A continuous sidedraw reactive distillation apparatus which withdraws unreacted feed material and refluxes the reaction

Abstract

This invention relates to a reactive distillation apparatus that continuously collects unreacted raw materials from the side stream and refluxes them into the reaction, belonging to the field of chemical reaction and separation coupling technology. The apparatus consists of a reactive distillation column (1), a rectification section (2), a reaction section (3), a stripping section (4), a heater (5), a top condenser (6), a reflux ratio controller (7), a top outlet valve (8), a top reflux valve (9), a side stream outlet (10), a side stream outlet valve (11), and a side stream reflux valve (12). Utilizing the difference in boiling points between the reactants and water, water or the lowest azeotrope of water and the product is collected from the top of the reactive distillation column (1). Unreacted raw materials are collected from the side stream outlet (10) and simultaneously refluxed into the reaction section (3) of the reactive distillation column to continue the reaction, promoting the forward reaction and improving the utilization rate and conversion rate of the raw materials. This invention has the advantages of simple structure, convenient operation, and high conversion rate.

Description

Technical Field

[0001] This utility model relates to a reactive distillation apparatus that continuously extracts unreacted raw materials from the side stream and refluxes them for further reaction, belonging to the field of chemical reaction and separation coupling technology. Background Technology

[0002] Reactive distillation is a process enhancement technology that couples chemical reactions with distillation separation. By removing products or byproducts (such as water) in situ, it breaks the chemical equilibrium limitations of the reaction, which can significantly improve reaction conversion and selectivity, reduce the proportion of raw materials, and reduce energy consumption and equipment investment. It is widely used in reversible reaction processes such as esterification, etherification, hydrolysis, and alkylation.

[0003] A reactive distillation column is a special type of column that couples chemical reactions and distillation separation within the same device. The spontaneous phase separation of the condensate at the top of the column enables in-situ selective separation of products. At the same time, by optimizing the reflux strategy, the reaction conversion rate can be improved, achieving a triple synergy of reaction, separation and energy utilization. It is especially suitable for reaction systems (such as esterification, etherification, etc.) in which products and by-products (such as water) form heterogeneous azeotropes. Summary of the Invention

[0004] The technical problem to be solved by this utility model is to provide a reactive distillation device with a simple process, convenient operation, high raw material utilization rate, high reaction conversion rate, and unreacted raw materials that are distilled and then refluxed back into the reaction section to participate in the reaction again.

[0005] The reactive distillation apparatus of this invention, which continuously draws unreacted raw materials from the side stream and refluxes them into the reaction, includes a reactive distillation column (1), a rectification section (2), a reaction section (3), a stripping section (4), a heater (5), a top condenser (6), a reflux ratio controller (7), a top outlet valve (8), a top reflux valve (9), a side stream outlet (10), a side stream outlet valve (11), and a side stream reflux valve (12). The apparatus is characterized in that: the reactive distillation column (1) consists of, from top to bottom, the rectification section (2), the reaction section (3), and the stripping section (4); a heater (5) is connected to the bottom of the reactive distillation column (1); and the top of the reactive distillation column (1) is connected to the inlet of the top condenser (6) via a pipeline. The outlet of the top condenser (6) is connected to the inlet of the reflux ratio controller (7), the inlet of the top product valve (8), and the inlet of the top reflux valve (9) via pipelines. The outlet of the reflux ratio controller (7) is connected to the rectification section (2) of the reactive distillation column via pipelines. The outlet of the top product valve (8) is directly collected by a container. The outlet of the top reflux valve (9) is connected to the reaction section (3) of the reactive distillation column via pipelines. The rectification section (2) of the reactive distillation column is provided with a side product outlet (10). The side product outlet (10) is connected to the inlet of the side product valve (11) and the inlet of the side reflux valve (12) via pipelines. The outlet of the side product valve (11) is directly collected by a container. The outlet of the side reflux valve (12) is connected to the reaction section (3) of the reactive distillation column via pipelines.

[0006] The operating temperature of the reactive distillation column (1) is 60℃~300℃, and the operating pressure is vacuum, atmospheric pressure, or pressurized pressure.

[0007] The reaction section (3) of the reactive distillation tower has one or two kinds of raw materials, which are fed by raw material pump A (13) or raw material pump B (15). The raw material pump A (13) is connected to the feed valve A (14) and the reaction section (3) of the reactive distillation tower in sequence through pipelines. The raw material pump B (15) is connected to the feed valve B (16) and the reaction section (3) of the reactive distillation tower in sequence through pipelines.

[0008] The catalyst packed in the reaction section (3) of the reactive distillation column is either a homolytically soluble catalyst or an insoluble solid catalyst. The solid catalyst is fixed by packing bags, granules, or bulk loading on trays.

[0009] The beneficial effects of this utility model are:

[0010] 1. This device can extract water or the lowest azeotrope of water and product produced by dehydration reaction (esterification, etherification, condensation, etc.) through the top of the reactive distillation column (1) via the top outlet valve (8). Unreacted raw material is returned to the reaction section (3) of the reactive distillation column through the side outlet (10) via the side reflux valve (12) to continue the reaction, pushing the reaction in the positive direction, thereby breaking the equilibrium conversion rate.

[0011] 2. This device can reflux unreacted raw materials during dehydration reactions (esterification, etherification, condensation, etc.) through the top of the reactive distillation column (1) via the top reflux valve (9) back into the reaction section (3) of the reactive distillation column to continue the reaction, thereby improving the utilization rate of raw materials and the conversion rate of the reaction, so that the conversion rate of the reaction exceeds the equilibrium conversion rate. At the same time, the water generated by the reaction or the azeotrope of water and product is extracted through the side line outlet (10) via the side line extraction valve (11).

[0012] 3. Reactive distillation integrates the reactor with the distillation column, achieving a synergistic effect of reaction-driven separation and separation-promoted reaction, making it particularly suitable for reversible reactions (such as esterification, etherification, and hydrolysis). Simultaneously, the exothermic reaction can be directly used for distillation vaporization, reducing heater energy consumption, and the efficient contact between the gas and liquid phases on the catalyst surface enhances the reaction rate. Attached Figure Description

[0013] Figure 1 A schematic diagram of a reactive distillation unit for continuous side-stream extraction of unreacted feedstock and reflux reaction. Detailed Implementation

[0014] The present invention will now be described in further detail with reference to the accompanying drawings:

[0015] like Figure 1The reactive distillation unit shown consists of a reactive distillation column (1), a rectifying section (2), a reaction section (3), a stripping section (4), a heater (5), a top condenser (6), a reflux ratio controller (7), a top outlet valve (8), a top reflux valve (9), a side outlet (10), a side outlet valve (11), and a side reflux valve (12). The reactive distillation column (1) consists of, from top to bottom, the rectifying section (2), the reaction section (3), the stripping section (4), a heater (5), a top condenser (6), a reflux ratio controller (7), a top outlet valve (8), a top reflux valve (9), a side outlet (10), a side outlet valve (11), and a side reflux valve (12). The reaction section (3) of the distillation column and the stripping section (4) of the reactive distillation column are connected to a heater (5) at the bottom of the reactive distillation column (1). The top of the reactive distillation column (1) is connected to the inlet of the top condenser (6) via a pipeline. The outlet of the top condenser (6) is connected to the inlet of the reflux ratio controller (7), the inlet of the top outlet valve (8), and the inlet of the top reflux valve (9) via a pipeline. The outlet of the reflux ratio controller (7) is connected to the rectification section (2) of the reactive distillation column via a pipeline. The outlet of the top outlet valve (8) is directly collected by a container. The top reflux valve (9) is connected to the top outlet valve (8). 9) The outlet is connected to the reaction section (3) of the reactive distillation column via a pipeline. The rectification section (2) of the reactive distillation column is equipped with a side-stream outlet (10). The side-stream outlet (10) is connected to the inlet of the side-stream outlet valve (11) and the inlet of the side-stream reflux valve (12) via a pipeline. The outlet of the side-stream outlet valve (11) is directly collected by a container. The outlet of the side-stream reflux valve (12) is connected to the reaction section (3) of the reactive distillation column via a pipeline. The reaction raw materials in the reaction section (3) of the reactive distillation column are of one or two kinds, which are fed by raw material pump A (13) or raw material pump B (15). Feeding: Raw material pump A (13) is connected to feed valve A (14) and reaction section (3) of reactive distillation column via pipeline. Raw material pump B (15) is connected to feed valve B (16) and reaction section (3) of reactive distillation column via pipeline. The catalyst packed in reaction section (3) of reactive distillation column is a homolytic catalyst or an insoluble solid catalyst. The solid catalyst is fixed by packing bags or granules or by bulk loading on trays. The operating temperature of reactive distillation column (1) is 60℃~300℃, and the operating pressure is vacuum, atmospheric pressure or pressurized pressure.

[0016] The description and application of this utility model herein are illustrative and are not intended to limit the scope of this utility model to the above embodiments. Therefore, this utility model is not limited to the embodiments described herein, and any technical solution obtained by equivalent substitution is within the protection scope of this utility model.

Claims

1. A reactive distillation apparatus for continuously side-streaming unreacted feedstock and refluxing it into the reaction, comprising a reactive distillation column (1), a rectification section (2), a reaction section (3), a stripping section (4), a heater (5), a top condenser (6), a reflux ratio controller (7), a top outlet valve (8), a top reflux valve (9), a side-stream outlet (10), a side-stream outlet valve (11), and a side-stream reflux valve (12), characterized in that: The reactive distillation column (1) consists of a rectification section (2), a reaction section (3), and a stripping section (4) from top to bottom. A heater (5) is connected to the bottom of the column. The top of the column is connected to the inlet of a top condenser (6) via a pipeline. The outlet of the top condenser (6) is connected to the inlet of a reflux ratio controller (7), the inlet of a top outlet valve (8), and the inlet of a top reflux valve (9) via pipelines. The outlet of the reflux ratio controller (7) is connected to the rectification section (2), the reaction section (3), and the stripping section (4) of the reactive distillation column from top to bottom. The distillation section (2) is connected, and the outlet of the top product valve (8) is directly collected by a container. The outlet of the top reflux valve (9) is connected to the reaction section (3) of the reactive distillation column through a pipeline. The distillation section (2) of the reactive distillation column is provided with a side product outlet (10). The side product outlet (10) is connected to both the inlet of the side product valve (11) and the inlet of the side reflux valve (12) through a pipeline. The outlet of the side product valve (11) is directly collected by a container. The outlet of the side reflux valve (12) is connected to the reaction section (3) of the reactive distillation column through a pipeline.

2. The reactive distillation apparatus for continuously side-stream extraction of unreacted feedstock and reflux reaction according to claim 1, characterized in that: The operating temperature of the reactive distillation column (1) is 60℃~300℃, and the operating pressure is vacuum, atmospheric pressure, or pressurized pressure.

3. The reactive distillation apparatus for continuously side-stream extraction of unreacted feedstock and reflux reaction according to claim 1, characterized in that: The reaction section (3) of the reactive distillation tower has one or two kinds of raw materials, which are fed by raw material pump A (13) or raw material pump B (15). The raw material pump A (13) is connected to the feed valve A (14) and the reaction section (3) of the reactive distillation tower in sequence through pipelines. The raw material pump B (15) is connected to the feed valve B (16) and the reaction section (3) of the reactive distillation tower in sequence through pipelines.

4. The reactive distillation apparatus for continuously side-stream extraction of unreacted feedstock and reflux reaction according to claim 1, characterized in that: The catalyst packed in the reaction section (3) of the reactive distillation column is either a homolytically soluble catalyst or an insoluble solid catalyst. The solid catalyst is fixed by packing bags, granules, or bulk loading on trays.

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