|Title of Invention||
PROCESS FOR THE PREPARATION OF SPECIALITY OIL FROM A MIXTURE OF C16-C28 OLEFINS
|Abstract||A process for the preparation of saturated oils is disclosed. The process comprises hydrogenating a hydrocarbon mixture consisting of C16-C28 olefines at a temperature in the range of from 150 to 170 degrees C in the presence of a catalyst.|
|Full Text||Form 2
THE PATENTS ACT, 1970 COMPLETE SPECIFICATION
"PROCESS FOR THE PREPARATION OF SPECIALITY OIL FROM A MIXTURE OF C16-C18 OLEFINS"
We, INDIAN PETROCHEMICALS CORPORATION LIMITED, a Government of India Company, incorporated under the Companies Act, 1956, of P. O. Petrochemicals, District Vadodara 391 346, Gujarat, India
The following specification particularly describes and ascertains the nature of the invention and the manner in which it is to be performed:
, Field of invention
The present invention relates to a process for the preparation of specialty oil from a mixture of predominantly branched C16-C28 olefins of low viscosity suitable for niche applications as such or after chemical treatment. More particularly, the present invention relates to a process for the preparation of specialty oil from a mixture of predominantly branched C16-C28 olefins of low viscosity obtained from the lighter fraction of oligomer of C4 raffinates. Background of the invention
Several olefins, which include the more popular a-olefins find use in the preparation of oligomer products. Such oligomers may vary widely in origin and composition, and many are particularly useful in preparing various types of functional fluids. After suitable chemical treatment, for instance, hydrogenation, the oligomers become inert, colorless, odorless, stable to heat and storage and thus are suitable for varied applications.
Oligomers of C4 olefins, for instance, from "the C4 raffinate" not only relate to butene oligomers but also isobutene oligomers and to butene and isobutene cooligomers. These oligomer products are usually viscous liquids. Polymers with molecular weight in the range 400-2000 are well known as polyisobutylenes and have varied applications. They can be used inter aha, as tackifiers and gasoline additives for two stroke engines. Dimers and trimers of butanes are suitable raw materials for preparing alkylates which find use as octane boosters in gasoline. However, the oligomer fraction in the carbon range C16. C28 has hardly any specific application. A suitable modification with improved properties, however, leaves scope for niche applications. Summary of the invention
The present invention relates to the recovery of C16- C28 olefin mixture from the lighter fraction of oligomer of C4 raffinate, followed by hydrogenation of the same and its conversion by chemical treatment using suitable reagents. More particularly, the present invention relates to a batch scale process for hydrogenation of paraffmic oil, derived from a mixture of C4 olefins, having molecular weight between 210 and 390. The components of the olefin mixture are present in variable proportions. Detailed description
The present invention relates to a process for the preparation of saturated oils which comprises hydrogenating a hydrocarbon mixture consisting of C16-C28 olefins at a temperature in the range of from 150 to 170°C in the presence of a catalyst of the kind such as herein described.
In spite of its variation in composition, the saturated oil resulting from the invention results in a product having consistent physico-chemical properties.
The composition of the oligomeric mixture of C4 raffinate after removal of lighters
contains predominantly C16, C2o, C24 and C28 olefins including their various isomers. The
presence of some amount of C12 olefins affects viscosity and flash point specifications of derived formulations. Hence this olefin is limited to a maximum 2% of the total olefin content. A typical composition of the ohgomer displays C16 olefins = 36-38%, C20 olefins = 33-35% and C16- C28 olefins = 26-27%.
Undesirable levels of moisture generally are detrimental to various chemical modifications of the oligomer. The moisture content in the olefin mixture is critical prior to hydrogenation. With the help of a suitable desiccant the moisture level has to be maintained lower than 100 ppm for hydrogenation, preferably 20-30 ppm of moisture. Those skilled in the art will know about subsequent purification before hydrogenate of the synthetic oil can be made.
The above ohgomer oil can be saturated to varying degrees by hydrogenation. Through it is preferred to fully saturate the above ohgomer for attaining superior properties in some applications, even partial saturation finds some use.
Hydrogenation of viscous hydrocarbon oils is a challenge in itself considering the severity of operating conditions. Such hydrogenation reaction find mention in the prior art as given in the British patent 1513,853 where hydrogenation of polysiobutylenes of molecular weight in the range of from 500 to 3000 can be carried out using platinum or nickel based catalysts. In the present invention hydrogenation can be carried out in a batch mode using a supported palladium catalyst selected from Pd/C, Pd/MgO, Pd/Al203 and similar other Pd catalysts can be efficiently used in the hydrogenation reaction. Pd/a-Al203 catalysts beads were found to be extremely useful. The hydrogenation is carried out at a temperature in the range 150-170°C while mamtaining H2 pressure of 60-70 kg/cm2.
In a preferred embodiment, the catalyst is selected from one or more Pd/C, Pd/MgO, Pd/Al203 and similar other Pd catalysts. Pd/a-Al203 is the most preferred.
In a further embodiment of the invention, the hydrogenation is carried out at a pressure of 60-70 Kg/cm2H2.
After hydrogenation, the saturated oil may preferably be subjected to treatments, for eg., for removal of odour. Any of the existing methods like use of clays, molecular sieves etc. can be employed to deodorize the saturated oil. The saturated oil can also be reacted with gases like Cl2 to introduce new functional groups on the backbone of the ohgomer molecule. Such modifications are necessitated by particular use of these oils.
In another embodiment of the invention, the mixture of C16-C28 olefinic mixture and the hydrogenated product have molecular weight in the range 210-390.
Preferably, the hydrogenated product has a bromine number of 0.5 - 0.7.
In a preferred embodiment, the hydrogenated product has properties as mentioned in Table- 1 and the hydrogenated lighter oil and hydrogenated heavier oil have the properties as mentioned in Table-2.
Following the modification, the saturated oils can be seen in comparison with the oligomer as such with changed physico-chemical properties, and other available materials in various user industries.
The present invention will now be explained with reference to the following examples which are merely illustrative and are in no way limiting as to the reaction conditions and catalyst employed. Example -1
In a 100 litre autoclave 50 litres of oligomer mixture (properties given in Table-1) was taken 1.0 kg of Pd (0.4 wt%)/a-Al203 was placed inside the reactor. After flushing with N2 initially and then by H2, the pressure was set at 700 psi at 25°C. The ohgomer mixture and the suspended catalyst were agitated at 300 rpm. The reactor was heated slowly over a period of Ihour tol50°C. The H2 pressure rose to 850 psi and H2 consumption started. As H2 pressure came down further H2 was fed into the reactor. This was followed until no more H2 was consumed. Finally, the temperature was raised to 160-170°C and the reaction was allowed to completion. The reactor was cooled to 25°C and H2 is slowly vented out. The resultant oil is a colorless and fully saturated oil (properties given in Table -1).
The catalyst separated from the saturated oil can be cycled for the next batch of reaction.
Properties Oligomer Mixture Hydrogenated Oil
Kinematic viscosity at 100°C, cSt 2.1 2.7
330C, cSt 8.8 10.5
Specific gravity at 15.5°C, gm/cc 0.82 0.85
330C, gm/cc 0.81 0.84
Bromine No. 85 0.5-0.7
Flash Point, 0C,OC 106 110
Flash Point CC 107 114
Colour, APHA 25 10
Example - 2
2 Litre of above hydrogenated oil of density 0.84 gm/cc was chlorinated by bubbling chlorine at 28°C continuously for 24h. A viscous and slightly brown coloured liquid was
obtained. The excess dissolved chlorine was removed by bubbling N2 continuously for an hour. The liquid has density of 1.14 gm/cc. Chemical analysis indicates substitution of 3 hydrogen atoms by chlorine atoms in the saturated hydrocarbon mixture. Example - 3
The hydrogenated oil, prepared by example 1, was distilled and the distillate (hydrogenated lighter oil) boiling at 96-110°C/3 mm Hg vacuum was collected. Properties of this oil and the hydrogenated heavier oil (residue) are given in Table 2. Hydrogenated lighter and heavier oils are suitable for water-oil emulsion and medium viscosity range industrial lubricant oil respectively.
Table - 2
Properties Hydrogenated hghter oil Hydrogenated heavier oil
C16H34, wt% 82-84 19.5
C20H42, wt% 16-18 41.1
C24H50, wt% - 25.2
C28H58, wt% - 14.2
Kinematic viscosity at 400C cSt 3.7-4.00 11-13.2
100°C, cSt 1.8-2.0 3
Appearance Clear Clear
Flash point 0C,CC 86 132
Pour point, °C -60 -
1. A process for the preparation of saturated oils which comprises hydrogenating a hydrocarbon mixture consisting of C16-C28 olefins at a temperature in the range of from 150 to 170°C in the presence of a catalyst of the kind such as herein described.
2. A process as claimed in claim 1 wherein said catalyst is selected from one or more Pd/C, Pd/MgO, Pd/Al203 and similar other Pd catalysts, preferably Pd/a- AI2O3.
3. A process as claimed in claim 1 or 2 wherein said hydrogenation is carried out at a pressure in the range of 60-70 Kg/cm2 H2.
4. A process as claimed in any preceding claim wherein said after hydrogenation, the saturated oil is subjected to treatment for removal of odour.
5. A process as claimed in any preceding claim wherein said odour is removed using clays or molecular sieves.
6. A process as claimed in claim 4 or 5 wherein said saturated oil is reacted with gases such as CI2 to introduce new functional groups on the backbone of the oligomer molecule.
7. A process as claimed in any preceding claim wherein said mixture of C16-C28 olefinic
mixture and the hydrogenated product has a molecular weight in the range 210-390.
8. A process as claimed in any preceding claim wherein said hydrogenated product has a bromine number of 0.5 - 0.7.
9. A process as claimed in claim 6 wherein said treated product has minimum 3 chlorine atoms on the hydrocarbon replacing equal number of hydrogen atoms.
10. A process for the preparation of saturated oils substantially as described herein with reference to and as illustrated in the foregoing examples.
Dated this the 25th day of June 2002
|Indian Patent Application Number||564/MUM/2002|
|PG Journal Number||13/2008|
|Date of Filing||26-Jun-2002|
|Name of Patentee||INDIAN PETROCHEMICALS CORPORATION LIMIITED|
|Applicant Address||P.O. PETROCHEMICALS, DISTRICT VADODARA 391 346, GUJARAT, INDIA|
|PCT International Classification Number||C07B 35/00|
|PCT International Application Number||N/A|
|PCT International Filing date|