JPS5820641B2 - Gas-stirred packed tower type liquid-liquid countercurrent continuous extraction device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a novel packed column type liquid-liquid countercurrent continuous extraction apparatus.

More specifically, in a packed tower type liquid-liquid countercurrent continuous extraction device, gas is introduced from the gas inlet provided at the bottom of the packed tower, and the gas bubbles rising up the packed tower agitate the liquid flowing countercurrently through the packed section. The present invention relates to a gas-stirred packed column type liquid-liquid countercurrent continuous extraction device which enhances the liquid-liquid contact effect and significantly improves the extraction efficiency.

Traditionally, liquid-liquid gravity countercurrent type continuous extraction equipment includes buckle towers, perforated plate extraction towers, packed towers, stirring type extraction towers that use stirring (e.g. rotating disk extraction towers), and extraction towers that use pulsation. Pulsating extraction towers (for example, perforated plate extraction towers or packed towers in which pulsation is applied to the liquid body, perforated plate extraction towers in which the perforated plate is vibrated, heavy liquid and light liquid in perforated plate extraction towers) A known method is one in which the supply of water is alternately and intermittently applied to alternately provide a pulsating flow.

However, ordinary baffle towers, perforated plate extraction towers, and packed towers have a problem of low extraction efficiency, and extraction towers that use stirring or pulsation can improve extraction efficiency considerably, but the equipment has many moving parts and is mechanically difficult. The problem is that it gets complicated.

If the equipment has many moving parts and the mechanism becomes complicated, equipment materials become a problem when processing corrosive liquids, and the equipment becomes extremely expensive or, in some cases, cannot be converted into equipment. Ru.

Furthermore, especially when airtightness is required, the large number of moving parts is disadvantageous.

However, the present inventors have conducted various studies in order to eliminate the problems with conventional liquid-liquid countercurrent continuous extraction devices and find a liquid-liquid countercurrent continuous extraction device with a simple mechanism and high extraction efficiency. In a packed column type liquid-liquid countercurrent continuous extraction device, gas is introduced from the bottom of the packed column and rises inside the packed column as bubbles, and the gas bubbles stir the liquid flowing countercurrently in the column. The present invention was achieved by discovering a completely new fact that the amount of energy can be significantly increased.

That is, the present invention provides a packed tower, a two-layer separation and rectification section provided at the lower part of the packed tower, a light liquid inlet, a heavy liquid outlet, a gas inlet,
Two-layer separation rectifier installed at the top of the packed tower, light liquid outlet,
a heavy liquid inlet and a gas outlet, connected to the heavy liquid outlet;
It consists of a regulator for adjusting the height of the interface between the light liquid separated in the upper two-layer separation and rectification section and the heavy liquid separated in the lower two-layer separation and rectification section, and lifts the liquid flowing countercurrently in the packed column. The present invention relates to a gas-stirred packed column-type liquid-liquid countercurrent continuous extraction apparatus, characterized in that it is configured to perform stirring using gas bubbles.

Next, the apparatus of the present invention will be explained with reference to the drawings.

FIG. 1 is a schematic cross-sectional view showing one embodiment of the gas-stirred packed column type liquid-liquid countercurrent continuous extraction apparatus of the present invention.

In FIG. 1, reference numeral 1 denotes a packed column, into which a packing material 2 is filled.

The upper and lower parts of the packed column 1 are respectively two-phase separation and rectification sections 3.
and 4.

A light liquid inlet 5, a heavy liquid outlet 6, and a gas port T are provided in the lower part of the packed column 1.

A light liquid outlet 8, a heavy liquid inlet 9 and a gas outlet 10 are provided in the upper part of the packed column 1.

The structure of the blowing part 7' of the gas man lower is not limited to (.

For example, it may be a single tube or may be provided with a perforated plate.

A regulator 11 for adjusting the height of the interface between the light liquid separated in the two-layer separation and rectification section 3 and the heavy liquid separated in the two-layer separation and rectification section 4 is connected to the heavy liquid outlet 6 via an appropriate tube 12. It is connected.

The heavy liquid flows out from an overflow port 13 provided in the regulator 11.

14 is a perforated plate that supports the filler, and 15 is a jacket for temperature regulation.

The extraction operation using the apparatus of the present invention is carried out as follows.

A heavy liquid (for example, a solution containing a solute (extractable material)) is introduced into the upper part of the packed column 1 through the heavy liquid inlet 9, and a light liquid (for example, an extraction solvent) is introduced into the lower part of the packed column 1 through the light liquid inlet 5. death,
The heavy liquid and the light liquid are made to flow countercurrently in the packed section (the section filled with the packing material 2) in the packed column 1.

Usually, the extraction solvent is used as a continuous phase and the solution to be extracted is used as a dispersed phase.

At the same time, gas is introduced into the lower part of the packed tower 1 from the blowing part 7' of the gas man lower to generate gas bubbles, and the rising gas bubbles agitate the heavy liquid and light liquid flowing countercurrently through the filling part to form the heavy liquid. Enhances the contact effect of light liquids.

(As a result, extraction is carried out efficiently, and the light liquid flows out from the light liquid outlet 8 at the top of the packed column 1, and the heavy liquid flows through the heavy liquid outlet 6 at the bottom of the packed column 1 to the overflow port 13 of the regulator 11. More leakage.

When a light liquid is used as the extraction solvent, the extracted material is taken out by an appropriate means.

If extraction cannot be completed completely in one stage, multiple stages of the apparatus of the present invention are connected to perform the extraction operation.

The gas that has risen through the packed tower 1 is discharged from the gas outlet 10,
This material will be collected and reused as appropriate.

Any conventional filler can be used.

Examples include Raschig rings, McMahons, balls, broken pieces, Lessing rings, Gutdrow packings, Cannon packings, and Dexon packings made of various materials such as iron, stainless steel, glass, porcelain, plastic, and carbon.

As the gas, any gas can be used as long as it is inert to the liquid used and does not dissolve very much, such as nitrogen gas, air, etc.

The amount of gas introduced varies depending on the filler used, but the effect of the amount introduced on the extraction efficiency is relatively small, and the amount is appropriately adjusted from a very small amount to a range that does not cause flushing.

Generally, in a liquid-liquid countercurrent continuous extraction device, in order to increase extraction efficiency, it is necessary to increase the liquid-liquid contact interface and make the flow of the liquid as close to a piston flow as possible.

Focusing on the flow of liquid, the dispersed phase has a flow velocity distribution that is relatively similar to a piston flow, but the continuous phase tends to have a completely mixed flow, and this tendency increases when the flow rate of the continuous phase is small compared to the hold-up amount. .

Therefore, in order to increase extraction efficiency, it is important to appropriately select the flow rate of the continuous phase for the packing material used.

One of the guidelines is to refer to the following experimental results.

Figure 2 is a schematic cross-sectional view of the experimental apparatus, and in the same figure, 2
1 is a packed tower, the packed tower 21 is filled with a packing material 22, the lower part of the packed tower 21 is provided with a gas port 23 and a liquid inlet or outlet 24', and the upper part of the packed tower 21 is provided with a gas port 23 and a liquid inlet or outlet 24'. An outlet 25 and a liquid outlet or inlet 26 are provided.

The height of the packing section is 1000mm, and the inner diameter of the column is 26.27ft.
It was set as 1L.

A concentration pulse is applied to the water introduced from the liquid inlet 24 or 26, and the response at the liquid outlet 26 or 24 is measured, and the maximum concentration and the temporal flooring of the 115 concentration θ are determined.
(115h) (min) and liquid flow rate (”/cA-m
In ) was determined by changing the type of filler, gas flow rate, and liquid flow direction as shown in the following table.

The results are shown in the graphs of Figures 3-6. Note that nitrogen gas was used as the gas, and the concentration pulse was given using 5% saline.

Therefore, it is more preferable to select the flow rate of the continuous phase within a range that does not significantly deviate from the piston flow, with reference to the results shown in FIGS. 3 to 6.

The reason why the extraction efficiency of the gas-stirred packed column liquid-liquid countercurrent continuous extraction apparatus of the present invention is significantly different is that the filtrate-liquid contact interface in the packing section is disturbed by gas bubbles rising inside the column, and the area This is presumed to be due to the fact that, although the flow rate increases significantly, the liquid flow is not significantly influenced by gas agitation in the continuous phase as well as in the dispersed phase, and maintains a flow velocity distribution close to that of a piston flow over a relatively wide flow rate range.

Although the extraction apparatus of the present invention has an extremely simple configuration in which a gas inlet and outlet is provided in a conventional packed column, it has the remarkable effect of significantly increasing extraction efficiency, and is extremely industrially advantageous. Useful.

Next, the present invention will be explained with reference to Examples and Comparative Examples.

Note that % in the examples is % by weight. Example 1 and Comparative Example In the apparatus shown in FIG.
A packed tower 1 having a diameter of mφ and packed with crushed coal having a particle size of 2000 to 4760 μm to a packing height of 820 μm was used.

Using the above apparatus, an aqueous acetic acid solution (heavy liquid) with an acetic acid concentration of 5.1% was extracted with ethyl acetate (light liquid) using ethyl acetate as a continuous phase.

Both the heavy liquid and the light liquid are supplied in fixed amounts using metering pumps, and the heavy liquid is supplied from the heavy liquid outlet 6 so that the height of the separation interface of both liquids does not change in the two-phase separation and rectification sections 3 and 4. (The same applies to the following examples).

An acetic acid aqueous solution was supplied from the heavy liquid inlet 9 at a rate of 8.8 ml/min, while ethyl acetate was supplied from the light liquid inlet 5 at a rate of 11.9 ml/min.
The extraction operation was carried out continuously by supplying nitrogen gas at a rate of 7/ml/min, and nitrogen gas at a rate of 47 ml/min from a gas manifold.

As a result, the acetic acid concentration in the acetic acid aqueous solution obtained from the heavy liquid outlet 6 was 0.7%, while the acetic acid concentration in the ethyl acetate obtained from the light liquid outlet 8 was 3.6%, and the extraction rate of acetic acid was 86%. It was .7%.

This corresponds to approximately 6 batch extraction operations.

For comparison, using the above device, acetic acid aqueous solution was added at 12.1 ml/min and ethyl acetate was added at 8.4 ml/min without flowing nitrogen gas. An experiment similar to the above was conducted by supplying the liquid at a rate of /min.

As a result, the acetic acid concentration in the acetic acid aqueous solution obtained from the heavy liquid outlet 6 was 2.3%, while the acetic acid concentration in the ethyl acetate obtained from the light liquid outlet 8 was 4.3%, and the extraction rate of acetic acid was 59%. It was .2%.

Example 2 A similar extraction experiment was conducted using the same apparatus as in Example 1, except that a 5 mmφ x 7 mvt glass Raschig ring was used as the filler.

Note that the flow rate of the acetic acid aqueous solution was 13.5 rrLl/min,
The flow rate of ethyl acetate is 11. Oml/min, and the flow rate of nitrogen gas was 4Qml/min.

As a result, the acetic acid concentration in the acetic acid aqueous solution obtained from the heavy liquid outlet 6 was 1.7%, while the acetic acid concentration in the ethyl acetate obtained from the light liquid outlet 8 was 40%, and the extraction rate of acetic acid was 69.5. %Met.

Example 3 In the apparatus shown in FIG.
A packed tower 1 having a diameter of mφ and filled with crushed glass pieces having a particle size of 2,830 to 4,760 μm to a filling height of 360 μm was used.

Using the above-mentioned apparatus, an acetic acid aqueous solution with an acetic acid concentration of 4.9% (
The heavy liquid) was extracted with water-saturated n-butanol (light liquid) as a water-saturated n-butanol continuous phase.

An acetic acid aqueous solution was supplied from the heavy liquid inlet 9 at a rate of 8.7 ml/mzn, while water-saturated n-butanol was supplied from the light liquid inlet 5 at a rate of 8.91 rL1. Nitrogen gas was supplied at a rate of 45 ml/min from a gas manifold, and the extraction operation was carried out continuously.

As a result, the acetic acid concentration in the acetic acid aqueous solution obtained from the heavy liquid outlet 6 was 0.45%, while the acetic acid concentration in the water-saturated butanol obtained from the light liquid outlet 8 was 2.6%, and the extraction rate of acetic acid was It was 91.2%.

Example 4 In the apparatus shown in FIG.
A packed tower 1 having a diameter of 00 mm and filled with coal crushed to a size of about 3.5 mm to a filling height of 1950 mm was used.

Using the above-mentioned apparatus, an acetic acid aqueous solution with an acetic acid concentration of 5.7% (
The heavy liquid) was extracted with ethyl acetate (light liquid) using ethyl acetate as the continuous phase.

An acetic acid aqueous solution was supplied from the heavy liquid inlet 9 at a rate of 104 ml/min, and ethyl acetate was supplied from the light liquid inlet 5 at a rate of 101 ml/min.
The extraction operation was carried out continuously by supplying nitrogen gas at a rate of 350111/min from a gas manifold.

As a result, the acetic acid concentration in the acetic acid aqueous solution obtained from the heavy liquid outlet 6 was 0.03%, while the acetic acid concentration in the ethyl acetate obtained from the light liquid outlet 8 was 3.9%, and the extraction rate of acetic acid was 99%. , 2%.

Example 5 Using the apparatus of Example 3, an acetic acid aqueous solution (acetic acid concentration approximately 10%) (heavy liquid) containing 3.2 x 10-mol/rnl of acetyl-L-methionine was continuously mixed with ethyl acetate. It was extracted as a phase.

An acetic acid aqueous solution was supplied from the heavy liquid inlet 9 at a rate of 6.7 ml/min, while ethyl acetate was supplied from the light liquid inlet 5 at a rate of 2.6 ml/min.
The extraction operation was carried out continuously by supplying nitrogen gas at a rate of 45 rnl/min from a gas manifold.

As a result, the concentration of acetyl-L-methionine in the acetic acid aqueous solution obtained from the heavy liquid outlet 6 was 2.8 x 10''
mol/rrtl, and on the other hand, the concentration of acetyl-L-methionine in ethyl acetate obtained from the light liquid outlet 8 is 6.9 x 10' mol/ml, and the extraction rate of acetyl-L-methionine is 93.2%. there were.

[Brief explanation of the drawing]

FIG. 1 is a schematic cross-sectional view showing an embodiment of the gas-stirred packed column type liquid-liquid countercurrent continuous extraction apparatus of the present invention, and FIG. 2 is a θ(1
15h) (min) and liquid flow rate (ml/ctA-7I
Figures 3 to 6, which are schematic cross-sectional views of the experimental apparatus used to determine the relationship between lin and lin, are graphs showing the relationship between φ (115h) (min) and liquid flow rate (ml/cfIL-min). (Main symbols in the drawing), 1: Packed tower, 5: Light liquid inlet, 6:
Heavy liquid outlet, 7: Gas inlet, 8: Light liquid outlet, 9: Heavy liquid inlet, 10: Gas outlet.

Claims (1)

[Claims] 1 Packed tower, two-layer separation and rectification section provided at the bottom of the packed tower, light liquid inlet, heavy liquid outlet, and gas inlet, two-layer separation and rectification section provided at the top of the packed tower, light liquid outlet, heavy liquid inlet and a gas outlet, a regulator connected to the heavy liquid outlet for adjusting the height of the interface between the light liquid separated in the upper two-layer separation and rectification section and the heavy liquid separated in the lower two-layer separation and rectification section. 1. A liquid-liquid countercurrent continuous extraction device of a gas-stirred packed column type, characterized in that the liquid flowing countercurrently in the packed column is agitated by rising gas bubbles.