1. A recycling system and a recycling device for gas-making condensate are characterized by comprising a pretreatment unit, a tempering unit, a concentration unit, a crystallization unit, a product water refining unit and a waste gas treatment unit. The waste water sequentially passes through a pretreatment unit, a conditioning unit, a concentration unit, a crystallization unit and a product water refining unit to generate product water and solid salt, waste gas generated in the process is discharged after being treated by a waste gas treatment unit, the pretreatment unit comprises one or more than one of a regulating tank, a resin exchanger, a flocculation reactor, a filter and an oxidation reactor, the tempering unit comprises one or more than one of a reaction tank, a degassing tower and a degassing membrane, the gas content of the wastewater after passing through the tempering unit is less than 200mg/L, the concentration unit adopts falling film evaporation, membrane technology or the combination technology of the two technologies for concentration, the mass fraction of the concentrated solution is less than 50 percent, the crystallization unit comprises a crystallizer and a miscellaneous salt crystallizer, and the product water refining unit comprises one or more of deamination, oxidation, activated carbon filtration, reverse osmosis, nanofiltration and degassing.

2. The recycling system and device for condensate of gas making as claimed in claim 1, wherein the resin exchanger in the pre-treatment unit is one or more of anion resin exchanger, cation resin exchanger, chelating resin exchanger, and adsorption resin exchanger.

3. The recycling system and device for gas making condensate as claimed in claim 1, wherein the flocculation reactor in the pretreatment unit is one or more of a high density sedimentation tank, a medium loading sedimentation tank, and an air flotation tank.

4. The recycling system and device for gas making condensate as claimed in claim 1, wherein the filter in the pre-treatment unit is one or more of activated carbon filter, multi-media filter, micro-filtration and ultra-filtration.

5. The recycling system and device for condensate of gas making as claimed in claim 1, wherein the oxidation reactor in the pretreatment unit is one or more of aeration tank, ozone oxidation reactor, ozone catalytic oxidation reactor, Fenton reactor, electro-catalytic reactor, and iron-carbon micro-electrolysis reactor.

6. The recycling system and device for gas making condensate as claimed in claim 1, wherein one or more of acid and alkali are added into the conditioning unit; the degassing tower adopts one or more of vacuum, air or water vapor to remove gas in the wastewater.

7. The recycling system and device for condensed liquid of gas making as claimed in claim 1, wherein the concentration unit employs falling film evaporation for concentration, the falling film evaporator can be one or more of vertical tube falling film evaporator, horizontal tube falling film evaporator and plate evaporator, and the process can be one or more of mechanical vapor compression falling film evaporation process, thermal vapor compression falling film evaporation process and external steam supply falling film evaporation process.

8. The recycling system and device for gas making condensate as claimed in claim 1, wherein the concentration unit employs membrane technology for concentration, and the membrane technology may be one or more of nanofiltration, reverse osmosis, electrodialysis, forward osmosis, and membrane distillation.

9. The system and apparatus as claimed in claim 1, wherein the crystallization unit is one or more of a forced circulation crystallizer, a DTB crystallizer, an OSLO crystallizer, a mixed salt crystallizer, a rake dryer, and a spray dryer.

10. The system and apparatus as claimed in claim 1, wherein the solid salt is one or more of ammonium chloride, ammonium sulfate, ammonium nitrate, ammonium phosphate, sodium carbonate decahydrate, sodium carbonate monohydrate, sodium bicarbonate, sodium chloride, and sodium sulfate.

11. The recycling system and device for gas making condensate as claimed in claim 1, wherein the waste gas treatment unit can adopt one or more of solution absorption, solid phase adsorption and combustion method.

Background

The high-salinity wastewater generally comes from the production processes of industries such as petrochemical industry, coal chemical industry, mining industry, power plants and the like, and after the traditional water treatment, inorganic salts in water are gradually concentrated, so that the formed wastewater has high inorganic salt content and also contains wastewater with high COD (chemical oxygen demand), ammonia nitrogen and the like.

Zero Discharge of Liquid (ZLD) refers to the concentration of Liquid wastewater to generate recycled water by a specific process technology, minimizing the Discharge of wastewater, and concentrating the salt and impurities in the wastewater to a solid. The liquid zero discharge technology comprehensively applies the processes of physical, chemical, biochemical, membrane separation, evaporative crystallization and/or drying and the like, and realizes the recovery and utilization of water.

The gas-making condensate contains a large amount of ammonia gas, carbon dioxide, COD, fluoride ions and other substances. Aiming at the treatment of the condensate, in order to meet the requirements of environmental protection and standard emission or zero emission, the traditional pretreatment, deamination, biochemistry, membrane concentration, evaporative crystallization and other processes are often needed, the process flow is long, and the investment and operation cost is high. Particularly, with the stricter environmental protection standards, the longer the traditional water treatment process unit is, the poorer the adaptability along with the fluctuation of water quality and water quantity is, and the long-term stable operation is difficult. Therefore, according to the water quality characteristics, the process unit is short, the equipment investment is low, and the process which is stable and reliable in operation and suitable for treating the gas-making condensate has important practical significance.

Disclosure of Invention

The invention aims to provide a recycling system and a recycling device for gas-making condensate, which can effectively reduce the investment cost and the operation cost. The device comprises a pretreatment unit, a conditioning unit, a concentration unit, a crystallization unit, a product water refining unit and a waste gas treatment unit. The waste water passes through the pretreatment unit, the conditioning unit, the concentration unit, the crystallization unit and the product water refining unit in sequence to generate product water and solid salt, and waste gas generated in the process is discharged after being treated by the waste gas treatment unit. The system and the device are characterized in that compared with the traditional liquid zero-discharge process, the process flow is short, and the equipment investment and the operating cost are obviously reduced.

The object of the invention can be achieved by the following measures:

a recycling system and a recycling device for gas-making condensate are characterized by comprising a pretreatment unit, a tempering unit, a concentration unit, a crystallization unit, a product water refining unit and a waste gas treatment unit. The waste water sequentially passes through a pretreatment unit, a conditioning unit, a concentration unit, a crystallization unit and a product water refining unit to generate product water and solid salt, waste gas generated in the process is discharged after being treated by a waste gas treatment unit, the pretreatment unit comprises one or more than one of a regulating tank, a resin exchanger, a flocculation reactor, a filter and an oxidation reactor, the tempering unit comprises one or more than one of a reaction tank, a degassing tower and a degassing membrane, the gas content of the wastewater after passing through the tempering unit is less than 200mg/L, the concentration unit adopts falling film evaporation, membrane technology or the combination technology of the two technologies for concentration, the mass fraction of the concentrated solution is less than 50 percent, the crystallization unit comprises a crystallizer and a miscellaneous salt crystallizer, and the product water refining unit comprises one or more of deamination, oxidation, activated carbon filtration, reverse osmosis, nanofiltration and degassing.

Further, the resin exchanger in the pretreatment unit may be one or a combination of more than one of an anion resin exchanger, a cation resin exchanger, a chelate resin exchanger, and an adsorption resin exchanger.

Further, the flocculation reactor in the pretreatment unit can be one or a combination of more than one of a high-density sedimentation tank, a medium loading sedimentation tank and an air floatation tank.

Further, the filter in the pretreatment unit can be one or more of activated carbon filter, multi-media filter, micro-filtration and ultra-filtration.

Further, the oxidation reactor in the pretreatment unit can be one or a combination of more than one of an aeration tank, an ozone oxidation reactor, an ozone catalytic oxidation reactor, a Fenton reactor, an electro-catalytic reactor and an iron-carbon micro-electrolysis reactor.

Further, one or more of acid and alkali or a combination of more than one of acid and alkali is added into the tempering unit; the degassing tower adopts one or more of vacuum, air or water vapor to remove gas in the wastewater.

Further, the concentration unit adopts falling film evaporation for concentration, the falling film evaporator can be one or a combination of more than one of a vertical tube falling film evaporator, a horizontal tube falling film evaporator and a plate evaporator, and the process can be one or a combination of more than one of a mechanical vapor compression falling film evaporation process, a thermal vapor compression falling film evaporation process and an externally supplied vapor falling film evaporation process.

Further, the concentration unit adopts a membrane technology for concentration, and the membrane technology can be one or a combination of more than one of nanofiltration, reverse osmosis, electrodialysis, forward osmosis and membrane distillation.

Further, the crystallization unit may adopt one or more of evaporation crystallization, cooling crystallization and melt crystallization, the crystallizer may be a forced circulation crystallizer, a DTB crystallizer and an OSLO crystallizer, and the miscellaneous salt crystallizer may be one or more of a forced circulation crystallizer, a rake dryer and a spray dryer.

Further, the solid salt refers to one or a combination of more than one of ammonium chloride, ammonium sulfate, ammonium nitrate, ammonium phosphate, sodium carbonate decahydrate, sodium carbonate monohydrate, sodium bicarbonate, sodium chloride and sodium sulfate.

Further, the waste gas treatment unit can adopt one or more of solution absorption, solid phase adsorption and combustion methods.

Compared with the prior art, the invention has the advantages that: the system and the device are characterized by short process flow, low investment and operation cost and higher economic value of the solid salt.

Drawings

Fig. 1 is a schematic diagram of the overall connection of the kit of the system and the apparatus of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The present invention will be described in further detail with reference to examples and specific embodiments.

Referring to the attached drawings, the recycling system and device of the gas making condensate are characterized by comprising a pretreatment unit, a tempering unit, a concentration unit, a crystallization unit, a product water refining unit and a waste gas treatment unit. The waste water sequentially passes through a pretreatment unit, a conditioning unit, a concentration unit, a crystallization unit and a product water refining unit to generate product water and solid salt, waste gas generated in the process is discharged after being treated by a waste gas treatment unit, the pretreatment unit comprises one or more than one of a regulating tank, a resin exchanger, a flocculation reactor, a filter and an oxidation reactor, the tempering unit comprises one or more than one of a reaction tank, a degassing tower and a degassing membrane, the gas content of the wastewater after passing through the tempering unit is less than 200mg/L, the concentration unit adopts falling film evaporation, membrane technology or the combination technology of the two technologies for concentration, the mass fraction of the concentrated solution is less than 50 percent, the crystallization unit comprises a crystallizer and a miscellaneous salt crystallizer, and the product water refining unit comprises one or more of deamination, oxidation, activated carbon filtration, reverse osmosis, nanofiltration and degassing.

Further, the resin exchanger in the pretreatment unit may be one or a combination of more than one of an anion resin exchanger, a cation resin exchanger, a chelate resin exchanger, and an adsorption resin exchanger.

Further, the flocculation reactor in the pretreatment unit can be one or a combination of more than one of a high-density sedimentation tank, a medium loading sedimentation tank and an air floatation tank.

Further, the filter in the pretreatment unit can be one or more of activated carbon filter, multi-media filter, micro-filtration and ultra-filtration.

Further, the oxidation reactor in the pretreatment unit can be one or a combination of more than one of an aeration tank, an ozone oxidation reactor, an ozone catalytic oxidation reactor, a Fenton reactor, an electro-catalytic reactor and an iron-carbon micro-electrolysis reactor.

Further, one or more of acid and alkali or a combination of more than one of acid and alkali is added into the tempering unit; the degassing tower adopts one or more of vacuum, air or water vapor to remove gas in the wastewater.

Further, the concentration unit adopts falling film evaporation for concentration, the falling film evaporator can be one or a combination of more than one of a vertical tube falling film evaporator, a horizontal tube falling film evaporator and a plate evaporator, and the process can be one or a combination of more than one of a mechanical vapor compression falling film evaporation process, a thermal vapor compression falling film evaporation process and an externally supplied vapor falling film evaporation process.

Further, the concentration unit adopts a membrane technology for concentration, and the membrane technology can be one or a combination of more than one of nanofiltration, reverse osmosis, electrodialysis, forward osmosis and membrane distillation.

Further, the crystallization unit may adopt one or more of evaporation crystallization, cooling crystallization and melt crystallization, the crystallizer may be a forced circulation crystallizer, a DTB crystallizer and an OSLO crystallizer, and the miscellaneous salt crystallizer may be one or more of a forced circulation crystallizer, a rake dryer and a spray dryer.

Further, the solid salt refers to one or a combination of more than one of ammonium chloride, ammonium sulfate, ammonium nitrate, ammonium phosphate, sodium carbonate decahydrate, sodium carbonate monohydrate, sodium bicarbonate, sodium chloride and sodium sulfate.

Further, the waste gas treatment unit can adopt one or more of solution absorption, solid phase adsorption and combustion methods.

When the system and the device are used in specific operation:

example 1: a stream of gas-making condensate of a certain factory needs to be subjected to liquid zero-discharge treatment, the wastewater enters a conditioning unit after being subjected to defluorination and COD removal by a pretreatment unit, sulfuric acid is added, the pH value is adjusted to be 4-5.5, then the wastewater enters a degassing tower for degassing, the gas is removed, then the wastewater enters a mechanical vapor compression falling-film evaporator for evaporation and concentration until the mass fraction is 30%, then the wastewater enters an evaporation crystallizer for evaporation and crystallization to obtain solid ammonium sulfate, and meanwhile, a stream of concentrated solution discharged from the evaporation crystallizer is subjected to salt removal crystallizer to obtain miscellaneous salts. And (4) passing the distillate through a deamination resin and an active carbon filter to obtain product water. And waste gas generated in the processes of the pretreatment unit and the conditioning unit is absorbed and treated by alkali liquor and then is discharged.

Example 2: a stream of gas-making condensate liquid of a certain factory needs to be subjected to liquid zero-emission treatment, the wastewater enters a conditioning unit after being subjected to cyanogen and fluorine removal by a pretreatment unit, hydrochloric acid is added, the pH value is adjusted to be 4-5.5, then the wastewater enters a degassing tower to be degassed and degassed by two stages of vacuum and air, the degassed wastewater enters a thermal vapor compression falling film evaporator to be evaporated and concentrated to 50% of mass fraction, then the wastewater enters a cooling crystallizer to be cooled and crystallized to obtain solid salt ammonium chloride, one part of cooling mother liquor returns to the falling film evaporation unit, and the other part of the cooling mother liquor is discharged outside to remove impurities and salt to obtain miscellaneous salts. And carrying out nanofiltration purification on the distillate to obtain product water. And waste gas generated in the process of the conditioning unit is absorbed and treated by a solid adsorbent and then is discharged.

Example 3: a stream of gas-making condensate in a certain factory needs to be subjected to liquid zero-discharge treatment, COD in the wastewater is removed through a pretreatment unit, the wastewater enters a tempering unit, sodium hydroxide is added, the pH value is adjusted to be 10-12, then a degassing membrane is adopted to remove gas, the removed gas enters an external steam-supplying falling film evaporator to be evaporated and concentrated to 30% by mass, then the wastewater enters a cooling crystallizer to be cooled and crystallized to obtain solid salt sodium carbonate decahydrate, one part of cooling mother liquor returns to the falling film evaporation unit, and the other part of cooling mother liquor is discharged outside the falling film evaporator to remove salt, so that miscellaneous salt is obtained. And filtering the distillate by active carbon to obtain product water. And waste gas generated in the process of the pretreatment unit is discharged after combustion treatment.

Example 4: a stream of gas-making condensate liquid of a certain factory needs to be subjected to liquid zero-emission treatment, the wastewater enters a conditioning unit after a pretreatment unit removes fluorine and suspended matters, sulfuric acid is added, the pH value is adjusted to be 4-5.5, then the wastewater enters a degassing tower to remove gas, the gas is removed, then reverse osmosis is adopted for concentration, the wastewater enters a mechanical falling film evaporator to be evaporated and concentrated to the mass fraction of 40%, then the wastewater enters a cooling crystallizer to be cooled and crystallized to obtain solid ammonium sulfate, one part of cooling mother liquor returns to a falling film evaporation unit, and the other part of the cooling mother liquor is discharged to a salt removing crystallizer to obtain miscellaneous salts. And mixing the reverse osmosis produced water and the distillate, and treating by deamination resin to obtain product water. And waste gas generated in the processes of the pretreatment unit and the conditioning unit is absorbed and treated by alkali liquor and then is discharged.

Example 5: a stream of gas-making condensate of a certain factory needs to be subjected to liquid zero-discharge treatment, the wastewater enters a conditioning unit after impurities are removed by a pretreatment unit, sulfuric acid is added, the pH value is adjusted to be 4-5.5, then the wastewater enters a degassing tower to be subjected to gas removal, reverse osmosis is firstly adopted to concentrate the wastewater after the gas removal, electrodialysis is then adopted to concentrate the wastewater to the mass fraction of 18%, then the wastewater enters an evaporation crystallizer to be subjected to evaporation crystallization to obtain solid ammonium sulfate, and meanwhile, a stream of concentrated solution discharged from the evaporation crystallizer is subjected to impurity salt removal crystallizer to obtain impurity salt. And mixing the electrodialysis fresh water and the distillate, and performing reverse osmosis purification to obtain product water. And waste gas generated in the processes of the pretreatment unit, the conditioning unit and the concentration unit is absorbed and treated by a solid adsorbent and then is discharged.

When the invention is actually used, the defects of long whole process flow and high investment and operation cost in the gas making condensate water treatment process can be solved; the gas making condensate recycling system and device provided by the invention can also solve the following problems existing in the conventional common gas making condensate water treatment process: with the stricter environmental protection standards, the longer the traditional common water treatment process units are made, the poor adaptability of the traditional common water treatment process units along with the fluctuation of water quality and water quantity, and the long-term stable operation is difficult.

Meanwhile, the system and the device have the characteristics of short process flow, low investment and operation cost and higher economic value of the solid salt.

The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, various changes and modifications can be made without departing from the inventive concept of the present invention, and these changes and modifications are all within the scope of the present invention.