin; et ilenglic-oles, such as mono-, di-, tri-ethylene glycols and polyethylene glycols; propylene glycols, such as mono-, di-, tri-propylene glycols and polypropylene glycols; block polymers of ethylene oxide / propylene oxide and random sequences thereof based on various chain initiators, such as fatty amines, fatty alcohols, glycerol, dipropylene glycol, etc .; oils such as castor oil, hydrogenated castor oil, ink oil, tallow oil and tar oil; mercaptans, such as dodecyl mercaptan. The process of the present invention is preferably carried out with the use of an alkylene oxide selected from the group comprising ethylene oxide, propylene oxide, butylene oxide, and mixtures thereof. In order to activate the alkoxylation reaction, to accelerate it, whenever necessary, the chain initiator is mixed with a catalyst in a mixing unit upstream of the reaction unit. In a particularly advantageous embodiment, the catalyst is selected from the group comprising the alkali metal hydroxides and alcoholates and alkaline earth metal hydroxides. The acid catalysts can nevertheless be chosen even when they are not preferred, since they have the disadvantage of increasing the concentration of dioxane in the product. The catalyst can be added either in the solid phase or in the aqueous solution. In order to take advantage of the chain initiator and the catalyst, these are fastened to a drying step in a unit located upstream of a first of the n reaction units, and downstream of the mixing unit, in order to remove the water of formation of the alcoholate, the water in which the catalyst is dissolved and any moisture present in the chain initiator. For this purpose, a falling film evaporator is used, which can be depressurized to various degrees of vacuum to accelerate the elimination of water. In this evaporator, the mixture to be dried is flowed in the form of a thin film along the heated walls thereof, thereby obtaining a high exchange of material and energy. The process of the invention does not however exclude the use of other conventional evaporators. In a preferred embodiment, there are fifteen reaction units divided into three groups of five units arranged in cascade. Preferably, diversion conduits are also provided for one or more reaction units, starting from the latter, provided that the type of reaction to be carried out requires a shorter total residence time in the reactors. In a particularly advantageous embodiment of the process of the present invention, the nth liquid mixture is subjected to a step in which its free alkylene oxide content is decreased. For this purpose one or more cylindrical reactors are provided, each accommodated with its substantially vertical longitudinal axis, and each having a supply device for supplying the liquid mixture and an outlet opening. In this or more reactors, the alkylene oxide and the chain initiator, which may still be present in the mixture, are reacted until the free oxide content of the mixture containing the reaction product has been reduced as far as possible. plus 1 ppm. The liquid flowing through the reactor (s) must be kept as still as possible to avoid backscattering. In this way, a homogenous residence time is obtained, assuring almost the total consumption of the free alkylene oxide. In a particularly advantageous embodiment of the process of the present invention, the step of lowering the free alkylene oxide content in the reaction product is carried out in three cascaded reactors. Preferably, the devices for supplying the alkylene oxide and the chain initiator to the reaction units are atomizers, each comprising a substantially frustoconic bodyhollow, which projects into the reactor wall from a larger diameter end thereof in which the atomizers are in fluid communication with the respective conduits to supply the reaction mixture and the alkylene oxide, a plurality being formed of nozzles in the hollow body, which are homogeneously distributed on the surface thereof. It should be emphasized that the frustoconical shape of the atomizers makes it possible for the nozzles to be oriented in the reactor, so that they supply the atomized liquid over a wide conical angle. Alternatively, completely conventional devices such as Venturi nozzles or other nozzles can be used to supply and distribute the alkylene oxide and chain initiator. The process of the invention can be carried out continuously, thereby increasing the total productivity of the plant and considerably simplifying maintenance, cleaning, etc. The process of the present invention also makes it possible for the reaction to be carried out with greater certainty, since the total volume occupied by the free alkylene oxide during the reaction is considerably less than that in the prior art. As the oxide is fed in small amounts along the entire reaction pathway, a good proportion thereof is consumed immediately, the concentration of the free oxide along the reaction path remains constant at a relatively low level. By virtue of the post-reaction step in which the free oxide content of the final product is, in any case, reduced to very low levels, the environmental impact of the entire process is also considerably improved, making it possible to omit the typical operations degassing at the end of batch productions. Since the process is continuous, the quality of the product is also improved by virtue of the absence of cross contamination due to changes in production in batch reactions. The process of the invention can be carried out with a wide range of chain initiators, and can easily be adapted to any type of kinetics and any type of product, making it possible in all cases to obtain an optimum quality. This is made possible by the fact that the residence time in each reactor can be easily varied by the control of the liquid level in it by suitable computer means. With the process of the present invention, it is also possible to control the complete residence time by excluding one or more reaction units by means of suitable deviations. In a further aspect thereof, the present invention provides a continuous process for the production of alkylene oxide polyadducts on a chain initiator which has at least one active hydrogen, characterized in that it includes the steps of: a) the provision of a reaction unit constituted by a tubular reactor that is substantially vertical having an upper part and a lower part, and a heat exchanger downstream of the tubular reactor, the tubular reactor having at least a first delivery device, for supplying the alkylene oxide, at least a second delivery device and an exit opening, the delivery devices being located on the inner surface of the upper part of the tubular reactor; b) supplying the reactor of the reaction unit with the chain initiator, preheated to a predetermined temperature, by means of at least one second supply device and with the alkylene oxide through at least one first delivery device; c) the reaction of the chain initiator with the alkylene oxide to obtain a liquid mixture containing the desired product; d) the cooling of the liquid mixture by means of the heat exchanger. In a further aspect the present invention provides a continuous process for the production of alkanolamine from ammonia and ethylene oxide or propylene oxide, characterized in that it comprises the steps of: a) the provision of n reaction units, where n is a whole number from 2 to 100, each constituted by a tubular reactor which is substantially vertical and has an upper part and a lower part, and a heat exchanger downstream of the tubular reactor, the tubular reactor having at least a first supply device , for supplying the ethylene oxide, at least a second delivery device and an exit opening, the delivery devices being located on the internal surface of the upper part of the tubular reactor; b) supplying ammonia to the reactor of a first of the n reaction units, preheated to a predetermined temperature by means of at least one second delivery device and with the alkylene oxide through at least one first delivery device; c) reacting the ammonia with the ethylene oxide to obtain a first liquid mixture containing an intermediate product; d) cooling the first liquid mixture by means of the heat exchanger; e) supplying the first liquid mixture to the reactor of a second of the n reaction units, through at least one second delivery device and with the ethylene oxide, through at least one first delivery device; f) the reaction of the first liquid mixture with the oxide to obtain a second liquid mixture; g) the repetition of steps d), e) and f) in each of the n-2 remaining reaction units, to obtain an nth liquid mixture containing the desired product; i) cooling and discharging the nth liquid mixture containing the desired product.

In a further aspect, the present invention provides a continuous process for the production of glycol ether from ethylene oxide and an alcohol, ROH, in which R is an alkyl group of from 1 to 4 carbon atoms, characterized in that includes the steps of: a) the provision of n reaction units, where n is an integer from 2 to 100, each constituted by a substantially tubular vertical reactor having an upper and a lower part, and a heat exchanger downstream of the tubular reactor, the tubular reactor having at least one first delivery device, for supplying the ethylene oxide, at least a second delivery device and an exit opening, the delivery devices are located on the inner surface of the upper part of the tubular reactor. b) supplying the reactor of a first of the n reaction units, with alcohol, preheated to a predetermined temperature, by means of at least one second delivery device, and with the ethylene oxide through at least one first device of supply; c) the reaction of the alcohol with the ethylene oxide to obtain a first liquid mixture containing an intermediate product; d) cooling the first liquid mixture by means of the heat exchanger; e) supplying to the reactor of a second of the n reaction units, the first liquid mixture through at least one second delivery device and with the ethylene oxide, through at least one first delivery device; f) the reaction of the first liquid mixture with the oxide to obtain a second liquid mixture; g) the repetition of steps d), e) and f) in each of the n-2 remaining reaction units, to obtain an nth liquid mixture containing the desired product; i) cooling and discharging the nth liquid mixture containing the desired product. In order to provide a better understanding, a preferred embodiment of the invention will now be described, purely by way of non-limiting example, the mode being shown schematically in the accompanying drawing. With reference to said drawing, a chain initiator is taken continuously from a storage container (not shown) and is flowed through a conduit 1, through a heat exchanger 2, supplied continuously with steam, with which is preheated to the reaction temperature. Alternatively, the exchanger 2 can be supplied with a diathermic fluid or with pressurized water. A catalyst is introduced to the reaction in desired amounts downstream of the heat exchanger 2, through a conduit 3 and is suitably mixed with the chain initiator in a static mixer 4. The hot chain initiator and the catalyst are then transported through a duct 5 to a dryer unit 6, in which the water for forming the alcohol, the water in which the catalyst is dissolved and any moisture in the chain starter, are eliminated through a line 7. The dryer unit 6 is a falling film evaporator, " which can be evacuated and the walls of which are heated by means of a fluid supplied from a conduit 8. Alternatively, conventional drying units can be used instead of the falling film evaporator.

The catalyzed, dry chain starter is then transported through a conduit 9 to a heat exchanger 10, where the desired reaction temperature is restored. The heat exchanger 10 is supplied with steam, but may also be supplied with diathermic oil, pressurized water or other conventional fluids for heat exchange. The catalyzed, dry initiator, heated to the reaction temperature, is then contacted with the alkylene oxide. For this purpose, a plurality of reaction units are used, in this embodiment three groups of five units each, with the first three and the last of these reaction units shown in the drawing, and each reaction unit comprising a reactor. 11 and a heat exchanger 14 located downstream of the reactor 11. Each reactor is tubular and accommodated with its longitudinal, vertical axis and includes an upper part and a lower part. The dry catalyzed chain initiator coming from the heat exchanger 10 is supplied to the reactor 11 of the first reaction unit through a plurality of atomizers 12, in example one, located at the apex of the reactor 11, and enters in intimate contact with the alkylene oxide supplied and atomized through a conduit 16 and a plurality of atomizers 13, in example one, also at the apex of the reactor 11. The alkylene oxide is added under the automatic control of its speed. mass flow and its reaction pressure. This initiates the absorption of the oxide by the droplets of the catalyzed chain initiator, in the upper part of the reactor 11, and therefore the chemical reaction in the lower part. In fact, the droplets, saturated with alkylene oxide, coalesce on the free surface of the liquid phase in reactor 11, where the alkoxylation reaction takes place. The liquid phase, after a suitable residence time, is discharged through an opening 15, pumped through the heat exchanger 14 to produce the acquired heat of the exothermic reaction, and is introduced through a conduit 22 and through medium of the atomizers 12 to the reactor 11 of the second reaction unit. The cycle is then repeated in the other fourteen reaction units, achieving a good defined molecular growth, current under each reaction unit.

As long as only some of the available reactors are used in order to reduce the total residence time, and therefore the total degree of molecular growth, it is possible to exclude one or more reaction units, starting from the last one and working again, by means of diversion conduits, not shown. The alkoxylation reaction occurs with a residence time which is kept strictly constant by the automatic control of the level of the liquid in the reactor 11. Since the mass flow rate of the alkylene oxide and the chain initiator leaving the bottom of the reactor 11, is fixed, the mass flow rate of the reaction product leaving each reactor 11, is constant. When the reaction is complete, the reaction mixture is subjected to a step in which its free alkylene oxide content is decreased. For this purpose, the flow leaving the reactor 11 of the last reaction unit in use, is transported towards the first of a plurality of reactors 17 arranged in cascade, there being three in the example shown, these reactors being tubular and accommodated with their substantially vertical longitudinal axes, and each having a supply device 18 for supplying the reaction mixture coming from the preceding reactor and an outlet opening 23. The diversion conduits are again provided whenever it is desired to exclude one or more reactors 17 to reduce the entire residence time. Once the alkylene oxide content has been decreased to a predetermined value, the product is cooled to the discharge temperature by means of a heat exchanger 19. If necessary, the product is finally neutralized by mixing in a static mixer 21 with an acid dosed through a conduit 20. Since the The process of the invention is continuous, the heat of the alkoxylation reaction produced up to the heat exchangers 14, can be recovered to generate the low pressure steam, to heat pressurized water or to effect the heat recovery by preheating the chain initiator .

Example 1 Production of 2500 kg / h of fatty alcohol of 12 to 14 carbon atoms + 1.8 moles of ethylene oxide In the plant described above, heated to 140 ° C, 1777 kg / h of fatty alcohol (195 mw), mixed with 7.5 kg / h of a 50% KOH solution and dried in unit 6 under a vacuum of 5 mbarias The catalyzed dry chain initiator was first heated in line at 160 ° C and then supplied to the first reactor 11, the first ten of the fifteen reaction units are activated for the alkoxylation reaction. Each reactor is characterized by an S / V ratio of 15.5 m "1, a reaction pressure of 6 bar and a reaction temperature of 160 ° C. 72.3 kg / h of ethylene oxide was supplied to reactor 11 of the first unit of reaction, and reacted with the chain initiator to give a reaction product that was discharged after a residence time of about 3 minutes, and supplied to reactor 11 of the second reaction unit, after it had been cooled by means of the heat exchanger 14 at the reaction temperature of 160 ° C. The above was repeated for each reaction unit and the product was discharged from the final unit to the first of the three reactors 17, so that the oxide The total residence time in the three reactors 17 was 30 minutes, the product was finally cooled down to 60 ° C, neutralized with 8 kg / h of glacial acetic acid and finally discarded. The quality of the resulting product was as follows: Appearance (25 ° C) Clear liquid Color, APHA 5 max Water (ppm) 0.1 max pH (3% aqueous solution, 25 ° C) 6-7 without hydroxyl (mg KOH / g) 204.5 +/- 2.0 Polyethylene glycol (% by weight) 0.50 max Dioxane ( ppm) 1 max free ethylene oxide 1 max Example 2 Production of 2500 kg / h of fatty alcohol of 12 to 14 carbon atoms + 2.8 moles of ethylene oxide. 1531 kg / h of fatty alcohol (MW 195) were heated to 140 ° C, mixed with 7.5 kg / h of a 50% potassium hydroxide solution dried in unit 6, at a vacuum of 5 mbar. The catalyzed dry chain initiator was first heated in line at 160 ° C and then supplied to reactor 11 of the first reaction unit, the first fourteen reaction units being activated by the alkoxylation reaction. Each reactor is characterized by an S / V ratio of 15.5 m_1, a reaction pressure of 6 bar and a reaction temperature of 160 ° C. The first reaction unit was supplied with 69.2 kg / h of ethylene oxide, which reacted with the chain initiator to give a reaction product which was discharged after a residence time of about 3 minutes and supplied to the reactor. the second reaction unit, after it had been cooled by means of the heat exchanger 14 to the reaction temperature of 160 ° C. The above was repeated for each reaction unit and the product was discharged from the final unit to the first of the three reactors 17 for the residual oxide to be consumed. The total residence time in the three reactors 17 was 30 minutes. The product was finally cooled to 60 ° C, neutralized with 8 kg / h of glacial acetic acid and finally discharged. The quality of the product was as follows: Appearance (25 ° C) Clear liquid Color, APHA 5 max Water (ppm) 0.1 max pH (3% aqueous solution, 25 ° C) 6-7 without hydroxyl (mg KOH / g) 176.0 +/- 2.0 Polyethylene glycol (% by weight) 0.50 max Dioxane (ppm) 1 max Free ethylene oxide 1 max It is noted that in relation to this date, the best method known by the applicant to carry out the aforementioned invention, is the one that results clear of the present description of the invention.

Having described the invention as above, property is claimed as contained in the following:

Claims

1. A continuous process for the production of alkylene oxide polyadducts on a chain initiator, having at least one active hydrogen, characterized the process because it comprises the steps of: a) the provision of n reaction units, where n is a whole number from 2 to 100, each constituted by a tubular reactor, which is substantially vertical and has an upper part and a lower part, and a heat exchanger downstream of the tubular reactor, the tubular reactor having at least one first device of supply for supplying the alkylene oxide, at least a second delivery device and an exit opening, the devices are located on the internal surface of the upper part of the tubular reactor; b) supplying the reactor of a first of the n reaction units, with the chain initiator, preheated to a predetermined temperature, through at least one second delivery device, and with the alkylene oxide through at least one a first delivery device; c) the reaction of the chain initiator with the alkylene oxide to obtain a first liquid mixture containing an intermediate product; d) cooling the first liquid mixture by means of the heat exchanger; e) supplying to the reactor of a second of the n reaction units, the first liquid mixture by means of at least one second supply device and alkylene oxide by means of at least one first delivery device; f) reacting the first liquid mixture with the oxide to obtain a second liquid mixture; g) the repetition of steps d), e) and f) in each of the n-2 remaining reaction units, to obtain an nth liquid mixture containing the desired product; i) cooling and discharging the nth liquid mixture containing the desired product.

2. A process according to claim 1, characterized in that the chain initiator is mixed with a catalyst in a mixing unit located upstream of the first reaction unit, to obtain a catalyzed chain initiator.

3. A process according to claim 2, characterized in that the catalyzed chain initiator is dried in a unit upstream of the first reaction unit, and downstream of the mixing unit.

4. A process according to claim 3, characterized in that the dryer unit is a falling film evaporator.

5. A process according to any of the preceding claims, characterized in that there are fifteen reaction units divided into three groups of five.

6. A process according to any of the preceding claims, characterized in that the nth liquid mixture containing the desired product is subjected to a step in which its free alkylene oxide content is decreased, and towards a neutralization step.

7. A process according to claim 6, characterized in that the step in which the content of free alkylene oxide is decreased, is carried out in one or more cylindrical reactors accommodated with their substantially vertical axes, one or more reactors being provided with a supply device for the supply of the nth liquid mixture and an outlet opening.

8. A process according to claim 7, characterized in that one or more reactors are constituted by three cascaded reactors.

9. A process according to any of the preceding claims, characterized in that the alkylene oxide is selected from the group comprising ethylene oxide, propylene oxide, butylene oxide and mixtures thereof.

10. A process according to any of the preceding claims, characterized in that the chain initiator is selected from the group comprising alkylphenols, natural and synthetic fatty alcohols and their mixtures, fatty amines and hydrogenated amines, fatty amides, fatty acids, sorbitan esters, monoglycerides and monostearates, pentaerythritol esters, ethylene glycols, prispilene glycols, block polymers made of ethylene oxide / oxide. propylene, and polymers obtained from random sequences of the latter, based on various chain initiators such as, for example, fatty amines, fatty alcohols, glyceriha, dipropylene glycol, etc., castor oil, hydrogenated castor oil, tallow , mink oil, tar oil and mercaptans.

11. A process according to any of the preceding claims, characterized in that the catalyst is selected from the group comprising alkali metal hydroxides and alcoholates and alkaline earth metal hydroxides.

12. A process according to any of the preceding claims, characterized in that the delivery devices are atomizers comprising a substantially frustoconical hollow body, projecting inwardly from the reactor wall from a larger diameter end in the which atomizers are in fluid communication with the respective conduits for supplying the reaction mixture and the alkylene oxide, a plurality of nozzles being formed in the hollow body and homogeneously distributed on the surface thereof.

13. A continuous process for the production of alkylene oxide polyadducts on a chain initiator having at least one active hydrogen, characterized in the process because it includes the steps of: a) the provision of a reaction unit constituted by a substantially vertical tubular reactor , having an upper part and a lower part, and a heat exchanger downstream of the tubular reactor, the tubular reactor having at least a first supply device for supplying the alkylene oxide, at least a second delivery device and an opening of output, the supply devices are located on the inner surface of the upper part of the tubular reactor; b) supplying to the reactor of the reaction unit, the chain initiator, preheated to a predetermined temperature, by means of at least one second delivery device and with the alkylene oxide through at least one first delivery device; c) the reaction of the chain initiator with the alkylene oxide, to obtain a liquid mixture containing the desired product; d) cooling and discharging the liquid mixture by means of the heat exchanger.

14. A continuous process for the production of alkanolamine from ammonia and ethylene oxide or propylene oxide, characterized the process because it includes the steps of: a) the provision of n reaction units, where n is an integer from 2 to 100 , each constituted by a substantially vertical tubular reactor having an upper part and a lower part, and a heat exchanger downstream of the tubular reactor, the tubular reactor having at least one first supply device for supplying ethylene oxide, at least a second delivery device and an exit opening, the delivery devices are located on the inner surface of the upper part of the tubular reactor; b) supplying the reactor of a first of the n reaction units, ammonia, preheated to a predetermined temperature by means of at least one second delivery device, and with alkylene oxide through at least one first delivery device; c) the reaction of the ammonia with the ethylene oxide to obtain a first liquid mixture containing an intermediate product; d) cooling the first liquid mixture by means of the heat exchanger; e) supplying to the reactor a second of the n reaction units, the first liquid mixture through at least one second delivery device, and ethylene oxide through at least one first delivery device; f) reacting the first liquid mixture with the oxide to obtain a second liquid mixture; g) the repetition of steps d), e) and f) in each of the n-2 remaining reaction units, to obtain an nth liquid mixture containing the desired product; i) cooling and discharging the nth liquid mixture containing the desired product.

15. A continuous process for the production of glycol ether from ethylene oxide and an alcohol, ROH, in which R is an alkyl group of 1 to 4 carbon atoms, characterized the process because it includes the steps of: a) the provision of n reaction units, where n is an integer from 2 to 100, each constituted by a substantially vertical tubular reactor, having a upper part and a lower part, and a heat exchanger downstream of the tubular reactor, the tubular reactor has at least a first supply device for supplying the ethylene oxide, at least a second delivery device and an exit opening, the supply devices are located on the internal surface of the upper part of the tubular reactor; b) supplying to the reactor of a first of the n reaction units, the alcohol, preheated to a predetermined temperature, by means of at least one second delivery device, and ethylene oxide through at least one first delivery device; c) reacting the alcohol with the ethylene oxide to obtain a first liquid mixture containing an intermediate product; d) cooling the first liquid mixture by means of the heat exchanger; e) supplying to the reactor a second of the reaction n-units, the first liquid mixture through at least a second delivery device, and the ethylene oxide through at least one first delivery device; f) reacting the first liquid mixture with the oxide to obtain a second liquid mixture; g) the repetition of steps d), e) and f) in each of the n-2 remaining reaction units, to obtain an nth liquid mixture containing the desired product; i) cooling and discharging the nth liquid mixture containing the desired product.