DE1260061B - Prevention of internal corrosion of storage tanks and transport lines for liquid hydrocarbons - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

GERMAN

PATENT OFFICE

EDITORIAL

Int. Cl .:

Number: File number: Registration date: Display day:

ClOl

German class: 23 b - 4/02

1 260 061
F47967IVd / 23b
December 18, 1965
1st February 1968

When storing heating oils, diesel oils and other hydrocarbons, forms through Temperature fluctuations Condensation water, which largely collects at the bottom of the storage tank. In this water sump, the metal wall is attacked with the formation of rust. the Experience has shown that the aqueous phase also contains alkali salts in addition to dissolved oxygen and carbonic acid and other inorganic ions that significantly increase aggressiveness. In the worst case, you can Rust through storage containers after 1 to 2 years. With the increasing conversion from coal to heating oil as a house fire, the risk of leaking heating oil contaminating the groundwater is significantly greater become than before. Similarly, transport systems (such as pipelines) are at risk from such corrosion.

From U.S. Patents 2,935,389, 2,684,292, 2,793,943, 2,944,969, 2,994,596, 3,003,858 and British Patent 868,990 it is known that certain amidocarboxylic acids, amines and their Salts as corrosion protection agents under static conditions in storage tanks for hydrocarbons are effective. Mixtures of this type have the disadvantage that they cause emulsification between favor the water sump and the heating oil. The emulsified water gives the heating oil a cloudy, unsightly appearance. In addition, the salts brought in with the water can cause blockages the burner nozzles.

The invention relates to the use of salts from acids of the general formula

Z - O - (C _x H _2x O) _1n - (CHA - COOH

where Z is an alicyclic or aromatic or aliphatic radical with at least 4 carbon atoms, χ 2 or 3, m 1 to 10 and η 1 to 4, and aliphatic, cyclic or aromatic amines to prevent internal corrosion of storage containers and transport lines for liquids Hydrocarbons, in particular heating oils.

The salt-forming components can be used in a ratio of 10:90 to 90:10, preferably 70:30 up to 30:70. The amount added to the filling material can be 0.0001 to 0.1%.

Amines in the context of the invention are primary, secondary and tertiary aliphatic and cyclic amines with a neutralization equivalent of 50 to 400. The cyclic amines include alicyclic and aromatic compounds that contain the basic nitrogen in the core, on the core or on the May contain side chain. In addition to nitrogen, the ring can also contain other heteroatoms, such as e.g. B.

Prevention of internal corrosion

of storage containers and transport lines

for liquid hydrocarbons

Applicant:

Farbwerke Hoechst Aktiengesellschaft
formerly Master Lucius & Brüning,
6000 Frankfurt, Brüningstr. 45

Named as inventor:

Dr. Heinz Müller,

Dr. Paul Kastner, 8261 Burgkirchen;

Engelbert Krempl, 8263 Burghausen;

Dr. Adolf May, 6238 Hofheim

Oxygen. The aliphatic amines contain saturated and unsaturated as the hydrophobic radical linear or branched chains, also through heteroatoms and other groupings can be interrupted.

The mixtures according to the invention are readily soluble in liquid hydrocarbons and, in the concentrations used, do not show any promotion of the tendency to emulsify between water and oil. The acids claimed can be prepared from the easily accessible oxyalkylates by known processes (German patent specification 887 497; Williamson synthesis). The rust protection effect was tested based on the practical conditions according to the static water drop test according to Baker and Z isma η (Ind. Chem. Eng. 41, 137 to 144 [1949]) or the American standard MiLL 17 353. A 3% saline solution served as the aqueous phase. Triangular test panels with a round recess were placed in Petri dishes 5 cm in diameter and 1.5 cm in height and covered with oil. The additives were dissolved in the oil to be tested with increasing concentration. After a contact time of 15 minutes, 1 ml of the 3% saline solution was added dropwise through the oil with a pipette. The figures given in the last column of the following table indicate the proportion of corrosion protection in g / m ³ heating oil that does not rust after a storage time of 2 weeks.

709 747/505

kicked. The emulsion tendency was determined by vigorously shaking equal parts of heating oil solutions with distilled Water noted. The numbers listed in column 4 of the table below give this Volume of the emulsion layer in percent that is still present 1 hour after shaking. To increase the resistance to aging, it is common to use antioxidants and antioxidants known to the heating oil Add heavy metal deactivators. In addition, oil-soluble ones can be used to identify the heating oil Dyes are used. The mixtures used according to the invention exercise on those mentioned Additives have no adverse effect, and the corrosion protection remains unchanged. Long term Storage tests have shown that the claimed mixtures improve the storage and color stability of the ul additionally improve.

From the table it can be seen that the claimed mixtures are excellent rust inhibitors are without the disadvantageous tendency to emulsify. The preparation of the mixtures can by simply stirring the amine and acid components together. The resulting In addition to their anti-rust effect, novel additives have the effect of their interfacial activity also better distribution in the atomizing burner. The burning behavior as such will not adversely affected. Long-term storage tests have shown that the storage and color stability the heating oil is increased.

Z - O - (C ₁ H _2. , - O) _m - 'CH ₃ \ CH- X m η Tabel 1 CH ₃ 2-aminododecane 2 Mix
relationship Emulsifying
Tilt
% Corrosion
protection
g / m ³ No - (CH ₂ J _n -COOH
Z O 2 3 1 -CH ₂ -C- NH ₂ 60:40 1 120 1 Q ₂ H ₂₅ j
PPT / ^ iI ₃ J ₂ 2 5 1 Amine CH ₃ Tallow fat propylenediamine 75:25 0 75 2 Q ₂ H ₂₅ 2 5 1 N-methyldodecylamine 70:30 1 100 3 QeH ₃₅ 2 10 1 N-lauryl ethylenediamine vi- phenyl, N-ethylethanol-
amine 80:20 2 80 4th QeH ₃₃ 2 4th 2 Coconut fatty amine 55:45 0 150 5 2-ethylhexyl - 3 4th 4th 3- [dodecyloxy] -
propylamine- (l) C ₈ H ₁₇ OC ₂ H ₄ 1 90:10 0 150 6th 2-methylpropyl - - O 3 Decylamine 75:25 0 100 7th Q ₂ H ₂₅ 2 5 2 Cyclooctylamine 10:90 1 200 8th QsH ₃₅ Morpholine 3 2 1 .N-CH ₂
Ci ₇ H ₃₃ C / I
^X N - CH ₂ 60:40 1 150 9 CH2 ~~ CH2 \
I-
C ₃ H ₇ - CH - CH ₂ / C ₂ H ₄ OH - (CH ₂ J ₃ -NH C.
tert-octylamine CH ₃ - C : h ₃ CH ₃ 2 5 2 55:45 2 100 10 3,5,7-trimethyldecyl CH ₉ 2 2 2 40:55 1 150 11 CH ₃ ^) CH ₉ 3 1 3 25:75 0 200 12th 2 6th 4th 70:30 1 100 13th

continuation

No. Z —0- (CrHo _1. -O) _m - Ί QH ₁₉ - ^) - .Y m 2 Amine 3 Mix
relationship Emulsifying
Tilt
° / o Corrosion
protection
g / ms - (CH.,) "- C00H
Z 3-NH-C ₃ H ₆ -η 14th 2 8th COOH- 1-NH-C ₂ H ₄ OH 85:15 2 150 Dodecylamine
N-dodecylpropylenediamine comparison
Oleoyl sarcoside C ₁₇ H ₃₃ CO-N-CH ₂ 65:35
70:30 40
60 150
120 ( : h ₃

Explanations for the previous table
Chain distribution of the amines mentioned in the table above

Surname R. Forrnef -NHo C ₈ Wed
do older
C ₁ , Ke ttenverte
C ₁ , elution before
C ₁ B ι R
C ₁ K Oleyl Coconut fatty amine R. - NH - (CH ₂ ) S - 8th 9 47 18th 8th 5 5 Tallow fat propylenediamine .... 6th 25th 24 45 -NH ₂

The surprising advantage of the claimed salts is that they are too effective Anti-rust agents, which in the application concentrations do not have a harmful emulsion tendency cause. In contrast, the rust protection effectiveness of the known salts depends heavily on the Origin and the contents of the fuel oil. They do not have a pronounced broad impact and

therefore do not work universally. With certain grades of heating oil, they show good rust inhibition; with others they fail completely.

The table below shows the superiority of the salts according to the invention in comparison to the previously known means depending on three different heating oil qualities:

Tabel

- CH ₂ COOH Amine amounts Amine Heating oil I K Heating oil II Heating oil III - CH ₂ COOH relationship 25th E. g / m ³ E. K E. K acid - CH ₂ COOH acid 20th ¹ Vu 75 % g / m ³ % g / m ³ 75 40 0 80 1 120 0 90 Table 1, No. 2 80 - 2 150 1 100 2 200 Table 1, No. 4 60 35 1 300 0 100 1 80 Table 1, No. 9 Dodecylamine 100 30th 10 150 1 300 2 1000 Ci ₇ H ₃₃ CONCH ₃ - Dodecylpropy
lenediamine 65 40 120 1 300 1 1000 Ci ₇ H ₃₃ CONCH ₃ - 50 parts 70 100 60 20th 400 80 600 Ci ₇ H ₃₃ CONCH ₃ - Soybean oil amine
25 parts 1,1,3, 3- 1000 Tetramethyl ■ - 10 8th 800 3 1000 comparison butylamine

"/ ο E = emulsion volume.

K = limit concentration at which no corrosion occurs after a storage time of 2 weeks.
The tendency to emulsify was tested in heating oils I to III with an addition of 100 g / m ^3.

Claims (3)

Patent claims: 1. Use of salts from acids of the general formula Z - O - (C _x H ₂ x O) _n , - (CH ₂ ), - COOH where Z is an alicyclic or aromatic or aliphatic radical with at least 4 carbon atoms, χ 2 or 3, m 1 to 10 and η 1 to 4, and aliphatic, cyclic or aromatic amines to prevent internal corrosion of storage containers and transport lines for liquids Hydrocarbons, in particular heating oils. 2. Use of salts according to claim 1, characterized in that the salt-forming Components in a ratio of 90:10 to 10:90, preferably 70:30 to 30:70, are used. 3. Use of salts according to claim 1 and 2, characterized in that they are in Amounts from 0.0001 to 0.1% can be used. ίο Publications considered: U.S. Patent Nos. 2,684,292, 2,793,943, 994,596, 3,003,858.