MXPA98003310A - Reactor of hydrolysis for the removal of urea, ammonia and carbon bioxide from a liquid phase comprising urea in solution acu - Google Patents

Abstract

A hydrolysis reactor for the removal of urea, ammonia and carbon dioxide from a liquid phase comprising urea in aqueous solution comprises, advantageously: a divider deflector (8) extending horizontally at a predetermined height in the reactor, in which defines a first and a second space, respectively, lower and upper reaction spaces (9, 10), means (11) for the collection and extraction from the reactor of a first portion of a gas phase comprising steam to high pressure and high temperature, fed previously to the first reaction space (9), and means (15) for feeding a second portion of the gas phase comprising high pressure steam and high temperature to the second reaction space (1)

Description

REACTOR OF HYDROLYSIS FOR THE REMOVAL OF UREA, AMMONIA AND CARBON BIOXIDE FROM A LIQUID PHASE COMPRISING UREA IN AQUEOUS SOLUTION FIELD OF THE INVENTION The present invention relates to a hydrolysis reactor for the removal of urea, ammonia and carbon dioxide from a liquid phase comprising urea in aqueous solution. As is known, the waste water resulting from the purification and recovery process of urea produced in a high pressure and high temperature synthesis reactor, have a high content of residual urea in aqueous solution, generally between 500 ppm and 30,000 ppm and, as such, can not be freely discharged into the environment, due to the strict laws against pollutants that are in force in the industrialized countries. Each urea production plant must, therefore, provide the appropriate equipment capable of removing or removing the residual urea from the waste water, so that it decreases its concentration to a few ppm, preferably less than 10 ppm. In the field of wastewater treatment resulting from the process of purification and recovery of P1167-9T urea, the requirement to have reactors of hydrolysis of residual urea available that, on the one hand, allowed to obtain non-polluting waste water with a urea content of less than 10 ppm and, on the other hand, to recover residual urea (in the form of ammonia) and carbon dioxide) contained in these wastewater fed to the hydrolysis reactor, is thus perceived with intensity.

BACKGROUND OF THE ART In order to comply with the aforementioned requirement, vertical hydrolysis reactors have been increasingly used, in which a liquid phase comprising urea in aqueous solution and a gas phase comprising steam at high pressure and high temperature, generally between 15 bar and 30 bar and between 150 ° C and 250 ° C. These reactors contain a plurality of perforated plates that extend horizontally. The perforated plates have the function of facilitating the mutual mixing of the phases to encourage intimate contact and, thus, the essential exchange of mass and heat for the hydrolysis reaction of urea in ammonia (NH3) and carbon dioxide ( CO2) and, for the simultaneous extraction of NH3 and CO2 from the liquid phase to the gas phase.

P1167-98 The heat necessary for the decomposition of the urea and the extraction of the reaction products from the liquid phase is provided by the vapor contained in the gas phase. The Canadian patent application CA-A-2 141 886, describes a reactor of this type in which they are made. flow the liquid phase and the gas phase concurrently from below or upwards through a plurality of horizontal perforated plates. Although in many ways, the hydrolysis reactor described above exhibits several drawbacks, the first of which is that in order to obtain the desired degree of decomposition of urea and the related extraction of NH3 and CO2 produced from the liquid phase, it is necessary to operate with an excess of steam to prevent the hydrolysis reaction from reaching equilibrium ahead of time and for the gaseous solution to be saturated with the reaction products during its passage through the reactor. As a result, to obtain an aqueous solution with a residual urea content of less than 10 ppm, it is necessary to use high quantities of high pressure and high temperature steam, with the consequent high consumption of energy and steam and high operating costs. 3P-A-63224 describes a urea hydrolysis reactor divided into two reaction spaces by a vertical baffle.

P1167-98 SUMMARY OF THE INVENTION The technical problem underlying the present invention is to have available a hydrolysis reactor for the removal of urea, ammonia and carbon dioxide from a liquid phase comprising urea in aqueous solution, that allows the operation with low consumption of steam and energy and low operating costs and that allows at the same time to obtain a liquid phase with a urea content below 10 ppm. According to a first embodiment of the present invention, the aforementioned problem is solved by a hydrolysis reactor for the removal of urea, ammonia and carbon dioxide from a liquid phase comprising urea in aqueous solution, comprising: a shell or external body substantially vertical cylindrical; a plurality of perforated plates superimposed and extending horizontally and in a mutual separation relationship in the shell; an inlet opening for the liquid phase arranged or arranged in a manner close to a lower end of the shell; a first means for supplying a first portion of a gas phase comprising steam at elevated P1167-98 pressure and high temperature, supported in the shell above the entrance opening of the liquid phase; an outlet opening for the liquid phase arranged or disposed proximate to an upper end of the shell; an inlet opening for the gas phase arranged or disposed proximate to the upper end of the shell; characterized in that it comprises: a divider deflector that extends horizontally at a predetermined height in the shell, in which defines a first and a second space, respectively, lower and upper reaction spaces; a means for collecting and extracting the shell from the first gas phase portion, supported next to the dividing deflector in the first reaction space; a second means for feeding a second portion of the aqueous phase comprising steam at high pressure and high temperature, supported above the deflector divider in the second reaction space. Advantageously, in the hydrolysis reactor according to the present invention, the reaction space in the shell is appropriately divided by a divider deflector in a first and second reaction spaces, each of which is fed P1167-98 with a respective portion of the gas phase comprising steam. In this way, it is possible to efficiently and rationally use the high pressure and high temperature steam necessary for the decomposition of the urea and the extraction of the reaction products, so that, for the same degree of purification of the phase, it is obtained liquid, a substantial reduction in the amount of steam that will be fed to the hydrolysis reactor with respect to the reactors of the prior art. Of course, thanks to the present invention, the purification of the liquid phase occurs appropriately in two different reaction spaces, each of which is fed the amount of steam strictly necessary to obtain a liquid phase outlet of the reactor of hydrolysis with a residual concentration of urea less than 10 ppm. In particular, the extraction of the first reaction space from the gas phase now saturated with the reaction products and the feed into the second reaction space of a new gas phase comprising steam at high pressure and temperature, also allows the electrolysis of the gases. Last traces of urea contained in the liquid phase, as well as the recovery of NH3 and CO2 in the gas phase, without having to use an excess of vapor.

PU67-98 The liquid phase purified in this way can be discharged to the environment but can also be advantageously reused as a high temperature and pressure water in the urea synthesis plant or for other industrial uses, such as, for example, water for boiler. Another advantage of the hydrolysis reactor which is the object of the present invention resides in the fact that, for an equal concentration of residual urea contained in the liquid exit phase, the residence time of the liquid phase in the reactor is significantly less than the residence time in the reactors of the prior art. This allows to build or manufacture a hydrolysis reactor with dimensions and investment costs considerably lower than those of the prior art. Particularly advantageous results were found by arranging or arranging the deflector divider at a height between 55% and 80% of the effective height of the shell. In the description given below and in the claims that follow, the term "useful height" refers to the height of the usable shell for the urea hydrolysis reaction. In this particular case, the useful height is defined by the level P1167-98 reached by the liquid phase in the shell. Preferably, the deflector divider is arranged or arranged at a height between 65% and 75% of the effective height of the shell. In this way, with small amounts of steam at high pressure and temperature and with low operating costs, a urea concentration in the liquid phase in the first reaction space is generally obtained between 30 ppm and 70 ppm and in the second space of reaction between 0 ppm and 5 ppm. In accordance with this first embodiment of the present invention, the hydrolysis reactor advantageously includes a divider baffle which extends horizontally over substantially the entire cross section of the shell. In addition, the collection and extraction means advantageously comprises: a collection chamber for the first portion of the gas phase, formed in the first reaction space between the divider deflector and an internal wall of the shell; a duct that extends coaxially in the shell between the collection chamber and the outlet opening of the gas phase for the extraction from the first reaction space of a biphasic flow P1167-98 gas / liquid. As a result, the practical implementation of the present invention is simple in its construction and low in cost of realization. Advantageously, the hydrolysis reactor further comprises a gas / liquid separator placed between the extraction duct and the outlet opening of the gas phase, so that the liquid phase if there is part trapped in the gas phase leaving the gas phase. reactor, can be recycled to the reactor and, thus, allow the recovery of the urea contained herein. According to a second embodiment of the present invention, the aforementioned problem is also solved by a hydrolysis reactor for the removal of urea, ammonia and carbon dioxide from a liquid phase comprising urea in aqueous solution, comprising: a shell or vertical external body substantially cylindrical; a plurality of superimposed perforated plates extending horizontally and in mutual separation relationship in the shell; an exit opening of the liquid phase arranged or arranged in a manner close to a lower end of the shell; - a first means to feed a first portion P1167-98 of a gaseous phase comprising steam at high pressure and high temperature, supported on the shell above the inlet opening of the liquid phase; an outlet opening for the gas phase arranged or disposed proximate to an upper end of the shell; and, characterized in that it comprises: a divider deflector that extends horizontally in the shell at a predetermined height and substantially throughout the cross section of the shell, the deflector defines in the shell a first and a second space, respectively, lower reaction spaces and superior; a collection chamber for the first aqueous phase portion, formed in the first reaction space between the divider deflector and an internal wall of the shell; a duct extending coaxially in the shell between the collection chamber and the aqueous phase outlet opening for the extraction of the first reaction space of a two-phase gas / liquid flow; a second means for feeding a second portion of the aqueous phase comprising steam at high pressure and high temperature, supported above the deflector divider in the second reaction space; P1167-98 an outlet opening for the liquid phase arranged or arranged in the second reaction space proximate and above the deflector divider. Advantageously, in this embodiment of the present invention, the liquid phase and the gas phase are flowed countercurrently in the second reaction space. In this way, it is possible to further improve the mixing of the phases and, hence, the exchange of mass and heat so as to facilitate the urea hydrolysis reaction and the absorption of the reaction products by the vapor. The characteristics and advantages of the hydrolysis reactor according to the invention are set forth in the description of a modality thereof provided below by way of non-limiting example with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS In the drawings: Figure 1 shows a longitudinal cross section of a urea hydrolysis reactor according to a first embodiment of the present invention; Figure 2 shows a cross section P1167-98 longitudinal of a urea hydrolysis reactor according to a second embodiment of the present invention; and Figure 3 shows a longitudinal cross-section to an enlarged scale of a detail of the hydrolysis reactor of Figure 1.

DETAILED DESCRIPTION OF A PREFERRED MODE With reference to Figures 1 and 2, the reference number 1 indicates as a whole a hydrolysis reactor for the removal of urea, ammonia and carbon dioxide from a liquid phase comprising urea in aqueous solution . The reactor 1 comprises a vertical outer shell 2 substantially cylindrical, provided at its lower end with an inlet opening 3 for a liquid phase comprising urea in aqueous solution and, a means 4 for feeding a first portion of a gas phase comprising high pressure steam and high temperature. The shell 2 also has an outlet opening 5 for the liquid phase and an outlet opening 6 for the gas phase arranged or arranged at an upper end of the reactor. A plurality of superimposed perforated plates, P1167-98 all indicated by the reference number 7, extend horizontally and in a mutual separation relationship in the shell 2. The plates 7 are distributed homogeneously along the useful height H of the shell and, are provided with the steps or conduits appropriate for the liquid phase and for the gas phase to facilitate the mixing of the phases. Figure 3 shows on an enlarged scale a detail of a perforated plate 7, provided in accordance with a particularly advantageous and preferred embodiment of the present invention, which can be installed in the hydrolysis reactor shown in Figure 1, as well as in the reactor of Figure 2. The perforated plate 7 comprises a plurality of elements 71 with substantially trapezoidal cross section, defining within it respective cavities 72, as well as openings 73 and 74 suitable for the passage of the liquid and gaseous phases, respectively. Alternatively, the element 71 may have a substantially rectangular cross section. The passage openings 74 of the gas phase are defined in an upper wall 75 of the elements 71. The passage openings 73 for the liquid phase are defined in a side wall 76 of the elements P1167-9T 71. Advantageously, the passage openings 73 of the liquid phase have a larger size than that of the openings 74 for the passage of the aqueous phase. In the description provided below and in the claims that follow, it is understood that the term "size" refers to the cross-sectional area of an opening. In the cavity 72 proximate the wall 75, a collection zone 77 of the gas phase is advantageously defined. Thanks to this particular structure of the plates, the gas phase separates from the liquid phase during the passage through the plates, to then mix again with the liquid phase in finely distributed form. In this way, it is possible to obtain a significant improvement in the mixing of the phases during the passage through the hydrolysis reactor. This involves another reduction in the amount of steam necessary for the performance of the hydrolysis and the extraction of the reaction products, as well as the residence time of the liquid phase in the reactor, with the resulting reduction in the reactor dimension, in steam and energy consumption and in operating costs and P1167-98 of investment compared the reactors of the prior art. For example, plates of this type are described in US-A-5 304 353, with reference to a urea synthesis reactor. The reference numeral 8 indicates a divider deflector which extends horizontally at a predetermined height of the shell 2. The deflector 8 defines in the shell a first reaction space 9 and a second reaction space 10, respectively, lower and upper. Advantageously, the. The deflector divider 8 extends horizontally by substantially the entire cross section of the shell 2. In the examples of Figures 1 and 2, a significantly reduced consumption of high pressure and high temperature vapor is achieved by arranging or arranging the deflector divider 8 to a height corresponding to approximately 70% of the useful height H of the shell 2. The means 11 for collecting and extracting from the shell 2 the first portion of the gas phase, is supported in a form close to the deflector divider 8 in the first reaction space 9. The medium 11 advantageously comprises a chamber 12 for collecting the first portion of the gas phase and a pipe 13 for extraction from the P1167-98 first reaction space 9 a two-phase flow of gas / liquid. The collecting chamber 12 is formed in the first reaction space 9 between the deflector divider 8 and an internal wall 14 of the shell 2. The extraction duct 13 is equipped with the respective inlet openings of the liquid phase and the phase gaseous and extends coaxially into the shell 2, between the collection chamber 12 and the outlet opening 6 of the gas phase. A second portion of the gas phase comprising vapor at high pressure and temperature is fed to the reactor by means of the appropriate means 15 supported or supported above the deflector divider 8 in the second reaction space 10. Preferably, the means for feeding the phase gaseous 4 and 15, are of the type comprising a feed duct connected to a gas distributor in shell 2. These means are generally known and commonly used in hydrolysis reactors of the prior art. With reference to Figure 1, the liquid phase outlet opening 5 is arranged or arranged in the second reaction space 10 near the upper end of the shell 2. In the example of Figure 2, the opening P1167-98 of outlet 5 for the liquid phase is arranged or arranged in the second reaction space 10 close to the divider 8 and above it. As shown in Figures 1 and 2, the hydrolysis reactor according to the present invention advantageously comprises a gas / liquid separator 16 placed between the extraction duct 13 and the outlet opening 6 for the gas phase. The gas / liquid separator 16 is of the type comprising a chamber 17 coaxial with the extraction duct 13, for the separation of the liquid phase from the gas phase and a mist eliminator 18 for the separation of the residual liquid phase contained in the gas phase. the gaseous phase leaving the chamber 17. In the example of Figure 1, the liquid phase obtained in the gas / liquid separator 16 is advantageously recycled to the second reaction space 10 by means of a recycling duct 19 which it extends externally and coaxially with the extraction duct 13 between the separation chamber 17 and the divider deflector 8. In the example of Figure 2, the recycling occurs through a liquid passage 20. In Figures 1 and 2, the arrows Fl and Fg indicate the various trajectories inside the hydrolysis reactor of the liquid phase comprising urea in P1167-98 aqueous and gaseous phase solution comprising high pressure steam and high temperature, respectively. The reference number 21 also indicates the highest level reached by the liquid phase in shell 2, while 22 indicates the level of the liquid phase in the gathering chamber 12. Operation of the hydrolysis reactor in accordance with this invention is as follows. With reference to Figure 1, a liquid phase comprising urea in aqueous solution is fed to the reactor 1 through the inlet opening 3 and is caused to flow concurrently from the bottom upwards with a first portion of the gas phase comprising high pressure steam (20-25 bar) and high temperature (200-220 ° C) along the first reaction space 9 in the shell 2. The gas phase is fed to the reactor 1 through the feed medium 4. In the reaction space 9, the liquid phase and the gas phase are mixed while passing through the perforated plates 7, so that part of the urea present in the aqueous solution is hydrolyzed and the resulting reaction products (NH3 and CO2) are extracted from the vapor present in the gas phase. In this first reaction space, the concentration of urea in the liquid phase fed to the reactor is advantageously reduced to a P1167-9T value which is generally between 40 ppm and 50 ppm. Closely next to the divider baffle 8, the liquid phase and the first portion of the gas phase are advantageously collected in the chamber 12 and transported via the duct 13 to the separation chamber 17 of the gas / liquid separator 16. In the chamber 17, the liquid phase coming from the first reaction space 9 is separated from the gas phase and recirculated to the second reaction space 10 near the divider divider 8 through the pipe 19. The gas phase, once it is separated of the liquid phase in the chamber 17, passes through the mist eliminator 18 and leaves the reactor 1 through the outlet opening 6. In the second reaction space 10, it is flowed to the liquid phase (still in the form concurrent) with a second portion of the gas phase comprising high pressure and high temperature steam. After passing through the perforated plates 7 and reaching level 21, the liquid phase leaves the reactor 1 through the outlet opening 5. The concentration of urea in the liquid phase leaving the second reaction space 10 is advantageously less than 10 ppm.

P1167-98 In turn, the second portion of the gas phase which has passed through the second reaction space 10 and which is enriched with NH3 and CO2, leaves the reactor 1 through the outlet opening 6. With reference to the Figure 2, the liquid phase coming from the first reaction space 9 and separating in the chamber 17 from the gas / liquid separator 16 is advantageously recycled through the conduit or passage 20 to the second reaction space 10 near the level 21 In accordance with this embodiment of the present invention, the liquid phase flows into the second reaction space 10 from top to bottom in counter current with the second gas phase portion to then exit the reactor 1 through the outlet opening. placed close to the divider deflector 8. The hydrolysis reactor according to the present invention operates at a pressure between 15 bar and 25 bar and at a temperature between 180 ° C and 215 ° C. The residence time of the liquid phase in the first reaction space is preferably between 20 min and 40 min, while in the second reaction space it is preferably between 10 min and 20 min.

EXAMPLE 1 In the following example, an P1167-98 comparing the amount of high pressure steam and temperature necessary to obtain a residual concentration of urea in the wastewater below 10 ppm, in the case where a prior art hydrolysis reactor or a reactor was used of hydrolysis in accordance with the various embodiments of the present invention. Reference is made to Figures 1 and 2. The hydrolysis reactors considered have the following dimensions. Internal diameter of the shell: 1.5 m Usable height: 14.0 m The operating conditions in the reactor are as follows. - Pressure: 20 bar Temperature: 210 ° C The reactors contain 10 horizontal perforated plates distributed along the useful height of the cylindrical shell. In the reactors according to the present invention, the divider deflector is arranged or advantageously arranged at approximately 68% of the useful height of the shell, between the sixth and seventh perforated plates. For additional structural details of these reactors, reference will be made to Figures 1 and 2 and a P1167-98 the related description. In the prior art reactor, as in which it is in accordance with the first embodiment of the present invention (Figure 1), the liquid and aqueous phases were caused to flow concurrently from bottom to top through the perforated plates . In the second reaction space of the reactor according to the second embodiment of the present invention (Figure 2), the liquid phase and the gas phase flow counter-current. The hydrolysis reactors were fed with 30,000 kg / h of a liquid phase having the following composition. - NH3 10,000 ppm - CO2 2,000 ppm - UREA 10, 000 ppm - H2O the rest The hydrolysis reactors were also fed with a gas phase comprising steam at a pressure of 25 bar and at a temperature of 215 ° C. To obtain a residual urea concentration of 1 ppm in the liquid phase leaving the reactor, steam consumption in the various cases is shown below. In the reactor according to the technique P1167-98 above, 30 kg of steam was used for 1,000 kg of liquid phase treated. In the reactor of Figure 1, 22 kg of steam per 1,000 kg of treated liquid phase was used. In the reactor of Figure 2, 20 kg of steam per 1,000 kg of treated liquid phase was used. As can be seen, thanks to the present invention, it is possible to achieve a significant reduction in steam consumption, approximately equal to 30% of the steam consumption required in the hydrolysis reactor of the prior art. This also results in a substantial decrease in energy consumption and operating costs. The results of the present example were obtained by calculating the algorithms available in the field. From the above discussion clearly emerge the numerous advantages achieved by the hydrolysis reactor according to the present invention. In particular, a reduction in the concentration of residual urea contained in wastewater was achieved to values below 10 ppm as well as a recovery of hydrolyzed urea, while operating with low consumption of steam and energy and with low operating and investment costs.

P1167-98

Claims (13)

1. NOVELTY OF THE INVENTION Having described the present invention, it is considered as a novelty and, therefore, the content of the following CLAIMS is claimed as property: 1. A hydrolysis reactor for the removal of urea, ammonia and carbon dioxide from a liquid phase comprising urea in aqueous solution, comprising: a substantially cylindrical vertical external shell; a plurality of perforated plates superimposed and extending horizontally in a mutually separate relationship within the shell; an inlet opening for the liquid phase arranged or disposed proximate to a lower end of the shell; a first means for feeding a first portion of a gas phase comprising steam at high pressure and high temperature, supported on the shell above the inlet opening for the liquid phase; means for feeding the liquid phase from the first reaction space to the second reaction space; an outlet opening for the liquid phase arranged or arranged in a manner close to the upper end P1167-98 of the shell; an outlet opening for the gaseous phase arranged or disposed proximate to the upper end of the shell; characterized in that it comprises: a divider deflector that extends horizontally at a precise height in the shell, in which defines a first and a second space, respectively, a lower reaction space and an upper one; a means for collecting and extracting from the shell the first gas phase portion, supported proximal to the splitter baffle in the first reaction space; a second means for feeding a second portion of the gas phase comprising steam at high pressure and temperature, supported above the deflector divider in the second reaction space.
2. 2. The reactor according to claim 1, characterized in that the deflector divider is arranged or arranged in the shell at a height between 55% and 80% of the effective height (H) of the shell.
3. The reactor according to claim 2, characterized in that the deflector divider is arranged or arranged in the shell at a height between P1167-98 65% and 75% of the useful height (H) of the shell.
4. The reactor according to claim 1, characterized in that the dividing baffle extends horizontally over substantially the entire cross-section of the shell and that the collection and extraction means comprises: a collection chamber for the first portion of the phase gaseous formed in the first reaction space between the deflector divider and an inner wall of the shell; a duct extending coaxially in the shell between the collection chamber and the outlet opening of the gas phase for the extraction of the first reaction space of a two-phase gas / liquid flow.
5. The reactor according to claim 4, characterized in that it comprises a gas / liquid separator located between the extraction duct and the outlet opening of the gas phase, for the separation of the liquid phase from the two-phase flow.
6. The reactor according to claim 5, characterized in that the gas / liquid separator comprises: a separation chamber for separating the liquid phase from the gas phase, coaxial with the extraction duct; P1167-98 a mist eliminator for the separation of the residual liquid phase contained in the gas phase leaving the separation chamber; a recycling duct that extends externally and coaxially with the extraction duct between the separation chamber and the divider divider, to recycle the liquid phase obtained in the separator in a manner close to the divisor deflector and above it.
7. The reactor according to claim 1, characterized in that the perforated plates comprise: a plurality of elements with substantially trapezoidal or rectangular cross section, defining within them the respective collection areas for the gas phase; a plurality of openings for the passage of the liquid phase defined in association with a side wall of the elements; a plurality of openings for the passage of the gas phase, defined in an upper wall of the elements in fluid communication with the collection areas; the openings for the passage of the liquid phase have a larger size than that of the openings for the passage of the gas phase. P1167-98
8. 8. A hydrolysis reactor for the removal of urea, ammonia and carbon dioxide from a liquid phase comprising urea in aqueous solution; comprising: a substantially cylindrical vertical external shell; a plurality of perforated plates superimposed and extending horizontally and mutually spaced apart in the shell; an inlet opening for the liquid phase, arranged or arranged in a manner close to the lower end of the shell; a first means for feeding a first portion of a gas phase comprising steam at high pressure and temperature, supported on the shell above the inlet opening of the liquid phase; and an outlet opening for the gas phase, arranged or arranged proximate the upper end of the shell; characterized in that it comprises: a divider deflector extending horizontally in the shell at a height defined by substantially the entire cross-section of the shell, the deflector defining in the shell a first and a second space, respectively, lower and upper reaction spaces; P1167-98 a collection chamber for the first gas phase portion formed in the first reaction space between the divider deflector and an inner wall of the shell; a duct extending coaxially in the shell between the collection chamber and the outlet opening of the gas phase, for the extraction of the first reaction space of a two-phase gas / liquid flow and for feeding the liquid phase from the first space of reaction to the second reaction space; a second means for feeding a second portion of the gas phase comprising steam at high pressure and temperature, supported above the deflector divider in the second reaction space; an inlet opening for the liquid phase arranged or arranged in the second reaction space in close proximity to and above the divider deflector.
9. 9. The reactor according to claim 8, characterized in that the deflector divider is arranged or arranged in the shell at a height between 55% and 80% of the useful height (H) of the shell.
10. The reactor according to claim 9, characterized in that the deflector divider is arranged or arranged in the shell at a height between 65% and 75% of the useful height (H) of the shell. P1167-98
11. 11. The reactor according to claim 8, characterized in that it comprises a gas / liquid separator placed between the extraction duct and the outlet opening of the gas phase, for the separation of the liquid phase from the two-phase flow. The reactor according to claim 11, characterized in that the gas / liquid separator comprises: a chamber for the separation of the liquid phase from the gas phase, coaxial with the extraction duct; a mist eliminator for the separation of the residual liquid phase contained in the gas phase leaving the separation chamber; a liquid phase to recycle the liquid phase to the second reaction space. The reactor according to claim 8, characterized in that the perforated plates comprise: a plurality of elements with a substantially trapezoidal or rectangular cross section, defining within them the respective collection areas of the gas phase; a plurality of openings for the passage of the liquid phase and defined in association with a side wall of the elements and, a plurality of openings for the passage of the P1167-98 gaseous phase and, defined in an upper wall of the elements in fluid communication with the collection areas; the openings for the passage of the liquid phase have a larger size than that of the openings for the passage of the gas phase. P1167-98