RU2046786C1 - Method of gasoline fraction preparing - Google Patents

Abstract

FIELD: oil processing and petrochemical industries. SUBSTANCE: product: gasoline fraction, yield is 47% octane number is 87 (motor method). Raw: olefin-containing gas. Catalyst: zeolite of type Z8m-5 ЦВМ with mole ratio SiO₂:Al₂O₃ 31.5-35% zirconium oxide 20% zinc oxide 2% aluminium oxide is up to 100% Process conditions: basic reactor: 350-370 C, 0.3-0.4 MPa, feeding rate is 300-700 h^-1; additional reactor: 550-600 C, 0.3-0.4 MPa, feeding rate is 300-700 h^-1. There is turbulent fluidized catalyst layer into both reactors. Stabilization gases isolated from the liquid phase of reaction products and fresh regenerated catalyst were fed into additional reactor. Partially depleted catalyst is transfered from additional reactor to the basic one by reaction products. Part of catalyst is removed from the basic reactor for regeneration and then fed into additional reactor. EFFECT: improved method of gasoline fraction preparing. 4 cl, 1 dwg, 5 tbl

Description

 The invention relates to a method for producing a gasoline fraction from olefin-containing raw materials and can be used for qualified processing of catalytic cracking gases, coking, thermal cracking and other olefin-containing gases in the oil refining and petrochemical industries.

Known methods for producing C _{5 +} oligomers _in contacting low olefins, preferably propylene, butylenes and mixtures thereof, as well as catalytic cracking effluent gases (CCFs) and dewaxing gases with a fluidized bed of a catalyst containing 17% H-ZSM-5 cyolite with a molar ratio SiO _2: Al ₂ O ₃ 80 or a catalyst containing 35% zeolite Zn-ZSM-5 having a molar ratio SiO _2: Al ₂ O ₃ 230, at a temperature of 150-350 ^{° C,} the volumetric space velocity of 1000-3000 h ^{- 1} and pressure from 0 to 0.6 MPa [1 and 2] Contacting is carried out in one reactor, in the lower part of the feedstock is fed under the distribution grid, and stripping gas is fed to the upper part of the fluidized bed, so that the olefins are oligomerized in the lower part and the oligomers are steamed from the catalyst in the upper part.

The disadvantage of these methods is the low yield of target products With _{5 + in} ; so, when the CCF off-gas is converted, the yield of C _{5 + in} is 66.1%, and when the propane-propylene mixture is converted, the conversion to C _{5 + in} is 61%
Closest to the proposed method in terms of technical nature and the achieved result is a method for producing a liquid C _{5 +} b product consisting of gasoline hydrocarbons with a high octane number (up to 90.3 points according to the research method) by catalytic conversion of ethylene-containing light gas or fuel gas CCF process containing up to 40 wt. ethylene and propylene in a turbulent fluidized bed vysokokremnezemnyh type zeolite catalyst ZSM-5 at an average reactor temperature of 315-510 ^C, preferably 315-430 ^{° C,} a weight space velocity of 0.1-5 h ^-1, based on the olefins in general feedstock, pressure 0.41-2.5 MPa with recycle of a significant portion of C ₄ and below the product into the reactor [3] The yield of C _{5 + in} hydrocarbons is 67.3 wt. on skipped ethylene and propylene.

The disadvantage of this method is also a low yield of C _{5 + in the} product.

 The aim of the invention is to increase the yield of gasoline fraction from olefin-containing raw materials.

According to the invention, the goal is achieved by the proposed method for producing a gasoline fraction by contacting an olefin-containing gas with a catalyst containing 35 wt. high-silica zeolite type CVM with a molar ratio of SiO ₂ : Al ₂ O ₃ 31.5, 20 wt. zirconium oxide, 2 wt. zinc oxide and 43 wt. alumina, at a pressure of 0.3-0.4 MPa in the reactor with turbulent fluidized bed partially spent catalyst at a temperature of 350-370 ^{° C,} the volumetric hourly space velocity hr ^-1 300-700, followed by separation of the reaction products into a liquid and a gaseous phase, stabilization of the liquid phase with the release of the gasoline fraction and stabilization gases, contacting the stabilization gases in an additional reactor with a turbulent layer of the same freshly regenerated catalyst at a temperature of 550-600 ^о С, volumetric feed rate of stabilization gases and 300-500 h ^-1 with the subsequent transfer of the partially spent catalyst by the reaction products from the additional reactor to the main reactor and then to the regenerator.

 The drawing shows a schematic flow chart of the process.

The source olefin-containing gas (I) passes through a heat exchanger 1, where it is heated by the reaction products from the main reactor 2, the heating furnace 3, and enters the distribution grid of the main reactor 2, where in the layer of turbulent fluidized partially spent catalyst at a pressure of 0.3-0.4 MPa , a temperature of 350-370 ^about With the volumetric feed rate of olefin-containing gas 300-700 h ^-1 occurs olefin oligomerization. The excess heat is removed by immersion refrigerators 4. The reaction products rise from bottom to top, are separated from the entrained particles of the catalyst in cyclones 5, then in the filter 6 and enter the separator 7, where the unstable condensate and the gaseous phase (II) are separated into the liquid phase. The gaseous phase is sent to the fuel network, and the unstable condensate is sent to the stabilization column 8, on top of which stabilization gas is taken, and the bottom is stable condensate. Stable condensate enters column 9 where it is separated into the target gasoline fraction NK-180 ^° C (III) and bottoms 180 ^° C KK (IV). Stabilize gas from column 8 is heated in furnace 10 and fed by a distribution grid auxiliary reactor 11 where at a temperature ^of 550-600 C and a pressure of 0.3-0.4 MPa and a bulk gas flow rate of 300-500 hr ^-1 stabilization occurs contacting with a turbulent fluidized bed of a freshly regenerated catalyst. The process goes with heat absorption. The reaction products in the additional reactor 11 rise up and move the partially spent catalyst from the additional reactor 11 to the main reactor 2 along the central transport riser 12; the reaction products of the main and additional reactors are mixed in the upper zone of the main reactor 2, and the catalyst from the riser 12 is poured into the fluidized bed of the main reactor 2. To maintain a constant activity of the catalyst in the main reactor 2, a part of the catalyst is led through a pipe 13 to a regenerator 14, from where a freshly regenerated catalyst line 15 is fed to the auxiliary reactor 11. The regeneration air is carried out (V) at ⁶⁰⁰ ° C, regeneration products (VI) through the cyclone, the filter 16 and the HRSG 17 receives chimney.

 Distinctive features of the proposed method is the process in two reactors with the subsequent transfer of the partially spent catalyst by the reaction products from the additional reactor to the main reactor.

 As the feedstock in the proposed method can be used purified from hydrogen sulfide and carbon dioxide fatty gas of catalytic cracking, coking gas, thermal cracking.

 The proposed method is tested on a pilot installation and is illustrated by the following example.

 PRI me R. As raw materials, an olefin-containing gas is used that is similar in composition to the catalytic cracking fatty gas (Table 1).

Used catalyst has a composition, wt. on a dry weight basis: TsVMSh zeolite with a molar ratio of SiO ₂ : Al ₂ O ₃ 31.5-35, zirconium oxide ZrO ₂ 20, zinc oxide ZnO 2.0, aluminum oxide Al ₂ O ₃ 43. The bulk density of the calcined catalyst is 0.607 g / cm ³ , the content of particles with a size of 0-40 microns 5 wt. 0-100 microns 63 wt. 0-150 microns 87 wt. 0-200 microns 98 wt.

 The catalyst preparation procedure is as follows.

20 l of water condensate is poured into a steel apparatus with a stirrer and heating and 2150 g of an aqueous pellet (PPC 80%) of aluminum hydroxide in 5 l of condensate is added with stirring. Then, a solution of zirconium nitrate Zr (NO ₃ ) ₂ ˙ 2H ₂ O (434 g of salt in 2 l of water condensate) and a solution of zinc nitrate Zn (NO ₃ ) ₂ ˙ 6H ₂ O (74.2 g of salt in 1 l) are added to the apparatus water condensate). The resulting suspension was stirred for 1 h, after which a suspension of 450 g of zeolite NH ₄ CVMS in 5 l of water condensate was added to the apparatus. The zeolite has the following indicators: crystallinity degree 100% silicate module SiO ₂ : Al ₂ O ₃ 31.5, static capacity, cm ³ / g for water vapor 0.08, for heptane vapor 0.24. After 30 minutes of stirring, the pH of the resulting system is measured and adjusted to 3.0 by the gradual addition of nitric acid. Then increase the temperature in the apparatus to 50-60 ^{° C,} the suspension was maintained at this temperature and constant stirring for 3 hours, then the suspension was fed to a laboratory spray dryer RLS-10 at a rotational speed of the spray disc 7500-8500 rev / min at 190 -220 ° ^C. The resulting microspheres calcined pellets in a muffle furnace at 550 ^{° C} for 6 hours to obtain 1,000 g of the above microspheroidal catalyst composition.

1.0 L of the catalyst is charged to the main reactor (0.8 L) and to the additional reactor (0.2 L). The starting olefin-containing gas after being preheated to 250 ^{° C} is supplied under distribution grid main reactor 2, where a turbulent fluidized catalyst bed at a temperature of 350-370 ^C and a pressure of 0.3-0.4 MPa and a space velocity of 300-700 hr ^-1 olefins are converted. Gas stabilization after preheating to 580 ^{° C} is supplied under distribution grid auxiliary reactor 11 where a turbulent fluidized catalyst bed at a temperature of 550-600 ^C and a pressure of 0.3-0.4 MPa and a space velocity hr ^-1 occur 300-500 conversion of olefins and paraffins. Both flows are mixed and sent for separation, after which the liquid part is subjected to stabilization, stabilization gas is sent as a raw material to an additional reactor, and the stable condensate is separated in a distillation column into the target gasoline fraction NK-180 ^о С and bottoms fraction 180 ^о С-КК.

 For comparison with the known method, contacting is carried out according to a one-reactor scheme without circulation to the reactor and according to a one-reactor scheme with circulation of stabilization gas to the reactor.

 The compositions of stabilization gas and fuel gas are presented in table 1, the choice of intervals for the process conditions in both reactors of temperature, pressure and space velocity are given in table. 2 and 3.

From the table. 2 and 3 it follows that according to the proposed method, the highest yield of the target gasoline fraction NK-1280 ^о С (46.5-47.8 wt.% For the initial olefin-containing gas) is achieved at a temperature in the main reactor of 350-370 ^о С, in an additional reactor 550 -600 ^{° C,} pressure 0.3-0.4 MPa, volumetric feed rate of feedstock into the main reactor 300-700 hr ^-1 space velocity and stabilization of gas in the auxiliary reactor 300-500 h ^-1.

 In the table. 4 shows a comparison of process indicators according to a one-reactor scheme without circulation, a one-reactor scheme with circulation to the reactor and the proposed method.

Comparison of key indicators in optimal conditions (Table 4) shows that the proposed method of output of the gasoline fraction NK-180 ^{° C} as the liquid yield _of C _{5 +} olefins _in at Original olefin-containing gas (47.6 and 80.4 wt . respectively), higher than in the single-reactor circuit (42.3 and 68.7 wt.%) and in the single-reactor circuit with circulation of stabilization gas to the reactor (43.5 and 71.3 wt., respectively).

The octane number of the gasoline fraction NK-180 ^C by the motor method are: 87 according to the proposed method, 86 of the loop reactor scheme stabilization gas into the reactor and 85 of reactor scheme without circulation. The characteristic of the target gasoline according to the proposed method is as follows:
Physico-chemical characteristics of the target gasoline fraction NK-180 ^о С Density, kg / m ³ 760
Fractional composition: the beginning of the boil, ^about C 29
10% is distilled at temperature, ^о С 43 30% the same 76 50% the same 105 70% the same 125 90% the same 147 The end of boiling, ^о С 181 Iodine number, g iodine / 100 g 45 Actual resins, mg / 100 g 6.5
Group hydrocarbon composition, wt. paraffin-naphthenic hydrocarbons 40 olefinic 20 aromatic 40 Octane number according to the motor method 87 Total sulfur, wt. out

From the data table. 4 and material balances (table 5) it follows that the application of the proposed method allows to increase, in comparison with the prototype, the yield of liquid products With _{5 + in} the calculation of olefins in the skipped feedstock by 13 rel. and the yield of the target gasoline fraction NK-180 ^° C was 9.5 rel.

 An increase in the yield of target gasoline and an increase in its octane number allows to improve the technical and economic indicators of the process of obtaining a gasoline fraction from olefin-containing raw materials.

Claims (4)

1. METHOD FOR PRODUCING A GASOLINE FRACTION by contacting an olefin-containing gas in the main reactor with a turbulent fluidized bed of a high-silica zeolite catalyst of the ZSM-5 type at a temperature of 350 370 ^o С and increased pressure followed by regeneration of the catalyst, separation of the reaction products into liquid and gaseous phases, stabilization with the release of the gasoline fraction and stabilization gases, characterized in that, in order to increase the yield of the target product, stabilization gases are sent to an additional an actor in which contact is made at 550 600 ^{° C.} with a turbulent fluidized bed of catalyst supplied after regeneration, followed by the transfer of partially spent catalyst by reaction products from the additional reactor to the main one.  2. The method according to p. 1, characterized in that the process in both reactors is carried out at a pressure of 0.3 to 0.4 MPa. 3. The method according to PP. 1 and 2, characterized in that the process in the main reactor is carried out at a volumetric feed rate of olefin-containing gas of 300,700 h ^{- 1} . 4. The method according to PP. 1 and 2, characterized in that the process in the main reactor is carried out at a volumetric feed rate of stabilization gases of 300,500 h ^{- 1} .

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