SU507618A1 - Method for dewaxing petroleum products - Google Patents

Description

 H3o6ffeTeHHe relates to methods for dewaxing oil products and can be used in the refining industry to dewax oil fractions to lower their pour point, increase their octane number and produce N-paraffins for petrochemical microbiological synthesis.

At present, several differences in the process of the carbamide depair preparation are known. All of them are intended primarily for dewaxing diesel fractions.

Option AzNII-dewaxing using water-isopropanol solution of carba; - mida. It has a number of significant drawbacks related mainly to the mutual solubility of isopropyl alcohol and petroleum products. EV:

it is difficult to maintain the constancy of the solvent composition, which makes the reaction rate and composition of the reaction mixture unstable;

the presence of alcohol regeneration stages, the removal of carbamide c. from the reaction products

and saturation of the raw material with alcohol greatly complicates the technological scheme of the process and leads to excessive loss of equipment and urea.

partial solubility of the dewaraffinate in an alcohol-water mixture worsens the quality of the N-parafive;

good emulsifiability of depirafilata in an alcohol-aqueous solution of urea hinders the separation of the deparaffinate and the complex, which

It also worsens the quality of paraffins.

Variant GrozNII-de-parasite dry carbamide in the presence of methyl alcohol. It also has a number of features related mainly to the absence of a second liquid phase in the reaction mixture:

the reaction rate and composition of the reaction mixture strongly depend on the quality of the urea used, which makes the process unstable;

the complex is obtained in a highly dispersed state and strongly retards deparaffipate, which requires disintegration of the reaction mixture by low-visibility products.

and it is very difficult for the separation step s; washing complex;

the degree of utilization of the carbond kekeball, therefore, it circulates in the system E quantity, several times the maximum breathing rate;

The process is very sensitive to the traces of feedstock in the feedstock and the system, which is very difficult to operate.

Option - dewaxing solution of urea. The reaction of krovodg B under thermal conditions, those / peratum - rz, is supported by the boiling of chlorine methylene, which in large bottles is introduced into the reaction. The second of this method is also characteristic of a series of masmasgray :. sv zhyh,. mainly with large quantities of methylene oxide in the reaction mixture:

with stirring of the reacting phases, an oil-in-water emulsion is formed due to the large dilution of the raw material; the phase does not fit into the water, i.e. its much-gel part remains in the dispersed state of the (free) state, the free oil is deparated very poorly in the phase, so the reaction time is about 1 hour;

the dispersed part of the oil phase is dewaxed quickly, so the vodka. From the phase it is almost impregnated, it thickens to grind it and create a close contact; ; ots agents need complex versions: Toshi devices;

for compressing vapors of methylene chloride, a powerful - compressed weed economy is established;

methylene chloride is aggressive and povit. therefore, the apparatus is made of materials and strictly sealed,

All considered variants of the carbamide dewaxing process of the road as due to the complexity of the technological process; Paragraphic design as well as due to the use of expensive reagents.

The known method for the dewaxing of distilled petroleum products with a water solution of urea, according to which / uy B aqueous solution of urea, the content of the seed {roTOBbifi complex from previous experience), well dispersed hydrocarbon ( not more than 1 min), the lapafino-urea complex is formed in the form of the smallest needle-shaped crystals, which are well preserved in the boundary of the section of the liquid phases, but relatively hydro; - snccr-aTJce me5nfazO ot - ii y / a. : -; ; - Dukhu Phase, Po -, ier.i.-: cho; -.-.-; ..,;. f: ..; D6n; -. ci - a: -ii.; s zdzky flse for: -, .m1: -. This: and;.; ,, jv) -aqer; cGjvi Л p.-Esl to phase out. ) YolteonyRp-si ": 1rk large concentration": ;; ll-seksg; water fvea thickens so that from the money; its honor when you touch it. y-logdadt; stick together. When mixed in an oil medium, such an aqueous phase decomposes –1 s; l into separate (spherical particles of a granule, With the concentration of the complex in the water phase of gralae CTajiOBHTCH, &) and more; Twerke. To the moment of granulirov .nin of the eodic phase MBsl: nak phase from it comes out almost completely. For half a day: LC pure: perafino1. granules must be harvested from a non-polar solvent; Pos.118 this complex is decomposed, best of all by heating.

With a stoichiometric excess of the D / -paraf. Shpv Bzhsd complex is determined by activating the concentration of urea, which, in turn, is determined by the difference between the temperature of & 1 of the urea solution and the final temperature of the reaction. If the saturation temperature of the initial solution of carbamide, then for granulating water: - (oh phase, the total unsteady reaction temperature should not exceed 35 ° C. This temperature is up to Izod granulation; phase a is plastic and can be smeared on a personal surface, therefore, truck-s. sorting:;:: cooling the reaction mixture wasps; | cest-in; 1 is difficult, and the reaction; com-formation is carried out under adiabatic conditions. Complexation g pet with heat release, As a result, the temperature of the products at the reactor inlet is lower than at Bbixo. , ne .: Therefore, to reduce the required temperature of the products, DL5 reacted under 3 zaiodic conditions to cool down / cool down.

.The process of calculation}. To the following conditions: T.- "m of the process, the solution and the ref of the solution, C, 74

volume ratio) if solution 1: 1

The reaction is carried out in an adlaBatic peai .. torus with a low-speed self-extracting ball. mei; all. th, graf; м бенз лег п ют лег лег бенз лег лег ко gasoline and ustgla layer co.; 10; P1e, the greenhouse, the complex is heated by heating it to 85 ° C, the reaction phases are cooled with water. However, the implementation of the proposed method to obtain a low-temperature water-carbamide pulp is extremely hard, even with the aid of artificial cooling, since when the hot solution is cooled, the carbamide crystals on the cooling wall form a dense and hard crust that impedes heat transfer. For its destruction, complex scraping devices are required. In the concentrated water-carbamide pulp there is little free aqueous phase, therefore when mixed. reagents part of the raw material remains in the undisturbed state and reacts with urea very slowly, which reduces the overall depth of dewaxing. Because of the low initial temperature of the reactants, the reaction proceeds under conditions far from equilibrium, which reduces the selectivity of the process and degrades the quality of W-paraffins . Due to the adiabatic nature of the reaction, the temperature of the starting products is lower than the process temperature, which increases the cost of cooling. The aim of the invention is to increase the depth and selectivity of dewaxing. To achieve this goal, the raw material is mixed not with a cold water-urea pool, but with an aqueous solution of urea having a temperature of 50-VO With subsequent cooling of the resulting reaction mixture to an equilibrium temperature mixture determined by the desired dewaxing depth and rubbing it to obtaining a granular, complex. Due to the presence of seed in the tank, a stable emulsion of oil in water is formed, and chemical equilibrium is established within a few seconds. By changing the temperature, the center of the complex and, therefore, con are easily changed. (Emulsion Synthesis. After the equilibrium emulsion is formed, further reaction is reduced to cooling it to the required temperature. The emulsion is cooled hydrophobically, does not adhere to metals whose water. When grinding and cooling the emulsion, the aqueous phase disintegrates into granules, and the deparaficate is completely released. For successful separation of the deparaffinate from the aqueous phase, the emulsion is cooled and need to be destroyed in an apparatus similar to a mechanical crusher and called a granulator. The reaction mixture is cooled in several ways: in a thin layer on a cooled conveyor, spraying cold gas in a stream and dispersing it in a urea-specific liquid, such as gasoline or deparaffinate. by cooling the dispersed system in a coil cooler in all ways. In all cooling methods, the reaction mixture is pumped through a heated pump and heated pipes of the minimum length. According to the first method, the reaction mixture is poured through a heated slit onto a cooled conveyor belt made of stainless steel. At the bend of the conveyor belt, the reaction products easily lag behind it and enter the mill, from which the mixture of the granular complex and the deparaffinate leaves. In the second cooling method, the apparatus used to obtain urea and other fertilizers in granular form is used. According to the third method of cooling, the temperature and flow rate of carbides indifferent to carbamide are selected so that after leveling the temperature, the droplets of the emulsion turn into solid particles, unable to adhere to metal surfaces. For fast and simultaneous cooling of all the particles, it is better to mix the reaction mixture with an indifferent liquid in a mechanical mixer - disperser. The suspension obtained with the aid of a dispersant is finely dispersed homogeneous and is well transported through the pipeline. With this composition of the reaction mixture, the depth of dewaxing and the structure of the reaction products are determined by the temperature at the outlet of the coil cooler. Therefore, in order to increase the depth of dewaxing and increase the flexibility of the process, especially in summer, in the last sections of the refrigerator, water cooling is replaced with artificial. To obtain the maximum depth of dewaxing, the raw materials can be fed to the installation periodically, and the deparaffinate is sent to the boiler instead of raw materials until the jipe individual depth of dewaxing is reached. In the proposed method, when mixing the reagents, all the raw materials are dispersed, and the reaction proceeds under conditions close to equilibrium, which increases the total depth of dewaxing and improves the quality of the resulting paraffins; There is no laborious step of crystallization of the urea solution, which greatly simplifies the process j, the reaction mixture transportable to heat is easy to carry out from it, therefore, there is no need for deep precooling of the starting products, which reduces the -aKcnnyaTauHOHKbie costs. Example 1. The dewaxing is carried out on a pilot plant with a life of 300 l / h on raw materials with cooling of the reaction emulsion in a stream of C {inflourifying deparaffinate. The process diagram is shown in the drawing. Raw materials and a hot solution of urea in a predetermined ratio from tanks 1 and 2 are fed to mixer 3, equipped with a MOGESH propeller stirrer, rotated at a speed of 3,9 RPM. Seed is introduced into the mixer P1. Equilibrium; The reaction emulsion of the mixer 3 is selected with a heated plunger pump and sent to the disperser 5. The heated plunger pump 6 is fed with a cold depressor. In a dispersant, the reaction mixture is somewhat cooled and dispersed in a deparaffinte. Next, the suspension of the reaction mixture in the deparafinate is cooled with tap water in the cooler 7 (type of pipe in the pipe) and fed to the granulator 8. From the granulator, the products enter the settling tank 9, the Deparafinate from the settling tank 9, with partial discharge to the receiver 1O, pump 6 is fed disperser 5. The balance part of the deparaffinate from the settling tank is discharged into the cdop of the deparafinate, the capacity of 2 carbamide solution, the mixer 3 and the solution pipeline, urea have shirts, c. which for {Maintaining: a given temperature from the heater 11 serves hot water HflcocoM 12. The pump 4 and the lines from the mixer to the disperser have a jacket into which the pump 14 pumps the same water with a strictly defined temperature of the heater 13. To reduce pulsation when piston pumps are running on. the Depatatina line is installed Receiver 1O. installation mode; The temperature of the solution of the raw material 20 is 20 ° C, and the carbamide 80 is emulsion E system70 The volume ratio of the raw material and the carbamide solution 1: 1 Temperature, ° C of water circulating in the jacket of the pump 4 and the emulsion pipelines 72 of the water in the 1195 heater output, C from the dispersant57: from the pelletizer 20 Plant capacity: L of the reaction emulsion, l / h 600 The raw material used is hydrotreated primary; diesel fraction of rlan oil with the following characteristics: Specific gravity, g / cm 0.834 Fractional composition Initial boiling point, ° C Distilled at a temperature, O C / 10% 237; BO% 284 90% 345 95% 363 Pour point, C minus 10 The result: dewaxing the suspension of the complex in the aqueous phase is a homogeneous dense granules with a diameter of 2 mm. After washing the granules with light gasoline (85-120 ° C) and decomposing them by heating, 22% are obtained, considering the raw material, H-paraffins with a pour point 14 C and a deparafin with a freezing point of minus 70 C, Example 2, Dep The first oil fraction and the TC-1 jet fuel fraction are arafined. The dewaxing is carried out on a laboratory scale under the following conditions. The saturation temperature of the aqueous solution of carbamide is 68 ° C. The volume ratio of phases is 1: 1. The equilibrium reaction mixture is prepared in a glass with a propeller stirrer at a temperature for the oil fraction of 65 ° C, for the G fraction: TS-1 50 C. The reaction mixture is cooled on a cooled metal baking sheet to a temperature of 25 ° C. porcelain mortar to obtain a granular complex. The complex is washed with gasoline to its constant refractive index when mixing. The complex, dried to constant H1 weight, is decomposed in hot water. As a result of deairing411isation, the freezing point of the product is frozen;