RU2408662C2 - Hydrolysed depressor additive for fuel oil - Google Patents

Abstract

FIELD: oil and gas production.

SUBSTANCE: here is disclosed hydrolysed depressor additive for fuel oil corresponding to hydrolysed copolymer of ethylene with vinyl-acetate. Also, a hydrolysed component corresponds to 27-33 % (wt) solution of copolymer ethylene with vinyl acetate in a hydrocarbon solvent with weigh share of links of vinyl acetate before hydrolysis 8.5 - less 10 %. Hydrolysed additive is preliminary dissolved in diesel fuel at amount of 5-15 wt %, further it is added to fuel oil at amount of 0.04 - 0.05 wt % (as additive). Potassium hydroxide (POH) is a hydrolysing agent preliminary disolved in alcohol (isopropyl or isobutyl, or butyl) at amount of 10 wt %, while hydrolysing agent is added to copolymer at amount of wt %: 1.5-2.8 at utilisation of isopropyl alcohol, 1.0-2.5 at utilisation of isobutyl alcohol and 1.0-1.5 at utilisation of butyl alcohol.

EFFECT: utilisation of claimed depressor additive ensures stable reduction of setting point of high viscous fuel oil.

3 cl, 5 tbl, 2 ex

Description

The invention relates to oil refining and can be used to reduce the pour point of fuel oil during transportation and storage.

The efficiency of oil refining is estimated by increasing the selection of light oil products. The latter is associated with the production of heating oils of high viscosity and high pour points. A decrease in the pour point of fuel oils is achieved by introducing various depressant additives into them.

Known depressant additive, which is a 20% solution of a thermopolymer of ethylene with vinyl acetate (37%) and maleic anhydride (0.5%) - VES-503 (Korotkov V.P., Konradi V.V., Tumanyan B.P. The use of depressant additives in the pipeline transport of high-curing oil mixtures of the northern fields of the Timan-Pechersk oil and gas province // Pipeline oil transportation. - 1994. - 11. - p.11).

Known depressant additive is not effective enough when the content of paraffin hydrocarbons in the product is more than 2%.

Common features are the use of the same product in the composition of both additives - a copolymer of ethylene with vinyl acetate.

From TU 38.401-58-340-2004 the depressant additive VES-408 is known, which is used in the production of heating oil, up to 15% of diesel fractions are introduced into it. The known additive is used in the form of a 30% solution in a hydrocarbon solvent to reduce the pour point of fuel oils. According to the physicochemical characteristics, the VES-408 additive complies with the requirements and standards set forth in table 1.

From (Terteryan R.A. Depressor additives to oils, fuels and oils. M .: Chemistry. - 1990. - p.88) it is known that the addition of additives grade VES-408 at a concentration of 0.01% (per copolymer) provides standard stability temperature of pour point of fuel oil grade F-5 (low-curing product) with the addition of light gas oil catalytic cracking or coking.

Common to the known and claimed depressant additives is that the additives are a copolymer of ethylene with vinyl acetate.

However, known additives are used only for low viscosity fuel oils. The possibility of its use as an additive to highly hardening and highly viscous heating oil has not been established.

The closest (prototype) in technical essence and technical result to the claimed hydrolyzed depressant additive are additives known from DE 2413434 A, 03.10.1974, additives that are hydrolyzed copolymers of ethylene with vinyl acetate, which contain 10-90% vinyl acetate units before hydrolysis. The additive can be introduced into the product in the form of a solution in diesel fuel in an amount of from 0.001 to 5% (preferably 25-75%).

It was also shown there that as a result of hydrolysis of a copolymer of ethylene with 32% vinyl acetate (molecular weight 2.4 · 10 ³ ), samples of different degrees of hydrolysis were obtained - from 23 to 81%. The introduction of this additive in a concentration of 0.1% in fuel oil (pour point 32 and 21 ° C) reduces the pour point and improves the pumpability of fuel oil. It was found that copolymers in which 30-70% of the acetate groups are hydrolyzed are optimal.

The disadvantage is that this depressant additive is used in larger quantities (preferably 25-75%) than the proposed one.

The objective of the invention is to expand the range of depressant additives with good performance (depressor) properties that can be used as an additive to high viscosity heating oils with a high pour point.

The technical result, the achievement of which is achieved by the implementation of the inventive hydrolyzed depressant additives, is to improve operational properties, namely:

- improving the depressant properties of additives brand VES-408,

- expanding the use of depressant additives brand VES-408,

- reducing the consumption of hydrolyzed additives.

The specified technical result from the implementation of a hydrolyzed depressant additive for heating oil, which is a hydrolyzed copolymer of ethylene with vinyl acetate, is achieved by hydrolysis of a 27-33% (wt.) Solution of a copolymer of ethylene with vinyl acetate in a hydrocarbon solvent, which has a mass before hydrolysis the proportion of vinyl acetate units 8.5 is less than 10%, the hydrolyzed additive is pre-dissolved in diesel fuel in an amount of 5-15 wt.%, and then added to fuel oil in an amount of 0.04-0.05 wt.% (per additive ). In this case, the hydrolyzing agent is potassium hydroxide (KOH), which is pre-dissolved in alcohol (isopropyl, or isobutyl, or butyl) in the amount of 10 wt.%, And the hydrolyzing agent is added to the additive VES-408 in the amount, wt.%: 1, 5-2.8 when using isopropyl alcohol, 1.0-2.5 when using isobutyl alcohol and 1.0-1.5 when using butyl alcohol.

A comparative analysis of the prototype and the proposed invention shows that it is common for the prototype and the present invention that both additives are hydrolyzed copolymers of ethylene with vinyl acetate.

The difference between the proposed hydrolyzed additive from the prototype is that a 27-33% (wt.) Solution of a copolymer of ethylene with vinyl acetate in a hydrocarbon solvent is subjected to hydrolysis, which before hydrolysis has a mass fraction of vinyl acetate units of 8.5 - less than 10%, the hydrolyzed additive is preliminarily 5-15 wt.% dissolved in diesel fuel, and then added to the fuel oil in the amount of 0.04-0.05 wt.% (additive). In this case, the hydrolyzing agent is potassium hydroxide (KOH), which is pre-dissolved in alcohol (isopropyl, or isobutyl, or butyl) in the amount of 10 wt.%, And the hydrolyzing agent is added to the additive VES-408 in the amount, wt.%: 1, 5-2.8 when using isopropyl alcohol, 1.0-2.5 when using isobutyl alcohol and 1.0-1.5 when using butyl alcohol.

The implementation of the invention and the possibility of obtaining a technical result is shown in the following examples.

Example 1. Preparation of a 10% alcohol solution of potassium hydroxide and a method of hydrolysis of the additive.

In 90 g of alcohol (isopropyl or isobutyl or butyl) add 10 g of 100% potassium hydroxide. The mixture is heated to a temperature of 50-70 ° C with constant stirring for 10-15 minutes to obtain a homogeneous solution and complete dissolution of potassium hydroxide in alcohols.

The hydrolysis process is as follows. A portion (35 g) of VES-408 additive in the form of a 30% (wt.) Solution of a copolymer of ethylene with vinyl acetate in a hydrocarbon solvent having a mass fraction of vinyl acetate units of 9.5%, the density at 20 ° C, 871 kg / m ^{3 is} heated to water bath to a temperature of 50-60 ° C. Then, with constant stirring, a predetermined amount of a hydrolyzing agent is introduced into it in the form of a 10% alcohol solution of potassium hydroxide. The duration of the hydrolysis is 15 minutes from the moment the hydrolyzing agent is introduced until a homogeneous solution is obtained.

The studies (Table 2) allowed us to determine the optimal concentration of the hydrolyzing agent - 100% potassium hydroxide, which was, wt.%: 1.5-2.8 when using isopropyl alcohol, 1.0-2.5 when using isobutyl alcohol alcohol and 1.0-1.5 when using butyl alcohol. It was shown that the depressant properties of the VES-408 additive were significantly improved due to its hydrolysis of KOH, as DTZ of non-hydrolyzed additive - VES-408 is significantly less than DTZ of hydrolyzed additive - VES-408A with the same amount (0.05 wt.%) Of additives in fuel oil.

It was found that the hydrolyzed product has a pH value of aqueous extract equal to 7.0. In the process of hydrolysis, potassium hydroxide completely reacts with copolymers of ethylene with vinyl acetate.

Example 2. The preparation of a 10% concentrate of hydrolyzed depressant additives and the preparation of fuel oil with a concentration of hydrolyzed depressant additives of 0.04-0.05 wt.% (Per additive).

In 90 g of summer diesel fuel (DTL), 10 g of hydrolyzed depressant additive VES-408A are added with stirring. Then the mixture is heated to a temperature of 60-70 ° C with constant stirring for 15 minutes until a homogeneous solution is obtained.

To prepare fuel oil with an additive concentration in the amount of 0.04-0.05 wt.%, A sample of 1.2-1.5 g of a 10% concentrate of hydrolyzed additive is taken, which is dissolved in 298.8-298.5 g of fuel oil (temperature solidification plus 33-35 ° C).

The effectiveness and stability of hydrolyzed depressant additives, i.e. the ability to maintain the low-temperature properties of fuel oil with an additive during long-term storage is evaluated by the depression of the pour point of the fuel oil (DTZ). The pour point of the fuel oil with the introduced depressant additive is determined on the day the mixture is prepared, and to assess the stability of the quality of fuel oil with the additive, it is determined after 1, 2 weeks and after a month of storage of the fuel oil samples. The data obtained are presented in tables 3, 4 and 5.

Studies have shown that the use of additives VES-408 (not hydrolyzed) as an additive to highly hardening and highly viscous heating oils is not possible, because a stable normalized (not more than 25 ° C) decrease in pour point is not ensured, while DTZ is only 5 ° C.

The addition of the inventive depressant additives in an amount of 0.04-0.05 wt.% (Per copolymer) provides a steady decrease in the pour point of high-viscosity heating oil from plus 33-35 ° C to 18-25 ° C, while DTZ is 8-17 ° C.

Table 1 Physico-chemical characteristics of the additive VES-408 Name of indicator Norm Diesel fuel solubility complete Mass fraction of active substance - ethylene vinyl acetate copolymer,% 27-33 Mass fraction of vinyl acetate units,% 8.5-11.5 Moisture contents lack of Density at 20 ° С kg / m ³ , no more 853-870

table 2 Dependence of pour point depression (DTZ) of fuel oil on solvent and concentration of hydrolyzing agent - KOH Used additive Wind farm-408 Hydrolyzed additive VES-408A Solvent - Isopropanol Butanol Isobutanol KOH concentration,
% wt. - 1,5 2,8 1,0 1,5 1,0 1,5 2.5 Indicators: 1. The pour point, ° C - fuel oil 35 35 35 35 35 35 35 35 - fuel oil + 0.05% additive thirty 21 23 23 eighteen 21 22 21 2. DTZ, ° C 5 fourteen 12 12 17 fourteen 13 fourteen

Table 3 The effectiveness and stability of the hydrolyzed additive VES-408A Product name: VES-408A Solvent: Isopropanol Isobutanol The concentration of KOH,% wt. 1,0 1,5 1,0 1,5 Indicators: 1. The pour point, ° C - fuel oil (norm no higher than 25) 33 33 33 33 - fuel oil + 0.05% additives: - on the day of preparation 22 eighteen 21 eighteen - in a week 24 twenty 21 22 - In 2 weeks 24 twenty 21 22 - a month later 25 22 21 22 2. DTZ, ° C: - on the day of preparation eleven fifteen 12 fifteen - in a week 9 13 12 eleven - In 2 weeks 9 13 12 eleven - a month later 8 eleven 12 eleven

Table 4 Dependence of DTZ of fuel oil with a pour point of 35 ° C on the amount of added additive VES-408A Product name VES-408A Solvent: Isopropanol The concentration of the introduced hydrolyzed additives VES-408,% 0.05 0.04 Indicators: 1. The pour point, ° C 21 21 2. DTZ, ° C fourteen fourteen

Table 5 Dependence of DTZ of fuel oil with a pour point of 35 C on the used solvent of the hydrolyzing agent of the added additive VES-408A Product name VES-408A Solvent: butanol Isobutanol The concentration of hydrolyzed additive VES-408 introduced into fuel oil,% 0.05 0.05 1. The pour point, ° C on the day of cooking 16 23 in a week eighteen 23 In 2 weeks eighteen 23 2. DTZ, ° C: on the day of cooking 17 10 in a week fifteen 10 In 2 weeks fifteen 10

Claims (3)

1. Hydrolyzed depressant additive for heating oil, which is a hydrolyzed copolymer of ethylene with vinyl acetate, characterized in that the hydrolysis is subjected to a 27-33 wt.% Solution of a copolymer of ethylene with vinyl acetate in a hydrocarbon solvent having a mass fraction of vinyl acetate units of 8.5 before hydrolysis. - less than 10%, the hydrolyzed additive is previously dissolved in diesel fuel in an amount of 5-15 wt.%, and then added to fuel oil in an amount of 0.04-0.05 wt.% (per additive). 2. Hydrolyzed depressant additive for heating oil according to claim 1, characterized in that the hydrolyzing agent is potassium hydroxide (KOH), which is pre-dissolved in alcohol (isopropyl or isobutyl or butyl) in an amount of 10 wt.%. 3. The hydrolyzed depressant additive for heating oil according to claim 1, characterized in that the hydrolyzing agent is added to the additive VES-408 in the amount, wt.%: 1.5-2.8 when using isopropyl alcohol, 1.0-2, 5 when using isobutyl alcohol and 1.0-1.5 when using butyl alcohol.