FR2789999A1 - Process for the treatment of hydrocarbon mixtures uses substituted amino acids to precipitate asphaltenes in heavy fuels and crude petroleum - Google Patents

Abstract

Additives based on nitrogen-substituted amino acids function as dispersants for asphaltenes contained in heavy fuels and crude asphaltenic petroleum. Use of amino acid derivatives as asphaltene dispersants is new. The derivatives comprise a fatty carboxylic chain with one or more amine functions which are nitrogen-substituted with carboxylic or sulfonic functions.

Description

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  process for treating hydrocarbon mixtures containing asphaltenes Asphaltenes are polyaromatic molecules containing hetero atoms O, N, S and heavy metals, of fairly high molecular weight (from 1,000 to 20,000 depending on the measurements) which, as a result physicochemical variations in the medium in which they are dissolved can precipitate, forming deposits and plugs and reduce the quality of

the combustion of heavy fuel oils.

  Products have been formulated and are used to improve combustion, increase the stability of products in storage and

  prevent or limit blockage of pipes.

  The use of salts of heavy metals soluble in hydrocarbons (combustion catalysts and tank stabilizers) of anionic and cationic surfactants and their mixtures has also been recommended.

  both in heavy fuel oil and in the production of problem crudes.

  In these various fields, it can be seen that, as a general rule, it is necessary for a given problem to carefully select the surfactants and their dosage, and it is found that groups of products which are remarkably effective in many cases do not

  are no longer relevant to other types of asphaltenes.

  This observation is probably due to the fact that under the physical phenomenon of precipitation, there are chemical reactions which bring about the bringing together and the aggregation of the flat molecules of asphaltenes, for example thanks to the interaction of the acid and basic functions found on the surface of molecular sheets. In this case, anionic and cationic surfactants chosen for the strength of their function and their hydrophilic and lipophilic balance may be introduced, which can prohibit inter-sheet bonds and surround each particle with a lipophilic film promoting their solubility in oil. However, other precipitating functions can intervene. It should be remembered that asphaltenes contain almost all of the residues

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  of chlorophyll type from organic components of oils. These chlorophyll structures are characterized by the existence of donor acceptor bonds (metal to nitrogen), not very sensitive to anionic and cationic functions but capable of causing precipitation.

  We found that molecules containing amino structures

  alkyl carboxylic or sulfonic were effective in all cases where the cationic anionic systems are ineffective; we get

  very good results on all types of asphaltenes encountered.

  The molecules we claim must contain at least one

  fatty chain of length C8 to C25.

  These structures can be obtained by condensation of carboxylic products or containing a sulphonic acid group and reacting easily on the primary, secondary and tertiary amine functions. One of the methods of choice consists in using polyamines of type R NH - ((CH2) n NH) m HOR is an aliphatic chain containing from 8 to 25 carbon atoms, n = 1 to 2, m = 0 to 5 The reagents used to introduce the carboxylic groups will be the alkaline and alkaline-earth salts of acetic halogen acids, acrylic and methacrylic acids and their esters and their

  amides, chloroethane sulfonic acid.

  Preparation methods 1 / from fatty amines

R R

I I

NH NH

+ I

2 Cl CH2 CO2 Na CH2- CH2-NH2

+ 3CI CH2CO2

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  Na R R H C02 CH2-N-CH2 C02 H + 2CI Na I

N-CH2-CH2 N-

CH2 COOH

I I-CH2

COO H

CH2 COO H +

  3CINa The esters and amides of the

  chloroacetic or acrylic or methacrylic acids.

  2 / Another mode of resolution is to start from molecules comprising an aliphatic fatty chain and a polyamine chain such as those obtained by condensation of fatty acids on polymers of

ethylene diamine.

  3 / Another appreciably different mode is to introduce a lipophilic group onto molecules manufactured industrially for their

  sequencing properties in an aqueous medium.

  A molecule of fatty alcohol or fatty amine can for example be condensed on a polyethylene-polyamine-polycarboxylic acid, by

  example ethylene diamine tetracetic acid or diethylene acid

  triamine-pentacetic, so as to make them soluble in oil.

  The field of application of the new molecules described here for their effects on asphaltenic hydrocarbons is vast and we will illustrate our invention with concrete examples. The amounts of additives to be added are of the order of 0.1 to 0.5% of the amount of asphaltenes to be dispersed.

Example 1

  Treatment of heavy fuel oils Heavy fuel oils are obtained by mixing petroleum distillation residues where the asphaltenes have accumulated and solvents suitably chosen so as to obtain fluid products at 60 ° C.

  and likely to be sprayed.

  We can see that the pressure of the volumes of residues and heavy fuel oils 1-- marketed means that the latter contain 10 (more or less 2)

% of asphaltenes.

  However, asphaltenes, even if properly dissolved at the start, slowly agglomerate by one of the above processes and form

  sludge which accumulates at the bottom of the tank.

  On the other hand, the size of these agglomerates being of the order of several microns, their combustion is difficult and they contribute to the formation

  solid unburnt products whose emission is severely regulated.

  The use of a suitably formulated asphaltene dispersant should make it possible to hinder the precipitation of sludge and improve combustion. Basic soaps of iron and manganese have met with some success in this area. They act as dispersants of asphaltenes but also by the catalytic effect of the transition metal, they improve combustion. We carried out a test on a heavy fuel oil with the following characteristics

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  Viscosity at 50 C 40 mps P / cm2 Sulfur content = 1.8% Asphaltenes content = 10.8% V = 35 ppm as V20 Ni = 43 ppm as Ni We will therefore compare the effectiveness of a commercial product with a product that we have prepared. The test consists in adding Precipitation test ml of fuel oil is diluted with 10% of Toluene and we add nml n heptane and we observe the degree of precipitation by the color of the "spot

test ".

  N ml heptane 0 0.2 0.4 0.6 0.8 Spot test O O + ++ We used the condensation product as product: 32 g of monochloroacetic acid on 32 g of diamineoleic in the presence

28 g of baking soda.

  The resulting product is dissolved in Toluene so as to obtain a

  25% active ingredient solution.

  The result with the commercial dispersant is as follows: (dosage 1 / 10,000) Heptane ml 0 0.2 0.4 0.6 0.8 1.6 3.2 6.4 12.8 Spot test 0 0 O 0 0 + ++ ++ The result with our product is as follows: (dosage 1 / 10,000) Heptane ml 0 0.2 0.4 0.6 0.8 1.6 3.2 6.4 12.8 Spot OOO test 0 0 0 0 + ++ Untreated fuel oil, stored in tanks, revealed a deposit

important in a month.

  The oil treated by our product does not show anything after two

months of storage.

  The transition metal salts of the products can also be used

  claimed which then have a combustion catalyst effect.

  We can see synergistic effects between the products described and the

alkyl benzene sulfonic acids.

Example 2

  An oil deposit produces 1,800 M3 of oil containing 4% of asphaltenes and its degree Api is 34. At the outlet of the tubing, the fluid is sent to a static water separator and then to an electric separator. The line between the two devices gets dirty quickly and a scraper plug must be passed every four days which eliminates

one hundred lg of deposits.

  On the other hand, the electrical separator is quickly blocked by several hundred kg of deposits composed of 95% asphaltenes. Of

  the more difficult the water separation is.

  Asphaltene deposits are still observed downstream in the

  storage tanks and in tankers.

  20 ppm of the product obtained by condensing 140 g of dimethyl acrylamide are introduced into the oil, just before the static separator.

g of oleyamine.

We can see that:

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  1 / the quantity of deposits recovered by the scraper cap is almost zero 2 / the cleaning of the electric separator which had to take place every

month is no longer required.

  3 / the water separates very easily.

  4 / in addition, deposits in the storage tanks formerly encountered

below the station have disappeared.

Claims (4)

Claims   1 / Compounds derived from amino acids comprising a fatty chain, one or more amine functions on which nitrogen or carboxylic or sulphonic functions have been substituted which are useful as dispersants for asphaltenes in heavy fuel oils and crude oils from asphaltenes. 2 / compounds according to claim 1, characterized in that they are obtained by reacting it with alkyllamine or alkylpolyamines monochloroacetic chloroacetate of acrylic acid and acid   methacrylic or the esters or amides of monochloroacetic acid.   3 / compounds according to claim 1, characterized in that they are obtained by making the etylene diamine tetraacetic acid oil-soluble, by reacting a molecule of fatty alcohol or fatty amine, the   chain length is from C8 to C25.   4 / compounds according to claim 3, characterized in that the ethylene diamine tetracetic acid is replaced by diethylene tetramine pentacetic acid. / use of the products according to claim 2 for the   precipitation of asphaltenes in a heavy fuel oil.   6 / use of the products according to any one of the claims   2,3 and 4 for the exploitation of crude oils.