US 5,154,857 AGrant
Demulsifying and Antifouling Agent Suitable for Separating Possibly Emulsified Water/Hydrocarbon Mixtures
Issue Date:1992-10-13
•12 Claims
Abstract
The invention relates to a water-soluble demulsifying and antifouling agent capable of separating possibly emulsified water/hydrocarbon mixtures, and particularly water/crude petroleum mixtures containing suspended matter. Said agent comprises from 10 to 60 percent by weight of a combination of the following compounds: at least one quaternary tetraalkylammonium halide; and at least one polyalkyloxylated alkylenediamine or its sulfate.
Metadata
Assignee
- Compagnie de Raffinage et de Distribution Total France
Inventors
- Marc Durrieu
- Patrice Herrenschmidt
- Claude Marty
Application Information
Application Number:US 7446683
Filing Date:1991-08-09
Priority Date:1987-01-16
Art Unit:223
Classifications
IPC:
B01D 1705C10G 3304
Field of Search:
208210252564289;188708338;344;358505
Patent Drawings
This patent does not have any drawings.
Description
The examples which follow will serve to illustrate in a non-limiting manner the effectiveness of the agents in accordance with the invention as used in the demulsification of water/hydrocarbon mixtures and in the prevention of fouling of heat exchangers.
Example 1
The purpose of this example is to compare on one and the same crude petroleum the washing and desalting efficiencies of the demulsifying and antifouling agents of the invention, designated X, with other, commercial demulsifiers C.sub.1 and C.sub.2, added individually to the crude phase. Its purpose is further to demonstrate the effectiveness of the agents X in the extraction of suspended matter from hydrocarbons.
The agents C.sub.1 and C.sub.2 are obtained from a mixture of commercially available substances. They are introduced only into the crude phase.
Agent C.sub.1 is a mixture of polyoxyethylated phenolic resins, dissolved in an aromatic solvent. Agent C.sub.2 is a combination of polyoxypropylated polyoxyethylated active substances comprising at least phenolic resins, ethylenediamines and block copolymers, these substances being dissolved in an aromatic solvent.
The agents X (X.sub.1 to X.sub.5) are composed of commercially available active substances, with the exception of those whose composition includes an alkylenediamine sulfate.
These sulfates were prepared batchwise on a pilot scale in a closed microreactor having a capacity of two liters and incorporating a sawtoothed-disk agitator immersed in a bath that was maintained at a constant temperature by means of a thermostat.
A proportioning micropump located upstream permits the continuous introduction of sulfur trioxide in liquid form into the microreactor at a controlled rate. Downstream of the reactor, a series of coolers and of cylinders are located for holding the solvent of the reaction, which here is 1,2-dichloroethane.
The sulfates are obtained by a sulfonation reaction of two commercially available alkyloxylated products, SYNPERONIC T 1302 and T 701, marketed by ICI.
This reaction consists of reacting sulfur trioxide, SO.sub.3, diluted from 5 to 25 weight percent in 1,2-dichloroethane (DCE), with 1,000 g of a feed consisting of one of the aforesaid commercially available products, diluted to 80 weight percent in DCE.
The operation conditions of the sulfation pilot unit are as follows:
At the end of the reaction, the reaction mixture is neutralized with 25% ammonia in water. The water phase containing the inorganic salts of the ammonium sulfate type is withdrawn after decantation of the organic phase consisting of the organic sulfates and the DCE solvent. This solvent is evaporated from the organic phase at between 45.degree. and 50.degree. C. under vacuum so as to reduce as much as possible the degree of hydrolysis of the organic sulfates so obtained. It should be noted that these sulfates are not pure products that are free of the commercial products from which they were derived.
To measure their efficiencies in washing and desalting a crude petroleum, these agents X as well as the commercial demulsifiers were tested in the laboratory in a pilot desalter comprising in particular a mixing valve for emulsification of the water and crude petroleum, and a miniaturized conventional so-called two-electrode electrostatic desalter/decanter.
The crude petroleum is a 20/80 blend of Maya and Brent crudes with a specific gravity d of 0.845.
The operating conditions of the pilot unit are as follows:
The proportion of the additive is adjusted to give 7.5 ppm of active substance, based on the crude.
The additive is injected either into the feedstock (B) or into the desalting water (E). Half of the desalting water is injected into the suction line of the crude-petroleum charge pump, and half ahead of the mixing valve.
Every hour, a sample of the crude petroleum is taken at the desalter outlet, and all of the water withdrawn from the desalter is collected.
On these samples, the following measurements are made:
On the crude petroleum feedstock and on the desalted crude petroleum: The water, salt and suspended-matter contents.
On the water withdrawn from the desalter/decanter: The hydrocarbon and chloride contents, the pH, and the extracted suspended matter.
The duration of a test is eight hours: Three hours for start-up and five hours for measurements.
The results of these tests are presented in Table 2 which follows.
These results demonstrate the superiority of the inventive agents, introduced into the water, to the existing commercially available additive, introduced into the crude petroleum, since the desalting and washing efficiencies of the inventive agents are better than those obtained with the additives C.sub.1 and C.sub.2. The suspended-matter extractive power of the agents X is also greater. The hydrocarbon contents of the water collected at the desalter outlet with the agents X are at the most equal to if not lower than those with the agents C.sub.1 and C.sub.2.
Table 2 further shows that the mixture of active substances, CTAC and ethylenediamines, improves the crude-petroleum desalting and washing efficiencies, and that the DA sulfate/CTAC mixture (X.sub.5) promotes the extraction of suspended matter from the crude petroleum.
Example 2
This example is intended to demonstrate the superiority of the agents X to the commercial additives C.sub.1 and C.sub.2 so far as fouling is concerned.
Fouling tests were run in a pilot unit with a crude-petroleum blend (Maya/Brent, 20/80) which had first been desalted with agent X.sub.4 or with one of the additives C.sub.1 and C.sub.2. The pilot unit comprises in particular a reactor which is electrically heated in such a way that its walls are maintained at a constant temperature of about 280.degree. C. The fouling is evaluated on the basis of the drop in temperature, expressed in .degree. C./hr , of the crude petroleum at the reactor outlet.
The results obtained are presented in Table 3 below.
It is apparent from Table 3 that the more suspended matter is extracted, the less fouling is observed. Agent X.sub.4 in accordance with the invention, introduced into the "water phase", is more effective with respect to fouling that the commercial demulsifiers C.sub.1 and C.sub.2, introduced into the "crude phase".
Claims
We claim:
1. A method for extracting suspended solid matter contained in crude petroleum which comprises: a. introducing into a wash water an effective amount of a water-soluble agent for demulsifying and anitfouling a water/hydrocarbon mixture, said agent comprising i. from about 10 to about 60 percent by weight, based on the weight of said agent, of (1) a combination consisting essentially of (a) from about 5 to about 40 percent, based on the weight of said agent, of at least one quaternary tetraalkylammonium halide of the formula ##STR4## wherein X is halogen, R.sub.1, R.sub.2 and R.sub.3 are alkyl groups having from 1 to 10 carbon atoms and R.sub.4 is an alkyl group having from 12 to 20 carbon atoms and (b) from about 5 to about 30 percent by weight, based on the weight of said agent, of at least one polyalkoxylated alkylenediamine of the formula ##STR5## wherein .ltoreq. u.ltoreq.4, .ltoreq. v.ltoreq.50 and 2.ltoreq.w.ltoreq.50 or (2) a combination consisting essentially of (a) from about 5 to about 40 percent by weight, based on the weight of said agent, of at least one quaternary tetraalkylammonium halide of said formula and (b) from about 5 to about 35 percent by weight, based on the weight of said agent, of at least one sulfate of a polyalkoxylated alkylenediamine of said formula or (3) a combination consisting essentially of (a) from about 5 to about 40 percent by weight, based on the weight of said agent, of at least one quaternary tetraalkylammonium halide of said formula, (b) from a trace to about 30 percent by weight, based on the weight of said agent, of at least one polyalkoxylated diamine of said formula and (c) from about 5 to about 35 percent by weight based on the weight of said agent, of at least one sulfate of a polyalkoxylated diamine of said formula and ii. from about 90 to about 40 percent, based on the weight of said agent, of an aqueous solvent containing from 0 up to about 50 percent by weight, based on the weight of said agent, of an alcohol selected from the group consisting of alkanols and polyols having from 1 to 10 carbon atoms; b. mixing the agent-containing wash water with the crude petroleum; c. emulsifying the mixture of agent-containing wash water and crude petroleum; d. introducing the emulsion into a decanting zone; e. separating said emulsion in said decanting zone into a water phase containing solid material and an oil phase; f. collecting and discharging the solid matter and g. recovering the thus-treated crude petroleum.
2. A method for extracting suspended solid matter as defined in claim 1 wherein said combination consists essentially of (a) from about 5 to about 40 percent, based on the weight of said agent, of at least one quaternary tetraalkylammonium halide of said formula and (b) from about 5 to about 30 percent by weight, based on the weight of said agent, of at least one polyalkoxylated alkylenediamine of said formula.
3. A method for extracting suspended solid matter as defined in claim 1 wherein said combination consists essentially of (a) from about 5to about 40 percent by weight, based on the weight of said agent, of at least one quaternary tetraalkylammonium halide of said formula and (b) from about 5 to about 35 percent by weight, based on the weight of said agent, of at least one sulfate of a polyalkoxylated alkylenediamine of said formula.
4. A method for extracting suspended solid matter as defined in claim 1 wherein said combination consists essentially of (a) from about 5 to about 40 percent by weight, based on the weight of said agent, of at least one quaternary tetraalkylammonium halide of said formula, (b) from a trace to about 30 percent by weight, based on the weight of said agent, of at least one polyalkoxylated diamine of said formula and (c) from about 5 to about 35 percent by weight, based on the weight of said agent, of at least one sulfate of a polyalkoxylated diamine of said formula.
5. A method in accordance with claim 1 wherein the method includes the further step of introducing a second agent for demulsifying and antifouling into the decanting zone at the interface between the water phase and the oil phase after step d. and before step e.
6. A method in accordance with claim 5 wherein said second agent is as defined for the agent in step a.
7. A method in accordance with claim 1 wherein said quaternary tetraalkylammonium halide comprises a cetyltrimethylammonium halide.
8. A method in accordance with claim 7 wherein said cetyltrimethylammonium halide comprises cetyltrimethylammonium chloride.
9. A method in accordance with claim 1 wherein u=2, 2.ltoreq.v.ltoreq.30 and 10.ltoreq.v.ltoreq.30.
10. A method in accordance with claim 1 wherein said alcohol comprises isopropanol.
11. A method in accordance with claim 1 wherein said effective amount ranges from about 1 to about 50 ppm, based on the crude petroleum.
12. A method in accordance with claim 1 wherein said decanter zone comprises an electrostatic decanter.
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