阅读说明：本技术 一种铁合金尾气的处理方法及处理系统 (Treatment method and treatment system for ferroalloy tail gas ) 是由 夏楠 王晓东 撒治富 赵凌 费宏岩 于 2021-08-13 设计创作，主要内容包括：本发明特别涉及一种铁合金尾气的处理方法及处理系统,属于尾气处理技术领域,方法包括：将铁合金尾气进行预处理,获得符合发酵条件的洁净气体；将所述洁净气体进行生物发酵处理,获得含菌体醪液和不含菌体清液；将所述含菌体醪液进行浓缩,获得重液和轻液；将所述重液进行干燥,获得产品蛋白饲料；将所述不含菌体清液和所述轻液进行混合,后进行蒸发,获得产品乙醇；将对环境有污染的铁合金工业尾气直接转化成清洁能源乙醇和高蛋白蛋白饲料,有效降低铁合金尾气对大气及周边环境的影响。(The invention particularly relates to a treatment method and a treatment system for ferroalloy tail gas, belonging to the technical field of tail gas treatment, wherein the method comprises the following steps: pretreating ferroalloy tail gas to obtain clean gas meeting fermentation conditions; carrying out biological fermentation treatment on the clean gas to obtain a mash containing thalli and a clear liquid without thalli; concentrating the mash containing the thalli to obtain heavy liquid and light liquid; drying the heavy liquid to obtain a product protein feed; mixing the clear liquid without thalli and the light liquid, and then evaporating to obtain a product ethanol; the ferroalloy industrial tail gas which pollutes the environment is directly converted into clean energy ethanol and high-protein feed, and the influence of the ferroalloy tail gas on the atmosphere and the surrounding environment is effectively reduced.)

1. A treatment method of ferroalloy tail gas is characterized by comprising the following steps:

pretreating ferroalloy tail gas to obtain clean gas meeting fermentation conditions;

carrying out biological fermentation treatment on the clean gas to obtain a mash containing thalli and a clear liquid without thalli;

concentrating the mash containing the thalli to obtain heavy liquid and light liquid;

drying the heavy liquid to obtain a product protein feed;

and mixing the clear liquid without the thalli and the light liquid, and evaporating to obtain a product ethanol.

2. The method for treating ferroalloy tail gas according to claim 1, wherein the step of pretreating ferroalloy tail gas to obtain clean gas meeting fermentation conditions comprises the following steps:

removing dust from the ferroalloy tail gas to obtain dust-free gas;

cooling the dust-free gas to obtain a suitable temperature gas;

tar removal is carried out on the gas with the proper temperature to obtain purified gas;

and deoxidizing and compressing the purified gas to obtain the clean gas meeting the fermentation conditions.

3. The method of claim 2, wherein the dust diameter of the non-dust-containing gas is less than 1 μm.

4. The method of claim 2, wherein the temperature of the hot gas is less than 30 ℃.

5. The method of claim 1, wherein the clean gas has an oxygen content of less than 1000ppm and a pressure of greater than 0.6 MPa.

6. A system for treating ferroalloy off-gas, the system comprising:

the pretreatment system is used for pretreating the ferroalloy tail gas to obtain clean gas meeting fermentation conditions;

the fermentation unit is communicated with the pretreatment system and is used for carrying out biological fermentation treatment on the clean gas to obtain a mash containing thalli and a clear liquid not containing thalli;

the concentration unit is communicated with the fermentation unit and is used for concentrating the mash containing the thalli to obtain heavy liquid and light liquid;

the protein drying unit is communicated with the concentration unit and is used for drying the heavy liquid to obtain a product protein feed;

and the distillation dehydration unit is respectively communicated with the fermentation unit and the concentration unit and is used for mixing the bacteria-free clear liquid and the light liquid and then evaporating to obtain a product ethanol.

7. The ferroalloy tail gas treatment system of claim 6, wherein the pretreatment system comprises:

the dust removal unit is used for removing dust from the ferroalloy tail gas to obtain dust-free gas;

the cooling unit is communicated with the dust removal unit and is used for cooling the dust-free gas to obtain a suitable temperature gas;

the decoking unit is communicated with the cooling unit and is used for removing tar from the gas with proper temperature to obtain purified gas;

and the deoxidation compression unit is communicated with the decoking unit and is used for deoxidizing and compressing the purified gas to obtain the clean gas meeting the fermentation conditions.

8. The ferroalloy tail gas treatment system of claim 6, further comprising:

and the tail gas treatment unit is communicated with the fermentation unit and is used for treating the tail gas generated by biological fermentation.

9. The ferroalloy tail gas treatment system of claim 6, further comprising:

and the sewage treatment unit is communicated with the distillation dehydration unit and is used for treating the wastewater generated by evaporation.

10. The ferroalloy tail gas treatment system of claim 6, further comprising:

and the ethanol storage unit is communicated with the distillation dehydration unit and is used for storing the product ethanol.

Technical Field

The invention belongs to the technical field of tail gas treatment, and particularly relates to a treatment method and a treatment system for ferroalloy tail gas.

Background

In the ferroalloy smelting industry, according to different product quality and quality requirements, a carbon reduction electric furnace is mainly adopted for refining, ferroalloy solution is continuously discharged from a taphole and is rich in CO and H₂And CO₂The equal-component tail gas is also continuously discharged in the electric furnace. In the prior art, the ferroalloy tail gas is mainly used for directly serving as a heat source to perform combustion power generation and the like, the energy utilization rate is low, and CO in the combustion tail gas is simultaneously combusted₂Dust, VOC and the like also cause certain pollution to the environment.

Disclosure of Invention

The application aims to provide a treatment method and a treatment system for ferroalloy tail gas, so that the ferroalloy tail gas is efficiently and cleanly utilized, and the pollution of the ferroalloy tail gas to the environment is further reduced.

The embodiment of the invention provides a treatment method of ferroalloy tail gas, which comprises the following steps:

pretreating ferroalloy tail gas to obtain clean gas meeting fermentation conditions;

carrying out biological fermentation treatment on the clean gas to obtain a mash containing thalli and a clear liquid without thalli;

concentrating the mash containing the thalli to obtain heavy liquid and light liquid;

drying the heavy liquid to obtain a product protein feed;

and mixing the clear liquid without the thalli and the light liquid, and evaporating to obtain a product ethanol.

Optionally, the iron alloy tail gas is pretreated to obtain clean gas meeting fermentation conditions, and the method specifically includes:

removing dust from the ferroalloy tail gas to obtain dust-free gas;

cooling the dust-free gas to obtain a suitable temperature gas;

tar removal is carried out on the gas with the proper temperature to obtain purified gas;

and deoxidizing and compressing the purified gas to obtain the clean gas meeting the fermentation conditions.

Optionally, the dust diameter of the dust-free gas is less than 1 μm.

Optionally, the temperature of the thermophilic gas is less than 30 ℃.

Optionally, the oxygen content of the clean gas is less than 1000ppm, and the pressure of the clean gas is greater than 0.6 MPa.

Based on the same inventive concept, the embodiment of the invention also provides a treatment system of ferroalloy tail gas, which comprises:

the pretreatment system is used for pretreating the ferroalloy tail gas to obtain clean gas meeting fermentation conditions;

the fermentation unit is communicated with the pretreatment system and is used for carrying out biological fermentation treatment on the clean gas to obtain a mash containing thalli and a clear liquid not containing thalli;

the concentration unit is communicated with the fermentation unit and is used for concentrating the mash containing the thalli to obtain heavy liquid and light liquid;

the protein drying unit is communicated with the concentration unit and is used for drying the heavy liquid to obtain a product protein feed;

and the distillation dehydration unit is respectively communicated with the fermentation unit and the concentration unit and is used for mixing the bacteria-free clear liquid and the light liquid and then evaporating to obtain a product ethanol.

Optionally, the pretreatment system includes:

the dust removal unit is used for removing dust from the ferroalloy tail gas to obtain dust-free gas;

the cooling unit is communicated with the dust removal unit and is used for cooling the dust-free gas to obtain a suitable temperature gas;

the decoking unit is communicated with the cooling unit and is used for removing tar from the gas with proper temperature to obtain purified gas;

and the deoxidation compression unit is communicated with the decoking unit and is used for deoxidizing and compressing the purified gas to obtain the clean gas meeting the fermentation conditions.

Optionally, the system further includes:

and the tail gas treatment unit is communicated with the fermentation unit and is used for treating the tail gas generated by biological fermentation.

Optionally, the system further includes:

and the sewage treatment unit is communicated with the distillation dehydration unit and is used for treating the wastewater generated by evaporation.

Optionally, the system further includes:

and the ethanol storage unit is communicated with the distillation dehydration unit and is used for storing the product ethanol.

One or more technical solutions in the embodiments of the present invention have at least the following technical effects or advantages:

the treatment method of the ferroalloy tail gas provided by the embodiment of the invention comprises the following steps: pretreating ferroalloy tail gas to obtain clean gas meeting fermentation conditions; carrying out biological fermentation treatment on the clean gas to obtain a mash containing thalli and a clear liquid without thalli; concentrating the mash containing the thalli to obtain heavy liquid and light liquid; drying the heavy liquid to obtain a product protein feed; mixing the clear liquid without thalli and the light liquid, and then evaporating to obtain a product ethanol; the ferroalloy industrial tail gas which pollutes the environment is directly converted into clean energy ethanol and high-protein feed, and the influence of the ferroalloy tail gas on the atmosphere and the surrounding environment is effectively reduced.

The foregoing description is only an overview of the technical solutions of the present invention, and the embodiments of the present invention are described below in order to make the technical means of the present invention more clearly understood and to make the above and other objects, features, and advantages of the present invention more clearly understandable.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on the drawings without creative efforts.

FIG. 1 is a flow chart of a method provided by an embodiment of the present invention;

FIG. 2 is a schematic structural diagram of a system provided by an embodiment of the invention;

FIG. 3 is a schematic diagram of the structure of a concentration unit, a distillation dehydration unit and a protein drying unit provided by the embodiment of the invention;

reference numerals: the method comprises the following steps of 1-a pretreatment system, 11-a dedusting unit, 12-a cooling unit, 13-a decoking unit, 14-a deoxidation compression unit, 2-a fermentation unit, 3-a tail gas treatment unit, 4-a concentration unit, 5-a distillation dehydration unit, 6-an ethanol storage unit, 7-a protein drying unit and 8-a sewage treatment unit.

Detailed Description

The present invention will be described in detail below with reference to specific embodiments and examples, and the advantages and various effects of the present invention will be more clearly apparent therefrom. It will be understood by those skilled in the art that these specific embodiments and examples are for the purpose of illustrating the invention and are not to be construed as limiting the invention.

Throughout the specification, unless otherwise specifically noted, terms used herein should be understood as having meanings as commonly used in the art. Accordingly, unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. If there is a conflict, the present specification will control.

Unless otherwise specifically stated, various raw materials, reagents, instruments, equipment and the like used in the present invention are commercially available or can be prepared by existing methods.

In order to solve the technical problems, the general idea of the embodiment of the application is as follows:

according to an exemplary embodiment of the present invention, there is provided a method for treating a ferroalloy off-gas, the method including:

s1, pretreating ferroalloy tail gas to obtain clean gas meeting fermentation conditions;

as an optional implementation manner, the iron alloy tail gas is pretreated to obtain clean gas meeting fermentation conditions, and the method specifically comprises the following steps:

s1.1, removing dust from the ferroalloy tail gas to obtain dust-free gas;

it should be noted that the dust-free gas is not completely dust-free, but almost dust-free, and the dust diameter is < 1 μm.

S1.2, cooling the dust-free gas to obtain a suitable temperature gas;

as an optional implementation mode, the temperature of the temperature-suitable gas is less than 30 ℃, and the specific cooling mode can be selected from common modes, such as spraying and the like.

S1.3, removing tar from the gas at the proper temperature to obtain purified gas;

in particular, tar removal can be achieved in the form of electrical tar capture.

S1.4, deoxidizing and compressing the purified gas to obtain clean gas meeting fermentation conditions;

in an alternative embodiment, the oxygen content of the clean gas is less than 1000ppm, and the pressure of the clean gas is greater than 0.6 MPa.

S2, carrying out biological fermentation treatment on the clean gas to obtain a mash containing thalli and a clear liquid without the thalli;

s3, concentrating the mash containing the thalli to obtain heavy liquid and light liquid;

specifically, the concentration may be performed by an evaporation concentration system.

S4, drying the heavy liquid to obtain a product protein feed;

and S5, mixing the clear liquid without the thalli and the light liquid, and evaporating to obtain a product ethanol.

According to another exemplary embodiment of the present invention, there is provided a system for treating a ferroalloy off-gas, the system including: the system comprises a pretreatment system, a fermentation unit, a concentration unit, a protein drying unit and a distillation dehydration unit.

The pretreatment system is used for pretreating the ferroalloy tail gas to obtain clean gas meeting fermentation conditions;

as an alternative embodiment, the pre-processing system comprises: the device comprises a dust removal unit, a cooling unit, a decoking unit and a deoxidation compression unit.

The dust removal unit is used for removing dust from the ferroalloy tail gas to obtain dust-free gas;

alternatively, the dust removal unit comprises a bag-type dust remover, a dust remover off-line blowing device and an explosion venting device. Specifically, the material of the filter bag of the bag-type dust collector is a needled felt. The bag-type dust remover and the off-line blowing device of the dust remover at any time are respectively communicated with the explosion venting device.

The cooling unit is communicated with the dust removal unit and is used for cooling the dust-free gas to obtain a suitable temperature gas;

alternatively, the cooling unit comprises a spray cooling tower, a spray circulating pump and a spray circulating pool. Specifically, stainless steel filler is arranged in the spray cooling tower. The spraying cooling tower and the spraying circulating pump are respectively communicated with the spraying circulating pool, and the spraying circulating pool is communicated with the spraying circulating pump.

The decoking unit is communicated with the cooling unit and is used for removing tar from the gas with proper temperature to obtain purified gas;

alternatively, the decoking unit comprises an electrical tar precipitator, a wash water tank, a wash water heating device and a tar storage device. The electric tar precipitator and the flushing water tank are respectively communicated with the tar storage device, and the flushing water tank is respectively communicated with the spray cooling tower and the flushing water heating device.

And the deoxidation compression unit is communicated with the decoking unit and is used for deoxidizing and compressing the purified gas to obtain the clean gas meeting the fermentation conditions.

Alternatively, the deoxidation compression unit comprises a gas compressor, a TSA purification tower, an electric heater, a deoxidation tower, a gas heat exchanger and a precision filter. The gas compressor is communicated with the TSA purification tower, the TSA purification tower is communicated with the electric heater, the electric heater is communicated with the deoxygenation tower, the deoxygenation tower is communicated with the gas heat exchanger, and the gas heat exchanger is communicated with the precision filter.

The fermentation unit is communicated with the pretreatment system and is used for carrying out biological fermentation treatment on the clean gas to obtain a mash containing thalli and a clear liquid not containing thalli;

alternatively, the fermentation unit comprises a fermentation tank, a fermentation liquor circulation pump and a fermentation mash filter. The fermentation tank is communicated with the fermentation liquid circulating pool and the fermentation circulating pump respectively. The fermentation tank is also communicated with the fermented mash filter.

The concentration unit is communicated with the fermentation unit and is used for concentrating the mash containing the thalli to obtain heavy liquid and light liquid;

alternatively, the concentration unit includes a first, second and third evaporative concentration devices, a terminal condenser, a terminal separator and a vacuum pump. The first concentration device is communicated with the second concentration device, the second concentration device is communicated with the third concentration device, the third concentration device is communicated with the terminal separator, and the terminal separator is communicated with the vacuum pump.

The protein drying unit is communicated with the concentration unit and is used for drying the heavy liquid to obtain a product protein feed;

alternatively, the protein drying unit comprises a drying device and an off-gas cleaning device. The drying device is communicated with the tail gas purification device. Specifically, the drying device is a centrifugal spray drying device or a pressure type spray drying device. Specifically, the tail gas purification device comprises a bag-type dust remover and a tail gas system washing tower, wherein the bag-type dust remover and the drying device are respectively communicated with the tail gas washing tower.

And the distillation dehydration unit is respectively communicated with the fermentation unit and the concentration unit and is used for mixing the bacteria-free clear liquid and the light liquid and then evaporating to obtain a product ethanol.

Alternatively, the distillation dehydration unit comprises an ethanol rectification concentration and membrane dehydration unit. The ethanol rectification concentration system is communicated with the membrane dehydration system.

As an optional implementation, the system further comprises: and the tail gas treatment unit is communicated with the fermentation unit and is used for treating the tail gas generated by biological fermentation.

Alternatively, the tail gas treatment unit comprises a burner, an oxidation furnace, a tail gas tower, a deaerator, a tail gas heat exchanger, and a steam drum. The combustor is communicated with the oxidation furnace, the oxidation furnace is communicated with the tail gas heat exchanger, the tail gas heat exchanger is communicated with the tail gas tower, and the deaerator is communicated with the steam drum.

As an optional implementation, the system further comprises: and the sewage treatment unit is communicated with the distillation dehydration unit and is used for treating the wastewater generated by evaporation.

As an option, the sewage treatment unit comprises an IC reactor, an anoxic and aerobic tank, a dephosphorization system and a sewage purification system. The IC reactor is communicated with the phosphorus removal system, the phosphorus removal system is communicated with the anoxic and aerobic tank, and the anoxic and aerobic tank is communicated with the sewage purification system.

As an optional implementation, the system further comprises: and the ethanol storage unit is communicated with the distillation dehydration unit and is used for storing the product ethanol.

Alternatively, the ethanol storage unit includes a finished ethanol storage system, a reject ethanol storage system, and an ethanol delivery system. The ethanol storage system is communicated with the ethanol delivery system, and the unqualified ethanol storage system is communicated with the distillation dehydration device.

The method and system for treating ferroalloy off-gas according to the present application will be described in detail below with reference to examples, comparative examples, and experimental data.

Example 1

A system for preparing ethanol by fermenting ferroalloy tail gas, which comprises a ferroalloy tail gas purification system, a ferroalloy tail gas fermentation ethanol production system, a product preparation and storage system and a waste gas and wastewater treatment system.

S1, obtaining purified ferroalloy tail gas: the ferroalloy tail gas exhaust pipe is communicated with the ferroalloy tail gas dedusting unit to remove particles such as dust in the ferroalloy tail gas and obtain purified gas with the dust content diameter less than 1 mu m; the ferroalloy tail gas dust removal unit is communicated with the spraying cooling unit, the temperature of the spraying cooling water is controlled to be less than 25 ℃, and purified gas with the temperature of less than 30 ℃ is obtained; the spraying cooling unit is communicated with the electric tar catching unit, the voltage of the electric tar catching unit is controlled to be 45KV +/-1 KVA, and more than 99% of tar in the ferroalloy tail gas is removed; the electric tar catching unit is communicated with the deoxidation compression unit to obtain purified gas with oxygen consumption less than 1000ppm and pressure greater than 0.6 MPa.

S2, obtaining ethanol-containing mash: the deoxidation compression unit is communicated with the fermentation unit to obtain a mash containing bacteria liquid with 3-10% of ethanol concentration and a clear liquid with 3.5-11% of ethanol concentration and almost no bacteria.

S3, preparation and storage of the product: the fermentation unit is communicated with the evaporation concentration unit and the distillation dehydration unit respectively, and the evaporation concentration unit is also communicated with the distillation dehydration unit. Obtaining the evaporation concentrated solution with the water content of 8-20 percent and obtaining the absolute ethyl alcohol with the water content of less than 0.5 percent. The ethanol storage unit is communicated with the distillation dehydration unit and is used for product storage and delivery. The protein drying unit is communicated with the evaporation and concentration unit to obtain protein powder with water content less than 10% and crude protein content greater than 70%.

S4, waste gas and waste water treatment: the distillation dehydration unit is communicated with the sewage treatment unit to obtain qualified water with COD less than 30mg/L and ammonia nitrogen less than 5 mg/L. The fermentation unit is communicated with the tail gas treatment unit to obtain steam and tail gas without CO.

Comparative example 1

In the comparative example, the ferroalloy industrial tail gas is directly used for combustion power generation.

Examples of the experiments

Comparing the ferroalloy tail gas fermentation with a fuel power generation equation:

fermenting ferroalloy tail gas: 6CO +3H₂O→C₂H₅OH+4CO₂；

And (3) burning ferroalloy tail gas to generate power: 2CO + O₂→2CO₂。

The yields of ethanol and protein powder, the emission of CO2, and the emission of dust were calculated for each example and comparative example, and the results are shown in the following table:

	yield of ethanol	Yield of protein powder	CO2Volume of reducing discharge	Dust discharge amount
					Example 1	＞98％	＞92％	33％	0％
Comparative example 1	0％	0％	0％	Unfixed and all discharged

As can be seen from the data in the table, the comparative example 1 is used for burning the ferroalloy industrial tail gas to generate power, no other by-products are generated, and dust in the ferroalloy tail gas is not recovered and fixed and is completely discharged into the atmosphere, so that the environmental pollution is caused; the method and the system provided by the embodiment of the application are adopted to treat the ferroalloy to obtain products such as ethanol, protein powder and the like, and CO is reduced for one-time emission reduction₂The amount is more than 33%, and no pollutant such as dust is discharged.

One or more technical solutions in the embodiments of the present invention at least have the following technical effects or advantages:

the method and the system provided by the embodiment of the invention are characterized in that ferroalloy industrial tail gas is subjected to dust removal, temperature reduction, tar electrical capture and deoxidation compression to obtain purified gas, the purified gas is subjected to anaerobic biological fermentation to obtain two mash rich in ethanol, the mash is subjected to evaporation, rectification and dehydration to obtain absolute ethanol with the water content of less than or equal to 0.5%, the evaporated concentrated solution is subjected to a protein drying system to obtain protein feed with the water content of less than 7%, the ferroalloy industrial tail gas is treated by the system provided by the invention to directly convert the ferroalloy industrial tail gas which pollutes the environment into clean energy ethanol and high protein feed, and the influence of the ferroalloy tail gas on the atmosphere and the surrounding environment is effectively reduced.

Finally, it should also be noted that the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus.

While preferred embodiments of the present invention have been described, additional variations and modifications in those embodiments may occur to those skilled in the art once they learn of the basic inventive concepts. Therefore, it is intended that the appended claims be interpreted as including preferred embodiments and all such alterations and modifications as fall within the scope of the invention.

It will be apparent to those skilled in the art that various changes and modifications may be made in the present invention without departing from the spirit and scope of the invention. Thus, if such modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include such modifications and variations.