JPH08246811A - Fresh water generation and salt manufacture by waste energy - Google Patents

Abstract

PURPOSE: To prevent waste water from causing environmental disruption by generating fresh water and manufacturing salt by the use of waste energy without discharging the waste water. CONSTITUTION: Steam generated in a refuse incinerator heat recovery unit 1 drives a generator 3 through a steam turbine 2. It is condensed by a salt manufacturing unit 6 and fed back to the heat recovery unit. Sea water pressured by a sea water pump 4 is desalinated by a desalination unit 5. Residual sea water is separated into salt and fresh water by the salt manufacturing unit 6.

Description

Detailed Description of the Invention

[0001]

In the method of the present invention, when producing drinking water or other fresh water from seawater, heat and electric energy obtained by incineration and gasification of wastes are used as main energy sources, and residual seawater is used. It is a method of producing sodium chloride and other salts from sewage and not discharging residual seawater.

The effective use of waste energy is an important measure not only as an energy problem but also as a measure against global warming. Due to the problem of corrosion due to hydrogen chloride contained in waste and its corrosive substances, the temperature of steam is usually limited to 300 ° C when recovering heat from ordinary materials, and expensive materials should be used to obtain steam above that level. is necessary.

One of the strategies for effective utilization of waste energy is to apply it to processes specified at relatively low levels of temperature. Desalination of seawater is a field suitable for effective use of waste energy because it requires a large amount of heat at a relatively low level.

[0004]

2. Description of the Related Art In recent years, some cities have been forced to supply limited water throughout the year due to drought. Desalination of seawater is being considered because it takes many years to develop a water source, but it has not been realized due to the fear of destruction of the ecosystem due to the discharge of residual seawater after obtaining freshwater from seawater. . Also, since fossil fuels and electric power are used as energy sources, high costs are inevitable.

[0005]

EFFECTS OF THE INVENTION According to the method of the present invention, a city suffering from a water shortage produces salt together with fresh water by effectively utilizing the energy of the waste generated in the city, thereby reducing the environment without destroying the environment. You can get tap water at a cost.

[0006]

The process for obtaining waste energy used in the method of the present invention is recovery of incineration heat of waste, which is the most common method. It is also possible to recover the heat generated by incineration.

[0007] The desalination method of seawater includes any of the conventional desalination processes such as the flash evaporation method, the reverse immersion membrane, the effect tube and the like. The method for obtaining the salt from the residual seawater may be an ordinary concentration and crystallization method.

[0008]

[Example] In Figure 1, the capacity of incinerator heat recovery equipment is 2
Waste of 00T / D (heat value 2,700kcal / kg)
It has the ability to process and generate maximum power. The raw seawater is pumped up, enters the reverse osmosis membrane, and reaches 18,000 fresh water.
T / D and concentrated 22,000 T / D were separated into concentrated saline solution and residual seawater in an electrodialysis facility.
T / D was obtained. The residual seawater of 20,000 T / D is mixed with the raw seawater and the pressure is increased by a pump.

[0009]

According to the method of the present invention, there is no risk of environmental damage due to discharge of residual seawater. Further, the amount of raw seawater required to obtain the target fresh water is about 30 to 50% of that in the conventional method, and a drainage pipe is not required, so that raw seawater collection, drainage-related equipment costs, and power costs are greatly reduced. In addition, the salt obtained from the high-concentration residual seawater produced as a byproduct in the desalination facility has high purity and is edible.
It can be used for medicinal purposes and has high added value.

The method of the present invention makes it possible to obtain low-cost fresh water by utilizing the heat, steam, and electric power generated from the energy of waste which is not evaluated as the price of ordinary energy. Needless to say, the present invention also applies to the case where electric power or fossil fuel other than waste energy is used supplementarily.

[0011]

[Fig. 1] In Fig. 1, the steam generated in the waste incinerator heat recovery equipment (1) drives the generator (3) in the steam turbine (2) and is condensed in the salt making equipment (6) to recover the heat. Return to equipment. Electric power generated by the generator (3) drives the seawater pump (4). Seawater that has been boosted by the seawater pump is desalinated by the desalination facility. The residual seawater is separated into salt and fresh water by a salt-making facility. Residual seawater generated in the salt production equipment is mixed with seawater at the inlet of the seawater pump and sent to the desalination equipment.

[Brief description of drawings]

FIG. 1 is a flow diagram of a water / salt making system using waste energy.

[Explanation of symbols]

 1 Incinerator heat recovery facility 2 Steam turbine 3 Generator 4 Seawater pump 5 Desalination facility 6 Salt production facility

Claims (1)

[Claims] 1. When desalinating seawater to produce drinking water or other fresh water, heat and electric energy obtained by incineration of waste or gasification are used as the energy, and sodium chloride or other A method for producing fresh water and salt, which comprises producing salt and producing fresh water without discharging residual seawater.