JPH0221904A - High-temperature adsorption treatment device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Objective of the Invention] (Industrial Application Field) The present invention is directed to the treatment of copper, iron, etc. eluted from piping systems, heat exchangers, etc. contained in high-temperature cooling water of fuel cells. This invention relates to a high temperature adsorption treatment device for capturing heavy metal corrosion products.

(Prior art) A fuel cell generates electricity by causing hydrogen and oxygen to slowly react in a reactor using a catalyst, and the chemical energy of the hydrogen and oxygen used as fuel is directly converted into electrical energy. It is more efficient than other power generation methods.

In this case, electricity is generated while producing water through the reaction between hydrogen and oxygen, but at the same time heat is also generated, so in order to maintain high power generation efficiency, the temperature inside the reaction vessel must be kept at 160-160℃.
It is necessary to maintain the temperature at 230°C, and cooling water is constantly flowing into the reactor. This cooling water is 5 to 10 degrees Celsius higher than the temperature inside the reactor.
Use a low one.

That is, it is a high temperature of 150 to 225°C. Corrosion products of heavy metals such as copper or iron are leached into the cooling water from the inner walls of cooling pipes and other piping, joints, tanks, heat exchangers, etc. Further, due to the structure of the fuel cell, a potential is applied to the cooling pipes and their joints, which not only accelerates corrosion but also tends to cause heavy metal corrosion products to attach or accumulate. This cooling water flows through a circulation channel, and if the treatment continues for a long time, adhesion and deposition will progress, clogging some of the cooling pipes and their joints, making the temperature distribution inside the reactor uneven, and reducing the power generation efficiency. and shorten battery life.

In order to suppress the adhesion and accumulation of heavy metal corrosion products to the cooling pipes and joints, it is necessary to maintain the quality of the cooling water at a high purity. Conventionally, some of this cooling water was taken out of the circulation system,
After the temperature was lowered to 40 to 60°C using a heat exchanger (cooler), low-temperature purification was performed using an ion exchange resin.

However, low-temperature purification using ion exchange resin causes a large energy loss, so this amount is reduced to 10% of the amount of circulating cooling water.
% or more was not practical and could not achieve sufficient purification. Therefore, it is desired to be able to remove heavy metal corrosion products from cooling water at high temperatures.

The present inventors have confirmed through experiments that manganese dioxide is optimal as a high-temperature adsorption filter material that can be applied to this treatment. It was also confirmed that electrolytic manganese dioxide produced by electrolysis is suitable as this manganese dioxide adsorption filter material.

(Problem to be Solved by the Invention) However, since this electrolytic manganese dioxide is produced by electrolysis of manganese sulfate, the block contains 1.5% or less (average 1%) of sulfate. The sulfate in this electrolytic manganese dioxide is absorbed by high-temperature water (such as fuel cell cooling water).
(150-225°C), it is eluted to become sulfuric acid H2SO4. If sulfuric acid is eluted into cooling water, it will corrode piping, fittings, tanks, etc., so sulfate must be completely removed before use.

An object of the present invention is to provide a high-temperature adsorption device that uses electrolytic manganese dioxide as a high-temperature adsorption filter material after completely removing sulfates to prevent corrosion caused by eluted sulfates.

[Structure of the invention]

(Means for Solving the Problems) The high-temperature adsorption treatment apparatus according to the present invention uses electrolytic manganese dioxide in which sulfate is eluted by flowing high-temperature pure water as an adsorption filter medium.

(Function) In the present invention, electrolytic manganese dioxide from which sulfates have been removed is used as an adsorption filter material, so sulfates do not elute into the high-temperature water to be treated, become sulfuric acid, and corrode various parts. It is possible to adsorb and treat heavy metals contained in

(Example) First, the results of a study on the removal of sulfate from electrolytic manganese dioxide will be explained. In the experiment, the temperature was 100℃ and 150℃.
The elution of sulfuric acid with respect to each type of pure water at °C and 200 °C was verified. The results are shown in FIG. From FIG. 2, sulfate in electrolytic manganese dioxide is eluted in pure water at 100°C.

It was confirmed that this elution amount decreased over time and finally stopped elution. Next, when the electrolytic manganese dioxide treated at 100°C was immersed in pure water at 150°C, no sulfate elution occurred. However, 200℃
It was confirmed that sulfate was eluted again in pure water.

This means that the sulfate in electrolytic manganese dioxide is
However, the entire amount is not eluted, and the remaining sulfate is eluted with pure water at about 200°C.

As a result of studying the above results, the present inventors found that as a preferable example for removing sulfate from electrolytic manganese dioxide, after eluting as much of the sulfate as possible in pure water at 100°C, the Provide for elution of the remainder in pure water. Although elution can be carried out in pure water at 200°C or higher from start to finish, the high temperature and pressure required will significantly increase equipment costs and require less energy compared to treatment with 100°C pure water. Loss is not a great idea.

An embodiment of the present invention is shown in FIG. 1 below. 1 is a reactor,
The outlet side of the built-in cooling pipe 2 is connected to a gas-liquid separator 3. A cooling water outlet pipe 4 from the gas-liquid separator 3 is connected to a circulation pump 5 and further connected to a high-temperature adsorption treatment tower 7 via an on-off valve 6.

This high-temperature adsorption treatment tower 7 contains electrolytic manganese dioxide as a high-temperature adsorption filter material. The outlet pipe 8 of the high-temperature adsorption treatment tower 7 is connected to the cooling 4W2 population via an on-off valve 9, thereby forming a cooling water circulation system. Further, the cooling water outlet pipe 4 is branched, and an example of the branch is an on-off valve lO.
After connecting to a cooler 11 via a cooler 11, it is connected to a low temperature purifier 12 made of ion exchange resin or the like. An outlet pipe 13 of the low temperature purifier 12 is connected to the gas-liquid separator 3 via a pump 14 and a heater 15. Further, the outlet pipe 8 of the high temperature adsorption tower 7 is also branched, and the branch side is connected to a cooler 17 via an on-off valve 16. The outlet pipe 18 of this cooler 17 is connected to a purifier 19 made of ion exchange resin or the like, and the outlet pipe 20 is connected to a pump 24. Heater 21. It is connected to the inlet pipe 23 of the high temperature adsorption tower 7 via the on-off valve 22.

In the above configuration, during operation, the on-off valves 6, 9.10 are opened and the on-off valve 16.22 is closed. Cooling water containing heavy metal corrosion products generated therefrom passes through the cooling pipe 2 in the reactor 1, the gas-liquid separator 3, and various piping, and is sent to the high-temperature adsorption treatment tower 7 by the circulation pump 5. The high temperature adsorption treatment tower 7 contains electrolytic manganese dioxide for adsorption treatment of these heavy metal corrosion products. It has been confirmed that this electrolytic manganese dioxide adsorbs heavy metals in high-temperature heat such as fuel cell cooling water extremely efficiently.

Note that this electrolytic manganese dioxide cannot adsorb anything other than heavy metals, for example, anions such as cQ-, 5ob-, etc., so low-temperature purification is also required. That is, a part of the cooling water in the circulation system is taken out from the on-off valve 10 and sent to the cooler 11.
After the temperature is lowered to 0 to 60°C, treatment is performed using a low-temperature purifier 12 such as an ion exchange resin. This treated liquid is pressurized by a pump 14 and heated by a heater 15, and then returned to the gas-liquid separator 3.

Here, since electrolytic manganese dioxide contains sulfate, the following sulfate removal is performed as a pretreatment for performing the high-temperature adsorption treatment of heavy metal corrosion products in the cooling water. The on-off valves 6 and 9.10 are closed, the on-off valve 16.22 is opened, and the purified water that has been ion-exchanged in the purifier 19 is pumped into the pump 2.
After pressurizing at step 4 and further raising the temperature to 100° C. using heater 21, it is supplied to high-temperature adsorption treatment tower 7 through inlet pipe 23 through on-off valve 22 (first step). In the high-temperature adsorption treatment tower 7, sulfate is eluted from electrolytic manganese dioxide with respect to pure water.

However, since pure water passes through it, the adsorption capacity of electrolytic manganese dioxide is not reduced. The pure water from which sulfuric acid has been eluted is sent to the outlet pipe 8. It passes through the on-off valve 16 and flows to the cooler 17, where 4
After the temperature is lowered to 0 to 60°C, it is purified in a purifier 19.

The treatment is continued in such a circulation system, and when sulfuric acid is no longer eluted into the 100°C pure water, the temperature of the pure water is raised to 200°C using the heater 21 (second step). These 20
When pure water at 0°C is passed through the high-temperature adsorption treatment tower 7, the sulfate that was not eluted into the pure water at 100°C is eluted from the electrolytic manganese dioxide again.

Since electrolytic manganese dioxide from which sulfates have been removed through pretreatment is used as a high-temperature adsorption filter material, corrosion of piping, tanks, joints, etc. due to sulfuric acid elution can be suppressed. Also,
Since the sulfate removal was carried out at 100°C as a first step and at 200°C as a second step,
Energy loss due to temperature rise and fall can be reduced compared to consistent implementation.

In the above embodiment, the high temperature treatment unit that removes heavy metal corrosion products in cooling water and the pretreatment unit that removes sulfate from electrolytic manganese dioxide are integrated.
The two may be separated and the electrolytic manganese dioxide from which sulfate has been removed in a pretreatment device may be charged into a high-temperature adsorption treatment device. In this case, the down time of the apparatus associated with pre-processing is shortened.

In addition, as mentioned above, the pretreatment device and the high temperature adsorption treatment device are separated, and the pretreatment device is further divided into the pretreatment device at 100°C and the high temperature adsorption treatment device.
It may be separated into a pretreatment device at 0°C.

The 100°C device uses normal pressure, so it is simple and has excellent operability. Processing at 200℃ is a high temperature.

Since equipment that can withstand high pressure is required, in order to pre-treat a large amount of electrolytic manganese dioxide, it is better to use separate processing equipment for 100°C and 200°C in terms of cost, processing time, and operability.

In the above embodiment, the first step was performed using pure water at 100°C, but pure water at 100°C or lower may be used.

However, since sulfate does not elute with pure water at room temperature (up to about 40°C), it is necessary to raise the temperature to about 60°C or higher. Of course, if the temperature of the pure water is low, the entire process will take a long time. Furthermore, the second step is not limited to pure water at 200°C, but may also be from 160 to 300°C. In other words, even if pure water of 150°C or lower is supplied to manganese dioxide after the first step, almost no sulfate elution occurs;
For pure water at about 60°C to 190°C, the elution of sulfate increases rapidly.

Of course, the higher the pure water temperature, the more active the sulfate elution becomes, but if the temperature exceeds 300°C, there is a possibility that the manganese dioxide itself will change in quality, so the temperature was set within the above range.

These values have been confirmed by the inventor through experiments.

Which of the above temperature ranges to adopt should be determined by considering processing time and efficiency.

In the above example, one high-temperature adsorption treatment tower was used, but it is also possible to use two towers, one tower performing high-temperature adsorption treatment of cooling water, and the other tower performing pretreatment of electrolytic manganese dioxide. good. In this case, if the high-temperature treatment performance deteriorates, continuous treatment can always be achieved by switching to the column that was on standby at the end of the pretreatment.

〔Effect of the invention〕

As explained above, according to the present invention, since the sulfate contained in the electrolytic manganese dioxide is removed as a pretreatment, it is possible to prevent corrosion of pipes, joints, tanks, etc. due to eluted sulfuric acid. 4゜

[Brief Description of the Drawings] Figure 1 is a system diagram showing an embodiment of the high temperature adsorption treatment apparatus according to the present invention, and Figure 2 is an example of the relationship between treatment time and elution concentration of sulfate contained in electrolytic manganese dioxide. FIG. 1... Reactor 2... Cooling pipe 3, gas-liquid separator 4... Cooling water outlet piping 5... Circulation pump
6, 9.10, 16.22...Opening/closing valve 7...High temperature adsorption treatment tower 8...Outlet piping 11.17...Cooler
12...Low temperature purifier 13...Outlet piping
14.24...Pump 15.21...Heater
18... Outlet piping 19... Purifier 20.
...Outlet piping 23...Inlet piping agent Patent attorney Nori Ken Yudo Daishimaru Ken C-dJ〕9g Ikapo Saiko (

Claims (1)

[Claims] In a high-temperature adsorption treatment device that removes heavy metal corrosion products such as copper and iron from the water to be treated, a high-temperature adsorption treatment tower containing an adsorption filter medium is provided in a flow path of high-temperature water to be treated, A high-temperature adsorption treatment apparatus characterized in that the adsorption filter medium is electrolytic manganese dioxide in which sulfate is eluted by flowing high-temperature pure water.