Composition for control and inhibition of polymerization of monomers, and method of use and preparation thereof

Abstract

The present invention relates to an additive composition for controlling and inhibiting polymerization of monomers, wherein the composition comprises a combination of (a) a phenol compound comprising catechol compound with (b1) an aliphatic tertiary amine, (b2) oxide treated derivative of the aliphatic tertiary amine, or (b2) a mixture thereof, wherein the aliphatic tertiary amine contains one or more hydroxyl groups in the alkyl chain of the aliphatic tertiary amine. In one embodiment, the present invention also relates to a method for controlling and inhibiting polymerization of monomers by employing the additive composition of the present invention. In another embodiment, the present invention also relates to a method of using the additive composition of the present invention for controlling and inhibiting polymerization of monomers. In another embodiment, the present invention also relates to methods for controlling and inhibiting polymerization of monomers in a primary fractionator (or an ethylene plant), and for operating a primary fractionator, and for reducing fouling and polymer deposits in a primary fractionator, and to extend a run-length of a primary fractionator or of an ethylene plant.

Claims

1. An additive composition for control and inhibition of polymerization of pyrolysis gasoline by controlling and inhibiting formation of deposits and fouling in the primary fractionator, wherein the composition consists of a combination of: (a) a phenol compound comprising a catechol compound; and (b) an oxide treated derivative of the aliphatic tertiary amine consisting of: (i) ethyl oxide treated derivative of tri-isopropanol amine (EO-TIPA); (ii) propyl oxide treated derivative of tri-isopropanol amine (PO-TIPA); or (iii) a mixture thereof.

2. The additive composition as claimed in claim 1, wherein the catechol compound comprises a tertiary butyl catechol (TBC).

3. The additive composition as claimed in claim 2, wherein the tertiary butyl catechol (TBC) comprises 4-tert-butyl catechol; 3,5-di-tert-butyl catechol; or a mixture thereof.

4. A method for controlling and inhibiting polymerization of pyrolysis gasoline, wherein the method comprises a step of treating the pyrolysis gasoline with the additive composition as claimed in claim 2.

5. A method of using the additive composition as claimed in claim 2 for controlling and inhibiting polymerization of pyrolysis gasoline, wherein the method comprises a step of treating the additive composition as claimed in claim 2 with the pyrolysis gasoline.

6. The method of using as claimed in claim 5, wherein the additive composition is added at a temperature range varying from about 60° C. to about 180° C.

7. A method for operating a primary fractionator by controlling and inhibiting polymerization of pyrolysis gasoline in the primary fractionator or an ethylene plant, wherein the method comprises treating the additive composition as claimed in claim 2 with the pyrolysis gasoline in the primary fractionator or an ethylene plant.

8. The method for operating as claimed in claim 7, wherein the additive composition is added at a temperature range varying from about 60° C. to about 180° C.

9. A method for reducing fouling and polymer deposits in a primary fractionator by controlling and inhibiting polymerization of pyrolysis gasoline in the primary fractionator, wherein the method comprises a step of treating the pyrolysis gasoline with the additive composition as claimed in claim 2.

10. A method to extend a run-length of a primary fractionator or of an ethylene plant by reducing fouling and polymer deposits in the primary fractionator by controlling and inhibiting polymerization of pyrolysis gasoline in the primary fractionator or an ethylene plant, wherein the method comprises a step of treating the pyrolysis gasoline with the additive composition as claimed in claim 2.

11. A method for controlling and inhibiting polymerization of pyrolysis gasoline, wherein the method comprises a step of treating the pyrolysis gasoline with the additive composition as claimed in claim 1.

12. A method of using the additive composition as claimed in claim 1 for controlling and inhibiting polymerization of pyrolysis gasoline, wherein the method comprises a step of treating the additive composition as claimed in claim 1 with the pyrolysis gasoline.

13. The method of using as claimed in claim 12, wherein the additive composition is employed at a temperature range varying from about 60° C. to about 180° C.

14. A method for operating a primary fractionator by controlling and inhibiting polymerization of pyrolysis gasoline in the primary fractionator, wherein the method comprises treating the additive composition as claimed in claim 1 with the pyrolysis gasoline in the primary fractionator or an ethylene plant.

15. The method for operating as claimed in claim 14, wherein the additive composition is added at a temperature range varying from about 60° C. to about 180° C.

16. A method for reducing fouling and polymer deposits in a primary fractionator by controlling and inhibiting polymerization of pyrolysis gasoline in the primary fractionator, wherein the method comprises a step of treating the pyrolysis gasoline with the additive composition as claimed in claim 1.

17. A method to extend a run-length of a primary fractionator or of an ethylene plant by reducing fouling and polymer deposits in the primary fractionator by controlling and inhibiting polymerization of pyrolysis gasoline in the primary fractionator or an ethylene plant, wherein the method comprises a step of treating the pyrolysis gasoline with the additive composition as claimed in claim 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

(1) As discussed herein, it is known that while manufacturing lighter hydrocarbon products such as ethylene, heavier hydrocarbons such as naphtha, condensate or diesel oil are cracked in pyrolysis heaters at higher temperatures, generally at a temperature of about 850° C. and form mixtures of smaller molecules including, but not limited to, ethylene, propylene, and butadiene. Such mixtures, commonly termed as cracked gases, are cooled and compressed in various stages of the ethylene plant until they are separated in the fractionation section of the ethylene plant.

(2) During primary heat recovery, the cracked gases pass through and are cooled by a series of heat exchangers, also termed transfer line exchangers, before being quenched with an oil, preferably an heavy oil. The heavy oil, which is commonly known as quench oil, pyrolysis fuel oil or bottoms quench oil, accumulates in the bottom section of the primary fractionator. The primary fractionator contains varying components of fuel oil species ranging from the bottom section of the column to the beginning of what is called the rectification section of the column.

(3) The rectification section of the column is prone to severe fouling problems caused due to presence of various monomers, such as styrene, indene, di-vinyl benzene, alpha-methyl styrene, indene derivatives, and other higher ring compounds/monomers or derivatives thereof, and polymers thereof.

(4) The polymerization products of the said monomers get deposited at a very rapid rate not only on upper tray surfaces, but also beneath tray surfaces. Due to this fouling problem, an increase in ‘column pressure drop’ along with reduction in ‘fractionation efficiency’ are experienced.

(5) Therefore, the quality of the gasoline condensing in the quench tower and also the quality of the fuel oil made from the system are negatively affected.

(6) Typically, the problem of fouling in the rectification section is also accompanied by poor viscosity control in the bottom section of the quench tower due to improper operations of the primary fractionator.

(7) Further, the deposition of the fouling substances, commonly known as polymers, obstructs the vapor and liquid flow inside the fractionator and due to the reduced surface area available, the environment is also conducive to increased froth/foam generation in the column.

(8) As the fouling continues to occur, the polymers deposit also continues to occur inside the column trays thus resulting in forcing the plant operators to reduce unit feed rates significantly and, ultimately, to shut down the plant for cleaning and/or maintaining the primary fractionator.

(9) With aim to overcome above-described problems of prior art and to achieve above-described objects of the invention, the inventor has found that when (a) a phenol compound comprising catechol compound is combined with (b1) an aliphatic tertiary amine and/or (b2) oxide treated derivative thereof, preferably with aliphatic tertiary amine having one or more hydroxyl groups in the alkyl chain of said aliphatic tertiary amine, the polymerization inhibition efficiency of the phenol compound comprising catechol compound surprisingly and unexpectedly increases.

(10) The prior art does not disclose composition for control and inhibition of polymerization of monomers, wherein the monomers may comprise styrene, indene, di-vinyl benzene, alpha-methyl styrene, and other higher ring compounds or monomers, or derivatives thereof to overcome above discussed existing problems of the industry particularly the above-discussed problems of formation of deposits and fouling in the primary fractionator, wherein the composition comprises a combination of: (a) a phenol compound comprising catechol compound; and (b1) an aliphatic tertiary amine and/or (b2) oxide treated derivative thereof, preferably an aliphatic tertiary amine having one or more hydroxyl groups in the alkyl chain of said aliphatic tertiary amine;
with aim to increase polymerization inhibition efficiency of the phenol compound including catechol compound and/or to reduce amount of the phenol compound including catechol compound for controlling and inhibiting polymerization of the monomers.

(11) Therefore, the present invention provides a composition which has been found to be suitable in reducing the formation of polymers of the monomers, and hence, has also been found to be suitable in preventing the fouling in the primary fractionator or ethylene plant, and thereby, to extend a run-length of the primary fractionator or of the ethylene plant.

(12) Accordingly, in one embodiment, the present invention provides an additive composition for control and inhibition of polymerization of monomers, wherein the composition comprises a combination of:

(13) (a) a phenol compound comprising catechol compound; and

(14) (b) an aliphatic tertiary amine, oxide treated derivative of the aliphatic tertiary amine, or a mixture thereof.

(15) Accordingly, in one of the preferred embodiments, the present invention provides an additive composition for control and inhibition of polymerization of monomers, wherein the composition comprises a combination of:

(16) (a) a phenol compound comprising catechol compound; and

(17) (b) an aliphatic tertiary amine, oxide treated derivative of the aliphatic tertiary amine, or a mixture thereof,

(18) wherein the aliphatic tertiary amine contains (or has) one or more hydroxyl groups in the alkyl chain of the aliphatic tertiary amine.

(19) In accordance with one of the preferred embodiments of the present invention, the aliphatic tertiary amine contains three or more hydroxyl groups in the alkyl chain of the aliphatic tertiary amine.

(20) In accordance with one of the preferred embodiments of the present invention, the aliphatic tertiary amine comprises tri-isopropanol amine (TIPA).

(21) In accordance with one of the preferred embodiments of the present invention, the oxide treated derivative of the aliphatic tertiary amine comprises:

(22) (i) ethyl oxide treated derivative of tri-isopropanol amine (EO-TIPA);

(23) (ii) propyl oxide treated derivative of tri-isopropanol amine (PO-TIPA); or

(24) (iii) a mixture thereof.

(25) In accordance with one of the preferred embodiments of the present invention, the phenol compound comprises a catechol compound.

(26) In accordance with one of the preferred embodiments of the present invention, the catechol compound comprises a tertiary butyl catechol (TBC).

(27) In accordance with one of the preferred embodiments of the present invention, the tertiary butyl catechol (TBC) may be selected from the group comprising 4-tert-butyl catechol; 3,5-di-tert-butylcatechol; or a mixture thereof.

(28) It may be noted that it is understood from the present description that the present invention aims at reducing the amount of TBC (the prior art additive) in the present compositions. Therefore, the TBC is a primary component of the present composition, and the TIP A, the EO-TIPA or the PO-TIPA is the additive component of the present composition, and it is the additive component which is added to the primary component, or say, to the composition comprising or consisting of TBC. Therefore, generally, it is the primary component of the present invention which is present in a major percent by weight amount and it is the additive component of the present invention which is present in a minor percent by weight amount. However, one of an ordinary skill in the art may use the present composition in reverse order.

(29) In accordance with the present invention, the monomers comprising or including styrene may be referred to as monomers or a monomer stream, which are intended to include or comprise but not limited to styrene.

(30) In accordance with one of the embodiments of the present invention, the phenol compound and the aliphatic tertiary amine or the oxide treated derivative thereof may be taken in a weight percent ratio varying from about 99.99:0.01 to about 0.01:99.99.

(31) In accordance with one of the preferred embodiments of the present invention, the phenol compound and the aliphatic tertiary amine or the oxide treated derivative thereof may be taken in a weight percent ratio varying from about 90:10 to about 10:90.

(32) In accordance with another embodiment of the present invention, the phenol compound and the aliphatic tertiary amine or the oxide treated derivative thereof may be taken in a weight percent ratio varying from about 80:20 to about 20:80.

(33) In accordance with still another embodiment of the present invention, the phenol compound and the aliphatic tertiary amine or the oxide treated derivative thereof may be taken in a weight percent ratio varying from about 70:30 to about 30:70.

(34) In accordance with yet another embodiment of the present invention, the phenol compound and the aliphatic tertiary amine or the oxide treated derivative thereof may be taken in a weight percent ratio varying from about 60:40 to about 40:60.

(35) In accordance with yet another embodiment of the present invention, the phenol compound and the aliphatic tertiary amine or the oxide treated derivative thereof may be taken in a weight percent ratio of about 50:50.

(36) In accordance with one of the embodiments of the present invention, about 0.01 to about 5000 ppm of the present composition may be used based on weight of the reacting material in polymerization of monomers.

(37) In accordance with another embodiment of the present invention, about 0.20 to about 5000 ppm of the present composition may be used based on weight of the reacting material in polymerization of monomers.

(38) In accordance with still another embodiment of the present invention, about 0.50 to about 5000 ppm of the present composition may be used based on weight of the reacting material in polymerization of monomers.

(39) In accordance with yet another embodiment of the present invention, about 1.0 to about 5000 ppm of the present composition may be used based on weight of the reacting material in polymerization of monomers.

(40) In accordance with yet another embodiment of the present invention, about 5.0 to about 5000 ppm of the present composition may be used based on weight of the reacting material in polymerization of monomers.

(41) In accordance with yet another embodiment of the present invention, about 10.0 to about 5000 ppm of the present composition may be used based on weight of the reacting material in polymerization of monomers.

(42) In accordance with one of the embodiments of the present invention, the additive composition of the present invention may be used or employed at a temperature range varying from about 60° C. to about 180° C., or preferably at a temperature range varying from about 80° C. to about 150° C.

(43) In one embodiment, the present invention relates to a method for controlling and inhibiting polymerization of monomers, wherein the method comprises a step of treating a monomer stream with the additive composition of the present invention.

(44) In another embodiment, the present invention also relates to a method of using the additive composition of the present invention for controlling and inhibiting polymerization of monomers, wherein the method comprises a step of using the additive composition of the present invention in a monomer stream.

(45) It may be noted that the present composition may be used for controlling and inhibition of polymerization of monomers of any composition.

(46) In one of the exemplary embodiments, the present composition is used for controlling and inhibition of polymerization of monomers, wherein the monomers may comprise styrene, indene, di-vinyl benzene, alpha-methyl styrene, and other higher ring compounds or monomers, or derivatives thereof.

(47) In another exemplary embodiment, the present composition is used for controlling and inhibiting polymerization of the monomers in the primary fractionator or the ethylene plant.

(48) Accordingly, in still another embodiment, the present invention also relates to a method for controlling and inhibiting polymerization of monomers in a primary fractionator (or an ethylene plant), wherein the method comprises a step of treating a monomer stream with the additive composition of the present invention.

(49) Accordingly, in yet another embodiment, the present invention also relates to a method for operating a primary fractionator by controlling and inhibiting polymerization of monomers in the primary fractionator (or an ethylene plant), wherein the method comprises a step of using the additive composition of the present invention in a monomer stream.

(50) Accordingly, in yet another embodiment, the present invention also relates to a method for reducing fouling and polymer deposits in a primary fractionator by controlling and inhibiting polymerization of monomers in the primary fractionator (or an ethylene plant), wherein the method comprises a step of treating a monomer stream with the additive composition of the present invention.

(51) Accordingly, in yet another embodiment, the present invention also relates to a method to extend a run-length of a primary fractionator or of an ethylene plant by reducing fouling and polymer deposits in the primary fractionator by controlling and inhibiting polymerization of monomers in the primary fractionator (or an ethylene plant), wherein the method comprises a step of treating a monomer stream with the additive composition of the present invention.

(52) It may also be noted that ‘in percent ratio’ means ‘in weight percent ratio’ or ‘in percent ratio by weight’ unless specifically otherwise provided.

(53) It may also be noted that the term ‘about’ is intended to include experimentally permissible errors in the field of the present invention.

EXAMPLES

(54) The present invention is now further illustrated with the help of accompanying examples, which are not intended to limit its scope.

Example—I

(55) The pyrolysis gasoline sample was taken in a tube with provision for nitrogen gas purging and the sample was treated at temperatures of about 90° C., about 120° C. and about 150° C. for about 2 hrs. and the polymer formed was separated by methanol precipitation and the percent polymerization in blank (without an additive), comparative sample (with 100 ppm additive consisting of TBC) and the invention sample (with 100 ppm of additive comprising TBC and TIPA in 40:10 weight percent ratio) was measured and has been presented in Table—I.

(56) It may be noted that as per the present invention and as described herein, the TIPA, the EO-TIPA and the PO-TIPA are the additive components of the present composition, and it is the additive component which is added to the primary component, or say, to the composition comprising or consisting of TBC. Therefore, as per the present examples, it is 10% by wt. of the TIPA which is mixed with 40% by wt. of the TBC to arrive at the invention composition of these examples.

(57) TABLE-US-00001 TABLE I Expt. 90° C. 120° C. 150° C. % Polymer % Polymer % Polymer % Polymer % Polymer % Polymer Additive by OD by methanol by OD by methanol by OD by methanol Blank 0.15 Nil 1.62 0.18 3.15 1.21 TBC 0.47 0.18 0.93 0.11 2.50 0.93 (Comparative Example) TBC + TIPA 0.42 0.10 0.48 0.07 1.95 0.43 (Present Invention)

Example—II

(58) The pyrolysis gasoline sample was taken in a tube and this time without nitrogen gas purging and the sample was treated at temperatures of 120° C. and 150° C. for 2 hrs. and the polymer formed was separated by methanol precipitation and the percent polymerization in blank (without an additive), comparative sample (with 100 ppm additive consisting of TBC) and the invention sample (with 100 ppm of additive comprising TBC and TIPA in 40:10 weight percent ratio) was measured and has been presented in Table—II.

(59) TABLE-US-00002 TABLE II Expt. 120° C. 150° C. % Polymer % Polymer % Polymer % Polymer Additive by OD by methanol by OD by methanol Blank 1.46 0.13 3.05 1.14 TBC 0.82 0.09 2.34 0.86 (Comparative Example) TBC + TIPA 0.43 0.04 1.80 0.41 (Present Invention)

(60) The above experiments confirm surprising, unexpected and synergistic effects of the presently provided compositions, because the efficiency of the phenol compound to control and inhibition of polymerization of monomers has increased on combining it with an aliphatic tertiary amine, and/or oxide treated derivative thereof.

(61) The above findings also confirm that compositions of present invention have technical advantages and surprising effects over the prior art additives and compositions, because the efficiency of the phenol compound to control and inhibition of polymerization of monomers has increased on combining it with an aliphatic tertiary amine, and/or oxide treated derivative thereof.