JPS58166922A - Desulfurizing and denitrating method - Google Patents

Abstract

PURPOSE:To desulfurize and denitrate waste gases contg. sulfur oxide (SOx) and nitrogen oxide (NOx) by mixing ammonia with said waste gases, and using carbonaceous adsorbents at temps. in a 110-180 deg.C. CONSTITUTION:The 1st reaction column 1 and the 2nd reaction column 2 consisting of a moving bed system packed with cabonaceous particles such as active carbon are communicated. A by-pass piping is provided to the 2nd column and a piping for injection of ammonia is provided in the inlets of the 1st and the 2nd columns. Waste gases are increased in pressure with a pressure increasing fan 3, whereafter ammonia is injected threrein to SOx/NH3=0/3-0.6, more preferably 0.4-0.5 with respect to the inlet SOx, whereby mainly desulfurization is accomplished in contacting with the active carbon in the 1st reaction column. 800-1,000hr<-1> may be selected for the 1st reaction column because the treatment therein is mainly the desulfurization for which the rate of desulfurization required is relatively low and 600-800hr<-1> may be selected for the 2nd reaction column because the treatment is mainly desulfurization for which a relatively high rate of desulfurization is required.

Description

[Detailed description of the invention] Unexploded 94 is made of sulfur oxide (1i0x) and nitrogen-based sheet metal (
Mixed with exhaust gas containing ammonia (NOx), lit)
~184) @CD Hankyoku 0 Temperature improvement method for decondensation and denitrification of gas using a charcoal collecting agent.

The following methods have been proposed as methods for removing 80x and Now O ##in from exhaust gas.

l) *A denitrification and denitrification method that combines a method of catalytic reduction at a temperature of 300° C. or higher using a catalyst based on a chemical compound, and a desulfurization method.

2) A method of simultaneously denitrifying and denitrifying KJIS at medium to low temperatures below 150°C using a carbonaceous skin suction wound (Special-1989-28)
674, Special IIAid 54-127691).

3) A method of simultaneously decondensing and denitrating at medium to high temperatures of 180 to 250°C (Patent No. 91895:1).

4) Two stages of curing at a skin temperature of 150°C, FjlJ
A method of renunciation as a king in the treason and renunciation as the king in Vkm (%-154-13736. Registered in 1977)
-14235).

However, all of the above methods have problems in terms of popularity, economy, etc.

For example, the method of punishment has the drawback of requiring a large catalyst and the 80% reduction due to rigid reaction. 80. The disadvantage is that the leakage ammonia reacts in the air heater, etc., producing ammonium salts and blocking the elements, etc., and when wet demolition m#tw is installed later, ``j1 wood minutes are mixed into the wastewater. If the wastewater is discharged for a long time, it will be used for mowing, swamps, and sea water will be turned into a mound, and the process of treating the wastewater will be a public expense, resulting in an increase in costs.

Method 2) The ammonia injected with Fi reacts with the coexisting Box to form salt of 30 to 4 (Jq.
Bi! [There is a drawback that only a low denitrification rate can be obtained.

In addition, a) oyj method can achieve a high denitrification rate of 80- or more, but the general temperature range of 11'm18U to 250℃ is within the appropriate temperature range with the temperature-sensitive concave of the waste slag. I can't see it,
For example, it is not only undesirable to use vertical suction in the kotith-containing area because of the large loss due to oxidation, but also
Low i with 1m characteristics! If you try to obtain a high desulfurization rate in this YMh reaction range due to dependence, there are six disadvantages, such as requiring public funds to use activated carbon, which has excellent desulfurization properties and is dangerous.

Therefore, Motoya et al. investigated the reason why only a low denitrification rate was obtained even though they were satisfied with the denitrification rate. It was found that the resistance was greatly affected by the resistance, and its resistance was as shown in Figs. 1 and 2 VC.

This test was carried out using a fixed-bed reaction tower containing activated carbon ljt based on synthesized υtocas.
The reaction time at 200pp of NO was summarized by graphical integration as the average depletion over a reaction time of 48 hours, and Figure 2 shows 8016! The results obtained using Hiki II at 25 u ppm are similarly summarized.

What is very noteworthy about this rice feeding is that when the inlet SOx yield is 301 J ppm or less, a good denitrification rate can be obtained.
Contrary to the conventional catalytic reaction, a moderation method was discovered that resulted in a very high denitrification rate with a low population NOx.

This is due to the fact that the denitrification effect lasts for a long time when the population SOx (59 degrees) is low, and the active points of activated carbon are less covered by the SOx rc caused by g & 7 # hibiki or live fire. It is estimated to be.
゛The activated carbon with reduced Vc activity can be prepared by a known method.
11. 100% sexual I11. I am hopeful that he will recover.

On the other hand, method 4) is a method that allows a relatively high denitrification rate to be obtained, but the method disclosed in Japanese Patent Application No. 13736/1983 uses a specific soft box at the outlet of the previous reaction field in the second stage reaction tower.
This means that areas with high levels of NOx and thorns will be treated, and this will not necessarily satisfy the denitrification conditions clarified by Kabutoaki et al., but it will be necessary to treat the denitrification rate under wide-ranging gas conditions. If you try, you'll end up with the third problem. Reprocessing in the fourth reaction tower is a public expense, and in order to satisfy the above denitrification conditions, it is necessary to significantly lower the initial stage Sv and/or activated carbon drying time, so it is not stationed. There were drawbacks.

Well, it was disclosed in the patent application No. 55-14235, and the second son law is 2hL.
- It seems that the aim is to lower the population box performance, but there is no clear indication of the range of ail117, and it is not necessarily 800 ppm or less. In addition, we intentionally avoid purchasing ammonia in the first stage. The same point of this method is that since there is no ammonia in the first stage, it is not possible to expect the denitrification rate to be reduced at mW. 20. As a result, the disadvantage is that one has to choose a very low BV and/or a low retention time.

Furthermore, the other effects of ammonia injection were
As disclosed in 387 and Sho 64-143 (18, etc.), the improvement of activated carbon's brawn rudder and denitrification performance, that is, the activation of activated carbon with ammonia, and the increase in utility costs due to ammonia madness. However, it seems that the above method does not fully enjoy the effect of oxidation.* Another problem with this method is that there are two reaction fields. As a result, the amount of activated charcoal is greater than that of the rice cultivation method, which increases the burden of eliminating WAK*.

The effect of ammonia injection is as mentioned in 1.
On the other hand, it is necessary to solve the problem of ammonia leakage. Under normal conditions, ammonia is absorbed and produced on activated carbon by the reaction shown by the following formula - Absorbed by acid a, 5 cfi 10 NH, → m4 HsoFl (1) NH + N ■ 1 → (Sunishi 802 ■ (Go shows the state where it is adsorbed to the axillary armpit.) and leaks are rare, but
If you try to cover more km* under low SOx conditions, the excess absorption of young fruit will not be able to absorb enough M, and there will inevitably be a drawback that leaks will easily occur, and there will be restrictions from this environment. It is preferable that the leakage be kept at 10 ppm or less, preferably at most ridge ppm, from the ridge point to prevent secondary leakage.

This improvement was made in order to solve the above problems, and by improving the 4) (D':)j method, it was inspired by the steering force of copper removal and copper removal, and it was also economically effective. It provides an advantageous dewaxing-dedewing method.

That is, the desulfurization/denitrification method of the present invention can be applied to
Contains 110 to 18 U'lc, and mixes annular scum into the sludge and then oxidizes the carbon XI and skin. In the method of denitration, the exhaust gas mixed with ammonia is led to the first reactor, and denitrification is performed concomitantly with a vc glare so that the sulfur compound a [: of the first reaction] is 30099 m or less. Then, the entire inside of the first reaction field or -St ammonia gas is injected into the second reaction tower through the nose, and denitrification and desulfurization are performed concomitantly.

The following is a detailed explanation of the embodiment shown in Fig. 3.
The second reaction tower 1 and the second reaction field 2 are connected, and the second reaction tower is equipped with a pipe I cess control, and the first and second reaction towers are equipped with ammonia injection arrangement. It is provided.

The plowing gas is the population SOx vc after being boosted by the booster fan 3rc.
Ammonia is injected so that So

However, the SOx performance at the outlet of the reaction field is preferably 300 ppm or less from the dead tree shown in Figure 1, which has been explained above.
Contains 8v and inn so that the concentration is below 250 ppm.
#f same is returned・ Construction population SOx production is 1. For OU Oppm machine
V is set to 800 to IO (10 hr). At this time, incidental denitrification is carried out 3 times (11 times). Then, the treated waste is transferred to the second reaction tower for reinjection of ammonia.

In order to raise the 5vFi 1st and 2nd reaction towers and reduce the amount of 9-oil grade boiling as much as possible, it is necessary to escape the sv. Since the desulfurization rate is good, SOU ~ 1,0 υ (lhr (normal temperature standard, same below) It's funny.

Also, the main reaction formula for the amount of ammonia is MIJ■, 0
Formula and the following ■Formula NO 10Y, 0. 1NH Hatake-+NI+3/2) 1.0
It is thought that i) will be encouraged. *Activated carbon in the plow
In the cass population -, the formula 0 is used, in the middle part the formula is based on the Fi[F] formula, and in the Taguchi part, the king is wgJb, and on average it can be considered that the whole is based on the formula. NOx in the primary normal exhaust gas is NO, NO,
It is known that there are few people, and it is safe to assume that the reaction based on the & Hakuhari style is the royal salary.

Therefore, in order to suppress the ammonia leak, the maximum allowable ammonia in the case of 7 can be determined from the chemical formula (1) and the formula (0). If the amount of ammonia injected is less than the appropriate amount, the leak will disappear, but the denitrification rate will decrease; if it is too much, the denitrification rate will increase, but the leakage vessel will suddenly rise sideways. Experimentally, the appropriate injection amount is determined from the following formula, and the coefficient is usually selected between 0.9 and 1.1. If the conjugate value is relatively high, the upper limit is selected, and if it is low, the lower limit is selected. leaks tend to be less.

(hi)Is) -K @((NOX)”?
+ (80X) ”'I B □ x)
010w Here (Nag): Magnificent Nl (, chain degree [PM body base] (NO): 2nd installation entrance NO Isogami (-') [SOx
]:1sOxlC#] "1iox" Denitrification rate of the second slope [-]η,. x:
l Removal rate (K): Constant (K-0, 9 to 1.1) The oil quality time of Sv and activated carbon is selected so that the removal rate of μl and rL in the 8g2m reaction tower are the same. Usually s■ is population hO
When xdkK is 200 to 800 ppm, suo to 80
(l hr is selected. In this case, the denitrification rate is 65 to 8
0chi, I1Ko is almost l0LIChi.

Therefore, the combined SX and second reaction tower has an excellent denitrification rate of 75 to 85 g6 and a continuity rate of approximately lu'Ll-.

Furthermore, Vcgx and the activated carbon discharged from the second reaction tower are led to a de-hemifying device 4 and converted into an inviscid gas 'I1. - The precursor is heated to 400° C. under air and returned to the first and second reaction sites, respectively. This exclusion &! AI collected Sow 1
11m gas can be recovered as sapon or simple sulfur at -j raw materials (b) collection equipment 5.

As can be understood from the above explanation, according to Takaaki Moto, due to the rational sharing of tin salt in the first and second RKs and the somai effect, the tin salt conditions in the first and second stages are relatively low compared to the wide range of scum conditions. Free Vc can be traced, relatively soft Sv and long activated carbon retention time can be selected for the t-tako building process, so it has the advantage of economical and low denitrification rate and dehydration. .

By the way, if you don't really want to break away from 4J14,
By bypassing part of the waste from the W42 reaction tower VC, a similar configuration can be obtained, and the second reaction 4 can be made smaller, so it is considered similar to tuna. Also, increase the dropout rate by projecting
If the sea bream is round and round, purge the off-scrap from the 11L second reaction tower outlet, and leave the rest in m.
It is sufficient to recycle it to the artificial reactor of 1 liters of reaction tower. Normally - Conversion of raw product recovered yarn to raw product 4A is 90 to 97 whispers, and the rest is recycled.

As a result, the population 5Oxal& will be 3-10%+%,
This method has been adopted since it is more reasonable than other methods such as using a dedicated salt treatment method. In addition, purging the off-scrap of the raw material collection equipment outside the system not only reduces the amount of 516 SOx emissions, but also reduces the amount of waste to be disposed of within the system. There is an advantage that the official fee, installation IiI valley tomb is a little more one-knight than the same as above.

Furthermore, this method has the advantage that it does not affect the denitrification rate and allows only the arm-body rate to be reduced because the NoxQ level is considerably lower than that of SOx in the off-gas.

4th cause (NH, Onjun line, copper raw materials collection Kyogi temple is 4wh
O) shows that the activated carbon discharged from the second reaction tower is completely supplied to the first reaction tower, and in this way, the purpose of 4% light is achieved.

In this case, it is discharged from w&l and the second reaction field'*fc
Depending on the balance of the amount of activated carbon supplied, the amount of activated carbon is bypassed to the desorption tower and the insufficient amount is taken from the t! Even if they try to provide L rice, it doesn't work. Box for tin salt in the second reaction field
Since the amount of il is small, the amount of oily urine excreted is 80. A is the level of the first reaction tower, 1410~150■
/9 Less intense than activated carbon, usually 3011v/j
' and is still sufficient Sθ! If the surplus gold layer in the ridge layer is supplied to the M1 reaction field, the decopper-removed momme in the 6th tower of the first reactor will be lowered, but the reduction will be lower unless there is a problem with the resistance of the now treated layer. minutes can be completed in the #IS2 reaction field.

Although the activation time for 21Xkcr oak will be shorter, the number of activated carbon violets that need to be treated in a row will be greatly reduced due to the series of young trees using this method. Compared to the conventional method, this method has the advantage of reducing losses due to pulverization of activated carbon, as well as the labor costs and equipment costs required for de-Nyu.

The above embodiments have been explained using a moving bed system, but in general, a cross-flow system with good site efficiency has prevailed, and it is the same even if Ma-7 is a fixed bed system and multiple units are switched using piping. If the effect is superior, it is also possible to use a mixed system in which the first reaction column is a moving bed and the second column is a fixed bed.

The charcoal 3 used in the present invention is made of activated carbon made from known power paper, semi-formed coke, activated char 01, and the following: It does not matter if the first reaction tower and the second bacterial reaction tower are filled with different materials.

Note that 6 in the figure indicates dan/l-f.

By way of example, implementation S will clarify the effectiveness of the present invention.

Machine mf#s 1.06011PIII 10 Box and a OOpp
Stone-fired exhaust gas containing M NOx vt10,0
00 NWI/hr MR discharge ammonia vth l
Q After mixing with pprm, 10 d (J
iV 1000hr-"Hikari Tenshi Ishio moving bed type reaction tower.

The cough reaction of activated charcoal was confirmed for 87 hours (transfer amount 0.
29 wl/by), the zeta-filtration desulfurization rate was 76.5.
-1 denitrification rate of 87- was obtained, exit 80x score was 249
ppm and Noxlli degree was 119 ppm.

Furthermore, add 4o of ammonia to this treated gas.

The same granular activated carbon with a temperature of 1B'0'C after mixing ppm4 14.9wt (8V670hr-"11"/v
41111 bed type reactions of L7tM2 were completed. The residence time of activated carbon in the reaction tower was 48 hr (transfer amount 0-31
wl/kr)vcW& was determined, and the outlet NOX linearity was 59 ppm.

The SOx performance level is ppm and the denitrification rate is 710-1 and the denitrification rate is 1.
00- was obtained and the ammonia leak was 5 pprm. Then @l! Combined hole total denitrification rate F of reaction tower
At i80.3, the removal rate is 10 (1-), and the activated carbon transfer amount is 0.1i0d/hr.

As is clear from this m-bottle, excellent denitrification and removal rates were obtained with a relatively low residence time (transfer amount) of activated carbon.

Example 2 In the apparatus of 1l Example 1, the activated carbon discharged from the second moving bed reaction tower was supplied to the first moving bed reaction tower, and the waste was passed through the sieve Io reaction tower under the same conditions as IUI4sI. Introduced to gi4! ! Oil trade time in vertical reaction tower i27
．． When set to 0kr (transfer amount 0.8? wt/kr), the exit 80x 111 degrees is 2 I Oppwa.

Nox ridge 1 has a nm sulfur rate of 256 ppm, 7 @, ll
1l.

A denitrification rate of 14.5 was obtained. After mixing 4 soppmN of ammonia into this treated gas, #! 2
The reactor was introduced into the reaction column of vh. OW in the second reaction column of activated carbon
When the trade time threshold was set to 40hr (transfer amount o, 37w1/by), the exit NOx girl JX was 59 ppm%80
x 11 degrees o ppm, 9 denitrification rate 77.

-1 removal -$100- is obtained, and ammonia leak is i
ppm.

Then $1. The h-denitrification rate including the f1 reaction is 8.
0.1, the desulfurization rate is 100-1, and the activated carbon transfer amount is OS 7 d/hh-. From Example 1! 1!
Excellent denitrification and desulfurization rates were obtained with low activated carbon transfer rates.

Example 3 Exhaust gas from Stone R-burning Zei 2 was introduced into a moving bed reaction tower filled with 10I of activated carbon at a temperature of 145° C., and the relationship between SOx performance (8 air velocity KCBV) and denitrification rate was tested. □In this case,
At the inlet 80x, the waste from the reaction tower outlet is recycled to the inlet, and the NOx loss is 0, and the shortage is NH,
Inject 1ll to oxidize it to 220 ppm at the inlet.
It was rich. The residence time of the activated carbon was 48 hr, and the ammonia injection lid was adjusted to the skin characteristic determined by formula 0 in the text, and the results shown in the table below regarding the denitrification rate were obtained.

No.l Red (The unit of O removal TI/4 rate in the table is -.) From this,
The relationship between deMl removal and 80K concentration warping Sv was clarified,
In particular, it should be noted that when performing desulfurization and denitrification*, it is clear that a high denitration rate can be obtained by lowering Sθx & Il (below 800 ppm). We tested the relationship between one population condition, the amount of ammonia injection, and the amount of ammonia leak.

When the inlet gas temperature was 145'C and the activated carbon residence time was 48 hours, the results shown in the table below were obtained.

(Left below) □ From the results in Table 2, the ammonia that should be injected is Salt Theory NH.
&W14 is certain that it is enough as long as the injection amount is satisfied. Also, in Gestom 1, there are many NH, injection lids, and then K NM.
, 80K in 9, tests A5 and 6, which have a large amount of leakage.
Since there is no ammonia at all, the activated carbon does not adsorb ammonia and the amount of ammonia leaks is large and dangerous.

On the other hand, test A4 was NH, and although the leakage amount was satisfactory, the denitrification rate was low due to the high 80K temperature.

In this way, the SOx sputum level and NHI in desulfurization and denitrification methods
2.The influence of the amount of personnel etc. on the desulfurization rate and the NOx removal rate is much larger than that of the non-electronics. 1.The present invention is the first to achieve excellent desulfurization and NOx removal rates based on the above knowledge.

[Brief explanation of the drawing]

Figure 1 shows the relationship between the inlet 80m& and the average denitrification rate.
Figure 2 shows the population No. 114 and the average denitrification rate! Indicates the person in charge. Figures 3 and 4 show a 1-meter view of the practical implementation of the present invention. l...m1 reaction tower 2...edition 2 reaction go 4...
Demitter S... - Raw material collection device patent applicant Sumitomo Heavy Industries, Ltd.

Claims (1)

[Claims] 1. Sulfur oxide, temperature [110 to 1] containing m-sulfur oxide
In the method of removing waste scum by mixing ammonia gas into 80℃ plow waste and filling two reaction towers at a construction site with a skin-damaging bulk absorbent, Anne 4 :
The exhaust gas mixed with air is transferred to JX and the reaction is 1 reaction.
rc removal and concomitant removal of 1at bamboo so that it is below pm,
A desulfurization and denitration method in which all of the log gas discharged from the first reaction tower or the ammonia gas is then injected into the 11th reaction tower and denitrified and additionally desulfurized. 2. Sulfur identification results of log gas emitted from the first reaction field [kai 250
1. The method of 1st filling in the range 111 of the watch, which is characterized by the amount of ppm or less. 3. A billing method characterized in that the amount of ammonia added to the first reaction #b loggas is determined based on the following formula. [NHs] = K ●((NOx) +
(130x) *ηBoz 'ow Here [Su. ] ; Injection warehouse. Performance record (ppm) (No!)
:ll *Reactive group population illillg enemy solidification BL (
ppm) (801): 2nd reaction tower person Royoh enemy vlI
Denitrification rate of reaction tower [-] da.., dewaxing rate of sag reaction [1] K: Constant (Ko.s ~ 1.1 n