阅读说明：本技术 一种基于离子交换膜的有机料液中氢氧化钾净化工艺 (Process for purifying potassium hydroxide in organic feed liquid based on ion exchange membrane ) 是由 黄春梅 纪镁铃 李燕玲 于 2020-06-10 设计创作，主要内容包括：本发明公开了一种基于离子交换膜的有机料液中氢氧化钾净化工艺,包括如下步骤：(1)预处理：对有机料液进行过滤处理,去除杂质,使其符合扩散渗析器的要求；(2)将经步骤(1)预处理后的有机料液和水分别输送至扩散渗析膜堆,节相对应的阀门开度,使预处理有机料液和水的流量比达到1:1-1:2,进行扩散渗析；(3)扩散渗析后将高氢氧化钾含量的回收液和低氢氧化钾含量的残液进行分离,得到净化和浓缩后的氢氧化钾。本发明所提供的净化工艺净化效果好,氢氧化钾的回收率大于90％,有机物的截流率大于90％。(The invention discloses a process for purifying potassium hydroxide in organic feed liquid based on an ion exchange membrane, which comprises the following steps: (1) pretreatment: filtering the organic feed liquid to remove impurities, so that the organic feed liquid meets the requirements of a diffusion dialyzer; (2) respectively conveying the organic feed liquid and water pretreated in the step (1) to a diffusion dialysis membrane stack, and adjusting the corresponding valve opening degree to enable the flow ratio of the pretreated organic feed liquid to the water to reach 1:1-1:2, and performing diffusion dialysis; (3) and separating the recovered liquid with high potassium hydroxide content from the residual liquid with low potassium hydroxide content after diffusion dialysis to obtain purified and concentrated potassium hydroxide. The purification process provided by the invention has good purification effect, the recovery rate of the potassium hydroxide is more than 90%, and the interception rate of organic matters is more than 90%.)

1. A process for purifying potassium hydroxide in organic feed liquid based on an ion exchange membrane is characterized by comprising the following steps:

(1) pretreatment: filtering the organic feed liquid to remove impurities, so that the organic feed liquid meets the requirement of a diffusion dialyzer, wherein the mass fraction of potassium hydroxide in the organic feed liquid is 20-35%, the mass fraction of organic matters is 5-10%, and the density of the organic feed liquid is 1.1-1.6 g/mL;

(2) respectively conveying the organic feed liquid and water pretreated in the step (1) to a diffusion dialysis membrane stack, and adjusting the corresponding valve opening degree to enable the flow ratio of the pretreated organic feed liquid to the water to reach 1:1-1:2, and performing diffusion dialysis;

(3) and separating by diffusion dialysis to obtain a recovered solution with high potassium hydroxide content and a residual solution with low potassium hydroxide content.

2. The potassium hydroxide purification process according to claim 1, wherein the filtration treatment in step (1) is filtration with 1-5 micron PP cotton to remove large particle impurities so as not to block the diffusion dialyzer module.

3. The potassium hydroxide purification process according to claim 2, wherein the PP cotton is 3-5 micron PP cotton.

4. The potassium hydroxide purification process according to claim 1, wherein the mass fraction of potassium hydroxide in the organic feed liquid is 25-35%, the mass fraction of organic substances is 6-8%, and the density of the organic feed liquid is 1.2-1.5 g/mL.

5. The potassium hydroxide purification process according to claim 1, wherein the peristaltic pump is flow calibrated with the organic feed solution and water, respectively, prior to feeding the organic feed solution and water, respectively, to the diffusion dialysis membrane stack.

6. The potassium hydroxide purification process according to claim 1, wherein the flow ratio of the organic feed liquid to the water in the step (2) is 1:1.2-1: 1.6.

7. The potassium hydroxide purification process according to claim 1, wherein the flow rate of the organic feed liquid in the step (2) is 0.8-1.8L/(h.m)²) Preferably 1.0-1.5L/(h.m)²)。

8. The potassium hydroxide purification process according to claim 1, wherein the flow rate of the water in the step (2) is 1.0-2.0L/(h.m)²) Preferably 1.2-1.8L/(h.m)²)。

Technical Field

The invention belongs to the technical field of chemical material recovery, and particularly relates to a process for purifying potassium hydroxide in organic feed liquid based on an ion exchange membrane.

Background

Various potassium hydroxide organic feed liquids are often produced in modern industries. For example, the textile industry, dyes, rayon, and the like. When producing dye, a large amount of potassium hydroxide is needed to be added to reach strong alkaline condition, after reaction, a large amount of alkali-containing organic material liquid is available, generally speaking, some potassium hydroxide can be added after dilution for recycling, but once the concentration of organic matter is too high, the yield and quality of dye can be affected, the organic material liquid can not be recycled, and only a large amount of acid can be added for neutralization, and organic matter is removed through biochemistry. This not only pollutes the environment, but also wastes a lot of potassium hydroxide and acid.

The traditional treatment of alkali-containing wastewater mainly comprises the following steps: acid neutralization, flocculation and chemical precipitation, and adding acid substances to treat alkaline waste water to neutralize the alkaline waste water to obtain neutral waste water. The traditional method for the waste alkali liquor has the defects of high energy consumption, complex operation, small application range and no general method. At present, a new treatment method is also gradually popularized, namely a diffusion dialysis alkali recovery method which is an ion exchange membrane separation process taking concentration gradient as a driving force of mass transfer. Cations preferentially enter the recovery chamber under the push of a concentration gradient, and OH is pushed by charges^-The small hydration radius and the small charge can preferentially pass through the ion channel, thereby realizing the effective recovery of alkali in the waste alkali. The method has the advantages of low energy consumption in the operation process, normal pressure operation and simple operation, and is an ideal membrane separation technology for recovering alkali.

The separation process of the diffusion dialysis sodium hydroxide is more researched in recent years and is relatively mature, the recovery rate is generally 70-80%, the recovery concentration ratio is generally 70-80%, and the feed flow rate is generally 0.6-0.8L/(h.m)²) However, the studies on the separation of potassium hydroxide from the organic material liquid are relatively few, and a few studies show that the recovery effect of potassium hydroxide is inferior to that of sodium hydroxide.

Disclosure of Invention

Aiming at the defects of the prior art, the invention aims to provide the process for purifying the potassium hydroxide in the organic feed liquid based on the ion exchange membrane, the potassium hydroxide in the organic feed liquid is recovered by a diffusion dialysis method, the operation is convenient, the energy consumption is extremely low, the concentration of the potassium hydroxide in the recovered liquid can be flexibly controlled or concentrated, and the recovery rate can reach more than 90%.

The invention adopts the specific technical scheme that:

a process for purifying potassium hydroxide in organic feed liquid based on an ion exchange membrane comprises the following steps:

(1) pretreatment: filtering the organic feed liquid to remove impurities, so that the organic feed liquid meets the requirement of a diffusion dialyzer, wherein the mass fraction of potassium hydroxide in the organic feed liquid is 20-35%, the mass fraction of organic matters is 5-10%, and the density of the organic feed liquid is 1.1-1.6 g/mL;

(2) respectively conveying the organic feed liquid and water pretreated in the step (1) to a diffusion dialysis membrane stack, and adjusting the corresponding valve opening degree to enable the flow ratio of the pretreated organic feed liquid to the water to reach 1:1-1:2, and performing diffusion dialysis;

(3) and separating by diffusion dialysis to obtain a recovered solution with high potassium hydroxide content and a residual solution with low potassium hydroxide content.

Preferably, the filtration treatment in step (1) is filtration with 1-5 micron PP wool to remove large particle impurities so as not to clog the diffusion dialyzer module.

More preferably, the PP cotton is 3-5 micron PP cotton.

Preferably, the mass fraction of the potassium hydroxide in the organic feed liquid is 25-33%, the mass fraction of the organic matter is 6-8%, and the density of the organic feed liquid is 1.2-1.5 g/mL.

Preferably, the peristaltic pumps are flow calibrated with the feed solution and water, respectively, prior to delivery of the organic feed solution and water, respectively, to the diffusion dialysis membrane stack.

Preferably, the flow ratio of the organic feed liquid to the water in the step (2) is 1:1.2-1: 1.5.

Preferably, the flow rate of the organic feed liquid in the step (2) is 0.8-1.8L/(h.m)²) Preferably 2.0-1.5L/(h.m)²)。

Preferably, the flow rate of the water in the step (2) is 1.0-2.0L/(h.m)²) Preferably 1.2-1.8L/(h.m)²)。

The invention has the beneficial effects that: the process realizes the separation of the organic matter and the potassium hydroxide by controlling the content of the organic matter and the potassium hydroxide in the organic feed liquid and setting the proper feeding and water inflow flow rate and the feeding and water inflow flow rate ratio, thereby achieving the purposes of purifying and concentrating the potassium hydroxide. The purification effect is good, the recovery rate of the potassium hydroxide is more than 90%, and the retention rate of organic matters is more than 90%. The method is simple and stable to operate, has extremely low energy consumption, and is a green and economic potassium hydroxide purification process.

Drawings

FIG. 1 is a flow chart of a process for purifying potassium hydroxide in an organic feed liquid;

FIG. 2 is a schematic diagram of a process for purifying potassium hydroxide in an organic feed liquid.

Detailed Description

The present invention will be described in further detail with reference to examples, but the embodiments of the present invention are not limited thereto, and various substitutions and alterations can be made without departing from the technical idea of the present invention as described above, according to the common technical knowledge and the conventional means in the field.

The embodiment provides a process for purifying potassium hydroxide in organic material liquid based on an ion exchange membrane, which comprises the following steps of 1, analyzing raw material liquid, testing the content of potassium hydroxide, the content of organic matters (dye) and the density of the raw material liquid in the raw material liquid; 2. filtering the raw material liquid; 3. setting flow rate, including setting feed liquid flow rate, setting water inlet flow rate and setting flow rate ratio; 4. and (4) analyzing the residual liquid and the recovered liquid, namely testing the mass fractions of potassium hydroxide and organic matters in the residual liquid, the mass fractions of potassium hydroxide and organic matters in the recovered liquid and the recovery rate of potassium hydroxide.

In a laboratory, after analyzing a raw material liquid, setting the flow rate of feeding (bottom in and top out) and the flow rate of water (top in and bottom out) according to the property of the raw material liquid through an alkali filter, starting a peristaltic pump, and taking residual liquid and recovered liquid every 0.5h for analysis to obtain purified and concentrated potassium hydroxide. The process is shown in fig. 1 and 2.

In order to better illustrate the preparation process of the present invention, the following specific examples are further described in detail.