FORM - 2
THE PATENTS ACT, 1970 (39 of 1970)
COMPLETE SPECIFICATION (SECTION 10; rule 13)
"Process for Manufacturing Phosphorus Pentachloride (PCI.sub.5.)"
PATEL VIVEK NATVARLAL
An Indian National having his address at,
202,Ameezara Complex,
Nr. Aakar Motors, National Highway No.8,
G.I.D.C, Vapi-396195. Gujarat State, India.
The following specification particularly describes the nature of this invention and the manner in which it is to be performed: -
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FIELD OF THE INVENTION
The present invention is related to a process for manufacturing phosphorus pentachloride (PCI.sub.5.). This invention particularly relates to a process for the production of high purity free flowing phosphorus pentachloride (PCI.sub.5.) in a powder form.
BACKGROUND OF THE INVENTION
This invention relates to a new process for manufacturing high purity free flowing dry powder of phosphorus pentachloride (PCI.sub.5.) by reacting phosphorus trichloride (PCI.sub.3.) and chlorine. Due to tremendous utilization of phosphorus pentachloride (PCI.sub.5.) as a raw material in the various industries it becomes necessary to produce the phosphorus pentachloride (PCI.sub.5.) with high purity.
There are various processes that produce phosphorus pentachloride. Amongst them,
(A) By reacting stoichiometric quantities of chlorine with Phosphorus Trichloride in solvent medium.
In this process stoichiometric quantity of chlorine is passed with phosphorus trichloride and is mixed with solvent in a liquid phase. In this process reactor of many types have to be constructed for e.g. Glass lined lead vessel or Nickel vessel equipped with heating and cooling arrangement, stirrer, reflux condense, and many others. During the process solid phosphorus pentachloride remains suspended in liquid medium. After the completion of the reaction the crystal product is filtered out and then the solvent is distilled
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from it. The product obtained by the process is in liquid form along with unreacted materials present with it. Hence, phosphorus pentachloride obtained with this process is in liquid form with unreacted materials present with it. Moreover, this process becomes lengthy and tedious.
(B) By passing chlorine gas in suspension of red phosphorus in a suitable
solvent medium.
During the process of manufacturing phosphorus pentachloride, by passing chlorine gas to Phosphorus trichloride in a solvent medium additional steps of separating the product from solvent medium such as filtration followed by drying the solids as well as recycling of the solvent medium contains traces of phosphorus pentachloride in it. Also part of phosphorus pentachloride remains in the liquid medium which results in to loss of the materials or has to treat more to dry it. This increases the production cost and additional time labor and moreover necessary equipments are also needed for performing various processes for extracting phosphorus pentachloride from solvent medium and may increase environmental pollution.
(C) By direct chlorination to Phosphorus trichloride.
In this process chlorine gas is passed with the vapour of phosphorus trichloride. During continuous reaction it becomes very difficult to maintain the ratio of phosphorus trichloride and chlorine for a long time. Also if the materials are not heated properly material gets suspended in liquid medium. It is also difficult to scrap the materials from the chambers, as in the continuous process hard cakes are formed on the chamber of the vessels which has to crush by screw which is time as well as energy consuming. Further more as it is difficult to maintain ratio in the continuous process for a long time the purity of the
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material is also not uniform which in turn decreases percentage of purity. With increase in percentage of impurity in the material might cause harmfulness in life savings bulk drugs and can also cause batch loss to production of company.
(D) By reaction between phosphoryl chloride, carbonyl chloride and carbon at
high temperature in region 300 to 500°C.
The product (Phosphorus pentachloride) obtained by batch or continuous process in the liquid phase or vapour phase or without or with solvent is in such a form that it is not readily usable without further processing.
(E) By chlorination to the vapours of phosphorus trichloride.
It has been observed that in the prevailing process the removal and separation of phosphorus pentachloride from the reactor is not very easy task. There are chances of the product getting decompose and when it is exposed to atmospheric moisture because of its deliquescent nature creates a major pollution problems as well as causes environmental hazards for the operators.
(F) By reaction of phosphorus trichloride and chlorine under pressure in an
autoclave.
Phosphorus pentachloride manufactured by the conventional process often forms lumps, clogs or plugs at the discharge outlets of the apparatus in turn causing digging and breaking of the materials from the chamber of the vessel which may be time consuming, high production cost as well as hazardous to environment.
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Present existing processes for manufacturing phosphorus pentachloride (PCI.sub.5.) has various disadvantages.
Downsides associated with the existing processes are stated below:
The existing processes do not produce high purity free flowing powder of
phosphorus pentachloride (PCI.sub.5.).
Phosphorus pentachloride (PCI.sub.5.) produce by the existing processes often forms lumps, clogs or plugs at the discharge outlets of the apparatus.
The existing processes do not maintain purity of phosphorus pentachloride (PCI.sub.5.) in every batch of production.
The existing processes do not produce ready to use phosphorus pentachloride (PCI.sub.5.), produces PCI.sub.5 which further needs
processing.
The existing processes are very lengthy, tedious and cumbersome to perform.
In the existing processes part of phosphorus pentachloride remains in the liquid medium which results in to loss of the materials or has to treat more to dry it. This increases the production cost and additional time labor and moreover necessary equipments are also needed for performing various processes for extracting phosphorus pentachloride from solvent medium and may increase environmental pollution.
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ADVANTAGES OF THE INVENTION
To overcome these drawbacks associated with the present practices, the inventor has developed a new process for manufacturing phosphorus pentachloride (PCI.sub.5.). The upsides associated with the proposed process are stated below:
The proposed process manufactures a high purity free flowing powder of phosphorus pentachloride (PCI.sub.5.).
The proposed process manufactures phosphorus pentachloride (PCI.sub.5.) in powder form which do not lump, clog or plug at the discharge outlets of the apparatus.
The proposed process maintains purity of phosphorus pentachloride (PCI.sub.5.) in every batch of production.
The proposed process produces readily useable phosphorus pentachloride (PCI.sub.5.) that does not need further processing.
The proposed process is not at all lengthy, tedious and cumbersome to perform.
Since the proposed process produces phosphorus pentachloride (PCI.sub.5.) of powder form with no remains of the said product in the solvent medium thus results in no product loss. Thus helps in reducing the production cost and an additional time labor and further no necessary equipments are needed for performing various processes for extracting phosphorus pentachloride from solvent medium.
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The proposed process produces phosphorus pentochloride (PCI.sub.5.) of free flowing powder nature which leads to no scrapping of the material from the chamber of the vessel. Thus, saves time as well as energy.
OBJECTS OF THE INVENTION
The main object of the proposed invention is to produce a high purity free flowing powder of phosphorus pentochloride (PCI.sub.5.).
Another object of the proposed invention is to manufacture phosphorus pentochloride (PCI.sub.5.) in powder form which do not lump, clog or plug at the discharge outlets of the apparatus.
Further object of the proposed invention is to maintain purity of phosphorus pentochloride (PCI.sub.5.) in every batch of production.
Further object of the proposed invention is to produce readily useable phosphorus pentochloride (PCI.sub.5.).
Further object of the proposed invention is to produce phosphorus pentochloride (PCI.sub.5.) of free flowing powder nature which avoids scrapping of the material from the chamber of the vessel. Thus further saves time as well as energy.
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SUMMARY OF THE INVENTION
The proposed invention provides a process for manufacturing free flowing dry powder phosphorus pentachloride (PCI.sub.5.) by direct reaction between phosphorus trichloride and chlorine. Phosphorus trichloride is boiled in the reaction vessel A between temperature 35 to 40°C by oil heater. After phosphorus trichloride starts boiling liquid chlorine is introduced from the nozzle A in an equal molar ratio and from nozzle B nitrogen gas is been introduced in the reaction vessel A. The temperature is maintained at 60 to 65 °C. Chlorination is continued till phosphorus trichloride (PCI.sub.3) is converted into phosphorus pentachloride (PCI.sub.5) in the form of solid cakes and/or lumps in the reaction vessel A and is kept for approximately 45 to 60 minutes at 35 to 40 °C. Now temperature is increased from 35 to 40°C to 160 to 170°C by oil heater and is maintained for approximately one hour where solid cakes and/or lumps of phosphorus pentachloride (PCI.sub.5) start to sublime from nozzle C which is connected to reaction vessel B and it is then collected in the same and where it is kept for 40 to 60 minutes. Simultaneously nitrogen gas is passed from nozzles B placed on the reaction vessel A placed above oil heater which helps phosphorus pentachloride (PCI.sub.5) to sublime and avoids mixing with atmospheric impurities. Phosphorus pentachloride (PCI.sub.5) sublimes from reaction vessel A placed above oil heater to reaction vessel B whose inner wall is of lead lining or nickel vessel. Fine crystalline powder of phosphorus pentachloride (PCI.sub.5) is collected in a container placed below reaction vessel B where the temperature is maintained at 25 to 30°C or at a room temperature, which is then packed in a container (not shown in fig) without any atmospheric exposed. Th e purity of phosphorus pentachloride produce is about 99 %. If any excess chlorine gas with fine particulates of phosphorus pentachloride (PCI.sub.5)
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is borne then the chlorine gas is vented out through pipe placed on
reaction vessel B.
DETAILED DESCRIPTION OF THE INVENTION
The proposed invention for manufacturing phosphorus pentachloride
(PCI.sub.5.) comprises of following apparatus:
Storage tank (1), reaction vessel A (2), oil heater (3), nozzle A (4), nozzle B
(5), nozzle C (6), reaction vessel B (7), container (8), pipe (9), thermometer
(10).
The proposed process will now be described with the help of accompanying drawing as stated below:
Fig 1 shows the diagram of process for manufacturing phosphorus pentachloride (PCI.sub.5.).
Referring to fig 1 the proposed process can be better understood for manufacturing free flowing dry powder phosphorus pentachloride (PCI.sub.5.) which comprises of following steps:
I. Phosphorus trichloride (PCI.sub.3.) stored in storage tank (1) is introduced in the reaction vessel A (2) by nozzle A (4). The reaction vessel A (2) is connected with oil heater (3). Thermometer (10) is placed on the reaction vessel A (2) in order to note the temperature.
II. Phosphorus trichloride (PCI.sub.3.) in the reaction vessel A (2) is boiled at temperature between 35 to 40°C by oil heater (3).
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III. After phosphorus trichloride (PCI.sub.3.) starts boiling liquid chlorine is introduced from nozzle A (4) in an equal molar ratio and from nozzle B (5) nitrogen gas is been introduced in the reaction vessel A (2). The temperature is maintained at 60 to 65 °C.
IV. The above step (III) is continued till phosphorus trichloride (PCI.sub.3.) is converted into phosphorus pentachloride (PCI.sub.5) in the form of solid cakes and/or lumps in the reaction vessel A (2) and is kept for approximately 45 to 60 minutes at 35 to 40 °C.
V. Now temperature is increased from 35 to 40°C to 160 to 170°C by oil heater (3) and is maintained for approximately one hour where solid cakes and/or lumps of phosphorus pentachloride (PCI.sub.5) start to sublime from nozzle C (6) and it is then collected in the reaction vessel B (7) and where it is kept for 40 to 60 minutes.
VI. Simultaneously nitrogen gas is passed from nozzle B (5) placed on the reaction vessel A (2) which helps phosphorus pentachloride (PCI.sub.5) to sublime and avoids with mixing with atmospheric impurities. Phosphorus pentachloride (PCI.sub.5) sublimes from reaction vessel A (2) to reaction vessel B (7) whose inner wall is of lead lining or nickel vessel.
VII. Fine powder of phosphorus pentachloride (PCI.sub.5) is collected in a container (8) placed below the reaction vessel B (7) where the temperature is maintained at 25 to 30°C or at a room temperature, which is then packed in a container (not shown in fig) without any atmospheric exposed.
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VIII. If any excess chlorine gas with fine particulates of phosphorus pentachloride (PCI.sub.5) is borne then the chlorine gas is vented out through pipe (9) placed on the reaction vessel B (7).
In this invention free flowing powder form of phosphorus pentachloride (PCI.sub.5.) is manufactured in a batch wise production having purity of about 99%.
The following examples are given by way of illustration and therefore should not be constructed to limit the scope of the present invention.
EXAMPLE
Phosphorus trichloride (PCI.sub.3.) 70 kgs is introduced into a reaction vessel A (2) by nozzle A (4) connected with the oil heater (3). The temperature of reaction vessel A (2) is maintain up to 35 to 40°C where the Phosphorus trichloride (PCI.sub.3.) starts to boil, there after liquid chlorine 40 Kgs is introduce drop wise from the same nozzle A (4) and also nitrogen gas is been introduce from nozzle B (5) and the temperature is maintain up to 60 to 65 °C the slow chlorination continues till the whole Phosphorus trichloride (PCI.sub.3.) is converted to phosphorus pentachloride (PCI.sub.5.) in a solid form in a reaction vessel A (2) which takes about 45 to 60 minutes to finished. Thus the solid cake and/or lumps of phosphorus pentachloride (PCI.sub.5.) is form in a reaction vessel A (2) which is now cooled down and let them settle down at temperature of 30 °C. As the hard lumps and cakes of phosphorus pentachloride (PCI.sub.5.) is very hazardous which is very difficult to take outside form the reaction vessel A (2) or it also difficult to dig out. Phosphorus pentachloride(PCI.sub.5.) lumps formed in a reaction vessel A (2) is now
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heated again by oil heater (3) attached to it now the temperature is rose to 30°C to 165°C to 170°C where the solid cakes and/or lumps of phosphorus pentachloride (PCI.sub.5.) starts to sublime from the nozzle C (6) which is kept for 40 to 60 minutes and in the meantime nitrogen gas passed form nozzle B (5) as there is no formation of clog in the nozzles B (5) and which also helps the phosphorus pentachloride (PCI.sub.5.) to sublime and does not mixed with other atmosphere impurities. Phosphorus pentachloride sublimes from reaction vessel A (2) to reaction vessel B (7) which collects in the reaction vessel B (7) whose inner wall are of lead lining through nozzle C (6). And then the crystalline/powder is collected in a container (8). Phosphorus pentachloride (PCI.sub.5.) in a powder form is produced in a batch wise production having purity of about 99%. If any excess chlorine gas with fine particulates of phosphorus pentachloride (PCI.sub.5) is borne then the chlorine gas is vented out through pipe (9) placed on the reaction vessel B (7).
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I Claim:
1. A process for manufacturing phosphorus pentachloride (PCI.sub.5.) wherein
I. Phosphorus trichloride (PCI.sub.3.) stored in storage tank is
introduced in the reaction vessel A by nozzle A connected
with oil heater, thermometer placed on the reaction vessel A
notes the temperature;
II. Phosphorus trichloride (PCI.sub.3.) in the reaction vessel A is boiled at temperature between 35 to 40°C by oil heater;
III. After phosphorus trichloride (PCI.sub.3.) starts boiling liquid chlorine is introduced from the nozzle A in an equal molar ratio and from nozzle B nitrogen gas is been introduced in the reaction vessel A where temperature is maintained at 60 to 65 °C;
IV. The chlorination is continued till phosphorus trichloride (PCI.sub.3.) is converted into phosphorus pentachloride (PCI.sub.5) in the form of solid cakes and/or lumps in the reaction vessel A and is kept for approximately 45 to 60 minutes at 35 to 40 °C;
V. Temperature is increased from 35 to 40°C to 160 to 170°C by oil heater and is maintained for approximately one hour where solid cakes and/or lumps of phosphorus pentachloride (PCI.sub.5) start to sublime from nozzle C and it is then collected in the reaction vessel B and where it is kept for 40 to 60 minutes;
VI. Simultaneously nitrogen gas is passed from nozzle B placed on the reaction vessel A which helps phosphorus pentachloride (PCI.sub.5) to sublime to reaction vessel B whose inner wall is of lead lining or nickel vessel;
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VII. Fine crystalline powder of phosphorus pentachloride (PCI.sub.5) is collected in a container placed below the reaction vessel B where the temperature is maintained at 25 to 30°C or at a room temperature, which is then packed in a container (not shown in fig) without any atmospheric exposed;
VIII. If any excess chlorine gas with fine particulates of phosphorus pentachloride (PCI.sub.5) is borne then the chlorine gas is vented out through pipe placed on the reaction vessel B.
2. A process for manufacturing phosphorus pentachloride (PCI.sub.5.) as claimed in claim 1 wherein free flowing phosphorus pentachloride (PCI.sub.5.) in a powder form is produced.
3; A process for manufacturing phosphorus pentachloride (PCI.sub.5.) as claimed in claim 1 and 2 wherein free flowing phosphorus pentachloride (PCI.sub.5.) in a powder form is produced in a batch wise production.
Dated this 05th day of November, 2007.

To,
The Controller of Patents,
The Patent Office,
At Mumbai.

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ABSTRACT
Phosphorus trichloride (PCI.sub.3.) in the reaction vessel A is boiled by oil heater, after PCI.sub.3. starts boiling liquid chlorine is introduced from nozzle A and from nozzle B nitrogen gas is introduced, chlorination is continued till PCI.sub.3. is converted into phosphorus pentachloride (PCI.sub.5) in the form of solid cakes and/or lumps and thereafter PCI.sub.5. cakes and/or lumps are heated by increasing the temperature by oil heater and maintained for approximately one hour where solid cakes and/or lumps of PCI.sub.5. start to sublime from nozzle C and it is then collected in the reaction vessel B, nitrogen gas is passed from nozzle B which helps PCI.sub.5 to sublime and avoids mixing with atmospheric impurities. Fine powder of phosphorus pentachloride with 99% of purity is collected and packed in container without any atmospheric exposed.