GB2148266A

GB2148266A - Process for producing an inhibitor of mineral salt deposition

Info

Publication number: GB2148266A
Application number: GB08328328A
Authority: GB
Inventors: Galina Fedoseevna Yaroshenko; Nina Mikhailovna Dyatolova; Rafail Khakimovich Samakaev; Anatoly Vladimirovich Barsukov; Natalya Evgenievna Khavchenko; Vladislav Vladimirovich Sizov; Leonid Terentievich Dytjuk; Leonid Ivanovich Kutyanin; Svetlana Nikolaevna Komova; Olga Alexandrovna Kulikova; Ljudmila Mikhailovna Kisil; Yakov Leonidovich Uskach
Original assignee: Individual
Current assignee: Individual
Priority date: 1983-10-12
Filing date: 1983-10-24
Publication date: 1985-05-30
Also published as: GB2148266B; GB8328328D0; BE898090A; NL8303604A; DD245336A3; DE3337523C2; DE3337523A1

Abstract

A process for producing an inhibitor of mineral salt deposition results in an inhibitor having the following weight percentage composition: mixture of 1,3-diaminopropanol-2 with a derivative of 1,3-diaminopropanol-2 of the following general formula: <IMAGE> where n equals 2 to 5...........................3 to 33 alkali metal chloride.....................2 to 25 water.....................................the balance. There are taken 255 to 300 weight parts of formaldehyde and 400 to 500 weight parts of phosphorus trichloride per 100 weight parts of mixture of 1,3-diaminopropanol-2 with the derivative of 1,3-diaminopropanol-2. The composition can find application in water treatment systems, in desalters of mineralized water, and in the production, conveyance and preparation of petroleum and natural gas.

Description

SPECIFICATION Process for producing an inhibitor of mineral salt deposition This invention relates to a process for producing an inhibitor of mineral salt deposition, which may be applied in water treatment systems, in desalters of mineralized water, and in the production, conveyance and preparation of petroleum and natural gas.

There is known a process for producing an inhibitor of mineral salt deposition by interaction of formaldehyde, phosphorous acid, a mixture of polyethylene-polyamine, monoethanolamine and carbamide, as well as ammonium chloride and/or hexamethylenetetramine, taken in a weight ratio of components equal to 100:55-75:25-40: 50-70:34-35 at 98 to 100 C (cf. USSR Inventor's Certificate No. 719,970).

This process is disadvantageous in that the resultant inhibitor has only a low protective effect against mineral salt deposition. In addition, the process is characterized by too high a temperature of the synthesis carried out.

There is also known a process for producing an inhibitor of mineral salt deposition, wherein formaldehyde is reacted with phosphorous acid and a nitrogen-containing condensation product resulting from interaction of dichloroethane and aqueous ammonia proceeding at 110 to 1 35"C. The nitrogen-containing condensation product has the following weight percentage composition: hydrochloride of polyethylene-polyamines ................... 38 to 70 ammonia ........................................ 0.1 to 1.0 ammonium chloride 1.0to6.0 water ........................................ 25 to 27.

The synthesis of the inhibitor is carried out at 98 to 100#C in dilute hydrochloric acid, the resultant solution being then treated with a sodium hydroxide solution until a pH value of 3.6 to 3.9 is obtained (cf. USSR Inventor's Certificate No.726, 123).

This process is however disadvantageous because of the high temperatures involved. In addition, the inhibitor of mineral salt deposition produced by this process is inadequately effective when used to stabilize supersaturated mineral salt solutions.

The present invention aims to provide a process for producing an inhibitor having high protective action against mineral salt deposition. The invention also aims to provide such a process that would be carried into effect at a lower temperature.

The present invention provides a process for producing an inhibitor of mineral salt deposition, comprising reacting formaldehyde, phosphorus trichloride and a nitrogen-bearing condensation product in an aqueous medium at 35 to 50"C; wherein the said nitrogen-bearing condensation product is the product of interaction of epichlorohydrin and aqueous ammonia at 5 to 20"C and in a molar ratio of the reactants of from 1:5 to 1:15, respectively, followed by treatment of the reaction mass with an alkali metal hydroxide taken in an amount of 1.0 to 1.1 mole per mole of epichlorohydrin and by removal of the unreacted ammonia by distillation, the said product having the following weight percentage composition: mixture of 1,3-diaminopropanol-2 and a derivative of 1,3-diaminopropanol-2 of the following general formula::

where n equals 2 to 5 ........................................ 3 to 33 weight % alkali metal chloride ................................. 2 to 25 weight % water ........................................ the balance, wherein 255 to 300 weight parts of formaldehyde and 400 to 500 weight parts of phosphorus trichloride are taken per 100 weight parts of mixture of 1 ,3-diaminopropanol-2 and the said derivative of 1,3diaminopropanol-2.

The protective effect produced by the inhibitor as obtained by the known process according to USSR Inventor's Certificate No.726,123 is as low as 38.4 per cent, whereas the protective effect produced by the inhibitor obtained according to the process of the present invention may be as high as 47.7 to 78.6 per cent.

In addition, the process according to the invention for producing an inhibitor of mineral salt deposition has a lower specific power consumption that the previously known processes. For instance, dichloroethane interacts with ammonia at 110 to 1350C according to the process of USSR Inventor's Certificate No. 726,123, whereas the reaction of epichlorohydrin with ammonia proceeds at as low a temperature as 5 to 200C according to the process of the present invention.

Furthermore, in the previously known process for producing an inhibitor of mineral salt deposition, the synthesis of the inhibitor proceeds at 98 to 100 C, whereas such synthesis in the process of the present invention is carried out at 35 to 50"C.

In the process of the present invention the nitrogen-bearing condensation product results from interaction of epichlorohydrin and aqueous ammonia at a molar ratio of the reactants of from between 1:5 to 1:15, respectively and at a temperature of from 5 to 20 C. A lower epichlorohydrin-to-ammonia molar ratio is undesirable due to formation of a water-insoluble polymer containing a considerable proportion of unreactive tertiary nitrogen. A higher epichlorohydrin-to-ammonia molar ratio results in increased cost for removal of surplus aqueous ammonia during the synthesis of the inhibitor.To carry out the reaction of epichlorohydrin with aqueous ammonia at a temperature lower than 5"C results in a considerably reduced rate of formation of a mixture of amines (1,3-diaminopropanol-2 and a derivative of 1,3-diaminopropanol-2 of the aforestated general formula), whereas a reaction temperature above 200C leads to formation of an undesirable polymer product, containing a considerable amount of tertiary nitrogen.

The interaction of formaldehyde, phosphorus trichloride and a nitrogen-bearing condensation product (i.e., the process of phosphonomethylation) is carried out at 35 to 50 C, while 255 to 300 weight parts of formaldehyde and 400 to 500 weight parts of phosphorus trichloride are taken per 100 weight parts of the mixture of 1,3-diaminopropanol-2 and a derivative of 1,3-diaminopropanol-2 of the aforestated general formula. To carry out the process of phosphonomethylation at a temperature below 35 C effects adversely the reaction rate and leads to incomplete phosphonomethylation of the aforementioned amines.On the other hand, carrying out the process at a temperature above 500C is also undesirable, since the process of phosphonomethylation is an extremely exothermic one, so that it is difficult to control the process at elevated temperatures. A lower proportion of formaldehyde and phosphorus trichloride with respect to the mixture of 1,3-diaminopropanol-2 and derivative of 1,3-diaminopropanol-2 than the amounts stated is undesirable, since there will inevitably result incomplete phosphonomethylation of the aminogroups in the aforesaid amines, whereas a higher proportion of formaldehyde and phosphorus trichloride with respect to the mixture of 1 ,3-diaminopropanol-2 and derivative of 1 ,3-diaminopropanol-2 than the amounts stated is also undesirable, since this would result in unnecessary increase in cost of the original reactants.

The process according to the invention for producing an inhibitor of mineral salt deposition is suitably carried out as follows.

Epichlorohydrin is added to aqueous ammonia at such a rate that the temperature of the reaction mass should not rise above a range of from 5 to 20 C. The original reactants (epichlorohydrin and ammonia) are used in a molar ratio of from 1 to 1 :15, respectively. Next an alkali metal hydroxide, e.g. NaOH or KOH, is added in small portions to the reaction mass, in order to neutralize the hydrogen chloride evolved. The molar ratio of epichlorohydrin to the alkali metal hydroxide is within the range 1 :1 to 1:1.1. Then the unreacted (surplus) ammonia is distilled off.

The result is a nitrogen-bearing condensation product of the following weight percentage composition: mixture of 1,3-diaminopropanol-2 and a derivative of 1,3-diaminopropanol-2 of the following general formula:

where n equals 2 to 5 3 to 33 alkali metal chloride ................................. 2 to 25 water ........................................ to make up 100 percent.

Then to the nitrogen-bearing condensation product of the aforestated composition there is added the estimated amount of formaldehyde and phosphorustrichloride. Once the reactants have been charged into the reaction vessel the temperature therein is raised to 35 to 500C and the reaction mass is held at this temperature for 3 to 6 hours.

The invention will be further described with reference to the following illustrative Examples.

Example 1 513 kg of 25-percent aqueous ammonia was charged into an enamelled reaction vessel provided with a reflux condenser and stirring, cooling and temperature and pH measuring devices, whereupon 22.6 kg of epichlorohydrin was added thereto at 5 C, the molar ratio of epichlorohydrin to ammonia being 1 :15. Then, for the purpose of neutralizing the hydrogen chloride evolved, 9.77 kg of grained sodium hydroxide (the epichlorohydrin-to-sodium hydroxide molar ratio being 1:1) was fed into the reaction vessel in small portions, and the reaction mass was allowed to stand for three hours.Next the unreacted (surplus) ammonia was distilled off to give 100 kg of a nitrogen-bearing condensation product having the following weight percentage composition: a mixture of 1 ,3-diaminopropanol-2 and derivatives of 1,3-diaminopropanol-2 of the aforestated general formula (80 percent - n = 1,10 percent - n = 2, 5 percent n = 3,3 percent- n = 4, 2percent-n=5) 22 sodium chloride ....................................... 15 water ........................................ to make up 100 percent.

Then there were charged into the reaction vessel under stirring 62.4 kg of formaldehyde and 100 kg of phosphorus trichloride (that is 283 weight parts of formaldehyde and 454 weight parts of phosphorus trichloride per 100 weight parts of the mixture of 1,3-diaminopropanol-2 and derivatives of 1,3diaminopropanol-2). After addition of the formaldehyde and phosphorus trichloride, the temperature in the reaction vessel was raised to 35 C and the reaction mass held at that temperature for 4 hours. As a result of the synthesis (the process of phosphonomethylation) 262 kg of the desired inhibitor was obtained.

Example 2 116.5 kg of 10-percent aqueous ammonia was charged into the reaction vessel as described in Example 1, and then 3.08 kg of epichlorohydrin was added thereto at 20 C, the epichlorohydrin-to-ammonia molar ratio being 1:10. Next 1.39 kg of sodium hydroxide (the epichlorohydrin-to-sodium hydroxide molar ratio being 1:1.05) was fed into the reaction vessel in small portions so as to neutralize the hydrogen chloride evolved, and the reaction mass was allowed to stand for 4 hours, and then the surplus ammonia was distilled off.

There were thus obtained 100 kg of a nitrogen-bearing condensation product having the following weight percentage composition: a mixture of 1 ,3-diaminopropanol-2 and derivatives of 1 ,3-diaminopropanol-2 of the aforestated general formula (75 percent - n = 1,15 percent - n = 2, 5 percent - n = 3,3 percent- n = 4, 2 percent- n = 5) ...................................... 3 sodium chloride ....................................... 2 water ........................................ to make up 100 percent.

Then there were charged into the reaction vessel under stirring 9 kg of formaldehyde and 15 kg of phosphorus trichloride (that is 300 weight parts of formaldehyde and 500 weight parts of phosphorus trichloride per 100 weight parts of the mixture of 1 ,3-diaminopropanol-2 with derivatives thereof) . After addition of the formaldehyde and phosphorus trichloride and temperature in the reaction vessel was raised to 50"C and the reaction mass was left to stand for 6 hours. The synthesis yielded 124 kg of the desired inhibitor.

Example 3 The reaction vessel described in Example 1 was charged with 302 kg of 25-percent aqueous ammonia, whereupon 33.9 kg of epichlorohydrin was added thereto at 1 50C (the epichlorohydrin4o-ammonia molar ratio being 1:5). Thereupon 19 kg of sodium hydroxide (the epichlorohydrin-to-sodium hydroxide molar ratio being 1:1.1) was fed to the reaction vessel in small portions in order to neutralize the hydrogen chloride evolved, and the reaction mass was kept for 3 hours, and then the surplus ammonia was removed by distillation.

There were thus obtained 100 kg of a nitrogen-bearing condensation product having the following weight percentage composition: a mixture of 1 ,3-diaminopropanol and derivatives of 1 ,3-diaminopropanol-2 of the aforestated general formula (86 percent - n = 1, 12 percent - n = 2, 1 percent - n = 3, 0.75 percent- n = 4, 0.25 percent -n=5 ............................. 33 sodium chloride ....................................... 25 water ........................................ to make up 100 percent.

There were then charged into the reaction vessel under stirring 85 kg of formaldehyde and 132 kg of phosphorus trichloride (that is 255 weight parts of formaldehyde and 400 weight parts of phosphorus trichloride per 100 weight parts of the mixture of 1 ,3-diaminopropanol-2 with derivatives thereof). After addition of the formaldehyde and phosphorus trichloride, the temperature in the reaction vessel was raised to 40 C and the reaction mass was left for 3 hours. The synthesis yielded 317 kg of the desired inhibitor.

Example 4 The desired inhibitor was produced in a manner similar to that described in Example 1 except that potassium hydroxide was used to neutralize the hydrogen chloride evolved as a result of interaction of epichlorohydrin and aqueous ammonia. The synthesis yielded 265 kg of the desired inhibitor.

Example 5 Reaction of epichlorohydrin with aqueous ammonia was carried out as described in Example 1 but at 1 5"C.

The process of phosphonomethylation was conducted similarly to Example 1 for 4 hours but at 45 C. The synthesis yielded 264 kg of the desired inhibitor.

Example 6 Reaction of epichlorohydrin with aqueous ammonia was carried out as described in Example 1, but at 20 C for 4 hours. The process of phosphonomethylation was conducted as in Example 1 for 4 hours but at 500C.

The synthesis yielded 265 kg of the desired inhibitor.

Example 7 Reaction of epichlorohydrin with aqueous ammonia was carried out as described in Example 2 except that the epichlorohydrin-to-ammonia molar ratio was 1:15.

Thereupon there were charged into the reaction vessel under stirring 8.6 kg of formaldehyde and 13.6 kg of phosphorus trichloride (that is 283 weight parts of formaldehyde and 454 weight parts of phosphorus trichloride per 100 weight parts of the mixture of 1,3-diaminopropanol-2 and derivatives of 1,3diaminopropanol-2 of the aforestated general formula). After addition of the formaldehyde and phosphorus trichloride, the temperature in the reaction vessel was raised to 400C and the reaction mass was left for 4 hours. There were thus obtained 122 kg of the desired inhibitor.

Example 8 Reaction of epichlorohydrin with aqueous ammonia was carried out as in Example 1 but at an epichlorohydrin-to-ammonia molar ratio of 1:10 and a temperature of 20 C. The process of phospho nomethylation was effected as in Example 1 but at 40 C for 4 hours. The synthesis yielded 260 kg of the desired inhibitor.

Example 9 Reaction of epichlorohydrin with aqueous ammonia was carried out as in Example 3 but at an epichlorohydrin-to-ammonia molar ratio of 1:15 and a temperature of 20 C.

The process of phosphonomethylation was effected as described in Example 3 at 40 C but for 4 hours. In this case there were charged into the reaction vessel 95 kg of formaldehyde and 150 kg of phosphorus trichloride (that is 300 weight parts of formaldehyde and 500 weight parts of phorphorus trichloride per 100 weight parts of the mixture of 1,3-diaminopropanol-2 and derivatives of 1,3-diaminopropanol-2 of the aforestated general formula). The synthesis yielded 345 kg of the desired inhibitor.

The inhibitor produced by the process of present invention has been tested for protective effect produced against deposition of mineral salts, such as calcium sulphate and carbonate.

The protective effect afforded by the inhibitor has been assessed by adding the inhibitor in a concentration of 10 mgil (in terms of a mixture of phosphonomethylated amines) to 750 ml of mineralized stratal water.

To this effect 200 ml of mineralized stratal water was poured into a steel beaker, the water containing an inhibitor obtained by the process of the invention in a concentration of 10 mgil, whereupon part of the water was evaporated by heating. In the course of evaporation the remaining 550 ml of mineralized stratal water doped with the inhibitor was continuously and gradually added to the beaker in order to maintain the effective volume of water therein constant (200 ml). The evaporation ratio in all the tests was equal to 2.75.

As the mineralized stratal water there was used water having the following characteristics: density, g/cm3 ........................................ 1.055 total mineralization, mg-eq/l ................... 2717.596 K + Na', mg-eq/l .................................... 1149.022 Ca2#, mg-eq/l ........................................ 135.763 Mg@, mg-eq/I ........................................ 74.013 Cl-, mg-eq/l ........................................ 1277.595 SO42- mg-eq/l ........................................ 77.991 HCO3-, mg-eq/l ........................................ 0.196 For the sake of comparison, an inhibitor produced by the known method according to USSR Inventor's Certificate No. 726,123 was tested by the same procedure.

The effective properties of the inhibitors of mineral salt deposition produced by the previously known method and by the process of the present invention was judged by the amount of precipitate deposited upon the beaker walls. For the sake of comparison a control test was conducted, using the afore-described procedure but without adding the inhibitor to the mineralized stratal water.

The estimation of the protective effect produced by the inhibitor of mineral salt deposition was obtained by the formula: A-B E = A . 100, where E - protective effect produced by the inhibitor, percent, A - weight of mineral salts deposited upon the beaker walls in the control test (without the inhibitor), g, B - weight of mineral salts deposited upon the beaker walls during the test with the inhibitor, g.

The table below gives numerical data relating to the protective effect obtained by the inhibitor produced by the process of the invention according to Examples 1 to 9 and by the inhibitor produced by the process according to USSR Inventor's Certificate No.726,123.

Process for producing an inhibitor Inhibitor Protective of mineral salt deposition concentration, effect, mg/l percent Control According to process of USSR Inventor's Certificate No.

726,123 10.0 38.4 Accordng to the process of the invention: Example 1 10.0 69.6 Example 2 Ditto 47.7 Example 3 Ditto 69.9 Example4 10.0 70.0 Example 5 Ditto 62.8 Example 6 Ditto 70.1 Example 7 Ditto 48.0 Example 8 Ditto 64.0 Example 9 Ditto 78.6 It is clear from the data tabulated above that the inhibitor of mineral salt deposition produced by the process of the present invention is much superior to that produced by the previously known process.

Claims

1. A process for producing an inhibitor of mineral salt deposition, comprising reacting formaldehyde, phosphorus trichloride and a nitrogen-bearing condensation product in an aqueous medium at 35 to 50 C; wherein the said nitrogen-bearing condensation product is the product of interaction of epichlorohydrin and aqueous ammonia at 5 to 200C and in a molar ratio of the reactants of from 1:15 to 1:15, respectively, followed by treatment of the reaction mass with an alkali metal hydroxide taken in an amount of 1.0 to 1.1 mole per mole of epichlorohydrin and by removal of the unreacted ammonia by distillation, the said product having the following weight percentage composition: mixture of 1,3-diaminopropanol-2 and a derivative of 1,3-diaminopropanol-2 of the following general formula: :

where n equals 2 to 5 3 to 33 weight % alkali metal chloride ........................................ 2to 25weight% water ........................................ the balance, wherein 255 to 300 weight parts of formaldehyde and 400 to 500 weight parts of phosphorus trichloride are taken per 100 weight parts of mixture of 1,3-diaminopropanol-2 and the said derivative of 1,3diaminopropanol-2.

2. A process according to Claim 1 for producing an inhibitor of mineral salt deposition, substantially as herein described in any of the foregoing Examples 1 to 9.

3. An inhibitor of mineral salt deposition, produced by the process as claimed in claim 1 or 2.