The present application generally relates to the field of industrial equipment. Particularly, but not exclusively, the present disclosure relates to the construction and arrangement of a stirred reactor system. More particularly, the present disclosure discloses a stirred reactor system with an enhanced heat transfer arrangement.
BACKGROUND OF THE DISCLOSURE
The information in this section merely provides background information related to the present disclosure and may not constitute prior art(s).
Furfuryl alcohol is an important chemical intermediate for the production of chemical products, such as furan resign, vitamin C, lysine, plasticizer, dispersing agent, and lubricant. Because of the importance of furfuryl alcohol in the chemical industry and the manufacture of furfural from a renewable resource, the liquid phase furfuryl alcohol production process has attracted great research interest. In the industrial liquid phase furfuryl alcohol production process, furfuryl alcohol is produced by reacting liquid furfural with gaseous hydrogen in presence of a solid suspended catalyst in pressure ranging from 30-60kg/cm2 and temperature 150-190°C. The reaction system involves all three phases' solid catalyst, liquid furfural, and gaseous hydrogen. For the mentioned reaction, hydrogen is dissolved in liquid furfural and reacts with furfural in the solid-liquid interphase of catalyst and furfural. Hence, enhancement of hydrogen mass transfer to liquid furfural has a great influence on the rate of reaction.
Hydrogenation reactions for various applications are conducted using different reactor configurations viz., batch, semi-batch, continuous stirred reactors, and fixed bed reactors. These reactions are generally highly exothermic in nature which requires continuous heat removal/dissipation to maintain the desired reaction temperature and conversions. However, some of the reactions are carried out specifically in the batch reactor due to the nature of the reaction & its scale.

Conventionally, these batch reactors are simple in configuration and consist of a storage tank, an agitator, heat transfer coil/jacket and have limitations in the heat transfer area. Liquids and solids are usually charged via connections in the top cover of the reactor. Vapors and gases also discharge through connections in the top. Liquids are usually discharged out of the bottom. Reactants within the batch reactors usually liberate or absorb heat during processing. Even the action of stirring stored liquids generates heat. In order to hold the reactor contents at the desired temperature, heat has to be added or removed by the heat transfer coil/jacket. Heating/cooling coils or external jackets are used for heating and cooling batch reactors. Heat transfer fluid passes through the jacket or coils to add or remove heat. The usual agitator arrangement is a centrally mounted driveshaft with an overhead drive unit. Impeller blades are mounted on the shaft. A wide variety of blade designs are used and typically the blades cover about two-thirds of the diameter of the reactor. Further, maintaining the desired mass transfer in a gas-liquid system with solids suspension is also a challenge in these reactors.
The present disclosure is directed to overcome one or more limitations stated above or any other limitations associated with the prior art.
OBJECTIVE OF THE DISCLOSURE
One or more drawbacks of conventional arrangements and in the prior art are overcome and additional advantages are provided through a multiphase stirred reactor system as described in the present disclosure. Additional features and advantages are realized through the technicalities of the present disclosure.
It is an aim of the present disclosure to provide a novel type of batch reactor system with enhanced heat transfer by providing vertical heat transfer tubes as baffles and also a mechanism for maintaining the vortex at the top of the reactor leading to enhanced

mass transfer of gas/hydrogen while maintaining the desired reaction temperature and conversions.
Another aim of the present disclosure is to provide a novel batch reactor handling the gas-liquid and suspended solids with enhanced heat transfer area by providing vertical tubes along with helical tubes.
Another aim of the present disclosure is to provide the vertical tubes which act as heat transfer areas and also as baffles that improve the fluid mixing.
Another aim of the present disclosure is to provide the vertical heat transfer tubes which are extended up to only a certain height from the bottom of the vessel to maintain the desired vortex formation on the liquid surface.
Another aim of the present disclosure is to provide a multi-level agitator in which the bottom agitator is used to maintain the solids in suspended form and the top agitator is to create vortex/swirl motion to absorb the gas/hydrogen from the surface above the liquid level.
Another aim of the present disclosure is to provide a gas distributor/sparger assembly below the agitator system which ensures that the gas/hydrogen is distributed uniformly in the reactor.
Accordingly, the present disclosure provides a novel type of stirred reactor system with enhanced heat transfer for the conversion of furfural to furfuryl alcohol.
SUMMARY OF THE DISCLOSURE
The present disclosure overcomes one or more drawbacks of conventional arrangements as described in the prior art and provides additional advantages through an arrangement

as claimed in the present disclosure. Additional features and advantages are realized through the techniques of the present disclosure. Other embodiments and aspects of the disclosure are described in detail herein and are considered a part of the claimed disclosure.
In one non-limiting embodiment of the present disclosure, a stirred reactor system is disclosed. The stirred reactor system comprises a reactor vessel configured for reacting a first fluid reactant with a second fluid reactant. The reactor vessel comprises an upper section and a lower section. A first fluid inlet is located in the upper section of the reactor vessel and configured to receive the first fluid reactant. A gas distributor assembly is located in the lower section of the reactor vessel and configured to distribute the second fluid reactant uniformly in a reactant mixture. A heat transfer unit is configured for maintaining the temperature inside the reactor vessel. The heat transfer system is comprising a plurality of helical tubes and a plurality of vertical heat transfer tubes for enhanced heat transfer in the reactor system.
In an embodiment of the present disclosure, the vertical heat transfer tubes are positioned in the lower section of the reactor vessel and are configured to maintain the vortex formation in the reactor vessel and to provide an additional surface area for heating and cooling the reactant mixture.
In an embodiment of the present disclosure, the stirred reactor system comprises an agitator extending vertically through the upper and lower sections of the reactor vessel.
In an embodiment of the present disclosure, the stirred reactor system comprises a reactant product outlet located in the upper section of the reactor vessel.
In an embodiment of the present disclosure, the agitator comprises a rotatory shaft and at least two impellers secured to the rotatory shaft.

In an embodiment of the present disclosure, the stirred reactor system comprises a motor coupled to the agitator through the rotatory shaft.
In an embodiment of the present disclosure, the reactor vessel is cylindrical and is capable of withstanding pressure.
In an embodiment of the present disclosure, the gas distribution assembly comprises a plurality of holes of two different sizes arranged in an alternate fashion to increase the fluid flow near the bottom of vertical heat transfer tubes.
In an embodiment of the present disclosure, the first fluid reactant is liquid furfural, and the second fluid reactant is gaseous hydrogen.
In an embodiment of the present disclosure, the heat transfer unit is configured to heat the reactant mixture by pressurized steam and cool the reactant mixture by cooling water.
The foregoing summary is illustrative only and is not intended to be in any way limiting. In addition to the illustrative aspects, embodiments, and features described above, further aspects, embodiments, and features will become apparent by reference to the drawings and the following detailed description.
BRIEF DESCRIPTION OF FIGURES
The novel features and characteristics of the disclosure are set forth in the description. The disclosure itself, however, as well as a mode of use, further objectives and advantages thereof, will best be understood by reference to the following detailed description of an embodiment when read in conjunction with the accompanying drawings. One or more embodiments are now described, by way of example only, with

reference to the accompanying drawings wherein like reference numerals represent like elements and in which:
Figure 1 illustrates a schematic view of a stirred reactor system, according to an embodiment of the present disclosure.
Figure 2 illustrates a front view of the stirred reactor system, according to an embodiment of the present disclosure.
Figure 3 illustrates a top view of a heat transfer system, according to an embodiment of the present disclosure.
Figure 4 illustrates a front view of vertical heat transfer tubes, according to an embodiment of the present disclosure.
Figure 5 illustrates a bottom view of a gas distribution assembly, according to an embodiment of the present disclosure.
Figure 6 illustrates a schematic view of the gas distribution assembly, according to an embodiment of the present disclosure.
Skilled artisans will appreciate that elements in the drawings are illustrated for simplicity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the drawings may be exaggerated relative to other elements to help to improve understanding of embodiments of the present invention.
DETAILED DESCRIPTION OF THE PRESENT DISCLOSURE
While the embodiments in the disclosure are subject to various modifications and alternative forms, specific embodiment thereof has been shown by way of example in

the figures and will be described below. It should be understood, however, that it is not intended to limit the disclosure to the particular forms disclosed, but on the contrary, the present disclosure is to cover all modifications, equivalents, and alternatives falling within the scope of the disclosure.
It is to be noted that a person skilled in the art would be motivated from the present disclosure and modify various features of the system or method, without departing from the scope of the disclosure. Therefore, such modifications are considered to be part of the disclosure.
Accordingly, the drawings show only those specific details that are pertinent to understand the embodiments of the present disclosure, so as not to obscure the disclosure with details that will be readily apparent to those of ordinary skilled in the art having the benefit of the description herein. Also, a multiphase reactor system of the present disclosure may be employed in any kind of reactor heating, cooling, mixing, and filtration system for reacting one or more gaseous components with one or more liquid components in the presence or absence of suspended fine solid or soluble catalyst in liquid in a semi-batch or continuous reactor.
The terms "comprises", "comprising", or any other variations thereof used in the disclosure, are intended to cover a non-exclusive inclusion, such that a system and method that comprises a list of components does not include only those components but may include other components not expressly listed or inherent to such system, method, or assembly, or device. In other words, one or more elements in a system or device proceeded by "comprises... a" does not, without more constraints, preclude the existence of other elements or additional elements in the system or device.
The following paragraphs describe the various components of the stirred reactor system of the present disclosure according to an embodiment of the present description.

In the present disclosure, a stirred reactor system is disclosed. The reactor system involving multi phases (gaseous reactant, liquid reactant, and a solid catalyst) is developed with enhanced heat transfer area by providing parallel helical tubes of the required size based on the scale-up requirement while maintaining the uniform temperature and agitation in the reactor with optimum reactor volume. The proposed configuration also takes care of the required heat transfer fluid velocity to prevent erosion in the tubes and keep the vibrations within allowable limits in the system with highly turbulent motion provided by external drives (such as agitators). The reactor system is also provided with vertical heat transfer tubes as baffles, which enhances the heat transfer area and also acts to generate the desirable vortex formation for absorbing the vapor/gas from the surface of the liquid and also prevents the deep vortex formation leading to higher reactor volume requirement.
To facilitate further description of several embodiments of the invention, reference is now made to Figure 1 which is a simplified schematic view of a stirred reactor system (10). The reactor system (10) includes a reactor vessel (12) having a vertically aligned, cylindrical configuration. The reactor vessel (12) comprises an upper section (12a) and a lower section (12b). The reactor vessel (12) is configured for reacting a first fluid reactant with a second fluid reactant. In an embodiment, the reactor vessel (12) includes a liquid phase reactant as the first fluid reactant which typically comprises catalysts and other constituents. In an embodiment, a first fluid inlet (14) is located in the upper section (12a) of the reactor vessel (12) and is configured to receive the first fluid reactant.
As shown in Figures 1 and 2, the reactor system (10) comprises an agitator (16) comprising a rotatory shaft (30) extending along an axis of the reactor vessel (12) from the upper section (12a) to the lower section (12b). The axis is preferably positioned vertically and at a central location within the reactor vessel (12). The rotatory shaft (30)

may be powered by a conventional motor (32) located outside the reactor vessel (12) and coupled to the agitator (16) through the rotatory shaft (30). In an embodiment, the rotatory shaft (30) is typically cylindrical with a circular cross-section but other configurations, e.g., polygonal, elliptical, etc. may also be used. The agitator (16) further includes an upper (18a) and a lower (18b) impeller(s) secured to the rotatory shaft (30) in the lower section (12b) of the reactor vessel (12). The purpose of the lower impeller (18b) is to maintain the catalyst in suspended form. The upper impeller (18a) is configured to create a vortex or swirl motion for inducing the gas and increasing the gas-liquid interfacial area into the liquids to enhance the mass transfer and hence increase the rate of reaction. Although two impellers are shown, one, two, or more impellers may be used in accordance with an embodiment of the present disclosure. In an embodiment, the term "impeller" can refer to a device that is used for agitating or mixing the contents of a stirred-tank reactor system. The impeller may agitate the fluid medium by stirring or other mechanical motion. The agitator (16) is used for mixing different process media - liquids, gas, and solids in the batch reactor vessel (12). The agitator (16) imparts energy through mechanical means by rotating the rotatory shaft (30) along with the impeller (18).
In an embodiment, the impeller (18) can simply be a flat blade type impeller with four blades and a diameter varying from 0.3-0.6 times the diameter of the reactor vessel (12) provided at two locations. The width of the blades is in the range of 0.1-0.2 times the impeller diameter. The upper impeller (18a) is placed to create a vortex that can suck the gas above the liquid surface into the first fluid reactant by creating more surface area of contact whereas the lower impeller (18b) is mainly to avoid settling of solid catalyst in the reactor vessel (12). The vortex formation in the lower impeller (18b) is avoided as it can increase the height of the liquid level and thus increases the reactor volume. The lower impeller (18b) is positioned at a height of 0.2-0.4 times the diameter of the reactor vessel (12) whereas the upper impeller (18a) is maintained at 0.5-0.7 times the

diameter of the reactor vessel (12). It is to be noted that the upper impeller (18a) should not be below the vertical heat transfer tubes (24) as shown in Figure 2.
Figure 1 shows a heat transfer unit (20) configured for maintaining the temperature inside the reactor vessel (12). The heat transfer unit (20) comprises a plurality of helical tubes (22) and a plurality of vertical heat transfer tubes (24) for enhanced heat transfer in the reactor system (10). The helical tubes (22) are used for temperature control inside the reactor vessel (12). In an embodiment, the heating/ cooling medium is provided in the helical tubes (22) through an inlet (22a) and is discharged out through the helical tubes (22) through an outlet (22b). The vertical heat transfer tubes (24) are configured inside the reactor vessel (12) for heating the reaction mixture with a hot fluid and subsequently maintaining the reaction temperature by removing the heat using a cooling fluid. In an embodiment, the heat transfer unit (20) is configured to heat the reactant mixture by pressurized steam and cool the reactant mixture by cooling water. The vertical heat transfer tubes (24) are positioned in the lower section (12b) of the reactor vessel (12). The vertical heat transfer tubes (24) are provided up to a certain height of the reactor vessel (12) as shown in Figure 1.
In an embodiment, the height of the vertical heat transfer tubes (24) can be from the bottom tangent line of the reactor vessel (12) up to a height of 0.5-0.7 times the diameter of the reactor vessel (12). The vertical heat transfer tubes (24) provide additional surface area for heating and cooling. Further, the vertical heat transfer tubes (24) help in maintaining uniform mixing and aids in vortex breakage as the vortex is not desirable at the bottom portion of the vessels (12) even though the agitator (16) is placed to maintain uniform mixing of all the phases. Thus, the reason for keeping the vertical heat transfer tubes (24) up to only a certain height from the bottom of the vessel (12) is to maintain the desired vortex formation on the liquid surface of the reactor system (10). In an embodiment, the vertical heat transfer tubes (24) act as baffles which further improves the fluid mixing. The proposed vertical heat transfer tubes (24) as disclosed

in the present disclosure also assist in the mixing of the reactants leading to reduced power consumption for the agitator (16).
As shown in Figures 3 and 4, the vertical heat transfer tubes (24) are located 90 degrees from each other, else they will cover the entire circumference of the reactor vessel (12) as shown in Figure 4. Further, to maintain proper heating/cooling, heating is done by heating medium from the top end (24b) and taken out from the bottom (24a) and cooling medium is provided from the bottom (24a) and taken out from the top (24b). The cooling/ heating medium is taken into the reactor vessel (12) through a common inlet and collected again in a common outlet out of the reactor vessel (12).
In an embodiment, a second fluid inlet (15) is configured to receive the second fluid reactant. As shown in Figure 2, the second fluid inlet (15) is in fluid communication with a gas distribution assembly (26). The gas distributor assembly (26) is located in the lower section (12b) of the reactor vessel (12) and configured to distribute the second fluid reactant uniformly in the reactant mixture. Figures 5 and 6 show a schematic view of the gas distribution assembly (26) in accordance with the present disclosure. The gas distribution assembly (26) plays an important role in the mixing of the second fluid reactant with the first fluid reactant which is surrounded by the solid catalyst. As shown in Figure 5, the gas distribution assembly (26) comprises a plurality of holes (34). The gas distribution assembly (26) is of typical construction as the holes (34) are of two different sizes arranged in an alternative fashion to increase the gas flow near the bottom of vertical heat transfer tubes (24). In an embodiment, the size of the holes (34) in the gas distribution assembly (26) is in the range of 7-10 mm. A pitch between the holes may be in the range of 150-200 mm. The holes (34) are arranged on the bottom side of the gas distribution assembly (26) as shown in Figure 5. In an embodiment, the holes (34) may also be provided on the sides at an angle of 9 = 45-60 degrees from the vertical axis depending on the size of the reactor as shown in Figure 6. In an embodiment, the small holes force the second fluid reactant near the bottom of the vertical heat transfer

tubes (24) to reduce dead zone formation. Further, smaller holes increase pressure drop and also increase the chances of choking with the solid catalyst. In an embodiment, a reactant product outlet (28) is typically located in the upper section (12a) of the reactor vessel (12) for removing reaction product effluent from the reactor vessel (12). In an embodiment, such reaction product effluent often comprises a liquid with some solids content in the form of a slurry, dispersion, or emulsion.
The liquid-gas-solid phase reactor system (10) as disclosed is useful for conducting a broad range of chemical processes involving both liquid and gas phase constituents in the presence or absence of solid catalyst, etc. within the same vessel. For example, the subject reactor system can be used for fermentation, hydrogenations, neutralizations, and oxidation reactions, particularly oxidation of aromatic alkyls, etc. In an embodiment of the present disclosure, the first fluid reactant is liquid furfural, and the second fluid reactant is gaseous hydrogen. Further, various catalysts may be used for the reactor system (10). However, the most common catalyst is copper-based. The reactivity of the first fluid reactant with the second fluid reactant depends on the size of the catalyst. The smaller the catalysts, the better is reactivity due to the large surface area but poses issues related to choking of downstream equipment and also creates issues to the moving and static parts inside the reactor vessel (12). As the operation involves both heating and cooling of the catalyst as well as agitation due to gas distribution and by agitator (16), the particle size of 25-50 micron may be selected for the catalyst so that the above-mentioned issues are managed.
In a preferred embodiment, the operation of the stirred reactor system (10) with enhanced heat exchange arrangement is disclosed. The arrangement is suitable for reacting one or more gaseous components with one or more liquid components in the presence or in absence of a suspended fine solid or soluble catalyst in liquid in the batch reactor vessel (12) for the production of furfuryl alcohol by reacting furfural and hydrogen in catalyst suspended in the liquid phase. It is inadvisable to allow the reaction

converting furfural into furfuryl alcohol to occur at temperatures above 200° C. Temperatures exceeding 200° C will reduce the selectivity of the reaction, i.e., materials other than the desired product, furfuryl alcohol, will be produced. Conventionally, only helical tubes (22) are provided without any additional heat transfer area for heating/cooling the reaction mixture. However, in the present disclosure, the vertical heat transfer tubes (24) are provided to take care of additional heat exchange during scale-up. Initially, the first fluid reactant is filled with the desired quantity of solid catalyst which is homogeneously mixed and heated to the reaction initiation temperature using the hot fluid through the heat transfer unit (20). Upon reaching the desired temperature, the second fluid reactant i.e. hydrogen (15) is fed in a controlled manner for the reaction to take place. This operation is continued till the hydrogen consumption is negligible in the reactor vessel (12). After completion of the reaction, the mixture is cooled using a cooling medium in the reactor vessel (12) and the batch is taken out and routed to the downstream section for purification.
While considerable emphasis has been placed herein on the particular features of this disclosure, it will be appreciated that various modifications can be made and that many changes can be made in the preferred embodiments without departing from the principles of the disclosure. These and other modifications in the nature of the disclosure or the preferred embodiments will be apparent to those skilled in the art from the disclosure herein, whereby it is to be distinctly understood that the foregoing descriptive matter is to be interpreted merely as illustrative of the disclosure and not as a limitation.
It is to be understood that a person of ordinary skill in the art may develop a system of similar configuration without deviating from the scope of the present disclosure. Such modifications and variations may be made without departing from the scope of the present invention. Therefore, it is intended that the present disclosure covers such modifications and variations provided they come within the ambit of the appended claims and their equivalents.

Equivalents:
With respect to the use of substantially any plural and/or singular terms herein, those having skill in the art can translate from the plural to the singular and/or from the singular to the plural as is appropriate to the context and/or application. The various singular/plural permutations may be expressly set forth herein for sake of clarity.
It will be understood by those within the art that, in general, terms used herein, and especially in the appended claims (e.g., bodies of the appended claims) are generally intended as "open" terms (e.g., the term "including" should be interpreted as "including but not limited to," the term "having" should be interpreted as "having at least," the term "includes" should be interpreted as "includes but is not limited to," etc.). It will be further understood by those within the art that if a specific number of an introduced claim recitation is intended, such an intent will be explicitly recited in the claim, and in the absence of such recitation, no such intent is present. For example, as an aid to understanding, the following appended claims may contain usage of the introductory phrases "at least one" and "one or more" to introduce claim recitations. However, the use of such phrases should not be construed to imply that the introduction of a claim recitation by the indefinite articles "a" or "an" limits any particular claim containing such introduced claim recitation to inventions containing only one such recitation, even when the same claim includes the introductory phrases "one or more" or "at least one" and indefinite articles such as "a" or "an" (e.g., "a" and/or "an" should typically be interpreted to mean "at least one" or "one or more"); the same holds true for the use of definite articles used to introduce claim recitations. In addition, even if a specific number of an introduced claim recitation is explicitly recited, those skilled in the art will recognize that such recitation should typically be interpreted to mean at least the recited number (e.g., the bare recitation of "two recitations," without other modifiers, typically means at least two recitations or two or more recitations). Furthermore, in those

instances where a convention analogous to "at least one of A, B, and C, etc." is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., "a system having at least one of A, B, and C" would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). In those instances, where a convention analogous to "at least one of A, B, or C, etc." is used, in general, such a construction is intended in the sense one having skill in the art would understand the convention (e.g., "a system having at least one of A, B, or C" would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). It will be further understood by those within the art that virtually any disjunctive word and/or phrase presenting two or more alternative terms, whether in the description, claims, or drawings, should be understood to contemplate the possibilities of including one of the terms, either of the terms or both terms. For example, the phrase "A or B" will be understood to include the possibilities of "A" or "B" or "A and B." While various aspects and embodiments have been disclosed herein, other aspects and embodiments will be apparent to those skilled in the art. The various aspects and embodiments disclosed herein are for purposes of illustration and are not intended to be limiting, with the true scope and spirit being indicated by the following claims.
List of reference numeral: -

Description Reference numerals
Stirred reactor system 10
Reactor vessel 12
Upper section 12a

Lower section 12b
First fluid reactant inlet 14
Second fluid reactant inlet 15
Agitator 16
Impeller 18
Upper impeller 18a
Lower impeller 18b
Heat transfer unit 20
Helical tubes 22
Inlet and outlet of helical tubes 22a, 22b
Vertical heat transfer tubes 24
Inlet and outlet of vertical heat transfer tubes 24a, 24b
Gas distribution assembly 26
Reactant product outlet 28
Rotatory shaft 30
Motor 32
Holes 34

WE Claim:

1. A stirred reactor system (10) comprising:
a reactor vessel (12) configured for reacting a first fluid reactant with a second fluid reactant, the reactor vessel (12) comprises an upper section (12a) and a lower section (12b);
a first fluid inlet (14) located in the upper section (12a) of the reactor vessel (12) and configured to receive the first fluid reactant;
a gas distributor assembly (26) located in the lower section (12b) of the reactor vessel (12) and configured to distribute the second fluid reactant uniformly in a reactant mixture;
a heat transfer unit (20) configured for maintaining the temperature inside the reactor vessel (12), wherein the heat transfer unit (20) comprising a plurality of helical tubes (22) and a plurality of vertical heat transfer tubes (24) for enhanced heat transfer in the reactor system (10).
2. The stirred reactor system (10) as claimed in claim 1, wherein the vertical heat transfer tubes (24) are positioned in the lower section (12b) of the reactor vessel (12) and are configured to maintain the vortex formation in the reactor vessel (12) and to provide an additional surface area for heating and cooling the reactant mixture.
3. The stirred reactor system (10) as claimed in claim 1, comprises an agitator (16) extending vertically from the upper section (12a) to the lower section (12b) of the reactor vessel (12).
4. The stirred reactor system (10) as claimed in claim 1, comprises a reactant product outlet (28) located in the upper section (12a) of the reactor vessel (12).

5. The stirred reactor system (10) as claimed in claim 3, wherein the agitator (16) comprises a rotatory shaft (30) and at least two impellers (18a, 18b) secured to the rotatory shaft (30).
6. The stirred reactor system (10) as claimed in claim 5, comprises a motor (32) coupled to the agitator (16) through the rotatory shaft (30).
7. The stirred reactor system (10) as claimed in claim 1, wherein the reactor vessel (12) is cylindrical and is capable of withstanding pressure.
8. The stirred reactor system (10) as claimed in claim 1, wherein the gas distributor assembly (26) comprises a plurality of holes (36) of two different sizes arranged in an alternate fashion to increase the fluid flow near the bottom of vertical heat transfer tubes (24).
9. The stirred reactor system (10) as claimed in claim 1, wherein the first fluid reactant is liquid furfural, and the second fluid reactant is gaseous hydrogen.
10. The stirred reactor system (10) as claimed in claim 1, wherein the heat transfer unit (20) is configured to heat reactant mixture by pressurized steam and cool reactant mixture by cooling water.