CN100348298C

CN100348298C - Process for eliminating SOx in flue by activated carbon based adsorbent

Info

Publication number: CN100348298C
Application number: CN 200410024151
Authority: CN
Inventors: 李春虎
Original assignee: Ocean University of China
Current assignee: Ocean University of China
Priority date: 2004-05-26
Filing date: 2004-05-26
Publication date: 2007-11-14
Anticipated expiration: 2024-05-26
Also published as: CN1583219A

Abstract

The present invention discloses a technology for eliminating SO2 in fume by using active carbon-base adsorbing agents. The technology comprises the following steps that the fume with SO2 is desulfurized by a desulfurizing tower or desulfurizing tank filled with the active carbon-base adsorbing agents, the active carbon-base adsorbing agents are regenerated by hot water washing or inert gas high-temperature sweeping when the SO2 outlet density of the desulfurizing tower or the desulfurizing tank surpass indexes, and the regenerated products are dilute H2SO4 or simple substance S. The technology has the advantages that the sulfur capacity and the service efficiency of the adsorbing agents can be obviously improved, the byproduct dilute H2SO4 or simple substance S is generated in the process of regeneration, the effect of the comprehensive utilization of resources is achieved, and the technology can be used in coal-fired power plants, coal-fired boilers, coal-fired shaft furnaces and other fume desulfurizing and purifying industries for environmental protection.

Description

A kind ofly utilize absorbent charcoal based adsorbent to remove SO in the flue gas 2Technology

Technical field

The present invention relates to a kind of SO in the flue gas that removes ₂Technology, more specifically say so and a kind ofly utilize absorbent charcoal based adsorbent to remove SO in the flue gases such as coal-burning power plant, coal-burning boiler and coal-fired furnace ₂Technology.

Background technology

Coal accounts for 69% in the energy consumption structure of China, a large amount of burnings of coal make national atmosphere be coal-smoke pollution, and particularly since the eighties, along with China's economy develops rapidly, the coal consumption amount increases day by day, SO ₂Discharge capacity constantly increases, and causes the atmospheric environment severe contamination.According to statistics, China SO in 1985 ₂Discharge capacity is 1,530 ten thousand tons, and nineteen ninety is 1,752 ten thousand tons, and nineteen ninety-five just rises to 2,370 ten thousand tons, estimates SO in 2000 at this rate ₂Discharge capacity will be 2,590 ten thousand tons.Because SO ₂A large amount of dischargings, cause environmental destruction, the acid rain phenomenon is serious.China's acid rain area has accounted for 40% of area at present, and national precipitation acidity on average raises 2-8 doubly, the rare Precipitation pH in the world occurs and is lower than 4 situation.Because the acid rain sedimentation is to agricultural, forestry and material damage are caused economic loss every year is up to more than 1,000 hundred million yuan.So cut down SO ₂Discharge capacity reduces SO ₂Concentration of emission prevents SO ₂Atmosphere pollution is based on national conditions, and developing the flue gas desulfurization technique that adapts to different scales has become current and following interior quite over a long time main task.

According to China's strategy of sustainable development and China's Agenda 21, the beginning of this century, national SO ₂Total emission volumn must not surpass 2,370 ten thousand tons of nineteen ninety-five.But with regard to present flue gas desulfurization technique, its investment and operating cost occupy high-leveled and difficult following, are difficult to promote, although cause environmental administration will strengthen SO year by year ₂The fine dynamics of discharging, but can't fundamentally provide correlation technique to be solved.Both at home and abroad at present industrialization and the flue gas desulfurization technique studied have hundreds of approximately, and these methods can be divided into dry method and wet method on technology, can be divided into from the recycling of adding desulfurizing agent and discard method and absorption method.Wherein the main method of industrialization or pilot scale has: 1) ammonium sulfite; 2) citrate method; 3) active carbon wet desulphurization; 4) phosphorus ammonia composite fertilizer is produced in wet desulphurization; 5) electronic beam method desulfurization; 6) lime-gypsum method desulfurization.Above method or investment are big, operating cost is high, be that waste desulfurizing agent can't utilize after the desulfurization, secondary pollution is arranged, for power plant's heavy duty boiler, the stacking of waste residue or be subjected to the restriction of freight charges or be subjected to the restriction that stack in the place, all be influence desulfur technology can business-like key factor.Therefore, these technology all are difficult to large-scale promotion and use in China at present.Wherein, the flue gas desulfurization technique of large-scale commercial applications application (the FGD pulverized limestone sprays into method) in the world, its technology maturity height, China also has power plant to introduce, but because cost height, big, not also none the example success of comprehensive utilization of by-product gypsum of investment.Most researchers thinks that modified active semicoke isoreactivity charcoal base adsorbent removes SO in the flue gas at present ₂The most rising.

Summary of the invention

The purpose of this invention is to provide and a kind ofly utilize absorbent charcoal based adsorbent to remove SO in the flue gas ₂Technology.

A kind ofly utilize absorbent charcoal based adsorbent to remove SO in the flue gas ₂Technology, it is to contain SO ₂Flue gas, by desulfurizing tower or the desulfurizer desulfurization that absorbent charcoal based adsorbent is housed, as desulfurizing tower or desulfurizer SO ₂Adopt hot wash or inert gas high temperature to purge absorbent charcoal based adsorbent when exit concentration surpasses index and regenerate, regeneration product is rare H ₂SO ₄Or simple substance S.

Concrete process condition of the present invention is at temperature 60-160 ℃ and air speed 500-2000h ^-1Following desulfurization, 60-90 ℃ with hot wash regeneration or 340-680 ℃ and air speed at 500-4000h ^-1Regenerate with inert gas purge down.The SO that contains in the common flue gas ₂Concentration is 0-5000ppm.Described absorbent charcoal based adsorbent can adopt ozone activation method or the preparation of high pressure hydrothermal chemistry activation method by active carbocoal, activated coke or active carbon isoreactivity carbon based material, and above-mentioned two kinds of preparation methods have applied for patent by the inventor.

Individual tower of process using three of the present invention (many) or the individual groove of three (many), their uses that also can be operated in parallel of both can having connected, common two desulfurization, a regeneration.

Advantage of the present invention is obviously to improve the Sulfur capacity and the service efficiency of adsorbent, and regeneration process in the rare H of by-product ₂SO ₄Or simple substance S, reached the effect of comprehensive utilization of resources.This technology can be used in the desulfurizing and purifying environmental protection industry of flue gases such as coal-burning power plant, coal-burning boiler and coal-fired furnace.

The specific embodiment

Describe the present invention in detail below in conjunction with accompanying drawing and by specific embodiment.

Fig. 1 is a process chart of the present invention.

Fig. 2 is the desulfurization process figure that adopts hot wash regeneration.

Fig. 3 is the desulfurization process figure that adopts inert gas purge regeneration.

Embodiment 1:

As shown in Figure 2, adopt three reaction towers separately or go here and there the operation of (also) connection. The reaction tower diameter is equal Be 70mm, every tower filling amount is 1 liter, and weight is the active semicoke adsorbing agent of 581 grams, in the desulfurization temperature Degree is 90 ℃, and air speed is 900h^-1, flue gas consists of SO₂800-2600ppm、O ₂9.5-14.8%, CO 75-435ppm, all the other are N₂And CO₂Under the condition, technological operation is as follows: at first open No. 1 and No. 2 valves, flue gas enters 1^#The desulfurization reaction tower, the flue gas after desulfurization purifies is after No. 2 valves enter purification Pipeline enters chimney; When 1^#Tower exit gas SO₂When detection is above standard (such as 200ppm), then close valve No. 2, open simultaneously No. 3 and No. 5 valves, this moment 1^#Desulfurization reaction tower and 2^#Desulfurization reaction tower string The connection operation; When 2^#SO in the tower exit gas₂When detection exceeds standard, then

close valve

1,2,3, No. 5, open simultaneously valve 4,6 and No. 8, this moment 2^#Tower and 3^#The tower serial operation carries out flue gas desulfurization; Simultaneously With hot water to 1^#Desulfurizing tower is regenerated, and opens valve A 90 ℃ of hot water with adsorbent volume equivalent (1.0 liters) are injected 1^#Reaction tower stopped after 1 hour, opened A ' valve, and the wash-out regenerated liquid is squeezed into dense H₂SO ₄In the accumulator tank; Then reusable heat water repeats aforesaid operations to 1^#Adsorbent in the tower is regenerated, and just regenerated liquid will be driven into rare H₂SO ₄In the groove; Treat from 1^#The regenerated liquid pH value that tower flows out equals 6 The time, stop regeneration. In like manner, when 3^#The tower SO that works off one's feeling vent one's spleen₂When exceeding standard, close 4,6 and No. 8 valve this moment Door; Open simultaneously valve 7,9 and No. 2, this moment 3^#After tower and the regeneration 1^#The tower serial operation carries out flue gas desulfurization, 2^#Tower carries out adsorbent reactivation, and its process is as follows: at first open the B valve, with pump with rare H₂SO ₄Rare H in the groove₂SO ₄Squeeze into 2^# Interior 1 liter of reaction tower stopped after 1 hour, opened B ' valve, and eluent is injected dense H₂SO ₄In the groove; 1 liter of the hot water of then regenerating injects 2^#After stopping 1 hour in the tower, eluent is imported rare H₂SO ₄In the groove, so repeatedly, until outlet eluent pH value rises at 6 o'clock, regenerated Entirely, so repeatedly carry out desulfurization and regenerative operation. So obtain the accumulation Sulfur capacity of absorbent charcoal based adsorbent Be 168%. This shows that this technology can obviously improve Sulfur capacity and the service efficiency of adsorbent.

Embodiment 2:

As shown in Figure 3, adopt independent or string (also) the connection operation of three reaction towers.The reaction tower diameter is 70mm, and every tower loadings is 1 liter, and weight is the active carbocoal adsorbent of 581 grams, is 90 ℃ at desulfurization temperature, and air speed is 900h ^-1, flue gas consists of SO ₂800-2600ppm, O ₂9.5-14.8%, CO75-435ppm, all the other are N ₂And CO ₂Under the condition, technological operation is as follows: at first open No. 1 and No. 2 valves, flue gas enters 1 ^#Desulfurization reaction tower, the flue gas behind desulfurizing and purifying pipeline after No. 2 valves enter purification enters chimney; When 1 ^#Tower exit gas SO ₂When detection is above standard (as 200ppm), then close valve No. 2, open simultaneously No. 3 and No. 5 valves, this moment 1 ^#Desulfurization reaction tower and 2 ^#The desulfurization reaction tower serial operation; When 2 ^#SO in the tower exit gas ₂When detection exceeds standard, then

close valve

1,2,3, No. 5, open valve simultaneously 4,6 and No. 8.This moment 2 ^#Tower and 3 ^#The tower serial operation carries out flue gas desulfurization; Use inert gas in the hot-blast stove to 1 simultaneously ^#Reaction tower is regenerated, and opens valve A ' and A, at temperature 340-680 ℃ and air speed 500-4000h ^-1Down to 1 ^#Adsorbent in the reaction tower carries out continuous purging from bottom to top, adsorbent will with the SO of absorption ₂And SO ₃Reaction generates sulphur steam, and reaction equation is as follows:

C+SO ₂＝S+CO ₂

3C+2SO ₃＝2S+3CO ₂

Exit gas is reduced to below 60 ℃ through temperature behind the cooler, and the sulphur steam in the gas becomes solid sulfur and reclaims at this moment, and the tail gas after the Recovered sulphur can continue to use behind hot-blast stove, and the gas sulfur content in the device to be cooled is reduced to 10mg/Nm ³When following, stop regeneration, open 1 ^#The feed bin discharge valve is to 1 ^#Reaction tower carries out adsorbent and replenishes, and adsorbent reaches scale 1 and is upgraded to and ends in reaction tower.This moment 1 ^#Reaction tower can carry out the next round desulphurization reaction.In like manner, when 3 ^#The tower SO that works off one's feeling vent one's spleen ₂When exceeding standard, close 4,6 and No. 8 valve this moment; Open valve simultaneously 7,9 and No. 2, this moment 3 ^#After tower and the regeneration 1 ^#The tower serial operation carries out flue gas desulfurization, 2 ^#Tower carries out adsorbent reactivation, and its process is with 1 ^#The regeneration of tower.Opening B ' and B valve, (mainly is CO with the tail gas after the Recovered sulphur ₂And N ₂Gas) squeeze into 2 through hot-blast stove ^#Tower carries out continuous purging from bottom to top, and it is regenerated.After the regeneration fully, open 2 ^#The feed bin discharge valve is to 2 ^#Reaction tower carries out replenishing of adsorbent.Carry out desulfurization and regenerative response so repeatedly.The accumulation Sulfur capacity that obtains absorbent charcoal based material adsorbent is 240%.This shows that this technology can obviously improve the Sulfur capacity and the service efficiency of adsorbent.

Claims

1. one kind is utilized absorbent charcoal based adsorbent to remove SO in the flue gas ₂Technology, it is characterized in that and will contain SO ₂Desulfurizing tower or the desulfurizer desulfurization of flue gas by absorbent charcoal based adsorbent is housed, as desulfurizing tower or desulfurizer SO ₂Adopting hot wash or inert gas high temperature to purge absorbent charcoal based adsorbent when exit concentration surpasses index regenerates.

2. according to claim 1ly remove SO in the flue gas ₂Technology, it is characterized in that described desulfurization is at temperature 60-160 ℃ and air speed 500-2000h ^-1Carry out under the condition.

3. according to claim 1ly remove SO in the flue gas ₂Technology, the regeneration that it is characterized in that described adsorbent be meant 60-90 ℃ with hot wash regeneration or 340-680 ℃ and air speed at 500-4000h ^-1Regenerate with inert gas purge down.

4. according to claim 1ly remove SO in the flue gas ₂Technology, it is characterized in that described desulfurizing tower or desulfurizer for three or more.

5. according to claim 1ly remove SO in the flue gas ₂Technology, it is characterized in that described desulfurizing tower or desulfurizer are three, two desulfurization, a regeneration.

6. describedly remove SO in the flue gas according to claim 1 or 4 ₂Technology, it is characterized in that described desulfurizing tower or desulfurizer are serial or parallel connection operation.

7. describedly remove SO in the flue gas according to claim 1 or 4 ₂Technology, it is characterized in that described desulfurizing tower or desulfurizer are serial operation.