CN105214450B

CN105214450B - A kind of selective absorbing SO2Absorbent and absorb SO2Process

Info

Publication number: CN105214450B
Application number: CN201510661913.2A
Authority: CN
Inventors: 黄锐
Original assignee: Individual
Current assignee: Keyon Process Co ltd
Priority date: 2015-10-14
Filing date: 2015-10-14
Publication date: 2017-11-10
Anticipated expiration: 2035-10-14
Also published as: CN105214450A

Abstract

The invention discloses a kind of selective absorbing SO₂Absorbent and absorb SO₂Process.The composition of the absorbent includes：The ionic liquid of 30%~70% mass fraction；The activator of 0.1%~4.0% mass fraction；The antioxidant of 0.1%~0.5% mass fraction；The corrosion inhibiter of 0.1%~0.5% mass fraction；Surplus is water.Using the absorbent to SO₂The process absorbed is：Flue gas after washing is passed through absorption tower from bottom, absorbs SO using described absorbent₂；Then absorption there is into SO₂Rich solution enter regenerator from top again, to SO₂Desorbed；The SO desorbed₂Lower workshop section is sent into, directly synthesizes H₂SO₄.The absorbent provided by the invention is to SO₂Good absorbing effect, selectivity are high；Ionic liquid therein uses organic acid, low to equipment corrosion, to more environment-friendly.The process stable performance, desulfuration efficiency are more than 99%, the SO of absorption₂Easy desorption and regeneration.

Description

A kind of selective absorbing SO2Absorbent and absorb SO2Process

Technical field

The invention belongs to SO₂A kind of gas handling techniques field, and in particular to selective absorbing SO₂Absorbent and suction Receive SO₂Process.

Background technology

China is a producing coal and is only second to the U.S. and Russia with coal big country, its reserves.China is a development China Family, the burning of coal at present, is still the most important energy that we are relied on.Inevitably produced during coal burning SO₂Deng dusty gas, so as to directly affect the ecological environment that we depend on for existence.

Along with China reform and open up to the outside world caused by rapid economic development, the consumption of coal is also growing day by day.At present, China turns into SO₂One of pollution country the most serious.Since 11th Five-Year, China has taken control SO₂The correlation of discharge is arranged Apply, but it is limited to produce effects.2014, national sulfur dioxide (SO2) emissions total amount was 1974.4 ten thousand tons, falls 3.4% on a year-on-year basis, but situation according to Old sternness.SO₂A kind of sour gas, it not only can the ecosystem such as damage to land, forest, rivers, while also can be to the mankind Building, industrial plants, cultural relics and historic sites etc. cause irremediable harm.In addition, the health for human body also has non- Often big influence.Therefore, how to effectively control SO₂The discharge of gas is extremely urgent.At present, countries in the world research and develop Flue gas desulfurization technique up to more than 200 is planted, but actual business application is considerably less.Currently, handling the prevailing technology of the flue gas is The ammonia absorption process abbreviation ammonia process of desulfurization, or lime stone slurry absorption process abbreviation wet method lime absorption.The ammonia process of desulfurization is because of raw material ammonia Chemical fertilizer, source is valuable, and cost is high, and certain production loss is caused to ammonia enterprise.And ammonia is volatile, easily cause top emit it is white Cigarette, produce aerosol secondary pollution.Lime stone absorbs, and source is convenient, and production cost is low, but caused gypsum is the one of solid waste Kind, economic value is low, and device water consumption is big.Therefore, develop the recyclable flue gas desulfurization technique of a set of green and seem particularly heavy Will.

So-called ionic liquid (Ionic Liquid, IL), refer to be in a liquid state near room temperature temperature or low temperature, completely by The material that ion is formed, also known as ionic liquid at room temperature (Room Temperature Ionic Liquid) or room temperature molten salt (Room Temperature Molten Salt) or organic ion liquid.Its maximum feature is almost do not have vapour pressure, and And there is good chemical stability and heat endurance.In addition, ionic liquid has for a variety of organic or inorganic gases Good dissolubility energy, and differ greatly, this shows ionic liquid as a kind of environmentally friendly green solvent, in gas Separation in terms of there is huge application prospect.Absorbent is used ionic liquid as to SO₂Carry out absorption and be treated as one New research direction.

The content of the invention

It is an object of the present invention to provide a kind of selective absorbing SO₂Absorbent and absorb SO₂Process, mainly Solves SO in the prior art₂Processing method in terms of energy-conserving and environment-protective and assimilation effect still dissatisfactory technical problem.

Present invention technical scheme used to achieve the above object is as follows：

A kind of selective absorbing SO₂Absorbent, the composition of the absorbent includes：The ion of 30%~70% mass fraction Liquid；The activator of 0.1%~4.0% mass fraction；The antioxidant of 0.1%~0.5% mass fraction；0.1%~0.5% The corrosion inhibiter of mass fraction；Surplus is water.The content of its reclaimed water is preferably 35%~65%.The content of ionic liquid is preferably 35%~55%.

The ionic liquid is cation by nitrogenous type organic matter, and organic acid is made up of anion.Further preferably Ground, the cation of the ionic liquid are selected from guanidinesalt class, alcamines, imidazoles, pyridines, four azoles, quaternary ammonium salt, thiazole One or more in class, dicyandiamide class material；The anion is selected from lactic acid, tartaric acid, citric acid, pyrovinic acid, apple One or more in acid, oxalic acid, acetic acid.The ionic liquid can be with the absorption SO of high selectivity₂, for other sour gas, Such as CO₂, hardly pick up.

The activator is one or both of organic alcohols material.Preferably, the activator is selected from n-butanol, just Hexanol, n-octyl alcohol.

The antioxidant is one or two kinds of compositions in phenols or quinones substance with week reduction.Preferably, institute State antioxidant and be selected from hydroquinones, dibutyl hydroxy toluene, TBHQ, naphthoquinones, anthraquinone and its derivative.

The corrosion inhibiter is one or both of inorganic salts material composition.Preferably, corrosion inhibiter is selected from basic carbonate One or both of copper, potassium metavanadate, arsenic trioxide, antimony trichloride.

As a kind of preferred embodiment, the composition of the absorbent is：TMG tartrate 45%, n-butanol 0.3%th, hydroquinones 0.15%, basic copper carbonate 0.2%, remaining is water.

The present invention also provides a kind of absorption SO₂Process, this method is：Flue gas after washing is passed through suction from bottom Tower is received, using above-mentioned selective absorbing SO₂Absorbent absorb SO₂；Then absorption there is into SO₂Rich solution again from top enter again Raw tower, to SO₂Desorbed.

Preferably, the condition on absorption tower is 10~110 DEG C of temperature in the process, and pressure is 0.01~0.2MPa, Preferably 40~90 DEG C, 0.05~0.2MPa；The condition of the regenerator is 100~150 DEG C of temperature, pressure is 0.01~ 0.2MPa, preferably 110~140 DEG C, 0.05~0.2 MPa.

Preferably, the SO desorbed₂Lower workshop section is sent into, directly synthesizes H₂SO₄。

In process of the present invention, the absorbent solution volume flow is 1 with flue gas volume flow-rate ratio:20~1: 20000, preferably 1:100~1:10000.

In process of the present invention, caused SO₂Concentration is up to more than 95%.If by SO₂Mixed with vapor, can Next workshop section is passed directly into, synthesizes the H of high concentration₂SO₄Byproduct.As SO in raw material flue gas₂Content reaches 10000mg/Nm³When, go out SO in implication₂Content will be less than 100 mg/Nm³, desulfuration efficiency is up to more than 99%.

Below by the absorbent to the present invention based on ionic liquid for main body, selective absorbing SO₂Technique carry out it is more detailed Thin description：

Absorbent provided by the invention based on ionic liquid, for SO₂Gas has good absorption and desorption ability, The desulphurization mechanism is as follows：

Net reaction：

R represents absorbent in above formula, and net reaction is reversible reaction.Under low temperature, reaction is carried out from left to right；Under high temperature, Reaction is carried out from right to left.The technique is exactly to utilize this principle, sulfur dioxide absorption at low temperature, under high temperature by sulfur dioxide from Desorbed in absorbent.So as to reach the purpose of sulfur dioxide in removing and recovered flue gas.

According to invention embodiment, ionic liquid selective absorbing SO provided by the invention₂Technological process and Operating method is as follows：

Referring to Fig. 1, the figure is the process chart that the absorbent carries out flue gas desulfurization.As shown in figure 1, flue gas passes through first After booster fan boosting, enter from the bottom of water scrubber 1.After the dedusting of water scrubber 1 cooling, absorption tower 2 is sent into.Go out from water scrubber 1 The washings come enter washing pump 7 by water diversion tank 10 and carry out cleaning supercharging, are sent to water scrubber top again, are reused for cold But flue gas.The flue gas cooled down by dedusting, enter absorption tower 2 from bottom, it is preferably 40~90 DEG C to absorb temperature, and pressure is preferably 0.05~0.2MPa.The now SO in flue gas₂Absorbed by absorbent, the flue gas after sulphur removal can be through sending flue to be directly vented.Inhale Receive SO₂Rich solution afterwards enters poor rich liquid heat exchanger 11 by bottom of towe through rich solution pump 4, enters to be sent to regenerator 3, desorption temperature after reclaiming heat Degree is preferably 110~140 DEG C, and pressure is preferably 0.05~0.2MPa.Absorption has SO₂Rich solution enter regenerator 3 from top, By stripping desorption part SO₂Afterwards, into reboiler 6, SO therein is made₂Further desorption.Desorb SO₂Lean solution afterwards is by regenerating The bottom outflow of tower 3, after lean pump 5, poor rich liquid heat exchanger 11, the heat exchange cooling of lean solution cooler 12, into the upper of absorption tower 2 Portion, reuptake SO₂；The SO that regenerator 3 parses₂, concentration is up to more than 95%, the SO₂Cooled down by condenser 8 laggard Enter gas-liquid separator 9, the SO after isolating and purifying₂Sulfuric acid apparatus production sulfuric acid is sent into, can also be cooled by pressurizeing, produce liquid SO₂Product, economic value are higher.

In above-mentioned sulfur removal technology, the replacement cycle of absorbent is relevant with the composition in flue gas.

In above-mentioned sulfur removal technology, desulfurized effect and SO in flue gas₂Concentration, ionic liquid species, temperature and pressure is absorbed, The ratio between desorption temperature and pressure and the volume flow of flue gas and absorbent are relevant.

Compared with prior art, beneficial effects of the present invention are as follows：

1st, it is provided by the present invention to be based on ionic liquid selective absorbing SO compared with traditional sulfur removal technology₂Technique tool Have the following advantages：Select this technique, have stable performance, vapour pressure are extremely low, selection sulfur dioxide absorption ability is strong, energy consumption is low, Desulfuration efficiency is high, the advantages that easy desorption and regeneration.

2nd, used in this technique based on organic cation and the ionic liquid absorbent of organic anion to SO₂ Assimilation effect it is more preferable, selectivity it is higher, desulfuration efficiency can be more than 99%.

3rd, relative to using ionic liquid absorbent of the inorganic anion for main body in the prior art, absorbent in the present invention Ionic liquid use organic anion, enable to absorbent lower to the corrosivity of equipment, it is also more friendly to environment.

Brief description of the drawings

Fig. 1 is the process chart of the absorbent progress flue gas desulfurization in the present invention.

Embodiment

Technical scheme is described in detail with reference to embodiment.

Embodiment 1

Certain large-scale coal chemical industry enterprises, SO in its boiler smoke₂Content be 5000~12000 mg/Nm³, temperature 140 DEG C, flue gas desulfurization is carried out using technological process as shown in Figure 1；Wherein, 1. water scrubber；2. absorption tower；3. regenerator；4. rich solution Pump；5. lean pump；6. reboiler；7. washing pump；8. condenser；9. gas-liquid separator；10. water diversion tank；11. poor rich solution heat exchange Device；12. lean solution cooler.

Flue gas first enters after booster fan boosts from the bottom of water scrubber 1.60 are cooled to through the dedusting of washing cooling tower 1 DEG C, it is sent into absorption tower 2 from bottom.The washings come out from water scrubber 1 can enter washing pump 7 by water diversion tank 10 and be cleaned Supercharging, cooler cooling and then it is secondary be sent to water scrubber top, be reused for cooled flue gas.The flue gas cooled down by dedusting, from Bottom enters absorption tower 2, and it is 60~70 DEG C to absorb temperature, and pressure is preferably 0.1MPa.The now SO in flue gas₂By absorbent institute Absorb, the flue gas after sulphur removal can be through sending flue to be directly vented.Absorb SO₂Rich solution afterwards enters poor rich solution by bottom of towe through rich solution pump 4 Heat exchanger 11, enter to be sent to regenerator 3 after reclaiming heat, desorption temperature is 120~130 DEG C, pressure 0.1MPa.Absorption has SO₂ Rich solution enter regenerator 3 from top, by stripping desorption part SO₂Afterwards, into reboiler 6, SO therein is made₂Further solution Inhale.Desorb SO₂Lean solution afterwards is flowed out by regenerator bottom, is exchanged heat through lean pump 5, poor rich liquid heat exchanger 11, lean solution cooler 12 cold But after, into the top on absorption tower 2, SO is reuptaked₂.Absorbent continuously circulates, and forms continuous absorption and desorption SO₂Technique Process.The SO that regenerator parses₂, concentration is up to more than 95%, by the SO₂Enter gas-liquid separator after being cooled down by condenser 8 9, the SO after isolating and purifying₂Back segment program is sent into, such as is sent into sulfuric acid apparatus production sulfuric acid, can also be cooled by pressurizeing, it is raw Produce liquid SO₂Product.SO in purified gas₂Concentration be reduced to 48mg/Nm³, desulfuration efficiency is more than 99%.

The absorbent that above-mentioned technological process uses is formed as (each proportion of composing is mass fraction)：TMG tartaric acid Salt 45%, n-butanol 0.3%, hydroquinones 0.15%, basic copper carbonate 0.2%, remaining is water.

The process operation result shows, using based on the absorbent that ionic liquid is main body, effectively can absorb in flue gas SO₂, absorption efficiency is high, and selectivity is good, and system can be run steadily in the long term.

Embodiment 2

Certain large-scale coal chemical industry enterprises, SO in its boiler smoke₂Content be 5000~12000 mg/Nm³, temperature 140 DEG C, flue gas desulfurization is carried out using technological process as shown in Figure 1, specific sweetening process is the same as embodiment 1.The absorbent composition of use For (each proportion of composing is mass fraction)：Melbine lactate 30%, n-butanol 0.3%, hydroquinones 0.15%, alkali formula Copper carbonate 0.2%, remaining is water.After the absorbent desulfurization, SO in purified gas₂Concentration be reduced to 50mg/Nm³, desulfurization effect Rate is more than 99%.

Embodiment 3

Certain large-scale coal chemical industry enterprises, SO in its boiler smoke₂Content be 5000~12000 mg/Nm³, temperature 140 DEG C, flue gas desulfurization is carried out using technological process as shown in Figure 1, specific sweetening process is the same as embodiment 1.The absorbent composition of use For (each proportion of composing is mass fraction)：Monoethanolamine tartrate 70%, n-butanol 0.3%, hydroquinones 0.15%, alkali formula Copper carbonate 0.2%, remaining is water.After the absorbent desulfurization, SO in purified gas₂Concentration be reduced to 70mg/Nm³, desulfurization effect Rate is more than 99%.

The part preferred embodiment of the present invention is above are only, the present invention is not limited in the content of embodiment.For ability For technical staff in domain, can there are various change and change in the concept of technical solution of the present invention, that is made appoints What changes and change, within the scope of the present invention.

Claims

A kind of 1. selective absorbing SO₂Absorbent, the composition of the absorbent includes：The ionic liquid of 30%~70% mass fraction Body；The activator of 0.1%~4.0% mass fraction；The antioxidant of 0.1%~0.5% mass fraction；0.1%~0.5% matter Measure the corrosion inhibiter of fraction；Surplus is water；The ionic liquid is cation by nitrogenous type organic matter, and organic acid is anion institute Composition, the cation of the ionic liquid are selected from guanidinesalt class, alcamines, imidazoles, pyridines, four azoles, quaternary ammonium salt, thiazole One or more in class, dicyandiamide class material；The anion is selected from lactic acid, tartaric acid, citric acid, pyrovinic acid, apple One or more in acid, oxalic acid, acetic acid；The activator is one or both of organic alcohols material.
A kind of 2. selective absorbing SO as claimed in claim 1₂Absorbent, it is characterised in that：The composition of the absorbent For TMG tartrate 45%, n-butanol 0.3%, hydroquinones 0.15%, basic copper carbonate 0.2%, remaining is water.
A kind of 3. selective absorbing SO as claimed in claim 1₂Absorbent, it is characterised in that：The antioxidant be with One or two kinds of compositions in the phenols or quinones substance of week reduction.
A kind of 4. selective absorbing SO as claimed in claim 1₂Absorbent, it is characterised in that：The corrosion inhibiter is selected from alkali formula One or both of copper carbonate, potassium metavanadate, arsenic trioxide, antimony trichloride.
5. one kind absorbs SO₂Process, this method is：Flue gas after washing is passed through absorption tower from bottom, will using right The absorbent described in 1 or 2 is asked to absorb SO₂；Then absorption there is into SO₂Rich solution enter regenerator from top again, to SO₂Solved Inhale.
A kind of 6. absorption SO as claimed in claim 5₂Process, it is characterised in that：Tower temperature is absorbed in the process Spend for 40~90 DEG C, pressure is 0.01~0.2MPa；The regenerator temperature be 100~150 DEG C, pressure be 0.01~ 0.2MPa。
A kind of 7. absorption SO as described in claim 5 or 6₂Process, it is characterised in that：The SO desorbed₂It is sent into Lower workshop section, directly synthesizes H₂SO₄。