阅读说明：本技术 一种高氯原料加氢过程的脱氯方法 (Dechlorination method for high-chlorine raw material hydrogenation process ) 是由 梁巍 郭凯 于 2021-11-01 设计创作，主要内容包括：本发明涉及一种高氯原料加氢过程的脱氯方法,特别的讲本发明涉及一种适用于废弃生物质燃料加氢过程产生的含有氯离子和固体颗粒的反应流出物的脱氯方法,在悬浮床反应部分,脱氯剂随悬浮床催化剂一起被加入到进料中,在反应器内,脱氯剂将氯离子转化为高熔点的氯盐,随反应产物进入后续热高压分离部分,在热高压分离部分,反应产物被分为气、液两相,液体携带催化剂颗粒和氯盐向下流动,气体向上流动。本方法适合于生物质燃料悬浮床加氢过程产生的氯离子的物流的热高分气的脱氯过程,解决热高分气中氯离子含量高,在降温过程对后续设备材料的氯离子腐蚀问题,提高热高分气进入后续系统的操作安全性。(The invention relates to a dechlorination method for a high-chlorine raw material in a hydrogenation process, in particular to a dechlorination method for a reaction effluent containing chloride ions and solid particles generated in a waste biomass fuel hydrogenation process. The method is suitable for the dechlorination process of the hot high-pressure gas of the chloride ion material flow generated in the biomass fuel suspension bed hydrogenation process, solves the problems of high chloride ion content in the hot high-pressure gas and chloride ion corrosion to subsequent equipment materials in the cooling process, and improves the operation safety of the hot high-pressure gas entering a subsequent system.)

1. A dechlorination method for a high-chlorine raw material hydrogenation process is characterized by comprising the following steps: the method comprises the following steps:

(1) in the reaction feeding part, a dechlorinating agent is added into the high-chlorine raw material feeding along with a suspension bed catalyst, and in the reaction system, the dechlorinating agent is added into the high-chlorine raw material feeding material at the temperature of 200-500 ℃, the pressure of 3.0-25.0 MPa and the volume ratio of hydrogen to oil of 50-2000: 1. the dechlorinating agent reacts with HCl gas generated in the hydrogenation process under the condition that the mass ratio of the dechlorinating agent to the oil is 0.001-2.0%, so as to generate metal chloride with high melting point, and the metal chloride is mixed in the hydrogenation reaction product;

(2) in the hot high-pressure separation part, the hydrogenation reaction product is separated into hot high-pressure gas and solid-containing hot high-pressure oil;

(3) in the cold high-pressure separation section, the hot high-pressure gas is cooled and separated into: a cold high-molecular gas mainly composed of hydrogen, a cold high-molecular oil liquid mainly composed of conventional gaseous hydrocarbon, impurity components and conventional liquid hydrocarbon;

(4) in the product separation part, the hot high-fraction oil and the cold high-fraction oil are converged and separated into hydrocarbon gas, distillate oil and solid residue oil at the bottom of the tower through a rectification process.

2. The dechlorination method for the hydrogenation process of the high-chlorine raw material according to claim 1, which is characterized in that: in the step (1), the operation conditions of the suspension bed hydrogenation part are as follows: the temperature is 320-450 ℃, the pressure is 8.0-20.0 MPa, and the volume ratio of hydrogen to raw oil is 300-1200: 1.

3. The dechlorination method for the hydrogenation process of the high-chlorine raw material according to claim 1, which is characterized in that: in the step (2), the chloride ion concentration in the hot high-pressure separation part is reduced to be less than 10 ppm.

4. The dechlorination method for the hydrogenation process of the high-chlorine raw material according to claim 3, characterized by comprising the following steps: in the step (2), the chloride ion concentration in the hot high-pressure separation part is reduced to be less than 5 ppm.

5. The dechlorination method for the hydrogenation process of the high-chlorine raw material according to claim 4, characterized in that: in the step (2), the chloride ion concentration in the hot high-pressure separation part is reduced to be less than 2 ppm.

6. The dechlorination method for the hydrogenation process of the high-chlorine raw material according to claim 1, which is characterized in that: in the step (3), in the cold high-pressure separation part, before the hot high-pressure gas enters the cold high-pressure separator, washing water is injected into the hot high-pressure gas, and the hot high-pressure gas is firstly cooled to be below 200 ℃ and then is mixed with the washing water; the cold high-pressure separation part comprises the steps of cooling and separating hot high-pressure gas after water injection, the temperature of the hot high-pressure gas after water injection is firstly reduced to 30-70 ℃, and in the temperature reduction process, the hot high-pressure gas after water injection is separated in a cold high-pressure separator as follows: the high-temperature-resistant oil-gas separator comprises a cold high-temperature-resistant gas mainly composed of hydrogen, a cold high-temperature-resistant oil liquid mainly composed of conventional gas hydrocarbon, conventional liquid hydrocarbon and dissolved hydrogen and a cold high-temperature-resistant water liquid mainly composed of water and dissolved with hydrogen sulfide and ammonia.

7. The dechlorination method for the hydrogenation process of the high-chlorine raw material according to claim 1, which is characterized in that: in the step (3), at least a part of the cold high-molecular gas is returned to the hydrogenation part to form the circulating hydrogen.

Technical Field

The invention relates to a dechlorination method for a high-chlorine raw material in a hydrogenation process; in particular, the invention relates to a dechlorination method which is suitable for the reaction effluent containing chloride ions and solid particles produced in the hydrogenation process of waste biomass fuels.

Background

At present, plastic products go deep into various aspects of people's life, bring great pressure to the environment while facilitating people's life, the recycling of waste plastics is an effective way for promoting the recycling of waste plastics, and especially the production of biodiesel by hydrogenating the waste plastics has wide application prospect and environmental protection significance under the condition of current energy shortage. However, in practical application, most plastics contain chlorine elements, certain compounds containing chloride ions, such as HCl, are generated in the hydrogenation process, the reaction effluent is separated into a gas-liquid two-phase at a high temperature, most of the compounds containing the chloride ions enter a subsequent cooling system along with the gas phase, and water vapor in the gas phase is condensed into liquid water along with the gradual reduction of the temperature, wherein the content of the chloride ions is more than 25ppm, and one or more of stress corrosion, small hole corrosion, pitting corrosion and crevice corrosion can occur in most equipment, such as a high-pressure heat exchanger, a high-pressure air cooler and the like, in the presence of the liquid water, so that high-pressure steel equipment is damaged, and potential safety hazards are brought.

Disclosure of Invention

In order to overcome the defects and shortcomings in the prior art, the invention aims to provide a dechlorination method for a high-chlorine raw material in a hydrogenation process.

The purpose of the invention is realized by the following technical scheme: a dechlorination method for a high-chlorine raw material hydrogenation process comprises the following steps:

(1) in the reaction feeding part, a dechlorinating agent is added into the high-chlorine raw material feeding along with a suspension bed catalyst, and in the reaction system, the dechlorinating agent is added into the high-chlorine raw material feeding material at the temperature of 200-500 ℃, the pressure of 3.0-25.0 MPa and the volume ratio of hydrogen to oil of 50-2000: 1. the dechlorinating agent reacts with HCl gas generated in the hydrogenation process under the condition that the mass ratio of the dechlorinating agent to the oil is 0.001-2.0%, so as to generate metal chloride with high melting point, and the metal chloride is mixed in the hydrogenation reaction product;

(2) in the hot high-pressure separation part, the hydrogenation reaction product is separated into hot high-pressure gas and solid-containing hot high-pressure oil;

(3) in the cold high-pressure separation section, the hot high-pressure gas is cooled and separated into: a cold high-molecular gas mainly composed of hydrogen, a cold high-molecular oil liquid mainly composed of conventional gaseous hydrocarbon, impurity components and conventional liquid hydrocarbon;

(4) in the product separation part, the hot high-fraction oil and the cold high-fraction oil are converged and separated into hydrocarbon gas, distillate oil and solid residue oil at the bottom of the tower through a rectification process.

Preferably, in the step (1), the operating conditions of the suspension bed hydrogenation reaction part are as follows: the temperature is 320-450 ℃, the pressure is 8.0-20.0 MPa, and the volume ratio of hydrogen to raw oil is 300-1200: 1.

Preferably, in the step (2), the chloride ion concentration in the hot high-pressure separation part is reduced to less than 10 ppm.

More preferably, in the step (2), the chloride ion concentration in the hot high-pressure separation part is reduced to less than 5 ppm.

Most preferably, in the step (2), the chloride ion concentration in the hot high-pressure separation part is reduced to less than 2 ppm.

Preferably, in the step (3), in the cold high-pressure separation part, before the hot high-pressure gas enters the cold high-pressure separator, washing water is injected into the hot high-pressure gas, and the hot high-pressure gas is firstly cooled to be below 200 ℃ and then is mixed with the washing water; the cold high-pressure separation part comprises the steps of cooling and separating hot high-pressure gas after water injection, the temperature of the hot high-pressure gas after water injection is firstly reduced to 30-70 ℃, and in the temperature reduction process, the hot high-pressure gas after water injection is separated in a cold high-pressure separator as follows: the high-temperature-resistant oil-gas separator comprises a cold high-temperature-resistant gas mainly composed of hydrogen, a cold high-temperature-resistant oil liquid mainly composed of conventional gas hydrocarbon, conventional liquid hydrocarbon and dissolved hydrogen and a cold high-temperature-resistant water liquid mainly composed of water and dissolved with hydrogen sulfide and ammonia.

Preferably, in the step (3), at least a part of the cold high-molecular-weight gas is returned to the hydrogenation reaction part to form recycle hydrogen.

The invention has the beneficial effects that: in the dechlorination method, in a suspension bed reaction part, a dechlorinating agent is added into a feed along with a suspension bed catalyst, in a reactor, the dechlorinating agent converts chloride ions into chloride salt with a high melting point, the chloride salt enters a subsequent thermal high-pressure separation part along with a reaction product, in the thermal high-pressure separation part, the reaction product is divided into a gas phase and a liquid phase, the liquid carries catalyst particles and the chloride salt to flow downwards, and the gas flows upwards; the method is suitable for the dechlorination process of the hot high-pressure gas of the chloride ion material flow generated in the biomass fuel suspension bed hydrogenation process, solves the problems of high chloride ion content in the hot high-pressure gas and chloride ion corrosion to subsequent equipment materials in the cooling process, and improves the operation safety of the hot high-pressure gas entering a subsequent system.

In the dechlorination method, in the hydrogenation feeding part, the dechlorinating agent and the suspension bed catalyst are added into the high-chlorine raw material together, so that the property of the fed oil slurry is not changed, a feeding pump is not required to be additionally arranged, and special equipment and pipelines are not required to be additionally arranged.

Drawings

FIG. 1 is a schematic process flow diagram of the present invention.

Detailed Description

For the understanding of those skilled in the art, the present invention will be further described with reference to the following examples and the accompanying fig. 1, and the description of the embodiments is not intended to limit the present invention.

The melting point refers to the temperature at which a substance is in equilibrium between a solid state and a liquid state at one atmosphere;

the conventional gaseous hydrocarbon in the present invention refers to hydrocarbon which is gaseous under conventional conditions, and includes methane, ethane, propane and butane.

The conventional liquid hydrocarbon refers to hydrocarbon which is liquid under the conventional conditions, and comprises pentane and hydrocarbon with higher boiling point.

The impurity components referred to in the present invention refer to the non-hydrocarbon components of the feedstock as converted products such as water, ammonia, hydrogen chloride, hydrogen sulfide, etc.

The specific gravity of the present invention refers to the ratio of the density of a liquid at ordinary pressure and 15.6 ℃ to the density of a liquid at ordinary pressure and 15.6 ℃ unless otherwise specified.

The distillate oil refers to hydrocarbons with the conventional boiling point of lower than 370 ℃;

the compositions or concentrations or amounts or yields of the components described herein are weight basis values unless otherwise specified.

The dechlorination agent of the invention can be a combination of 1 or 2 or more of the following dechlorination agents: CaO-ZuO series dechlorinating agent and CaO-Al₂O₃Series of antichlors, Na₂O-Al2O₃Series of dechlorinating agents, K₂OIe₂O₃Series of antichlors, Na₂CO₃-NaOH-Bentonite series dechlorinating agent, Ca (NO)₃)₂-Al(NO₃)₃Series antichlor, Ca (OH)₂-Al(NO₃)₃Series of antichlor, Ca (NO)₃)₂-Al(OH)₃Series antichlor, Ca (OH)₂-Al(OH)₃A series of dechlorinating agents.

Referring to fig. 1, a dechlorination method for a high chlorine raw material hydrogenation process comprises the following steps:

(1) in the reaction feeding part, a dechlorinating agent is added into a high-chlorine raw material feed together with a suspension bed catalyst, the high-chlorine raw material feed enters a reaction system, and the dechlorinating agent reacts with HCl gas generated in the hydrogenation process to generate metal chloride with a high melting point and is mixed in a hydrogenation reaction product under the conditions of the temperature of 200-500 ℃, the pressure of 3.0-25.0 MPa, the hydrogen/oil volume ratio of 50-2000: 1 and the dechlorinating agent/oil mass ratio of 0.001-2.0% in the reaction system.

The suspension bed hydrogenation of the invention refers to a hydrogen-consuming reaction process of raw oil under the condition of hydrogen and catalyst and at a proper temperature.

The operating conditions of the suspension bed hydrogenation reaction part are preferably as follows: the temperature is 320-450 ℃, the pressure is 8.0-20.0 MPa, and the volume ratio of hydrogen to raw oil is 300-1200: 1.

(2) In the hot high-pressure separation part, the hydrogenation reaction product is separated into hot high-pressure gas and hot high-pressure oil.

(3) In the cold high-pressure separation section, the hot high-pressure gas is cooled and separated into: one consisting essentially of hydrogen and one consisting essentially of normally gaseous hydrocarbons, contaminant components, and normally liquid hydrocarbons.

In the cold high pressure separation section, wash water is typically injected into the hot high pressure gas before it enters the cold high pressure separator. The hot high-molecular gas is usually first cooled to a temperature below 200 ℃ and then mixed with the washing water.

The cold high-pressure separation part comprises the steps of cooling and separating hot high-pressure gas after water injection. In this case, the temperature of the hot high-pressure gas after water injection is usually first reduced to 30 to 70 ℃, and in this temperature reduction process, the hot high-pressure gas after water injection is separated in the cold high-pressure separator as follows: the high-temperature-resistant oil-gas separator comprises a cold high-temperature-resistant gas mainly composed of hydrogen, a cold high-temperature-resistant oil liquid mainly composed of conventional gas hydrocarbon, conventional liquid hydrocarbon and dissolved hydrogen and a cold high-temperature-resistant water liquid mainly composed of water and dissolved with hydrogen sulfide and ammonia.

At least a part of the cold high-molecular gas is returned to the hydrogenation reaction part to form recycle hydrogen as described above.

(4) In the product separation part, the hot high-fraction oil and the cold high-fraction oil are converged and separated into hydrocarbon gas, distillate oil and solid residue oil at the bottom of the tower through a rectification process.

The tower bottom solid residue-containing oil refers to a mixture composed of hydrocarbons with the conventional boiling point higher than 370 ℃ and solid particles of catalyst, metal chloride and the like.

The above-described embodiments are preferred implementations of the present invention, and the present invention may be implemented in other ways without departing from the spirit of the present invention.