CN104437067A - Method for strengthening activity of limestone-gypsum wet-method flue gas desulfurization slurry - Google Patents
Method for strengthening activity of limestone-gypsum wet-method flue gas desulfurization slurry Download PDFInfo
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Abstract
The invention relates to a method for strengthening the activity of limestone-gypsum wet-method flue gas desulfurization slurry, and belongs to the technical field of flue gas desulfurization processes. An activation pipe network is arranged at the bottom of a limestone slurry box; a rear smoke channel of an oxygen-enriched combustion boil system feeds a part of system-captured high-concentration CO2 gas into the activation pipe network to activate the desulfurization slurry in the limestone slurry box; the activated limestone slurry is fed into an absorption tower and is subjected to countercurrent contact and absorption with the SO2 gas; activated and leaked CO2 gas returns to the rear smoke channel of the oxygen-enriched combustion boil system through a CO2 gas overflow opening at the top of the limestone slurry box. The method for strengthening the activity of the limestone-gypsum wet-method flue gas desulfurization slurry improves the reaction efficiency of CaCO3 and the SO2 by facilitating the dissolution of CaCO3 and the SO2.
Description
Technical field
The invention belongs to flue gas desulfurization technique technical field, be specifically related to the method for a kind of intensified lime stone-gypsum wet flue gas desulfurizing slurry activity.
Background technology
Current era, the coal-fired important environmental problem pollution of air having been become to the world, especially China, coal consumption has accounted for 70% of energy resource consumption, is in absolute predominance status.Threaten the safety of environment and the health of the mankind by pollutant moment such as coal fire discharged a large amount of CO2 and SO2, energy and environment have become inevitable problem in Chinese society evolution.Therefore, numerous clean coal utilizes technology to be suggested, and wherein oxygen-enriched combustion technology can effectively discharge by control CO2 as one, and the New type coal combustion technology simultaneously reducing the pollutant precipitations such as SO2 receives extensive concern.Oxygen-enriched combustion technology is while control CO2 discharges, and in order to reach the discharge standard of SO2, conventional flue gas desulfurization technique obtains to be continued to use, particularly wet desulfurization of flue gas by limestone-gypsum method technology.
Wet desulfurization of flue gas by limestone-gypsum method technology is that the lime stone slurry utilizing concentration to be about 30% contacts with each other in absorption tower with the flue gas containing SO2, after the series reaction such as heat transfer, mass transfer, absorption and oxidation, generate CaSO4, then desulfurization product CaSO4 slurries make gypsum byproduct after condensing crystallizing.This technology, because desulfurizing agent wide material sources, technical maturity, treatment quantity are large and accessory substance is convenient to the advantages such as recycling, have become the first-selected sulfur removal technology of coal-burning power plant of China, has accounted for more than 85% at home in Desulphurization for Coal-fired Power Plant facility.But due to the character of lime stone itself and technique restriction, it is also faced with, and lime stone solubility is low, equipment scaling, investment and the limitation such as operation and maintenance cost is high and floor space is large.Especially in oxygen-enriched combustion technology, compared to conventional combustion, the rising of the SO2 concentration that flue gas recirculation causes and the obvious reduction of flue gas total flow all bring new impact to wet desulfurization of flue gas by limestone-gypsum method technology; And in order to alleviate the immense pressure that current pollutant emission causes environment, country to the discharge of coal-burning boiler SO2 propose definitely with strict standard (GB13223-2011).So how to be optimized conventional limestone-gypsum wet flue gas desulfurizing technology in Rich Oxygen Combustion, to improve the reactivity of desulfurizing agent, improve the utilization rate of desulfuration efficiency and lime stone, the deep removal realizing SO2 is the key issue faced at present.
In absorption tower dilatation or gas residence time, Ca/S mole when operational factor such as liquid-gas ratio, go adjustment if simple in wet desulfurization of flue gas by limestone-gypsum method technology, the increase of investment operating cost and energy consumption will certainly be caused.Therefore, receive about the research improving wet desulfurization of flue gas by limestone-gypsum method efficiency and pay attention to more.In desulphurization reaction, the course of dissolution of absorbent lime stone is the important rate-determining steps of lime stone and SO2 reaction speed, because the solubility of CaCO3 in water is lower, improve the optimization of its course of dissolution to smoke-gas wet desulfurization system to have great importance, will have greatly improved to whole sulfur removal technology.The method dropping into additive in desulphurization system that adopts to reach the object of reinforcing desulfuration effect more at present, although these additives serve the effect to limestone desulfurizer activation to a certain extent, but the kind of additive is comparatively numerous and diverse at present, application randomness is larger, select evaluation of programme without reliable additive, there is larger potential safety hazard; And due to power plant strict to the instructions for use of chemicals, existing additive can not produce good effect to whole technique and ensure the quality of desulfurizing byproduct, and applicability is poor.Therefore be starved of and find a kind of cost low, be easy to realize, without the technique of the intensified lime stone-gypsum wet flue gas desulfurizing of adverse consequences, improve the activity of limestone desulfurization slurries, raising desulfuration efficiency, increase the stability that desulphurization system is run, save system energy consumption; For technology such as oxygen-enriched combustings.
Summary of the invention
Object of the present invention is exactly the defect for prior art, provides the method for a kind of intensified lime stone-gypsum wet flue gas desulfurizing slurry activity.The method can improve solubility and the reactivity of lime stone, eliminates two film effects of CaCO3 particle surface, and then improves desulfuration efficiency, and reduce energy consumption and the cost of system, be specially adapted to the techniques such as oxygen-enriched combusting.
The technical solution used in the present invention is: a kind of method of intensified lime stone-gypsum wet flue gas desulfurizing slurry activity, comprises the following steps:
(1), in the bottom of lime stone slurry case arrange activation pipe network, the high concentration CO 2 gas trapped by oxygen-enriched combustion boiler system back-end ductwork extension system enters activation pipe network and activates the desulfurization slurry in lime stone slurry case;
(2) lime stone slurry, after activation enters absorption tower and SO2 gas carries out counter current contacting and absorption, and after activation, the CO2 gas overflowing mouth of CO2 gas through slurry tank top of spilling returns former oxygen-enriched combustion boiler system back-end ductwork.
Principle of the present invention: described CO2 gas is in the activation process of lime stone slurry, the dissolving ionization of CO2, provide basic group, change the ionic equilibrium of slurries, enhance the mass transfer factor of liquid film, facilitate the dissolving of CaCO3 and accelerate its rate of dissolution, decreasing the liquid-film resistance between solid phase and liquid phase; Under normal temperature, the solubility (S=16.6) of Ca (HCO3) 2 in water is much larger than the solubility (S=0.0065) of CaCO3 in water.Principle of the present invention can be illustrated by chemical equation below:
The dissolving ionization of CO2
The dissolving of CaCO3
And in absorption tower sweetening process subsequently, the lime stone slurry after activation can also promote the dissolving of SO2, reduce the resistance to mass tranfer between gas phase and liquid phase.In addition, because the dissolving ionization of CO2 is reversible reaction, the dynamic equilibrium of H+, CO22-and HCO3-plasma in desulfurization slurry can also the change of snubber tower slurries pH, improve mass transfer and diffusion effect, promote liquid reactive in sweetening process carrying out, and then cause desulfuration efficiency to improve further.
Further, in described lime stone slurry, the particle diameter of lime stone is less than 63 μm, and serum density is 1300 ~ 1400kg/m3.
Further, in described activated gas, the volumetric concentration of CO2 can reach 80 ~ 90%.
Further, in described step 1 activation while can pass in lime stone slurry steam with by lime stone slurry heating temperatures to 20 ~ 70 DEG C.
Further, described activation gas liquid ratio (CO2 gas and activated sludge volume ratio) (0.5 ~ 1) × 10
-3m3/L; Described soak time is 1 ~ 3h.
The invention has the beneficial effects as follows: the oxygen-enriched combustion technology of Novel clean combines with original wet desulfurization of flue gas by limestone-gypsum method technology, only current wet desulfurization of flue gas by limestone-gypsum method technology need be changed slightly, method of the present invention can be used.The present invention is except inheriting the advantage of existing wet desulfurization of flue gas by limestone-gypsum method method, also there is larger advantage, specific as follows: 1. that the CO2 gas that the present invention adopts oxygen-enriched combustion technology itself to trap activates limestone desulfurization slurries, take full advantage of original technique, technological transformation is simple, reliability is high, counter investment is few, and can not produce secondary pollution, reaches the target of energy-saving and emission-reduction; 2. in the present invention, lime stone slurry is after CO2 gas activation, and the rate of dissolution of lime stone and solubility increase, and desulphurization reaction is accelerated, and liquid-gas ratio reduces, and the utilization rate of desulfuration efficiency and lime stone all improves; 3. in the present invention the reduction of liquid-gas ratio and desulfuration efficiency raising can minimizing slurry circulating pump in various degree usage quantity or reduce its operate power, energy consumption and the operating cost of system all reduce; 4. the present invention can make desulphurization system maintain within the scope of a wider pH, and Load Regulation is flexible, strong adaptability, system run all right; 5. inventive desulfurization accessory substance is still gypsum, and can not impact its quality.
The present invention is by promoting the dissolving of CaCO3 and SO2, improve the reaction efficiency of CaCO3 and SO2, more SO2 can be made under same physical condition to be absorbed, so that when not carrying out larger transformation to existing desulphurization system, solve the SO2 concentration occurred in oxygen-enriched combusting to raise, exhaust gas volumn reduces, the problems such as flue gas flow rate reduction, and make desulphurization system meet new coal-burning boiler SO2 emission limit, there is good economic and social benefit.
Accompanying drawing explanation
Fig. 1 is the impact of CO2 activation on CaCO3 solubility under different temperatures;
Fig. 2 is that SO2 separates out the change curve of concentration with the reaction time;
Fig. 3 is the change curve of desulfuration efficiency with the reaction time.
Detailed description of the invention
Below in conjunction with the drawings and specific embodiments, the present invention is described in further detail, is convenient to be well understood to the present invention, but they do not form restriction to the present invention.
The present invention includes following steps:
(1), in the bottom of lime stone slurry case arrange activation pipe network, the high concentration CO 2 gas trapped by oxygen-enriched combustion boiler system back-end ductwork extension system enters activation pipe network and activates the desulfurization slurry in lime stone slurry case;
(2) lime stone slurry, after activation enters absorption tower and SO2 gas carries out counter current contacting and absorption, and after activation, the CO2 gas overflowing mouth of CO2 gas through slurry tank top of spilling returns former oxygen-enriched combustion boiler system back-end ductwork.
Embodiment 1
Utilize glass tank reactor (internal diameter 100mm, high 200mm), first lime stone slurry activation experiments is carried out, reactor is added by 300mL distilled water and the analytically pure CaCO3 pressed powder of 10g, stir 3 hours subsequently to the CO2 gas passing into 30mL in reactor continuously, make CaCO3 solution.The temperature of reactor is controlled by horizontal tepidarium, and activation temperature gets 20 ~ 60 DEG C; PH value is by the portable pH meter Real-Time Monitoring of Starter300; CO2 gas is by the confession of steel cylinder air lift, and flow is controlled by mass flowmenter.Activate rear taking-up CaCO3 slurry samples, through filter paper, the CaCO3 solute that may be taken out of by funnel elimination, make saturated aqueous solution; Then use ten thousand/electronic balance weighing, adopt liquid evaporation to obtain solute CaCO3, obtain the solubility of CaCO3 as calculated afterwards.Under different temperatures, CO2 activation on the impact of CaCO3 solubility as shown in Figure 1.This figure illustrates and adopts after the present invention, and the solubility of CaCO3 in slurries obviously increases, and along with the rising of activation temperature, dissolves and strengthen gradually.
Then adopt flue gas disappear molten method to activation before and after lime stone slurry carry out desulfurization test.Oxygen-enriched combusting simulated flue gas adopts steel cylinder gas (O2, CO2 and SO2) quantitative by mass flowmenter, then after gas mixer fully mixes, enters reactor and lime stone slurry reacts; Flue gas total flow is 500mL/min, wherein the flow of O2 and CO2 be respectively 100 and 400mL/min, SO2 volumetric concentration be about 1000ppm.Limestone slurry liquid measure is 200mL, and slurry temperature controls at about 50 DEG C.The composition importing and exporting simulated flue gas uses triumphant grace KM9106 and KM950 two flue gas analyzers to measure in real time respectively.SO2 separate out concentration with the reaction time change curve as shown in Figure 2.Adopt after the present invention, the absorbability of lime stone slurry to SO2 obviously strengthens, and along with the rising of activation temperature, the absorbability of slurries to SO2 strengthens gradually.
Embodiment 2
The continuous reaction test of wet desulfurization of flue gas by limestone-gypsum method is carried out in the desulphurization system of laboratory.Absorption tower is the circular reactor that lucite is made, and absorb tower height 1.5m, external diameter is 0.05m.In process of the test, by steel cylinder gas (O2, CO2 and SO2) as source of the gas, total flow is 2m3/h, and smoke components is that O2:0.4m3/h, CO2:1.6m3/h, SO2 volumetric concentration is about 1000ppm.Simulated flue gas flows through absorption tower from bottom to top by smoke inlet after first mixing and be heated to 120 DEG C by gas mixer and preheater; And the lime stone slurry that the concentration be made up of the lime stone of 20 ~ 63 μm of particle diameters is 5% is sprayed from top jet nozzle by pump, contact with flue gas adverse current and absorb SO2 gas.Pump capacity is stablized to 150L/h by control valve, and slurry temperature is controlled by slurries heater and is stabilized in 45 ~ 50 DEG C.SO2 concentration before and after desulfurization in flue gas adopts triumphant grace KM950 and KM9106 type flue gas analyzer Real-Time Monitoring respectively.In slurry pool of absorption tower, the pH of slurries is by the portable pH meter Real-Time Monitoring of Starter300, and by regulating the addition of fresh limestone slurries to make it control between 5.2 ~ 5.6.Desulfuration efficiency after system run all right with the reaction time change curve as shown in Figure 3.This figure illustrates, adopts CO2 gas activation (activation gas liquid ratio 0.6 × 10
-3m3/L, activation temperature 45 ~ 50 DEG C, soak time 3h) after lime stone slurry when running, the desulfuration efficiency of system has about brought up to 96.1% by 92.9%.
Embodiment 3
Certain power plant 2 × 350WM unit, adopts the full flue gas desulfurization technique of Gypsum Wet, stove one absorber desulfurization device, and it is a set of that desulfurization absorbs the system share such as preparation and gypsum slurries dehydration.Design coal sulfur-bearing rate 0.6 ~ 1.2%.Limestone wet ball milling pulping system is adopted in sulfur removal technology, limestone particle size≤63 μm (90% by 250 orders), the serum density of lime stone slurry case is about 1300 ~ 1350kg/m3, and the lime stone slurry density domination in absorption tower is at 1120 ~ 1160kg/m3, slurry pH value is between 5.2 ~ 5.6, and Ca/S ratio is 1.03.In inlet flue gas, SO2 concentration is 1800 ~ 2000mg/m3, and in exiting flue gas, SO2 concentration is 80 ~ 90mg/m3.When desulphurization system is run, 3 slurry circulating pump longtime running, liquid-gas ratio is about 14.8L/m3, and desulfuration efficiency is about 95.2 ~ 95.7%; And a slush pump of stopping transport, namely during 2 serum recycle pump operations, liquid-gas ratio reduces to 9.8L/m3, and desulfuration efficiency is reduced to 90.3 ~ 90.8%.
System adopts CO2 gas activation (activation gas liquid ratio 0.8 × 10
-3m3/L, activation temperature 50 DEG C, average activation time 3h) after lime stone slurry when running, in exiting flue gas, SO2 concentration has been reduced to 40 ~ 60mg/m3, and desulfuration efficiency reaches 96.6 ~ 98.2%.When desulfuration efficiency is comparatively stablized, carry out energy-saving run Adjustment Tests, a slurry circulating pump of namely stopping transport, in exiting flue gas, SO2 concentration has risen to 90 ~ 100mg/m3, desulfuration efficiency has been reduced to 94.4 ~ 95.0%, meets the requirement of country to coal fired boiler of power plant Air Pollutant Emission.
The content that this description is not described in detail belongs to the known prior art of professional and technical personnel in the field.
Claims (5)
1. a method for intensified lime stone-gypsum wet flue gas desulfurizing slurry activity, is characterized in that: comprise the following steps:
(1), in the bottom of lime stone slurry case arrange activation pipe network, the high concentration CO 2 gas trapped by oxygen-enriched combustion boiler system back-end ductwork extension system enters activation pipe network and activates the desulfurization slurry in lime stone slurry case;
(2) lime stone slurry, after activation enters absorption tower and SO2 gas carries out counter current contacting and absorption, and after activation, the CO2 gas overflowing mouth of CO2 gas through slurry tank top of spilling returns former oxygen-enriched combustion boiler system back-end ductwork.
2. the method for the intensified lime stone-gypsum wet flue gas desulfurizing slurry activity according to claims 1, is characterized in that: in described step 1 activation while can pass in lime stone slurry steam with by lime stone slurry heating temperatures to 20 ~ 70 DEG C.
3. the method for a kind of intensified lime stone-gypsum wet flue gas desulfurizing slurry activity according to claims 1, it is characterized in that: in described lime stone slurry, the particle diameter of lime stone is less than 63 μm, serum density is 1300 ~ 1400kg/m3.
4. the method for a kind of intensified lime stone-gypsum wet flue gas desulfurizing slurry activity according to claims 1, is characterized in that: in described activated gas, the volumetric concentration of CO2 is 80 ~ 90%.
5. the method for a kind of intensified lime stone-gypsum wet flue gas desulfurizing slurry activity according to claims 1, is characterized in that: described control activation gas liquid ratio is (0.5 ~ 1) × 10
-3m3/L; Soak time is 1 ~ 3 hour.
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Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1701837A (en) * | 2005-04-08 | 2005-11-30 | 沈阳化工学院 | Technology for improving utilization rate of limestone desulfurizer in flue gas desulfurization |
| EP1764145A1 (en) * | 2005-09-20 | 2007-03-21 | Messer Group GmbH | Process for regulating the concentration of sulphur dioxide in flue gases |
| CN102380301A (en) * | 2011-08-15 | 2012-03-21 | 西安热工研究院有限公司 | Limestone-plaster wet method flue gas desulfurization composite synergistic agent |
| CN103752164A (en) * | 2014-01-16 | 2014-04-30 | 华中科技大学 | Limestone-gypsum wet flue gas desulfurization device |
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- 2014-11-03 CN CN201410607024.3A patent/CN104437067B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1701837A (en) * | 2005-04-08 | 2005-11-30 | 沈阳化工学院 | Technology for improving utilization rate of limestone desulfurizer in flue gas desulfurization |
| EP1764145A1 (en) * | 2005-09-20 | 2007-03-21 | Messer Group GmbH | Process for regulating the concentration of sulphur dioxide in flue gases |
| CN102380301A (en) * | 2011-08-15 | 2012-03-21 | 西安热工研究院有限公司 | Limestone-plaster wet method flue gas desulfurization composite synergistic agent |
| CN103752164A (en) * | 2014-01-16 | 2014-04-30 | 华中科技大学 | Limestone-gypsum wet flue gas desulfurization device |
Non-Patent Citations (4)
| Title |
|---|
| 《第二次气候变化国家评估报告》编写委员会: "《第二次气候变化国家评估报告》", 30 November 2011, 科学出版社 * |
| 大唐国际发电股份有限公司: "《火力发电厂辅机集控岗位认证教材理论部分》", 31 August 2013, 中国电力出版社 * |
| 韦迎旭等: "《绿色燃煤发电技术》", 31 May 2011, 中国电力出版社 * |
| 骆仲泱等: "《二氧化碳捕集 封存和利用技术》", 31 May 2012, 中国电力出版社 * |
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