JPS61153123A - Method for recovering alcohol from alcohol-containing air - Google Patents

Abstract

PURPOSE:To recover efficiently alcohol with a small number of stages, to improve the work environment, and to utilize effectively resources by heat- exchanging alcohol-contg. air in a building with air of reduced alcohol content, and then cooling the alcohol-contg. air with a refrigerant to condense the alcohol vapor. CONSTITUTION:Alcohol-contg. air in buildings 1A and 1B such as a sake storehouse is introduced by a blower 3 into the first-stage treating apparatus 5 consisting of a heat-pipe-system heat exchanger 51 and a cooler 52. The alcohol- contg. air is firstly heat-exchanged with a refrigerant in the heat pipe at a precooling part 511, and then cooled by the cooler 52. A part of the alcohol is condensed, and the condensate is recovered in an alcohol receiver 8 through discharge pipes 421 and 422 and a recovery line 43. Moreover, the air is similarly treated in the second-stage treating apparatus 6 consisting of a heat exchanger 61 and a cooler 62, and remaining alcohol is recovered. The air coming out from the cooler 62 is heat-exchanged with a heat medium at heating parts 612 and 512 through a return pipe 44 and heated. The heated air is returned to the buildings 1A and 1B.

Description

[Detailed description of the invention]

Field of the Invention The present invention relates to a method for recovering alcohol from alcohol-containing air existing in a building. This invention can be applied to various chemical factories, printing factories, liquor manufacturing/processing factories, storage facilities, etc. that handle alcohol (hereinafter simply referred to as "alcohol"), and can be used to prevent environmental pollution and improve the working environment. It is extremely useful for improving infrastructure and recovering and reusing resources.

[Conventional technology]

Alcohol vapors are generated during the production, use, or storage of alcohol. If such alcohol-containing air is directly discharged to the outside of the system, alcohol as an effective resource will be reduced, which will not only be uneconomical but also cause environmental pollution. Furthermore, if the alcohol concentration increases inside the building, it goes without saying that it is not a desirable working environment, and there is a risk that it will reach the explosive limit. Conventional methods for removing alcohol from such alcohol-containing air include a cleaning method using water or the like, and an adsorption method using granular or fibrous activated carbon. However, in the former case, removal is insufficient when the partial pressure of alcohol is low. In the latter method, when the adsorption capacity of activated carbon decreases, it is necessary to replace it with a new one. To regenerate and use it, a large amount of water vapor is blown into it to desorb the adsorbed alcohol, and the desorbed alcohol and water vapor are condensed, resulting in a large amount of dilute alcohol solution. As described above, the conventional method requires many steps and energy to regenerate and recover the adsorbent and alcohol, and is economically disadvantageous.

[Problems to be solved by the invention]

The purpose of the present invention is to solve the above-mentioned problems and provide a method that can efficiently recover alcohol from alcohol-containing air existing in a building in a few steps, thereby preventing environmental pollution and improving work efficiency. The aim is to improve the environment and use resources effectively. R Clothing Five Seals

[Means to solve the problem]

The alcohol recovery method of the present invention is a method for recovering alcohol from alcohol-containing air existing in a building, and includes a heat exchanger and a heat exchanger for exchanging heat between alcohol-containing air and air with a reduced alcohol content. Using at least one stage of treatment equipment consisting of a cooler for cooling the alcohol-containing air of the exchanger with a refrigerant, the alcohol-containing air led out from the building is introduced into the heat exchanger of the treatment equipment and then into the cooler. By this, alcohol vapor is condensed and recovered from the air, and the air with a reduced alcohol content is passed through the heat exchanger and then returned to the building for condensation and recovery.

[For use]

The alcohol-containing air is first precooled in the heat exchanger and further cooled in the cooler, and alcohol vapor is condensed and recovered from the air. Then, the cooled air with a reduced alcohol content undergoes heat exchange with new alcohol-containing air in a heat exchanger and returns to the building. in this way,
Alcohol recovery is carried out efficiently through a small number of simple steps, and the working environment can be improved in a short period of time. The recovery of alcohol takes place in a closed system formed by a building, such as a liquor store, in which alcohol-containing air is present, and at least one stage of processing equipment consisting of the heat exchanger and cooler described above. Therefore, during alcohol recovery, alcohol-containing air is not discharged outside the system, and problems such as environmental pollution do not occur. [Embodiment] The alcohols to be recovered in the present invention include methanol,
It is a lower aliphatic alcohol that may have a branched group with 1 to 5 carbon atoms, such as ethanol, propatool, and isopropatool, but it is especially useful for ethanol recovery in buildings where barreled whiskey etc. are stored for long periods of time. be. There is no particular limit to the alcohol concentration, 100001)l)
111 or higher, and alcohol can be recovered more effectively at higher concentrations, but alcohol can be recovered more effectively at higher concentrations, but alcohol at relatively lower concentrations, i.e., within the range of 1000 to 110000 pp. It is preferable to collect and remove. Although it is possible to use a normal shell-and-tube type heat exchanger constituting the processing apparatus, since heat exchange is performed between gases, the pressure loss (ΔP) becomes large. On the other hand, in the heat pipe type, both gases pass through the outside of the tube, so the problem of ΔP is much smaller.
The heat exchanger itself can be formed compactly, and the alcohol condensate can be easily recovered, which is preferable. In addition,
In the case of the shell-and-tube type, if alcohol-containing air is passed through the shell side, condensate can be recovered within the heat exchanger, and when it is passed through the tube side, a gas-liquid separator is installed on the outlet side. That's fine. Furthermore, in order to enhance the cooling effect, the tubes used in these heat exchangers are preferably provided with fins. The cooler may be of any type as long as the alcohol-containing air is indirectly cooled by a refrigerant, and in order to enhance the cooling effect, it is preferably equipped with fins, like the heat exchanger. The alcohol-containing air treatment device, which is composed of a heat exchanger and a cooler, is provided in one stage or in multiple stages. The number of stages is preferably determined based on the concentration of water vapor and alcohol vapor in the air to be treated, the capacity of the cooling device for cooling the refrigerant, etc. Particularly when the air contains a large amount of water vapor, the treatment equipment is multi-staged to remove most of the water vapor from the air by processing at a relatively high processing temperature in the first stage, and then in the second stage. Preferably, the alcohol is primarily recovered from the air by successive treatments at low temperatures. In this way, the occurrence of frost within the processing equipment can be reduced, and there is no fear that the condensate will freeze. By using multi-stage processing equipment, alcohols with different concentrations can be easily obtained. The cooling temperature for alcohol recovery is selected as appropriate depending on the alcohol concentration in the air to be treated and the goal of maintaining the alcohol concentration within the building, but usually O'C Below, preferably -10 to -
The temperature shall be 40°C. Next, the alcohol recovery method according to the present invention will be specifically explained with reference to the drawings. In FIG. 1, 1A and 1B are buildings such as liquor storage, and the alcohol-containing air that exists in them is
The blower 3 introduces the heat into the first stage processing device 5 which includes a heat exchanger 51 and a cooler 52 . The heat exchanger 51 is of the heat pipe type described above, and
Reference numeral 1 indicates a so-called thermal energy inflow section (hereinafter referred to as a "precooling section"), and numeral 512 indicates a so-called thermal energy release section (hereinafter referred to as a "heating section"). Alcohol-containing air is first passed from the supply line 41 to the precooling section 511.
There, it is precooled by heat exchange with the heat medium inside the heat pipe, and is subjected to first stage cooling in the cooler 52, where a part of the alcohol is condensed, and together with the condensed liquid in the precooling section 511, The alcohol is collected into the alcohol receiving tank 8 via the discharge pipes 421 and 422 and the collection line 43. The air whose alcohol content and temperature have been reduced by the first-stage cooling is then introduced into the second-stage processing device 6, which includes a heat exchanger 61 and a cooler 62. This introduced air is pre-cooled in the pre-cooling section 611 in the same manner as described above, and then subjected to second-stage cooling in the cooler 62, where the remaining alcohol is condensed, and together with the condensed liquid in the pre-cooling section 611, the detection tube 423 .424 and recovery line 43. The second-stage cooled air that comes out of the cooler 62 passes through the return line 44 and is successively heated in the heating sections 612 and 512, where its temperature is increased by heat exchange with the heat medium inside the heat pipe in the same way as described above. After that, it is returned to building 1A or 1B. Therefore, a part of the building is locally cooled and no condensation occurs inside the building. Further, in order to prevent the inside of the building from drying out, the air led out from the heating section 512 may be humidified by a humidifier (not shown) and then returned to the inside of the building. Note that 53 and 63 are the coolers 52, respectively.
．． 62 is a refrigerant cooling device. When the above method is carried out, so-called frost is generated in the processing equipment. The degree of frost generation varies depending on the humidity and alcohol concentration of the air being treated, as well as the temperature inside and outside the building, but a large amount occurs especially when the alcohol concentration is low and the humidity is high. Since the occurrence of frost is detected, for example, by an increase in the discharge pressure of the blower 3 caused by the adhesion of frost, defrosting may be performed when the pressure increases significantly or when the set pressure is reached. This defrosting process will be carried out using the heat contained in buildings, storage tanks, etc. For example, while the supply of refrigerant to the cooler 52, 62 is stopped, alcohol-containing air is
The air introduced from IIA or 1B to the processing device 5.6 and passed through there is circulated to the buildings 1A and 1B to melt the frost generated in the device. According to this method, there is no need for a separate device for defrosting, and once the blower discharge pressure has returned to normal, the alcohol recovery process will automatically start once the refrigerant supply to the cooler is restarted. I will do it. This defrosting does not need to wait for the blower discharge pressure to rise as described above, but the alcohol recovery step and the defrosting step may be performed at regular intervals by sequential operation using a timer or the like. [Example] In a building with an internal volume of 52,000 m3 (internal temperature 30°C),
Air containing ethanol vapor (ethanol concentration aoo
13.oppm> to the two-stage processing device shown in FIG. O
As a result of introducing the air at a rate of OONm3/hr, cooling it to -32°C, and removing the condensate, the air was returned to the building, and the ethanol concentration in the building decreased to below 1500 DE)Ill after 24 hours. The operating conditions for each part of the processing apparatus are as shown in FIG. The graph shown in FIG. 3 shows changes over time in the concentration of ethanol vapor in the building and the amount of ethanol recovered. In addition, the following table shows 1 after the start of processing.
This is the processing result for the time slot. Table line numbers a, b...
.correspond to line numbers a, b, . . . in FIG. 2, respectively. The recovery rate of ethanol reaches 81.3% in 24 hours, but about 60% of this recovery amount is achieved in a short period of 5 to 6 hours after the start of operation. Line number a b c Temperature (℃) 30
15 −7 molar flow m (kmo, l! /
Hr) 7″ -565,56→→engineering
A Ethanol 4.64 4.
41 3.07 Wed 9
．． 75 2.80 0.50 go
Total 579.94 572.7
6 569.13EIul flow 0 la <KVto1") Eng:z< 16384.2
= -Kipu C ethanol 213.7 203.
1 141.5 water 175.
6 50.4 9.0 go
Total 16773.5 16637.7
16534.7d e f
g-1,060,53→ → 0.10 0.05 → →5
66.72 566.14 → →
49.0 2/1.3 →
→1.9 0.9 → →
16435.1 16409.4 →
→And Plate Heishi According to the present invention, alcohol can be effectively recovered from alcohol-containing air with fewer steps and the working environment can be improved. By using multi-stage processing equipment, alcohols with different concentrations can be easily obtained. Furthermore, since the air after alcohol recovery is returned to the building, there is no risk of environmental pollution. In general, even if frost occurs inside the processing device, it can be easily defrosted without requiring a separate device.

[Brief explanation of drawings]

FIG. 1 is a flowchart showing an example of an apparatus implementing the present invention. FIG. 2 is an explanatory diagram showing the operating conditions of each part of the processing device in one embodiment of the present invention. FIG. 3 is a graph showing changes over time in the concentration of ethanol vapor in the building and the amount of ethanol recovered in the same Example. 1A, IB...Building 3...Blower 41...Supply line 43...Recovery line 44...Return line 5.6...Processing equipment (first stage, second stage) 51.61・
...Heat exchanger 52.62...Cooler 53.63...Cooling device 8...Alcohol tank Patent applicant Suntory Ltd. JGC Corporation

Claims (8)

[Claims] (1) A method for recovering alcohol from alcohol-containing air existing in a building, including a heat exchanger for exchanging heat between the alcohol-containing air and air with a reduced alcohol content, and the alcohol-containing air after heat exchange. The alcohol-containing air extracted from the building is introduced into the heat exchanger of the processing equipment, and then into the cooler to remove alcohol from the air. A method characterized in that the steam is condensed and recovered, and the air with a reduced alcohol content is returned to the building after passing through the heat exchanger. (2) The method according to claim 1, which uses a heat exchanger constituted by a heat pipe. (3) The method according to claim 2, which uses a heat exchanger in which the heat pipe has fins. (4) The method according to claim 1, which uses a cooler composed of fin tubes. (5) While the supply of refrigerant to the cooler is stopped, alcohol-containing air is introduced from the building to the processing equipment, and the air that has passed through the processing equipment is circulated back to the building to remove frost that has formed inside the processing equipment. The method according to any one of claims 1 to 4, wherein the supply of refrigerant to the cooler is then restarted to condense and recover alcohol vapor from the alcohol-containing air. (6) The method according to claim 5, wherein the defrosting operation is performed by detecting an increase in pressure within the processing device. (7) The method according to claim 5, wherein the operation of condensing and recovering the alcohol vapor and the operation of defrosting the inside of the processing device are repeatedly performed using a timer. (8) The method according to any one of claims 1 to 7, wherein the alcohol is an alcohol that may have a branched group having 1 to 5 carbon atoms.