The present invention relates to a vapor fractionating column plant, in particular a fractionating column plant with a distillation condenser. The invention further relates to a vapor fractionating process carried out in said fractionating column plant.

The operation of the fractionating column plant according to the present invention is based on the principle of so-called "continuous flash distillation - equilibrium distillation". In particular, the distillation process carried out in the plant according to the invention is a single-stage continuous process, without recirculation, in which the separation of two components having different volatility is carried out.

The distillation process consists in partially vaporizing a mixture of volatile liquids, obtaining a vapor phase richer in the more volatile component and a poorer liquid phase. The distillation process is carried out by two successive and opposite steps of state: evaporation/boiling and condensation.

As is known, each solid or liquid substance has a characteristic vapor pressure which increases as the temperature increases. The vapor pressure is the pressure exerted, in a closed vessel, by the vapor on its liquid under liquid-vapor equilibrium conditions, that is, when the number of molecules leaving the liquid surface is equal to the number of those falling therein (dynamic equilibrium). According to Henry's law, at constant temperature, the solubility of a gas is directly proportional to the pressure that the gas exerts on the solution. Once equilibrium is reached, the liquid is defined saturated with that gas at that pressure. This state of equilibrium remains until the external pressure of the gas remains unchanged; otherwise, if it increases, other gas enters the solution; if it decreases, the liquid is in an oversaturation situation and the gas is released, returning to the outside, until the pressures are again balanced.

In the plant according to the invention, the use of continuous flash distillation - distillation of equilibrium - allows to obtain successive vapor fractions which are increasingly rich in the most volatile component. In particular in the plant according to the present invention, with reference to the continuous flash distillation - distillation of equilibrium: 1. it is used for mixtures of volatile and miscible liquids, which are obtained by the molecular dissociation of various materials, characterized by relatively close boiling temperatures or for complex mixtures of liquids; 2. it is based on a vaporization-condensation that takes place inside serpentine means inserted in a column container containing refrigerant;

3. it unwinds along the column, in which increasingly lower temperatures are established as one moves away from the steam inlet zone. Thanks to these temperature steps, called theoretical plates, it is possible to arrive at the complete separation of the initial components.

The column plant of the present invention is functionally combined with a molecular dissociation device for both organic and inorganic materials, wherein said molecular dissociation device carries out a transformation of the treated material only under the action of heat (dry distillation or pyrolysis).

US 4 247 369 A and US 2018/328658 Al disclose a vapor fractionating column plant as above specified.

It is an object of the present invention to provide a vapor fractionating column plant, in particular a fractionating column plant with a distillation condenser, which allows to improve and simplify the "continuous flash distillation - equilibrium distillation" process. Another object of the invention is to provide a plant as specified, which allows to optimize the separation of the derived products (gas and condensate liquid) with a minimum energy consumption.

A further object of the invention is to provide a plant as specified, which allows to reduce plant costs.

Yet another object of the invention is to provide a plant as specified, which allows to recover a part of the energy used.

A still further object of the invention is to provide a vapor fractionating process carried out in the above specified fractionating column plant, which is simple, advantageous and effective to implement.

In view of these objects, the present invention provides a vapor fractionating column plant, in particular a fractionating column plant with a distillation condenser, the essential characteristic of which is the subject of claim 1.

The vapor fractionating process according to the invention, carried out in the above- mentioned fractionating column plant, is essentially the subject of claim 8.

Further advantageous features of the invention are described in the dependent claims. Features and advantages of the invention will become apparent from the following detailed description of an embodiment, with reference to the accompanying drawing, which shows details important to the invention, as well as from the claims.

The characteristics illustrated herein do not necessarily have to be understood to scale and are represented in such a way that the peculiarities according to the invention are clearly pointed out.

Brief description of the drawing

- Figure l is a schematic view, in front elevation and in partial section, of the fractionating column plant according to an embodiment of the present invention, comprising a molecular dissociation device and a fractionating column;

- figure 2 is a schematic view, in side elevation and in section, of a variant of embodiment of the molecular dissociation device of the plant of figure 1;

- figures 3 and 4 are top plan views, respectively according to arrows III of figure 1 and IV of figure 2.

With reference to the drawing, 100 indicates the fractionating column plant according to an embodiment of the present invention.

The plant 100 is, in particular, a fractionating column plant with a distillation condenser and comprises a molecular dissociation device I and a fractionating column 8.

The molecular dissociation device I decomposes, for example, organic material and produces, among other things, vapor under pressure, which is evacuated from an outlet 1.1 of vapor under pressure, and it is provided with thermocouple means 16 and pressure gauge means 15, for monitoring the temperature and pressure values of the vapor under pressure at the outlet.

A pressurized vapor conveying tube 2 is hydraulically branched hermetically from said pressurized vapor outlet 1.1 of the molecular dissociation device I to a pressurized vapor inlet 15.1 of first balancing and control valve means 15, calibrated to a first pressure value, which have a pressurized vapor outlet 15.2, hydraulically connected in a sealed manner with respect to a pressurized pressure inlet 3.1 of pressurized vapor filter means 3 comprising a carbon steel filter. Said first valve means 15 open automatically when the pressurized vapor reaches or exceeds said first preset pressure value and feed, through said inlet 3.1, the pressurized vapor into said filter means 3, which effect a filtration and a first cooling of the pressurized vapor at the inlet. A pressurized vapor outlet 3.2 of said filter means 3 is hydraulically connected hermetically to a pressurized vapor inlet 4.1 of heat exchange serpentine means 4 contained in a column container 8.1 of said fractionating column 8. Said serpentine means 4 are arranged coaxially with respect to said column container 8.1 and comprise a tube wound on itself in a cylindrical helix. Said pressurized vapor inlet 4.1 is arranged in the upper part of said serpentine means 4. Said column container 8.1 is filled with coolant, which is fed from above, through an inlet 11 of coolant liquid, arranged in the upper part of the column container 8.1, and which exits from said column container 8.1 through an outlet 9 of coolant liquid, disposed in the lower part of said column container 8.1. Flow-cutoff valve means 9.1 allow to selectively close and open said outlet 9 of coolant liquid.

A condenser 5 comprises a linear condensation tube 5.1 which is arranged inside said coil means 4, in coaxial arrangement. Said condensation tube 5.1 has an upper head region 5.2, above said serpentine means 4, with respect to which separator means 6, configured, for example, as carbon steel separator diaphragm, are hydraulically connected in a sealed manner, in order to separate gas from the pressurized vapor and remove liquids entrained by the vapor. An outlet 6.1 of pressurized gas of said separator means 6 is hydraulically connected in a sealed manner, by means of a duct 10, with respect to second balancing and control valve means 16, calibrated at a second pressure value, which provide a controlled outlet of pressurized gas from said fractionating column 8.

Moreover, said condensation tube 5.1 has a lower end region 5.3, with respect to which the third balancing and control valve means 17 are hydraulically connected in a sealed manner, which are calibrated at a third pressure value.

It should be noted that said first pressure value, said second pressure value and said third pressure value are independent of each other.

Said serpentine means 4 have a lower end portion 4.2 hydraulically connected in a sealed manner with respect to said lower end region 5.3 of said condensation tube 5.1. Through said lower end 4.2 of the serpentine means 4, pressurized condensation liquid, separated in said separating means 6, reaches said lower end region 5.3 of said condensation tube 5.1, above said third balancing and control valve means 17, which provide a controlled outlet of liquid under pressure. In particular, the pressurized vapor entering, through the inlet 4.1, in the upper part of the serpentine means 4, is cooled by heat exchange, by means of the refrigerated liquid of the column container 8.1, and is forced to travel said serpentine means 4 downwards. During this path, the cooled vapor undergoes distillation by condensation and is divided into a gaseous fraction and a liquid fraction.

The condensate liquid drops downwards and exits from the condensation tube 5.1, 5.3 through said third valve means 17, when the pressure of the liquid is equal to or greater than said third pressure value preset in said third balancing and controlling valve means 17. The condensation liquid that has leaked from said third valve means 17, and hence from the fractionating column 8, is collected in a container 7, arranged at the base of the column 8.

The residual gaseous fraction goes back into the condensation tube 5.1 until it reaches said separator means 6, passes through said separator means 6 - in which it is carried out the separation of the pressurized gas and the removal of liquids entrained by the vapor, that fall on the bottom 5.3 of the condensation tube 5.1 - and the pressurized gas exits, by means of said conduit 10, through said second balancing and control valve means 16, when the gas pressure is equal to or greater than said second preset pressure value in said second balancing and control valve means 16, which provide a controlled outlet of pressurized gas from said fractionating column 8.

It is pointed out that the fractionating column 8 operates in a direction contrary to the usual, with an inclination favorable to the inlet of the pressurized vapor in said filter means 3.

It is further pointed out that, by means of the characteristic arrangement described above, in which:

- when the pressure of the vapor coming from said molecular dissociation device I is equal to or greater than said first pressure value, said first balancing and control valve means 15 introduce the pressurized vapor into the upper part of said heat exchange serpentine means 4, through said filter means 3,

- when the pressure of the gas coming from said separator means 6 is equal to or greater than said second pressure value, said second balancing and control valve means 16 provide a controlled gas outlet from said fractionating column 8; - said heat exchange serpentine means 4 are connected, by means of the lower end 4.2, with said bottom region 5.3 of said condensation tube 5.1 and feed the pressurized condensation liquid into said bottom zone 5.3,

- when the pressure of the condensation liquid coming from said condensation tube 5 is equal to or greater than said third pressure value, said third balancing and control valve means 17 provide a controlled outlet of liquid under pressure from said fractionating column 8,

- said first pressure value, said second pressure value and said third pressure value are independent of each other and their operating combination achieves an optimum setting of the operation of the plant 100, the fractionating operation of the pressurized vapor, produced by the molecular dissociation device I, is carried out in the fractionating column plant 100, according to the embodiment of the invention, under ideal temperature and pressure conditions (saturation pressure), which allow to obtain a homogeneous liquid condensate and a gas almost free of a moist part, which can be easily treated in its subsequent use.

It is also pointed out that, according to the embodiment of the invention, the cooling of the coil is carried out with an open vessel. This solution is economical and is mainly used in small plants with a maximum flow rate of 1 m ³ per hour of gas.

For plants with a higher flow rate, the cooling systems, not shown in the present exemplary embodiment and known per se, can comprise:

1) chiller means, comprising a machine which removes heat from a liquid through a vapor compression cycle, or through a heat absorption cycle;

2) absorbing means, comprising absorbing devices, that transform thermal energy - introduced in the form of hot water, at even relatively low temperatures up to 70°C - into cold energy in the form of chilled water, with minimum temperatures up to 5.5°C. The absorbing means, therefore, can be considered as the most suitable solution for large-capacity plants, since they operate in an ecologically clean manner and with very low consumption of electrical energy, so as to be considered as a real energy recovery device. To confirm this, from studies carried out, by way of example, a 100 kW absorber, operated for 4000 h in a year, avoids the emission in the same year of 50.94 tons of C02. This thermal energy recovery system is considered as trigeneration (CHCP = combined heat Cool and Power). In practice, the management of the plant according to the invention, in the liquid-gas separation process, must respect well-defined parameters such as: temperature, pressure and timing of the process in its dissociation and distillation steps, with a precise balance between the various components.

Said dissociation device I comprises a treatment cell 1 (hereinafter, for the sake of brevity, called "cell"), open and closed at the top by means of cover means 2.1 and gas-tight seal means 3.3, arranged between said cell 1 and said cover 2.1.

Said cell 1 comprises an interspace II, provided between the side walls and the bottom wall of an outer casing 12 and the side walls and the bottom wall of an inner container 13, configured as a treatment chamber, open at the top. Said interspace II is thermally insulated with respect to the environment outside the cell 1. Said treatment chamber

13 is gas-tight, when said cover means 2.1 and said seal means 3.3 close said cell 1.

Heat generating means 14 configured for the production of thermal energy are arranged in said interspace II. Said heat generating means 14 surround, at least in part, said treatment chamber 13 of the cell 1. In particular, said heat generating means 14 are located in different positions inside the interspace II: for example, if the treatment chamber 13 of the cell 1 is configured as a vertical container, said heat generating means 14 are arranged at different levels or heights with respect to the side walls of the container (if the container is of parallelepiped shape), respectively with respect to the side wall (if the container is cylindrical). In particular, said heat generating means

14 comprise a plurality of electric resistor arrays 14.1, respectively arranged at different levels or heights with respect to the treatment chamber 13.

Furthermore, a column electric resistor 14.2 is arranged coaxially in said cell 1 and fixed with respect to said cover 2.1.

Said electric resistor arrays 14.1, 14.2 are electrically connected with respect to an electric power supply and control circuit known per se and not illustrated. In particular, each array of electric resistors 14.1. 14.2 is controlled by means of electronic dimmer control means provided in said electric power supply and control circuit.

Moreover, said cell 1 comprises thermocouple means 16, for example of ATEX type, pressure gauge means 15, designed to monitor respective physical parameters within the treatment chamber 13. Moreover, said cell 1 is provided with safety valve means.

It should be noted that said thermocouple means 16 are configured to detect the internal temperature of the treatment chamber 13 of the cell 1, and said pressure gauge means 15 are configured to detect the internal pressure of the treatment chamber 13 of the cell 1, when said cover means 2.1 with gasket 3.3 close said cell 1. Moreover, said thermocouple means 16 and said pressure gauge means 15 are electrically connected with respect to said electrical supply and control circuit. By means of the aforesaid arrangement, said electrical supply and control circuit performs the control of the electrical supply of each of said resistor arrays 14.1, 14.2, according to the aforesaid parameters. Therefore, one or more resistor arrays 14.1, 14.2 are electrically supplied, varying the current intensity according to the different temperatures prevailing in the treatment chamber 13, and according to different times of use, depending on the material to be treated placed in the treatment chamber 13 of the cell 1.

In particular, said electric resistor arrays 14.1, 14.2 can be electrically controlled by means of said electronic dimmer means during the various phases of the molecular dissociation of the material treated in the treatment chamber 13, on the basis of the temperature and pressure detected in said chamber. This allows the use of electrical energy in the real times of need and with the necessary power.

Furthermore, stirring means 16 are provided for moving the treatment cell 1. They, for example, comprise a partial external lining of the treatment chamber 13 rigidly connected to piezoelectric vibratory means (known per se and not shown).

The operation of cell 1 is based on the physical/chemical principle of molecular disintegration.

Through a pair of check valves VI (provided in the lid 2.1), open, the materials to be treated are introduced into the treatment chamber 13 of the containment cell 1. The valves VI are closed.

The treatment chamber 13 is heated by convection and/or by heat transmission provided by the electric heat generating means 14 through the side wall of the treatment chamber 13, respectively within said treatment chamber 13, until the optimum temperature and pressure for carrying out the molecular dissociation process, in oxygen deficiency, are reached.

During the dissociation process, the material inside the treatment chamber 13 is dragged from top to bottom, on the basis of the real-time data obtained by the thermocouple means and the pressure gauge means, to move the colder material (the one arranged inside) toward the side wall of the treatment chamber 13, heated by convection. This operation is carried out only for the time necessary for the displacement of the material itself. All this allows to drastically reduce the molecular dissociation times, to save energy and to obtain a homogeneous disintegration of the treated material, with consequent improvement of the quality of the derived products.

Under these operating conditions, any organic material undergoes a dissociation process, with the consequence that it is decomposed into four main gases: carbon monoxide CO, carbon dioxide CO2, hydrogen H2 and methane CH4. The gases thus obtained are evacuated from the treatment chamber 13 through the conveying tube 2.

The gases are fed to a separation column 8, in which they are cooled with refrigerated liquid, for example water.

Through said separation column 8 are recovered: a- Syngas, synthesis gas, leaving the upper part of the separation column 8 through the valve means 16; b- amber colored liquid (similar to pyrolysis oil), similar to a fuel oil which comes out of the lower part of the separation column 8, through the discharge valve means 17.

The remainder of the treated material and which is separated from the gases during the solid or liquid phase purification step (tar, heavy hydrocarbons, various solid particles), can be returned to the treatment chamber 13 for further energy recovery as a useful gas.

Once the molecular dissociation of the material introduced into the treatment chamber 13 has been completed, a carbonaceous residue remains on the bottom wall of the chamber.

The dry residues are evacuated from the treatment chamber 13 through a check valve V2, provided in a truncated -conical bottom wall of the cell 1.

It is pointed out that, during the molecular dissociation process, there are no emissions into the atmosphere, since it is a process of transformation carried out in a sealed environment.

Figures 2 and 4 illustrate a variant embodiment of the molecular dissociation device I, in which the heat generating means 14 comprise a plurality of column electric resistors 14.3, similar to the axial column electric resistor 14.2 and arranged in the chamber 13 as a crown and equidistant in the radial direction with respect to said axial column electrical resistor 14.2. Said column electric resistors 14.3 are fixed to the cover 2.1. Said electric resistors 14.2, 14.3 are electrically connected with respect to said electric supply and control circuit and are individually controlled by electronic dimmer adjust- merit means, provided in said electric supply and control circuit, on the basis of the temperature and to the pressure detected in said treatment chamber 13 during the various phases of the molecular dissociation of the material treated in the treatment chamber 13.

The present invention provides a vapor fractionating process carried out in the fractionating column plant 100, wherein said plant 100 comprises:

- a molecular dissociation device I and a fractionating column 8, wherein said fractionating column 8 comprises a column container 8.1 containing coolant liquid and wherein said molecular dissociation device I breaks down some material and produces vapor under pressure, which is evacuated from a pressurized vapor outlet 1.1 of said molecular dissociation device I.

The aforesaid method is characterized in that:

- first balancing and control valve means 15 are provided, which are calibrated to a first pressure value and are hydraulically connected in a sealed manner, by means of a vapor pressure inlet 15.1, with respect to said pressurized vapor outlet 1.1 of said molecular dissociation device I and, by means of a pressurized vapor outlet 15.2, with respect to a pressurized vapor inlet 3.1 of pressurized vapor filter means 3 having a pressurized vapor outlet 3.2;

- heat exchange serpentine means 4 are provided, arranged in said column container 8.1 of said fractionating column 8; wherein a pressurized vapor inlet 4.1 is disposed in the upper part of said serpentine means 4 and is hydraulically connected in a sealed manner with respect to said pressurized vapor outlet 3.2 of said filter means 3; and wherein:

- when the pressure of the vapor coming from said molecular dissociation device I is equal to or greater than said first pressure value, said first valve means 15 introduce the pressurized vapor, through said vapor inlet 4.1, in said serpentine means 4 and the pressurized vapor is cooled by heat exchange, by means of the refrigerated liquid of the column container 8.1, and is forced to travel down said serpentine means 4, in such a way that it undergoes distillation by condensation and is subdivided into a gaseous fraction and a liquid fraction;

- a condenser device 5, 5.1 is provided, which is arranged inside said serpentine means 4 and has an upper head region 5.2 and a lower end region 5.3; - separator means 6 are provided, comprising an outlet 6.1 of pressurized gas and are connected in a hydraulic seal with respect to said upper head region 5.2 of said condenser device 5 and are configured to separate gas from the pressurized vapor and remove liquids entrained by the vapor;

- second balancing and control valve means 16 are provided, which are calibrated to a second pressure value and are connected hydraulically in a sealed manner with respect to said outlet 6.1 of pressurized gas of said separator means 6;

- in such a way that said residual gaseous fraction rises in said condensation device 5, 5.1, until it reaches said separator means 6, passes through said separator means 6, in which it is carried out the separation of pressurized gas and the removal of liquids entrained by the vapor, which fall on the bottom, that is, in the lower end region 5.3 of said condensation device 5, 5.1, and the pressurized gas exits through said second valve means 16, when the gas pressure is equal to or greater than said second pressure value preset in said second valve means 16, which provide a controlled outlet of pressurized gas from said fractionating column 8;

- a lower end portion 4.2 of said serpentine means 4 is provided, which is hydraulically connected in a sealed manner with respect to said lower end region 5.3 of said condensation device 5, 5.1, in which pressurized condensation liquid arrives, separated by means of said separator means 6;

- third balancing and control valve means 17 are provided, which are calibrated to a third pressure value and are hydraulically connected in a sealed manner with respect to said lower end region 5.3 of said condensation device 5, 5.1 and which provide a controlled outlet of liquid under pressure from the fractionating column 8, when the liquid pressure is equal to or greater than said third pressure value preset in said third valve means 17, and in that said first pressure value, said second pressure value and said third pressure value are set independently of each other.

As is apparent from the foregoing, the present invention allows to achieve the objects set forth in the introductory part of the present description.