CN109897126A - A kind of polyethylene catalysts solvent - Google Patents

Abstract

It is mass ratio is (1-3): the mixture of (1-3) propane and C4~C6 alkane the present invention relates to a kind of polyethylene catalysts solvent.Compared with prior art, the present invention is formulated novel dissolvent as Main Components blending using the C4~C6 alkane for limiting the propane of the particular technology requirement of ratio, particular technology requirement,, good fluidity low with viscosity, the uniform distinguishing feature of dispersibility, and fabulous inertia is presented for catalyzed polyolefin reaction, polyolefin is normally produced and final products nonhazardous acts on, the novel dissolvent is also equipped with low boiling point, volatile feature, can be easy to be desorbed from the polyolefin resin that reaction generates.

Description

A kind of solvent for polyethylene catalyst

technical field

The invention relates to a solvent for catalysts, in particular to a special solvent for mixed alkane polyethylene polyethylene catalysts.

Background technique

The solvent used in the catalyst prepolymerization or catalyst preparation used in the polyolefin industry requires process conditions such as low viscosity, volatile, stable chemical properties, easy desorption, and non-toxicity. At present, the polyolefin industry commonly used in the polyolefin industry is composed of a single linear or branched alkane with 4 to 10 carbon atoms, such as hexane, or a cycloalkane or aromatic hydrocarbon with 4 to 10 carbon atoms, which is difficult to meet the above requirements at the same time. . In addition, the commonly used linear or branched alkanes with 4 to 10 carbon atoms, such as hexane, or cycloalkanes or aromatic hydrocarbons with 4 to 10 carbon atoms, are usually not easy to desorb or have aromatic hydrocarbon impurities, which are all suitable for production. The quality of the process and the final product has a negative impact and is not good for health and the environment.

In CN1041162, a single alkane propane is used in the catalyst prepolymerization process, because its volatility is too strong, the flash point is low, and the operation safety is reduced.

In CN1330087, aliphatic paraffins and naphthenes above hexane, such as heptane, octane, decane, kerosene, etc., are used as solvents, but they are difficult to volatilize and remove in polyethylene production and catalyst preparation and removal processes.

CN105085750 adopts C5-C6 straight chain alkane and its isomers as polypropylene catalyst prepolymerization solvent, which is not completely removed in the polyethylene production process, and is prone to produce peculiar smell in the polyethylene product.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a solvent for polyethylene catalyst with low viscosity, good fluidity and uniform dispersibility in order to overcome the above-mentioned defects of the prior art.

The purpose of the present invention can be achieved through the following technical solutions: a solvent for polyethylene catalyst, characterized in that it is a mixture of (1-3): (1-3) propane and C4-C6 alkane in mass ratio.

The specific gravity of the solvent under the temperature test condition of 15.6°C is 0.58-0.62.

The acidity of the solvent is less than 2ppm by weight; the solvent contains other hydrocarbons by weight less than 5%, the concentration of unsaturated hydrocarbons is less than 500ppm, the concentration of water is less than 20ppm, and the sulfur Concentration by weight <5ppm, chroma<15, non-volatile matter <0.001g/100ml, concentration by weight of peroxide <0.1ppm, concentration by weight of benzene <0.1ppm, no suspended matter.

The specific gravity of the propane under the temperature test condition of 15.6°C is 0.50-0.52.

The weight percentage concentration of the propane is 95%.

The acidity of the propane is less than 2ppm by weight; the weight percentage concentration of other hydrocarbons in the propane is less than 5%, the concentration of unsaturated hydrocarbons is less than 500ppm, the concentration of water is less than 20ppm, and the sulfur Concentration by weight <5ppm, chroma<15, non-volatile matter <0.001g/100ml, concentration by weight of peroxide <0.1ppm, concentration by weight of benzene <0.1ppm, no suspended matter.

The specific gravity of the C4-C6 alkanes under the temperature test condition of 15.6°C is 0.55-0.65.

The weight percent concentration of the C4-C6 alkanes is greater than or equal to 95%.

The acidity of the C4-C6 alkanes has a concentration by weight <2ppm; the C4-C6 alkanes contain other hydrocarbons in a weight percent concentration <5%, unsaturated hydrocarbons have a concentration by weight <500ppm, and water is by weight concentration <20ppm, sulfur concentration <5ppm by weight, color <15, non-volatile matter <0.001g/100ml, peroxide concentration <0.1ppm by weight, benzene concentration <0.1ppm by weight , no suspended solids.

During preparation, at normal temperature, propane and C4-C6 alkanes can be uniformly mixed in proportion.

The advantage of the present invention is that at present, the polyolefin industry mainly uses linear or branched alkanes with 4 to 10 carbon atoms such as hexane, or cycloalkanes or aromatic hydrocarbons with 4 to 10 carbon atoms as the main component as the catalyst to prepare the solvent , because the linear or branched alkanes with 4 to 10 carbon atoms such as hexane, or the cycloalkanes or aromatic hydrocarbons with 4 to 10 carbon atoms have large molecular weight and are not easily volatile, they are not easily desorbed in the subsequent removal operation and can High consumption, and there is a risk of fire and explosion. The present invention uses propane of specific technical requirements and C4-C6 alkanes of specific technical requirements as the main components to be blended and formulated into a new type of solvent which solves the above problems well. The main advantages are as follows:

1. The preparation method is simple and can be prepared according to the proportion.

2. The solvent has the remarkable characteristics of low viscosity, good fluidity and uniform dispersibility, and exhibits excellent inertness for the catalytic reaction of polyolefin, and has no toxic effect on the normal production of polyolefin and the final product.

3. The new solvent also has the characteristics of low boiling point and easy volatility, which makes it easy to desorb from the polyolefin resin produced by the reaction. Compared with the traditional solvent, the residual volatile matter in the polyolefin resin is greatly reduced, so It greatly reduces the loss of solvent in the polyolefin production process, reduces the drying temperature in the desorption process, reduces the nitrogen consumption, saves energy consumption, and effectively eliminates the potential safety hazards of the granulation plant and pellet silo in the polyolefin industry. The safety of the post-processing process is improved.

4. Since it does not contain benzene series, it avoids the potential harm to human health caused by traditional solvents, and fully meets the requirements of high standards of health and environmental protection.

Detailed ways

The embodiments of the present invention are described in detail below. This embodiment is implemented on the premise of the technical solution of the present invention, and provides a detailed implementation manner and a specific operation process, but the protection scope of the present invention is not limited to the following implementation. example.

Example 1

1. Select propane with the following technical requirements as raw material:

Specific gravity under 15.6℃ temperature test condition: 0.5050

Propane weight percentage concentration 95% of specific technical requirements

Acidity Concentration 2ppm by weight

5% by weight of other hydrocarbons

Unsaturated hydrocarbon concentration 500ppm by weight

Water concentration 20ppm by weight

Sulfur concentration 5ppm by weight

Chroma 15

Non-volatile matter 0.001g/100ml

Peroxide concentration by weight 0.1ppm

Benzene concentration by weight 0.1ppm

Suspended matter: none

2. Select C4-C6 alkanes with the following technical requirements as raw materials:

Specific gravity under 15.6℃ temperature test condition: 0.55～0.65

The specific technical requirements of the C4 ~ C6 alkane weight percentage concentration of 95%

Acidity 2ppm

5% by weight of other hydrocarbons

Unsaturated hydrocarbon concentration 500ppm by weight

Water concentration 20ppm by weight

Sulfur concentration 5ppm by weight

Chroma 15

Non-volatile matter 0.001g/100ml

Peroxide concentration by weight 0.1ppm

Benzene concentration by weight 0.1ppm

Suspended matter: none

3. the preparation ratio of the solvent of the present invention:

The weight of the propane raw material required by the above-mentioned specific technology: the weight of the C4-C6 alkane raw material required by the specific technology = 1:1

Technical parameters of the solvent obtained by mixing uniformly at room temperature:

Propane of specific technical requirements + C4-C6 alkane concentration of specific technical requirements 95%

Specific gravity under 15.6℃ temperature test condition: 0.620

Acidity 2ppm

5% by weight of other hydrocarbons

Unsaturated hydrocarbon concentration 500ppm by weight

Water concentration 20ppm by weight

Sulfur concentration 5ppm by weight

Chroma 15

Non-volatile matter 0.001g/100ml

Peroxide concentration by weight 0.1ppm

Benzene concentration by weight 0.1ppm

Suspended matter: none

Example 2

1. Raw materials refer to technical indicators

Propane for specific technical requirements:

Specific gravity under 15.6℃ temperature test condition: 0.52

Propane weight percentage concentration required by specific technical requirements: 96%

Acidity Concentration by weight: 1ppm

Concentration of other hydrocarbons by weight: 4%

Concentration of unsaturated hydrocarbons by weight: 300 ppm

Water concentration by weight: 10ppm

Sulfur concentration by weight: 1ppm

Chroma: 10 (Platinum-Cobalt)

Non-volatile matter <0.001g/100ml

Peroxide concentration by weight < 0.1 ppm

Benzene concentration by weight <0.1ppm

Suspended matter: none

2. C4 ~ C6 alkane technical indicators for specific technical requirements

Specific gravity under 15.6℃ temperature test condition: 0.621

Weight percent concentration of C4-C6 alkanes required by specific technical requirements: 96%

Acidity concentration by weight <1ppm

3% by weight of other hydrocarbons

Unsaturated hydrocarbon concentration by weight 300ppm

Water concentration by weight: 12ppm

Sulfur concentration by weight: <1ppm

Chroma: 5

Non-volatile matter <0.001g/100ml

Peroxide concentration by weight: <0.1ppm

Benzene concentration by weight <0.1ppm

Suspended matter: none

3. The proportion of solvent preparation:

Weight of propane raw material required by specific technology: weight of C4-C6 alkane raw material required by specific technology = 3:2

Technical parameters of the solvent obtained after mixing at room temperature:

Specific gravity under 15.6℃ temperature test condition: 0.620

Propane of specific technical requirements + C4-C6 alkanes weight percent concentration of specific technical requirements: 96%

Acidity weight percent concentration: 1.1ppm

Weight percent concentration of other hydrocarbons: 3%

Weight percent concentration of unsaturated hydrocarbons: 300ppm

Water weight percent concentration: 11ppm

Sulfur weight percent concentration: <1ppm

Chroma: 8

Non-volatile matter <0.001g/100ml

Peroxide weight percent concentration <0.1ppm

Benzene weight percentage concentration <0.1ppm

Suspended matter: none

Example 3

1. Raw materials refer to technical indicators

Propane for specific technical requirements:

Specific gravity under 15.6℃ temperature test condition: 0.520

Propane weight percentage concentration required by specific technical requirements: 99%

Acidity weight percent concentration: 1ppm

Concentration of other hydrocarbons by weight: 0.5%

Weight percent concentration of unsaturated hydrocarbons: 100ppm

Water weight percent concentration: 10ppm

Sulfur weight percent concentration: 1ppm

Chroma: 10

Non-volatile matter <0.001g/100ml

Peroxide weight percent concentration <0.1ppm

Benzene weight percentage concentration <0.1ppm

Suspended matter: none

2. C4 ~ C6 alkane technical indicators for specific technical requirements

Specific gravity under 15.6℃ temperature test condition: 0.55

The weight percent concentration of C4-C6 alkanes required by specific technical requirements: 99.5%

Acidity <1ppm

Other hydrocarbons by weight 0.2%

Unsaturated hydrocarbon weight percent concentration 100ppm

Water weight percent concentration: 12ppm

Sulfur weight percent concentration: <1ppm

Chroma weight percent concentration: 5

Nonvolatile weight percent concentration <0.001g/100ml

Peroxide weight percent concentration: <0.1ppm

Benzene weight percentage concentration <0.1ppm

Suspended matter: none

3. Solvent preparation ratio:

Weight of propane raw material required by specific technology: weight of C4-C6 alkane raw material required by specific technology = 3:2

Technical parameters after mixing:

Specific gravity under 15.6℃ temperature test condition: 0.620

Propane of specific technical requirements + C4-C6 alkanes weight percent concentration of specific technical requirements: 99.25%

Acidity Concentration by weight: 1ppm

Concentration of other hydrocarbons by weight: 0.5%

Concentration of unsaturated hydrocarbons by weight: 100 ppm

Water concentration by weight: 10ppm

Sulfur concentration by weight: <1ppm

Chroma: 8

Non-volatile matter <0.001g/100ml

Peroxide concentration by weight < 0.1 ppm

Benzene concentration by weight <0.1ppm

Suspended matter: none

Example 4

1. Raw materials refer to technical indicators

Propane for specific technical requirements:

Specific gravity under 15.6℃ temperature test condition: 0.52

Propane weight percentage concentration required by specific technical requirements: 96%

Acidity Concentration by weight: 1ppm

Concentration of other hydrocarbons by weight: 3%

Concentration of unsaturated hydrocarbons by weight: 120 ppm

Water concentration by weight: 12ppm

Sulfur concentration by weight: 1ppm

Chroma: 10

Non-volatile matter <0.001g/100ml

Peroxide concentration by weight < 0.1 ppm

Benzene concentration by weight <0.1ppm

Suspended matter: none

2. C4 ~ C6 alkane technical indicators for specific technical requirements

Specific gravity under 15.6℃ temperature test condition: 0.620

The weight percent concentration of C4-C6 alkanes required by specific technical requirements: 99.5%

Acidity concentration by weight <1ppm

Other hydrocarbons by weight 0.2%

Unsaturated hydrocarbon concentration by weight 100ppm

Water concentration by weight: 12ppm

Sulfur concentration by weight: <1ppm

Chroma: 5

Non-volatile matter <0.001g/100ml

Peroxide concentration by weight: <0.1ppm

Benzene concentration by weight <0.1ppm

Suspended matter: none

3. Preparation ratio:

Weight of propane raw material required by specific technology: weight of C4-C6 alkane raw material required by specific technology = 2:3

Technical parameters after mixing:

Specific gravity under 15.6℃ temperature test condition: 0.620

Propane of specific technical requirements + C4-C6 alkanes weight percentage concentration of specific technical requirements: 97.25%

Acidity Concentration by weight: 1ppm

Concentration of other hydrocarbons by weight: 0.5%

Concentration of unsaturated hydrocarbons by weight: 100 ppm

Water concentration by weight: 10ppm

Sulfur concentration by weight: <1ppm

Chroma: 8

Concentration of non-volatile matter by weight <0.001g/100ml

Peroxide concentration by weight < 0.1 ppm

Benzene concentration by weight <0.1ppm

Suspended matter: none

The invention is applied to catalyst preparation or prepolymerization in polyolefin industry.

Claims (9)

1. A solvent for polyethylene catalyst, characterized in that it is a mixture of (1-3): (1-3) propane and C4-C6 alkane in mass ratio. 2 . The solvent for polyethylene catalyst according to claim 1 , wherein the specific gravity of the solvent under the temperature test condition of 15.6° C. is 0.58-0.62. 3 . 3. The solvent for polyethylene catalyst according to claim 1, wherein the acidity of the solvent is less than 2 ppm by weight; the solvent contains other hydrocarbons with a weight percent concentration of less than 5%, unsaturated Hydrocarbons <500ppm by weight, Water <20ppm by weight, Sulfur <5ppm by weight, Color <15, Nonvolatiles <0.001g/100ml, Peroxides < 0.1ppm, the concentration of benzenes by weight is <0.1ppm. 4 . The solvent for polyethylene catalyst according to claim 1 , wherein the propane has a specific gravity of 0.50-0.52 under a temperature test condition of 15.6° C. 5 . 5. The solvent for polyethylene catalyst according to claim 1 or 4, wherein the weight percentage concentration of the propane is 95%. 6. The solvent for polyethylene catalyst according to claim 1 or 4, wherein the acidity of the propane is less than 2 ppm by weight; the propane contains other hydrocarbons with a weight percent concentration of less than 5%, Unsaturated hydrocarbons < 500 ppm by weight, water < 20 ppm by weight, sulfur < 5 ppm by weight, color < 15, nonvolatiles < 0.001 g/100ml, peroxides Concentration < 0.1 ppm, concentration of benzenes < 0.1 ppm by weight. 7 . The solvent for polyethylene catalyst according to claim 1 , wherein the specific gravity of the C4 to C6 alkanes under a temperature test condition of 15.6° C. is 0.55 to 0.65. 8 . 8. The solvent for polyethylene catalyst according to claim 1 or 7, wherein the weight percent concentration of the C4-C6 alkanes is greater than or equal to 95%. 9 . The solvent for polyethylene catalyst according to claim 1 , wherein the acidity of the C4～C6 alkanes has a concentration by weight of <2ppm; the C4～C6 alkanes contain other hydrocarbons in weight percent concentration. 10 . <5%, unsaturated hydrocarbon concentration <500ppm by weight, water concentration <20ppm by weight, sulfur concentration <5ppm by weight, color <15, nonvolatiles <0.001g/100ml, peroxide Concentration by weight < 0.1 ppm, concentration by weight of benzenes < 0.1 ppm.