CA1146875A - Free base amino alcohols as electrostatic precipitator efficiency enhancers - Google Patents
Free base amino alcohols as electrostatic precipitator efficiency enhancersInfo
- Publication number
- CA1146875A CA1146875A CA000346853A CA346853A CA1146875A CA 1146875 A CA1146875 A CA 1146875A CA 000346853 A CA000346853 A CA 000346853A CA 346853 A CA346853 A CA 346853A CA 1146875 A CA1146875 A CA 1146875A
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- Prior art keywords
- additive
- gas stream
- free base
- gas
- sulfur
- Prior art date
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Classifications
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B03—SEPARATION OF SOLID MATERIALS USING LIQUIDS OR USING PNEUMATIC TABLES OR JIGS; MAGNETIC OR ELECTROSTATIC SEPARATION OF SOLID MATERIALS FROM SOLID MATERIALS OR FLUIDS; SEPARATION BY HIGH-VOLTAGE ELECTRIC FIELDS
- B03C—MAGNETIC OR ELECTROSTATIC SEPARATION OF SOLID MATERIALS FROM SOLID MATERIALS OR FLUIDS; SEPARATION BY HIGH-VOLTAGE ELECTRIC FIELDS
- B03C3/00—Separating dispersed particles from gases or vapour, e.g. air, by electrostatic effect
- B03C3/01—Pretreatment of the gases prior to electrostatic precipitation
- B03C3/013—Conditioning by chemical additives, e.g. with SO3
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- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- General Chemical & Material Sciences (AREA)
- Treating Waste Gases (AREA)
- Electrostatic Separation (AREA)
Abstract
Abstract of Disclosure A method is disclosed for improving operation of an electrostatic precipitator. By adding free base amino alcohol to a particle-laden gas being treated by the precipitator, the efficiency of particle removal is significantly enhanced.
Description
1~46875 FREE BASE AMINO ALCOHOLS AS
ELECTROSTATIC PRECIPITATOR EFFICIENCY
ENHANCERS
Techn1cal Field S The use of an electrostatic prec1pitator for remov1ng part1cles from gas ts indeed well known. Typ1cally, th1s type of dev1ce ut11 kes the corona discharge effect, i.e., the charg1ng of the particles by passing them through an ion1zation field established by a plurality of d1scharge electrodes. The charged partlcles are then attracted to a grounded collect1ng electrode plate from which they are removed by v1bration or rapp1ng.
Th1s type of prec1pitator ls exempl1f~ed ~n U.S.
3,109,720 to Cumm1ngs and 3,030,753 to Penn1ngton.
A common problem assoc1ated w~th electrostatic precip-~tators 1s maxim1z1ng the efficiency of particle removal. For example, 1n the ut111ty ~ndustry, failure to meet part1cle emiss10n standards may necessitate reduct10n ~n power output ~derat1ng). Gas cond1tion1ng ~s an important method for accompl~sh1ng th1s goal as described in a book entitled "INDUSTRIAL ELECTROSTATIC PRECIPI-TATION" by Harry J. White, Addison-Wesley Publishing Company, Inc.
, (Reading, Massachusetts, 1963), p. 309.
An early patent disclosing a gas conditioning method for improving electrostatic precipitator performance is U.S. 2,381,879 to Chittum according to which the efficiency of removal of "acidic" particulates is increased by adding organic amine to the gas, specifically, primary amines such as methyl-amine, ethylamine, _-propylamine and sec-butylamine; secondary amines such as dimethylamine, diethylamine, dipropylamine and diisobutylamine; tertiary amines such as trimethylamine, tri-ethylamine, tripropylamine and triisobutylamine; polyaminessuch as ethylenediamine and cyclic amines such as piperidine.
Chittum does not disclose the use of alkanolamines as gas conditioners for electrostatic precipitators. However, U.S. 4,123,234 to Vossos does disclose the use of what he alleges to be alkanolamine phosphate esters for that purpose and has been patented over Chittum.
Description of the Invention The Yossos patent allegedly demonstrates the operability of the alkanolamine phosphate esters as electrostatic precipi-tator efficiency enhancers through a fly ash bulk electricalresistivity test according to which resistivity of a treated sample in a conductivity cell was determined by applying an electrode to the sample, applying voltages to the cell and measuring voltage across and current through the fly ash. The patent fails to disclose that the add1t1ves were ever tested 1n an electrostat1c prec1pltator.
It 1s doubted by the present inventors that aqueous solution chem-1stry as ut111zed 1n Vossos can be used to pred~ct behavior of chem1cals ~n the gas system found ~n electrostat1c prec1p~tators.
In fact, when tested for eff~c~ency enhancement in an electrostatic precipitator system, i~ was d~scovered that these compounds demon-strated l~ttle, 1f any, eff~cacy. In the tests conducted, the alkanolam1ne phosphate ester actually decreased efficiency.
Upon further 1nvest1gat1On 1t was unexpectedly d1scovered that, as compared to the alkanolam~ne phosphate esters touted by Yossos, tested free base unneutral1zed amino alcohols were far super1Or as electrostat1c prec1pitat~on eff~c1ency enhancers. These compounds w~ll here1nafter be referred to as free base am1no al-cohols, and any such reference 1s ~ntended to 1nclude m1xtures of such compounds.
.
free base am1no alcohols cons1st of molecules conta~n1ng pr1mary, secondary, or tert1ary am1nes wh1ch are unneutral1zed, that 1s, they are ~n the bas1c form w1th an unbonded pa1r of electrons ava11able for react1On. These compounds also have free hydroxyl funct~onallt1es and could, accordingly, be subjected to those react1Ons 1nvolv1ng hydroxyl groups.
Qulte d1st1nct~vely from the above-descr~bed free base am1no alcohols, the alkanolamine phosphate esters of Vossos are pre-~.
~46875 pared by the reaction of alkanolamine with phosphor~c acid. As aresult, the amine funct~onal~ty ~s neutralized making lt no longer ava11able to react as an amine. Also, the reaction of alkanolamine w1th phosphor1c acid causes reactlon of the alcohol functionality to form the phosphate esters, thus, reducing or eliminating the alcohol functional~ty present ~n the molecules.
Amino alcohols can be categorized as aliphatic, aromatic and cycloaliphatic. Illustrative examples oF aliphatic amino alcohols are as follows:
ethanolamine diethanolamine triethanolamine propanolamine dipropanolamine tripropanolamine isopropanolamine di~sopropanolamine tr~isopropanolam1ne diethylaminoethanol
ELECTROSTATIC PRECIPITATOR EFFICIENCY
ENHANCERS
Techn1cal Field S The use of an electrostatic prec1pitator for remov1ng part1cles from gas ts indeed well known. Typ1cally, th1s type of dev1ce ut11 kes the corona discharge effect, i.e., the charg1ng of the particles by passing them through an ion1zation field established by a plurality of d1scharge electrodes. The charged partlcles are then attracted to a grounded collect1ng electrode plate from which they are removed by v1bration or rapp1ng.
Th1s type of prec1pitator ls exempl1f~ed ~n U.S.
3,109,720 to Cumm1ngs and 3,030,753 to Penn1ngton.
A common problem assoc1ated w~th electrostatic precip-~tators 1s maxim1z1ng the efficiency of particle removal. For example, 1n the ut111ty ~ndustry, failure to meet part1cle emiss10n standards may necessitate reduct10n ~n power output ~derat1ng). Gas cond1tion1ng ~s an important method for accompl~sh1ng th1s goal as described in a book entitled "INDUSTRIAL ELECTROSTATIC PRECIPI-TATION" by Harry J. White, Addison-Wesley Publishing Company, Inc.
, (Reading, Massachusetts, 1963), p. 309.
An early patent disclosing a gas conditioning method for improving electrostatic precipitator performance is U.S. 2,381,879 to Chittum according to which the efficiency of removal of "acidic" particulates is increased by adding organic amine to the gas, specifically, primary amines such as methyl-amine, ethylamine, _-propylamine and sec-butylamine; secondary amines such as dimethylamine, diethylamine, dipropylamine and diisobutylamine; tertiary amines such as trimethylamine, tri-ethylamine, tripropylamine and triisobutylamine; polyaminessuch as ethylenediamine and cyclic amines such as piperidine.
Chittum does not disclose the use of alkanolamines as gas conditioners for electrostatic precipitators. However, U.S. 4,123,234 to Vossos does disclose the use of what he alleges to be alkanolamine phosphate esters for that purpose and has been patented over Chittum.
Description of the Invention The Yossos patent allegedly demonstrates the operability of the alkanolamine phosphate esters as electrostatic precipi-tator efficiency enhancers through a fly ash bulk electricalresistivity test according to which resistivity of a treated sample in a conductivity cell was determined by applying an electrode to the sample, applying voltages to the cell and measuring voltage across and current through the fly ash. The patent fails to disclose that the add1t1ves were ever tested 1n an electrostat1c prec1pltator.
It 1s doubted by the present inventors that aqueous solution chem-1stry as ut111zed 1n Vossos can be used to pred~ct behavior of chem1cals ~n the gas system found ~n electrostat1c prec1p~tators.
In fact, when tested for eff~c~ency enhancement in an electrostatic precipitator system, i~ was d~scovered that these compounds demon-strated l~ttle, 1f any, eff~cacy. In the tests conducted, the alkanolam1ne phosphate ester actually decreased efficiency.
Upon further 1nvest1gat1On 1t was unexpectedly d1scovered that, as compared to the alkanolam~ne phosphate esters touted by Yossos, tested free base unneutral1zed amino alcohols were far super1Or as electrostat1c prec1pitat~on eff~c1ency enhancers. These compounds w~ll here1nafter be referred to as free base am1no al-cohols, and any such reference 1s ~ntended to 1nclude m1xtures of such compounds.
.
free base am1no alcohols cons1st of molecules conta~n1ng pr1mary, secondary, or tert1ary am1nes wh1ch are unneutral1zed, that 1s, they are ~n the bas1c form w1th an unbonded pa1r of electrons ava11able for react1On. These compounds also have free hydroxyl funct~onallt1es and could, accordingly, be subjected to those react1Ons 1nvolv1ng hydroxyl groups.
Qulte d1st1nct~vely from the above-descr~bed free base am1no alcohols, the alkanolamine phosphate esters of Vossos are pre-~.
~46875 pared by the reaction of alkanolamine with phosphor~c acid. As aresult, the amine funct~onal~ty ~s neutralized making lt no longer ava11able to react as an amine. Also, the reaction of alkanolamine w1th phosphor1c acid causes reactlon of the alcohol functionality to form the phosphate esters, thus, reducing or eliminating the alcohol functional~ty present ~n the molecules.
Amino alcohols can be categorized as aliphatic, aromatic and cycloaliphatic. Illustrative examples oF aliphatic amino alcohols are as follows:
ethanolamine diethanolamine triethanolamine propanolamine dipropanolamine tripropanolamine isopropanolamine di~sopropanolamine tr~isopropanolam1ne diethylaminoethanol
2-am~no-2-methylpropanol-1 1-dimethylaminopropanol-2 2-aminopropanol-1 N-methylethanolamine dimethylethanolamine N,N-diisopropylethanolamtne N-am~noethylethanolamine N-methyldiethanolam~ne ~14687S
~-ethyldiethanolamine N-2-hydroxypropylethylenediam~ne N-2-hydroxypropyldiethylenetriamine amlnoethoxyethanol S N-methylaminoethoxye~hanol N-ethylaminoethoxyethanol l-amino-2-butanol di-sec-butanolamine tri-sec-butanolamine 2-butylaminoethanol dibutylethanolamine l-am1no-2-hydroxypropane 2-am~no-1,3-propanediol aminoethylene glycol dimethylaminoethylene glycol methylaminoethylene glycol aminopropylene glycol
~-ethyldiethanolamine N-2-hydroxypropylethylenediam~ne N-2-hydroxypropyldiethylenetriamine amlnoethoxyethanol S N-methylaminoethoxye~hanol N-ethylaminoethoxyethanol l-amino-2-butanol di-sec-butanolamine tri-sec-butanolamine 2-butylaminoethanol dibutylethanolamine l-am1no-2-hydroxypropane 2-am~no-1,3-propanediol aminoethylene glycol dimethylaminoethylene glycol methylaminoethylene glycol aminopropylene glycol
3-aminopropylene glycol 3-methylaminopropylene glycol 3-dimethylamlnopropylene glycol 3-amino-2-butanol Illustrative examples of aromatic amino alcohols are as follows:
p-aminophenylethanol o-aminophenylethanol phenylethanolamine phenylethylethanolamine p-aminophenol p-methylaminophenol Q-dlmethylamlnophenol o-am~nophenol Q-aminobenzyl alcohol p-dimethylaminobenzyl alcohol Q-a0inoethylphenol Q-dimethylaminoethylphenol Q-d~methylamlnoethylbenzyl alcohol l-phenyl-1,3-dihydroxy-2-aminopropane 1-phenyl-1-hydroxy-2-amlnopropane l-phenyl-l-hydroxy-2-methylaminopropane Illustrative examples of cycloaliphatic am~no alcohols are as follows:
cyclohexylam~noethanol d~cyclohexylaminoethanol
p-aminophenylethanol o-aminophenylethanol phenylethanolamine phenylethylethanolamine p-aminophenol p-methylaminophenol Q-dlmethylamlnophenol o-am~nophenol Q-aminobenzyl alcohol p-dimethylaminobenzyl alcohol Q-a0inoethylphenol Q-dimethylaminoethylphenol Q-d~methylamlnoethylbenzyl alcohol l-phenyl-1,3-dihydroxy-2-aminopropane 1-phenyl-1-hydroxy-2-amlnopropane l-phenyl-l-hydroxy-2-methylaminopropane Illustrative examples of cycloaliphatic am~no alcohols are as follows:
cyclohexylam~noethanol d~cyclohexylaminoethanol
4,4'-di(2-hydroxyethylamino)-d~-cyclohexylmethane 2-am~nocyclohexanol 3-amlnocyclohexanol 4-amlnocyclohexanol 2-methylam1nocyclohexanol 2-ethylam~nocyclohexanol d~methylam~nocyclohexanol d~ethylam~nocyclohexanol am~nocyclopentanol amlnomethylcyclohexanol Of course, the al~phat~c and cycloaliphatic amino alcohols can be grouped together under the category alkanolam~nes.
The amount of free base am~no alcohol requ~red for effect-1veness as an electrostat~c prec~p~tator eff~c~ency enhancer (EPEE) S may vary and w~ll, of course, depend on known factors such as the nature of the problem belng treated. The amount could be as low as about 1 part of active am~no alcohol per m~ on parts of gas be~ng treated (ppm); however, about 5 ppm is a preferred lower l~m~t. S~nce the systems tested required at least about 20 ppm act~ve am~no alcohol, that dosage rate represents the most preferrsd lower l~m~t. It ~s bel~eved that the upper l~m~t could be as h~gh as about 200 ppm, w~th about 100 ppm represent~ng a preferred maxi-mum. S~nce ~t ~s bel~eved that about 75 ppm act~ve am1no alcohsl w~ll be the h~ghest dosage most co~monly exper~enced in actual pre-c~pitator systems, that represents the most preferred upper l~mit.
Wh~le the treatment could be fed neat, ~t ~s preferablyfed as an aqueous solut10n. Any well known feed~ng system could be used, prov~ded good d~str~but~on across the g~s stream duct ~s ensur-ed. For example, a bank of a~r-atom~zed spray nozzles upstream of the prec1p1tator proper has proven to be qu~te effect~ve.
If the gas temperature ~n the electrostat~c prec~p~tator exceeds the decompos~t~on po~nt of a part~cular am~no alcohol be~ng cons~dered, a h~gher homolog w~th a h~gher decompos~t1on po1nt should be used. For example, ~n certa~n tests conducted, d~ethanol-amine was not e ff ect~ve as an EPEE at about 62~F, but a h~gherhomolog, such as tr~ethanolam~ne, should be su~table at such t~mper-ature.
EXAMPLES
A series of tests were conducted to determine the efficacy of various amino alcohols using a pilot electrostatic precipitator system comprised of four sections: (1) a heater section, (2) a par-t1culate feeding section, (3) a precip~tator proper and (4) an exhaust section.
The heater section consists of an electric heater in series with an air-aspirated oil burner. It is fitted with several in~ection ports perm~tting the addition of a chemical and/or the formulation of synthetic flue gas. Contained within the heater section ~s a damper used to control the amount of air flow ~nto the system.
Following the heater section is the particulate feeding section which consists of a 10 foot length of ~nsulated duct wor~
leading lnto the precip~tator proper. Fly ash is added to the air stream and enters the flue gas stream after passing through a venturi throat. The fly ash used was obtained from ~ndustrlal sources.
The precip~tator proper cons~sts of two duct-type pre-cipitators, referred to as ~nlet and outlet fields, placed in series. Particulate collected by the unit is depos1ted ~n hoppers located directly below the precipitator fields and ~s protected from reentra~nment by suitably located baffles.
g The exhaust section contains a var~able speed, 1nduced-draft fan which prov1des the alr flow through the prec~p1tator.
Sampl1ng ports are located 1n the duct-work to allow eff1c~ency determlnat10ns to be made by standard stack sampl1ng methods.
Opt~cal density, O.D., is a measure of the amount of light absorbed over a specif~c d1stance. Optical density is proportional to particulate concentrat~on, C, and optical path length, L, accord-1ng to:
O.D. ~ KLC, where K 1s a constant and 1s a function of the partlcle s1ze d~stri-bution and other physical properties of the particle.
S1nce opt1cal density 1s directly proport10nal to part~cu-late concentration 1t may be used to mon1tor em~ss10ns. Accord1ng-ly, an optical denstty monltor located 1n an ex1t duct of an elec-trostat1c preclp1tator would mon1tor part~culate em1ss10ns w1th and w1thout the add1t~on of chem1cal treatments to the gases. Treat-ments wh1ch 1ncrease the eff1c1ency of a un1t would result 1n decreased dust load~ngs 1n the exit gas. Th1s would be reflected by a decrease 1n O.D. To ensure reproducibility of results, part~culate s1ze distr~but10r. and other part1culate properties, such as dens1ty and refract1ve 1ndex, should not change s1gn~f1cantly w~th t~me.
~146875 Accordingly, in the tests conducted, a Lear Siegler RM-41 optical density monitor located ln the exit duct-work was used to evaluate precip~tator collect10n performance.
The use of the pllot electrostat~c precipitator and opt kal density monitor for evaluatlng the efficacy of a chemical treatment as an EPEE is illustrated below in Example 1.
Example 1 Fly ash produced as the combustion by-product of an approxlmately lX sulfur coal was found to have a resistivity of 1011 ohm-cm at 300F. Util1zing this ash type and a flue gas similar to that of an industrial utility plant, pilot electrostat k precipitator studies were performed to determine whether or not a gas conditioning agent could enhance the collection efficiency.
The results of the trial are presented in Table 1.
RESULTS OF FLUE GAS CONDITIONING
STUDY PE~FORMED IN LOW SULFUR SIMULATION
Parameter Test #1 Test ~2
The amount of free base am~no alcohol requ~red for effect-1veness as an electrostat~c prec~p~tator eff~c~ency enhancer (EPEE) S may vary and w~ll, of course, depend on known factors such as the nature of the problem belng treated. The amount could be as low as about 1 part of active am~no alcohol per m~ on parts of gas be~ng treated (ppm); however, about 5 ppm is a preferred lower l~m~t. S~nce the systems tested required at least about 20 ppm act~ve am~no alcohol, that dosage rate represents the most preferrsd lower l~m~t. It ~s bel~eved that the upper l~m~t could be as h~gh as about 200 ppm, w~th about 100 ppm represent~ng a preferred maxi-mum. S~nce ~t ~s bel~eved that about 75 ppm act~ve am1no alcohsl w~ll be the h~ghest dosage most co~monly exper~enced in actual pre-c~pitator systems, that represents the most preferred upper l~mit.
Wh~le the treatment could be fed neat, ~t ~s preferablyfed as an aqueous solut10n. Any well known feed~ng system could be used, prov~ded good d~str~but~on across the g~s stream duct ~s ensur-ed. For example, a bank of a~r-atom~zed spray nozzles upstream of the prec1p1tator proper has proven to be qu~te effect~ve.
If the gas temperature ~n the electrostat~c prec~p~tator exceeds the decompos~t~on po~nt of a part~cular am~no alcohol be~ng cons~dered, a h~gher homolog w~th a h~gher decompos~t1on po1nt should be used. For example, ~n certa~n tests conducted, d~ethanol-amine was not e ff ect~ve as an EPEE at about 62~F, but a h~gherhomolog, such as tr~ethanolam~ne, should be su~table at such t~mper-ature.
EXAMPLES
A series of tests were conducted to determine the efficacy of various amino alcohols using a pilot electrostatic precipitator system comprised of four sections: (1) a heater section, (2) a par-t1culate feeding section, (3) a precip~tator proper and (4) an exhaust section.
The heater section consists of an electric heater in series with an air-aspirated oil burner. It is fitted with several in~ection ports perm~tting the addition of a chemical and/or the formulation of synthetic flue gas. Contained within the heater section ~s a damper used to control the amount of air flow ~nto the system.
Following the heater section is the particulate feeding section which consists of a 10 foot length of ~nsulated duct wor~
leading lnto the precip~tator proper. Fly ash is added to the air stream and enters the flue gas stream after passing through a venturi throat. The fly ash used was obtained from ~ndustrlal sources.
The precip~tator proper cons~sts of two duct-type pre-cipitators, referred to as ~nlet and outlet fields, placed in series. Particulate collected by the unit is depos1ted ~n hoppers located directly below the precipitator fields and ~s protected from reentra~nment by suitably located baffles.
g The exhaust section contains a var~able speed, 1nduced-draft fan which prov1des the alr flow through the prec~p1tator.
Sampl1ng ports are located 1n the duct-work to allow eff1c~ency determlnat10ns to be made by standard stack sampl1ng methods.
Opt~cal density, O.D., is a measure of the amount of light absorbed over a specif~c d1stance. Optical density is proportional to particulate concentrat~on, C, and optical path length, L, accord-1ng to:
O.D. ~ KLC, where K 1s a constant and 1s a function of the partlcle s1ze d~stri-bution and other physical properties of the particle.
S1nce opt1cal density 1s directly proport10nal to part~cu-late concentration 1t may be used to mon1tor em~ss10ns. Accord1ng-ly, an optical denstty monltor located 1n an ex1t duct of an elec-trostat1c preclp1tator would mon1tor part~culate em1ss10ns w1th and w1thout the add1t~on of chem1cal treatments to the gases. Treat-ments wh1ch 1ncrease the eff1c1ency of a un1t would result 1n decreased dust load~ngs 1n the exit gas. Th1s would be reflected by a decrease 1n O.D. To ensure reproducibility of results, part~culate s1ze distr~but10r. and other part1culate properties, such as dens1ty and refract1ve 1ndex, should not change s1gn~f1cantly w~th t~me.
~146875 Accordingly, in the tests conducted, a Lear Siegler RM-41 optical density monitor located ln the exit duct-work was used to evaluate precip~tator collect10n performance.
The use of the pllot electrostat~c precipitator and opt kal density monitor for evaluatlng the efficacy of a chemical treatment as an EPEE is illustrated below in Example 1.
Example 1 Fly ash produced as the combustion by-product of an approxlmately lX sulfur coal was found to have a resistivity of 1011 ohm-cm at 300F. Util1zing this ash type and a flue gas similar to that of an industrial utility plant, pilot electrostat k precipitator studies were performed to determine whether or not a gas conditioning agent could enhance the collection efficiency.
The results of the trial are presented in Table 1.
RESULTS OF FLUE GAS CONDITIONING
STUDY PE~FORMED IN LOW SULFUR SIMULATION
Parameter Test #1 Test ~2
5 Chem~cat Feed Rate, ppm 0 66 Inlet Mass Load~ng, gr/scf 4.1605 4.1605 Outlet Mass Load~ng, gr/scf .2314 .0212 X Eff~c~ency 94 44 99 49 Opt1cal Dens~ty Basel~ne .175 .166 10 Opt~cal Dens~ty After Treatment - .026 X Reduction ~n Opt~cal Dens~ty - 84.34 As seen ~n Table 1, the chem1cal add~ttve at 66 ppm ef-fected an increase 1n prec~p~tator eff~c~ency of from 94.44X to 99.49X. The s19n~flcantly enhanced eff~c~ency 1s also reflected 15 by the 84.3X reduct~on 1n opt1cal denslty.
Example 2 The am~no alcohols were tested for EPEE act~v~ty us1ng several d~fferent ~ndustrial fly ashes. The var~ous fly ashes were characterlzed by known standard slurry analysis, and x-ray ftuor-escence and opt~cal em~ss~on spectra w~th the follow~ng resutts asreported ~n Table 2.
, ~ , CHARACTERIZATION OF fLY ASH SAMPLES
Fly Ash Des~gnation I II III IV
X Sulfur in coal 1-4 1-1.2 1.0-1.5 0.5 Resistivity ~ohm-cm) lolo<107 sX1o11 7.6Xlolo SLURRY ANALYSIS:
Calc1um as Ca, ppm 27 14 13 97 Magnesium as Mg, ppm 1.2 11 7 Sulfate as 504, ppm 92 67 44 56 10 Chloride as Cl, ppm .6 .6 Total Iron as Fe, ppm .05 .05 .10 Soluble Zinc as Zn, ppm .10 Sodium as Na, ppm 1.6 3.5 5.9 3.6 L1th1um as Li, ppm <.1 <.1 .2 .6 INORGANIC ANALYSIS:
(Weight ~) Loss on ign1t~on 3 21 4 3 Phosphorous, P205 1 ~1 - 1 Sulfur as S, S02, 503 Magnes~um as MgO
Aluminum as Al203 18 17 19 16 Silicon as SiO2 57 48 66 63 Calcium as CaO 3 < 1 1 6 TABL 2 (Contlnued) Fly Ash Deslgnat10n I II III IV
Iron as Fe203, Fe304 16 lO 6 8 5 T~02 2 Equ11~br~um pH slurry 6.9 6.6 8.411.7 The results of the tests evaluat~ng the e~f~cacy of var~ous amlno alcohols are reported below ~n Table 3 ~n terms of ~ decrease 1n opt~cal dens~ty (~ dØ0.). The var~ous fly ash de-s1gnat10ns are taken from Table 2. The column headed "Fly AshContent" is the amount of fly ash ln the gas ~n gra1ns per actual cub~c foot (gr/ACF). 6as flow rates ~n the p110t prec1p~tator are reported as actual cub1c feet per m1nute at 310F, and the S02 and S03 reported are the respect~ve amounts conta1ned ~n the gas 1n terms of parts per mill~on parts of gas. The H20 ~s approxlmate volume X ~n the gas. The chem~cal feed rates are parts of act~ve treatment per m~ on parts of gas.
.
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1~46875 As can be seen from Table 3, the amino alcohols were ef-fect1ve as electrostatic prec1p~tator eff1c~ency enhancers. Whlle the compounds tested were al~anolam~nes, 1t ~s bel~eved that am~no alcohols as a class would be effect1ve for the purpose. Also, wh~le S the test gas conta~ned fly ash and S02, which are cond~tions typ1cally found ~n coal-f1red bo11ers, ~t ~s bel~eved that the EPEE's accord~ng to the present 1nvention would be effective in other gas systems where part1culate matter is to be removed by an electrostatic prec1p~tator.
As a result of these tests, d1ethanolam~ne, being the most act~ve compound, ~s cons1dered to be the most preferred add1t~ve.
Example 3 To prov~de a compar~son w1th a phosphate ester accord~ng to the above-noted Yossos Patent, d1ethanolam1ne was tested for EPEE
eff1cacy as was d1ethanolam~ne phosphate ester made accord1ng to the patent.
In prepar1ng the alleged ester, 0.435 mole of phosphor1c ac1d was reacted w1th 0.435 mole of d1ethanolam~ne to y~eld an equ1molar m1xture. After allow~ng approx1mately 1.35 hours of react1On t1me, the mater~al was tested.
The results of these tests are reported below ~n Table 4 1n terms of reduct~on 1n O.D. (X d.O.D). The fly ash used was fly ash IY from Table 2.
o ,~
~ l l .
c a~ o o o . o o o ~ s~ l o ,_ ~ o ^ ~ C~l C~ C~ ~ ~
' S
z _ .c ~ o~ ~ o 8 8 ~ ~, ~,.
J Z
'I = '' ~ ~
~ o ~ ~e c~ N
--o ~
) ~1 ~ ;'1:
0~ ~:
Z~ _ 3 s~O ~o o ~, ~n ~
C,_ q, c o C~.
E e _ _ C o o O
~ C C o E tl~ ~ _ S L S
L O
Z
As can be seen from Table 4, the dlethanolam~ne was far super~or to the d1ethanolam~ne phosphate ester as an EPEE. The neg-at~ve ~ d.O.D. value for the phosphate ester run meant that the part~clè collect~on eff~c~ency of the pllot prec~p~tator was actual-ly decreased by th1s compound.
Prel~m1nary results of f~eld trials presently being con-ducted at a ut~11ty plant confirm the above-reported EPEE efficacy stud~es.
Industr~al bo~ler systems com~only ~nclude the bo~ler proper and heat exchanger means to rece1ve hot combust~on gas from the bo~ler. The heat exchanger can be e~ther an economlzer, wh~ch uses the combust~on gas to heat boiler feedwater, or an a~r preheat-er, used to heat a~r fed to the bo~ler. In e~ther case, the heat exchanger acts to cool the combust~on gas.
The most widely used bo~ler fuels are o~l or coal, both of which conta~n sulfur. Accord1ngly, the combust~on gas can conta~n sulfur tr~ox~de wh~ch reacts w~th mo~sture In the combust~on gas to produce the very corros~ve sulfur~c ac~d. Slnce the corros~ve effects are,~ndeed, qu~te ev~dent on metal surfaces ~n the heat exchanger equ~pment, cold-end add~t~ve treatments are ~n~ected ~nto the combust~on gas upstream of the economizer or a~r preheater to reduce corros~on.
If a boiler ~s coal-fired, electrostatic precipitator equlpment is somet1mes provided downstream of the heat exchanger to remove fly ash and other particles from the combustion gas. To im-prove the efficiency of particle collection, electrostatic precipi-S tation efficiency enhancers are typically added to the combustiongas at a location between the heat exchanger means and the precipi-tator, that is, downstream of the heat exchanger means.
8ased on economic and/or efficacy considerations, it may be desirable to blend various amino alcohols for optimization pur-poses.
It is understood that the amino alcoho1 can be fed direct-ly or formed ~n the gas stream, e.g., a decomposition product.
Havlng thus described the invention, what is claimed is:
Example 2 The am~no alcohols were tested for EPEE act~v~ty us1ng several d~fferent ~ndustrial fly ashes. The var~ous fly ashes were characterlzed by known standard slurry analysis, and x-ray ftuor-escence and opt~cal em~ss~on spectra w~th the follow~ng resutts asreported ~n Table 2.
, ~ , CHARACTERIZATION OF fLY ASH SAMPLES
Fly Ash Des~gnation I II III IV
X Sulfur in coal 1-4 1-1.2 1.0-1.5 0.5 Resistivity ~ohm-cm) lolo<107 sX1o11 7.6Xlolo SLURRY ANALYSIS:
Calc1um as Ca, ppm 27 14 13 97 Magnesium as Mg, ppm 1.2 11 7 Sulfate as 504, ppm 92 67 44 56 10 Chloride as Cl, ppm .6 .6 Total Iron as Fe, ppm .05 .05 .10 Soluble Zinc as Zn, ppm .10 Sodium as Na, ppm 1.6 3.5 5.9 3.6 L1th1um as Li, ppm <.1 <.1 .2 .6 INORGANIC ANALYSIS:
(Weight ~) Loss on ign1t~on 3 21 4 3 Phosphorous, P205 1 ~1 - 1 Sulfur as S, S02, 503 Magnes~um as MgO
Aluminum as Al203 18 17 19 16 Silicon as SiO2 57 48 66 63 Calcium as CaO 3 < 1 1 6 TABL 2 (Contlnued) Fly Ash Deslgnat10n I II III IV
Iron as Fe203, Fe304 16 lO 6 8 5 T~02 2 Equ11~br~um pH slurry 6.9 6.6 8.411.7 The results of the tests evaluat~ng the e~f~cacy of var~ous amlno alcohols are reported below ~n Table 3 ~n terms of ~ decrease 1n opt~cal dens~ty (~ dØ0.). The var~ous fly ash de-s1gnat10ns are taken from Table 2. The column headed "Fly AshContent" is the amount of fly ash ln the gas ~n gra1ns per actual cub~c foot (gr/ACF). 6as flow rates ~n the p110t prec1p~tator are reported as actual cub1c feet per m1nute at 310F, and the S02 and S03 reported are the respect~ve amounts conta1ned ~n the gas 1n terms of parts per mill~on parts of gas. The H20 ~s approxlmate volume X ~n the gas. The chem~cal feed rates are parts of act~ve treatment per m~ on parts of gas.
.
o c~ o o o o o ~Q
~n u~ u3 ~ --_ 'e ~o~ , , , , , , o I I I I I o o , C~ ~Y
l_ ~
L~ Z
J _C~l ~ D _ O O U~ O O C~
ZO ~ c~
Z
e e~_ e ~ ~ ~ _ ~, ,~, ~ ,~, ~ ,~, ," ,~, Zo ~Y
3~e o C- - .
z ~ e ~o o 1~ o o o ~ o ~ ~ co o o L~ ~
e c ~:_ _ _ _ _ _ _ _ ____________ __ ~ ~___._____________ O~^ _ d- I` O O ~ _ ~ ~ ~ ~O ~ ~ ~` O O
¢I E I.o ~ ~ m o Lt~
,~ CL
a E
o C o ~c a~ ~ ~ c ~ _ ~ c ._ E
a o _ _ ~ ~
~C ~ ~ o o E a~ ' ~: ~
E ~ ~1 c a Z I ~ ~ ~ . o l_ Zl E21 ~ ~-- E
1~46875 As can be seen from Table 3, the amino alcohols were ef-fect1ve as electrostatic prec1p~tator eff1c~ency enhancers. Whlle the compounds tested were al~anolam~nes, 1t ~s bel~eved that am~no alcohols as a class would be effect1ve for the purpose. Also, wh~le S the test gas conta~ned fly ash and S02, which are cond~tions typ1cally found ~n coal-f1red bo11ers, ~t ~s bel~eved that the EPEE's accord~ng to the present 1nvention would be effective in other gas systems where part1culate matter is to be removed by an electrostatic prec1p~tator.
As a result of these tests, d1ethanolam~ne, being the most act~ve compound, ~s cons1dered to be the most preferred add1t~ve.
Example 3 To prov~de a compar~son w1th a phosphate ester accord~ng to the above-noted Yossos Patent, d1ethanolam1ne was tested for EPEE
eff1cacy as was d1ethanolam~ne phosphate ester made accord1ng to the patent.
In prepar1ng the alleged ester, 0.435 mole of phosphor1c ac1d was reacted w1th 0.435 mole of d1ethanolam~ne to y~eld an equ1molar m1xture. After allow~ng approx1mately 1.35 hours of react1On t1me, the mater~al was tested.
The results of these tests are reported below ~n Table 4 1n terms of reduct~on 1n O.D. (X d.O.D). The fly ash used was fly ash IY from Table 2.
o ,~
~ l l .
c a~ o o o . o o o ~ s~ l o ,_ ~ o ^ ~ C~l C~ C~ ~ ~
' S
z _ .c ~ o~ ~ o 8 8 ~ ~, ~,.
J Z
'I = '' ~ ~
~ o ~ ~e c~ N
--o ~
) ~1 ~ ;'1:
0~ ~:
Z~ _ 3 s~O ~o o ~, ~n ~
C,_ q, c o C~.
E e _ _ C o o O
~ C C o E tl~ ~ _ S L S
L O
Z
As can be seen from Table 4, the dlethanolam~ne was far super~or to the d1ethanolam~ne phosphate ester as an EPEE. The neg-at~ve ~ d.O.D. value for the phosphate ester run meant that the part~clè collect~on eff~c~ency of the pllot prec~p~tator was actual-ly decreased by th1s compound.
Prel~m1nary results of f~eld trials presently being con-ducted at a ut~11ty plant confirm the above-reported EPEE efficacy stud~es.
Industr~al bo~ler systems com~only ~nclude the bo~ler proper and heat exchanger means to rece1ve hot combust~on gas from the bo~ler. The heat exchanger can be e~ther an economlzer, wh~ch uses the combust~on gas to heat boiler feedwater, or an a~r preheat-er, used to heat a~r fed to the bo~ler. In e~ther case, the heat exchanger acts to cool the combust~on gas.
The most widely used bo~ler fuels are o~l or coal, both of which conta~n sulfur. Accord1ngly, the combust~on gas can conta~n sulfur tr~ox~de wh~ch reacts w~th mo~sture In the combust~on gas to produce the very corros~ve sulfur~c ac~d. Slnce the corros~ve effects are,~ndeed, qu~te ev~dent on metal surfaces ~n the heat exchanger equ~pment, cold-end add~t~ve treatments are ~n~ected ~nto the combust~on gas upstream of the economizer or a~r preheater to reduce corros~on.
If a boiler ~s coal-fired, electrostatic precipitator equlpment is somet1mes provided downstream of the heat exchanger to remove fly ash and other particles from the combustion gas. To im-prove the efficiency of particle collection, electrostatic precipi-S tation efficiency enhancers are typically added to the combustiongas at a location between the heat exchanger means and the precipi-tator, that is, downstream of the heat exchanger means.
8ased on economic and/or efficacy considerations, it may be desirable to blend various amino alcohols for optimization pur-poses.
It is understood that the amino alcoho1 can be fed direct-ly or formed ~n the gas stream, e.g., a decomposition product.
Havlng thus described the invention, what is claimed is:
Claims (32)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. In an electrostatic precipitator system, a method for removing par-ticles from a particle-laden gas stream, the improvement comprising adding to said gas stream an effective amount for enhancing the efficiency of said precipitator of effective free base amino alcohol additive.
2. The method of claim 1, wherein said additive is added as an aqueous solution.
3. The method of claim 1, wherein said additive is free base alkanolamine.
4. The method of claim 2, wherein said additive is free base alkanolamine.
5. The method of claim 1, wherein said gas stream is the combustion gas of a boiler system fired by sulfur-containing coal.
6. The method of claim 3, wherein said gas stream is the combustion gas of a boiler system fired by sulfur-containing coal.
7. The method of claim 6, wherein said additive is added in an amount of from about 1 to about 200 parts of active additive per million parts of gas.
8. The method of claim 7, wherein said additive is spray-ed into said gas stream.
9. The method of claim 8, wherein said additive is added In an amount of from about 5 to about 100 parts of active additive per million parts of gas.
10. The method of claim 1, wherein said gas stream con-tains fly ash.
11. The method of claim 10, wherein said additive is added as an aqueous solution.
12. The method of claim 10, wherein said additive is free base alkanolamine.
13. The method of claim 11, wherein said additive is free base alkanolamine.
14. The method of claim 10, wherein said gas stream is the combustion gas of a boiler system fired by sulfur-containing coal.
15. The method of claim 12, wherein said gas stream is the combustion gas of a boiler system fired by sulfur-containing coal.
16. The method of claim 10, wherein said gas stream also contains sulfur dioxide.
17. The method of claim 16, wherein said additive is added as an aqueous solution.
18. The method of claim 16, wherein said additive is free base alkanolamine.
19. The method of claim 17, wherein said additive is free base alkanolamine.
20. The method of claim 16, wherein said gas stream is the combustion gas of a boiler system fired by sulfur-containing coal.
21. The method of claim 17, wherein said gas stream is the combustion gas of a boiler system fired by sulfur-containing coal.
22. In a method for removing particles from a particle-laden gas stream in an electrostatic precipitator system comprising heat exchanger means for cooling said gas stream and electrostatic precipitator means connected to said heat exchanger means for receiving said cooled gas stream, the improvement comprising adding to said gas stream at a location between said heat exchanger means and said electrostatic precipitator an effective amount for enhancing the efficiency of said precipitator of effective free base amino alcohol additive.
23. The method of claim 21, wherein said gas stream contains fly ash.
24. The method of claim 22, wherein said gas stream also contains sulfur dioxide.
25. The method of claim 23, wherein said additive is free base alkanolamine.
26. The method of claim 24, wherein said gas stream is the combustion gas of a boiler system fired by sulfur-containing coal.
27. The method of claim 3, 12 or 18 wherein said additive is water-soluble, aliphatic alkanolamine.
28. The method of claim 1, 10 or 16 wherein said additive is at least one member selected from the group consisting of monoethanolamine, di-ethanolamine, triethanolamine, methylethanolamine, N-aminoethylethanolamine, and N,N diethylethanolamine.
29. The method of claim 1, 10 or 16 wherein said additive is di-ethanolamine.
30. The method of claim 25 wherein said additive is water-soluble, aliphatic alkanolamine.
31. The method of claim 20 or 22 wherein said additive is at least one member selected from the group consisting of monoethanolamine, diethanol-amine, triethanolamine, methylethanolamine, N-aminoethylethanolamine, and N,N diethylethanolamine.
32. The method of claim 20 or 22 wherein said additive is diethanol-amine.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US2941479A | 1979-04-12 | 1979-04-12 | |
| US029,414 | 1979-04-12 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1146875A true CA1146875A (en) | 1983-05-24 |
Family
ID=21848886
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000346853A Expired CA1146875A (en) | 1979-04-12 | 1980-03-03 | Free base amino alcohols as electrostatic precipitator efficiency enhancers |
Country Status (6)
| Country | Link |
|---|---|
| EP (1) | EP0018084B1 (en) |
| JP (1) | JPS55142554A (en) |
| AU (1) | AU529243B2 (en) |
| CA (1) | CA1146875A (en) |
| DE (1) | DE3062681D1 (en) |
| NZ (1) | NZ193148A (en) |
Families Citing this family (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4294588A (en) * | 1980-04-14 | 1981-10-13 | Betz Laboratories, Inc. | Electrostatic precipitator efficiency enhancement |
| US4439351A (en) * | 1982-07-06 | 1984-03-27 | Calgon Corporation | Use of anionic or cationic polymers to lower the electrical resistivity of fly ash |
| JPH02303558A (en) * | 1989-05-16 | 1990-12-17 | Ebara Res Co Ltd | Method for charging fine particle in gas |
| DE4105214C2 (en) * | 1991-02-20 | 1993-10-14 | Bischoff Gasreinigung | Process for cleaning the exhaust gas flow of a sintering plant |
| JP3367038B2 (en) * | 1997-04-21 | 2003-01-14 | 株式会社 本家松浦酒造場 | Alcohol solution alcohol separation equipment |
| US7094274B2 (en) * | 2003-04-17 | 2006-08-22 | Afton Chemical Intangibles Llc | Use of manganese compounds to improve the efficiency of and reduce back-corona discharge on electrostatic precipitators |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2381879A (en) * | 1944-07-18 | 1945-08-14 | Western Precipitation Corp | Method of electrical precipitation |
| US4070162A (en) * | 1976-08-02 | 1978-01-24 | Apollo Chemical Corporation | Method of agglomerating particles in gas stream |
| US4123234A (en) * | 1977-12-12 | 1978-10-31 | Nalco Chemical Company | Alkanol amine phosphate for improving electrostatic precipitation of dust particles |
-
1980
- 1980-03-03 CA CA000346853A patent/CA1146875A/en not_active Expired
- 1980-03-17 NZ NZ19314880A patent/NZ193148A/en unknown
- 1980-03-17 AU AU56507/80A patent/AU529243B2/en not_active Ceased
- 1980-03-18 EP EP19800300810 patent/EP0018084B1/en not_active Expired
- 1980-03-18 DE DE8080300810T patent/DE3062681D1/en not_active Expired
- 1980-04-11 JP JP4854280A patent/JPS55142554A/en active Pending
Also Published As
| Publication number | Publication date |
|---|---|
| JPS55142554A (en) | 1980-11-07 |
| EP0018084A1 (en) | 1980-10-29 |
| EP0018084B1 (en) | 1983-04-13 |
| NZ193148A (en) | 1983-03-15 |
| DE3062681D1 (en) | 1983-05-19 |
| AU5650780A (en) | 1980-10-16 |
| AU529243B2 (en) | 1983-06-02 |
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