Document MJbB0pQr0z8wYyVNQ6VqdQBmy

pnccr work in Great BritaJ^j . ril*- * Respirator Cartridge .Efficiency Studies: - J* 'a ' V. Effect of Solvent Vapor ~ N ms: Health of Mu"i wfe*; TUI.rt (J91B): Final Report. T,A- h and Efficiency; H.M.S.O., * >**>- jn liguc Research Board: Rtp^T* 19-1929), H.M.S.O., London?*?, ' 0^ ~- G. O. NELSON and C. A. HARDER Lawrence Livermore Laboratory, Livermore, California 94550 ', alth Research Board: Repor^J 929-1939). 3H : Reports Nos. 85-90 (194^ J O., London. iealth at Wort. Report byit j mitiee 1970-73. H.M.S.O., Lo*,l 4 (1972). ocess of reviewing * ailing on interested crs. Our field has re have been many We have determined the service lives of organic vapor respirator cartridges for 121 solvent vapors and gases Including aromatics, alcohols, acetates, alkanes, ketones, amines, and chlorinated materials. We passed the vapor and air mixtures through the cartridges and monitored the downstream concentration with a flame ionization detector (FID). Monitoring continues until the cartridge is completely saturated. We compared breakthrough times to values calculated from the adsorption isotherm and Mecklenburg equation and obtained reasonable agreement. In general, the activated carbon has greater affinity for the less volatile materials. Also, the higher the boiling point of the solvent, the greater is the weight of solvent adsorbed. Water vapor, in genera], decreases the amount of solvent vapor adsorbed, especially of the more volatile solvents and those soluble in water. The effect of concentration n breakthrough time was briefly investigated and found to conform to the baric Freundlicb equation. which we serve, new professionals being received by manuscripls from uating the validity rocedures, calcula- a contribution to is c. idiation, air Is, aoministration. lether or not the rtbiguities or omislersianding. Your c as possible and le Editor and the ence. except when rs. The comments > the authors. The jssible, within two rer of manuscripts |C Editor and give ct areas and types and qualifications broad as you wish, ect .the reviewers, merican Industrial i. The University Introduction THIS IS THE FIFTH in a scries of papers concerning respirator cartridge efficiency. The previous reports have described our pro gram goals,1 the testing apparatus,2 develop ment of a mechanical breathing simulator,* and a comparison of the effects of steadyitate and pulsating flow.4 We observed no significant difference in cartridge service life between steady-state and pulsating flow. This conforms to basic adsorption theory; equilibrium between the vapor and adsorbent should be practically instantaneous.3 We discarded the breathing simulator, therefore, and in all subsequent testing employed steady-state flow. We also observed that the amount of solvent adsorbed at a given temperature, humidity, and concentration is essentially constant (sec Figure 1) and is independent of the flow rate in the range normally asso ciated with human breathing. Since the equilibrium rates are so rapid, the time to teach a predetermined breakthrough is in TSii work *11 performed under the auspices of the United Smici Atomic Eoer*y Commission, versely proportional to the flow rate. That is, doubling the flow through the cartridges will halve the effective service life if all the other test parameters remain the same. The present investigation sought to deter mine how the cartridge service life varies with the type of solvent vapor adsorbed. We investigated 121 solvent vapors and gases and compared observed breakthrough times with the values calculated from the adsorp tion isotherm and the Mecklenburg equation. This report, in some respects, respresents an 16 T~!---- T ' izl-- ft P - Toluene 8" e 4 -- Acetone _L 20 40 CO SO 100 Flow rate - l/ln Figure 1. Contaminant adsorbed as a function of flow rate. 391 :'rf -( - jr i| 1 im4 i .y- A, . v ' //-I ' " *Y -*4 . * \ - , 'V .W. ; 'V ... - X yV.r-. .v - . * c. -A- .-V'MV ' . * DO 078131 OONFTDFNT - 1;; extension of the investigation by Freedman et al*>^: \ ,V. - ;- Our standard test conditions included a solvent concentration of 1000 ppm, 50% relative humidity, and 53.3-liter/min flow, s7~"'. equivalent to a moderately heavy work rate of 830 kg-m/min. The solvents tested in cluded aromatics, alcohols, actetates, al kanes, ketones, amines, and chlorinated ma terials. Some preliminary investigations on the effect of concentration (125 to 2000 pp) were also initiated. Experimental Procedure The apparatus used to generate and moni tor the test concentrations is basically the same as that described in refs. 2 and 4. Several minor changes appear in Figure 2. The humidifier now consists of a Lucite reservoir with a. level switch and solenoid valve assembly to maintain a constant water volume. A 126-watt spot heater on the reservoir bottom controlled by a humidity monitor bolds the humidity constant. A 2-inch plug of glass wool added to the solvent vapor injection port aids in evaporat ing the solvents, especially those with higher boiling points. Maintaining the block tem perature as close to the boiling point as possible avoids decomposing the solvent and plugging the needle. The activated carbon plug downstream further smooths solvent evaporation irregularities. - - .... . . 1 - ' V'.r-- Housing V1t . 35/25 $ joint -- V5* Cartridge Adapter Figure 3. Schematic diagram of dual caruidj holder. - - ' *! *V? M 100 -r- ........| jr so * Bwzftfe-v y . rJI V3i 60 40 -- *mbt 20 9 p-Cymenc ^/^Toluene. m-Xyln^* Ethyl benxene /^Meiltylfnc, Cmtni l 50 100 150 200 u Tie - min Figure 4. Breakthrough curves for aromati boiling in the range 80 to 177C- MS -tSfV ^ F*ij* JV;'*?r: *v -'',"i?ti' a -?h !Jl L<r.it%,is sf * *-**-**** - ; -v. | I; . Regulator., Actlvsted cerbonHested block Solvent Inlet Flowmeter Humidity. controller^ Impressed Hr Inlet level switch Solenoid Hirniidity senior Figure 2. Schematic diagram of humidifier and solvent vaporizer. i i i i I i i i i | i i r-i | i i i -i-j i i i < | I i i i | ^4-MethyW-pentanol -tthyl-l-butanol r2-Pentenol 3-Hethyl-l-butsnol ePentanol -Butanol 1111,1--_ iso 200 Time - min Figure 3. Breakthrough curves for alcohols he ing in the ranges (a) 65 to 100oC and (b) 118" I47C. y , ' ^ . i.-` V j' -,i I ^ w 4 s* w jm* * 1 ^ _ f w * . ..... - *_ 1 , * , -j v.. . ..................... .. .i_ confidfnt1w.. *' 't'm'T- J~ - i '~',1 ' . . , ;' ' v ' rv* W *f r. ' v'-r . * . v. c '~'M* `*jiTicrican Industrial Hyyirnr Association Journal : ` .- '' v*'- ii-r-V'-i-" 393 'J Y~-' }f; v The cartridges were vacuum-dried and Stored in a cabinet for at least 2 days at $0% relative humidity and 22C.4 Two 'cartridges were tested simultaneously in the "parallel configuration shown in Figure .3. 'far The test gas entered through a 35/25 ground brass socket joint and passed through - `.(jjc cartridges held in individual polyethylene adaptors. Anodized aluminum housings, se' cured with wing nuts, collected the down- stream gases and conducted them to the common sample outlet.'M .. " Type 1 cartridges (see ref. 4 for cartridge diagram of dual cartridge'' ISO ic - Min 200 250 4 .'iCl Ugh curves for aromatics! i to 177C. - | 1 1 1 ' | I * I 1 | I 1 l l j l rr "a1lcohi!. uPropano1 sec-Butanol I i i t i I i i i i I .... I ... | -r-| I I I I |-< rMethyl chloride Vinyl chloride. Ethyl chloride gZ-chloropropene ;A11yl chloride 1-Chloropropane 2-Ch1oro-2-acthy1propane ~ 1-Chlorobutane Z-Chloro-2-nethylbutane _ i.... I.... I i i_. i I I | I I I I | I I I I | . I I 'I | I TI I | ITT I ^3-{ChioromethylJheptane 1-Chioroheptine 1-Chlorohexene 1-Chloropentane b. O-Chlorotoluene Chlorocyclopentane -- Chlorobenzene jX.__________ 150 200 250 300 3S0 Tin* -- Bln Figure 6. Breakthrough curves for monochlorides boiling in the ranges (a)) --24 to 86C and (b) 108 to 172C. ' 1' ' I ' 1 " I t-Dichloromethane ftrani-l,2-D1ehloroethylne rl.l-DIChloroethane Ytli-1. 2-Dlchloroethylene rl,2- Dlehloroethane fl-2-D1chloropropane rl.3-01chiorepropene I I I | I I | I f I | ' I I I 1 I ' I I|TT1 I | ITT * Carbon tetrachloride b. fPentachloroethane Perchloroethylcnc 100 80 60 40 1,1,2.2-Tetre- 20h , ,- diloroethane _ . . 1. . . X L/.C . 1 i . i I t m i I i . . i .. J 0 50 too ISO ZOO 250 300 Tine - Bln Figure 8. Breakthrough curves for (a) trichlo rides and (b) tetra- and pentachlorides boiling in the ranges 61* to 156*C and 77B to 161"C, respec tively. ISO 2DO 2SD 300 Ise -- Bin h curves for alcohols hoDlo 100C and (b) 118" lo * ] 0-01chlorobenzene 1.4-Dichlorobutane I I_______________________ . 1 * L ISO 200 liae -- Bln Figure 7. Breakthrough curves for dichlorides hoiling in the range 40 to 180C. 100 ISO 200 Tine -- ale Figure 9. Breakthrough curves for acetates boil ing in the ranges (a) 57 to 104* and (b) 112* to 169"C . .' , '' 7 J " .`'7' ' *00 0781 37 ' ^ ` .. . ; . z>~._r' -.*r;--* .">v gonftdfnttal ;- Mealtyl oxide-. 4-Methyl 1' - 2-pentanone 3-Pentanone- 2-Bvtanone Ac*tone Ii i i Ii i i|ii i 2-Pentanone * 2.4-Pentanedlone " Cyelopentanone ~ ij I I i I I l.l I.I..1 I I I 1.1.J.l i i | i i i [*r i i i; TT'i'i [ Dllsobutyl ketone 3-Heptanone 11 i'i1 i-Methyl-3-heptenone 2-Hep ta none 1-Methylcyclohexanone 4-Mehtylcyclohexanone rp-n- b. characteristics) were tested ^rith alcohols, esters, and chlorinated inaie^i type 2 cartridges were tested with ket^p alkanes, amines, and most miscdlanSp^ compounds.' Results - ,t. % Effect of Solvent Vapor Figures 4 through 13 show how the tridge service life varies when tes'ed'^fleach class of solvent vapor. The percent breakthrough (the ratio of the downstream -S 100 150 200 . .. ...................... 250 300 Tine -- aln _ 1. Figure ]0. Breakthrough curvet for ketones boiling in tbe ranges (a) 56 to 104C and (b) 112 to 169C. t i i I i i i I i i i i I i i i I i i ' I > I (Pentane (Methyl cyclopentane \2,3-Dimethyl butane, Cyclohexane r2,2.4-Trimethylpentane ISO 200 Tine - ain Figure 12. Breakthrough curves for amines boflTy ing in the ranges (a) --7 to 56C and (b) 7gs u!.` 159C. Acrylonitrile Methyl iodide. ITT". . I | . I . , | pichlorahydrin ii..I .... I > i . i I i 5-Ethyl Idene-Z- norbomene Nonane 2,2,5-Triaethylhexane Oecane .1,3.5-Cyelohep-- tatriene Methyleyelohexane ~ Cyclooctane 1 1 * * . 1 * * 1 . 100 150 200 250 300 350 Tine -- nln Figure 11. Breakthrough curves for alkanes boil ing in the ranges (a) 39" to 99C and (b) 101s to 174C. Z-Methoiyethsnol- Dibronoaethane _ Pyridine a-- W.J. 2-Ethoxyethyl acetate -j r l.?-D1broMocthi>c / Vl-llUropropjn 100 - 2-Methoxyethyl J -i ----- ----- 80 acetete*\j^ 6U 40 nhAycdertiidc #"fyCXS/iYy0/^*l2ro-mEtohboexnytetntheanol ' -- 20 n .......... r'Z-Methoxyethenol b." X.I.. . .1 . . . 1 1 . 0 50 1 00 150 200 250 300 350 *>v .1^ Tlae - ala Figure 13. Breakthrough curves for miscellane ous solvents boiling in the ranges (a) 42s to 124C and (b) 132s to 156C- -- >* J 7. ,-V < *'" it,,-- vJ*,. v -Ti." - - rt t ;* : tr-> .\k: I;;*-:.., <v 7-*v,v y p /. *::* ` - * , ` ' , ...r->j > *:( - * 17.; j'! '* . 6 o' T21 o i1 O-1 oNj,:.*" "n oo 2h Ou ; '> ]->H ',D .'* , entail* Toluene Ethyl benttne 0.1 72.4 110.6 21 ,t 136.2 7.01 -Xylene Cuaine Helltylene p-Cyaena Alcohol!1 131.4 1S2.4 164, T 176.7 6.16 3. 34 1.73 1.21 Methanol 64.7 96. Ethanol 70.4 43.6 Iiopropenol 2.3 32.4 Ally! alcohol - 97.0 21.4 Propanol 97.1 14.4 aac-iutanol 99.9 12.6 utanol 117.7 S.6S 2-P*ntanol 119.9 4,36 3-Hathyl-l-butanol 131.2 2.4 4-Hathyl-2-pentanol 131.1 3.9 Pent anol 137.9 1. *2 2-Ethyl-1-butanol 146.6 1.36 0.0932 0.0149 0.0755 0.0670 0.0677 0.0663 0.0630 0.1S20 0.1161 0.1013 0,1021 0.0993 0.0191 ! 0.0161 0.0721 0,0709** 0,0633** 0.0716 0.06S31* , - Y'-.r: c 146 144 141 141 146 147 141 141 146. 14 5; 14 S 144 144 143 . 147 147 14 141 ISO 59.1 . '! 73.3 It.6 170 : 57.3 94.3 114 196 55.9 3.7 105 223 59.7 91.7 116 193 60.0 11.2 103 153 59.5 ; 15,5 105, 119 56.9 . 75.6 92 ;9 253 55.4 0,2 ,3.1 47.0 55.5 21.0 45.3 207 55.7 .. 54.3 11.1 24 7 . 55.4 65.5 105 210 55.7 70.4 111 250 55.9 96.0 121 196 55.5 , 115 141 235 56.7 6. 111 277 55.0 97.0 121 195 55.7 75.4 96,1 243 55.0 55.7 102 76.5 130 101 20* 257 0.214 0.334 0.352 0.311 0.359 0,32 0.394 0.249 0.327 0.397 0.473 , Him* 0.432 0.450 0.447 0.460 O.S73 : 0.021 a *71, 0.536 0.531 0.565 j 'f .> * tf-.'!*VV 0.022 * Ck / '/ .- vy.i, 0.476 0.594 , i V!';M w 0.0003 0.051 0.004 0.079 o.oii. o.iei 0.129 0.11a 0.314 0.152 0.169 0.211 0,340 0.291 0.344 0.306 0 ;361 0.234 0.362 . 0.255 0,314` 0.347 0.431 0.409 0.512 0.373 0.517 0.421 0.525 O.ltl 0.145 0.451 0.551 0.1 ii o.oos .. 0.050 ' r' 5 ` V V7:t | 0.016 'O.OIO 0.00 V 0.041 i j v $^ `7=vW |1 !9* sjl it>*' v r V \.4 ' **1' 3,*(1 ,:\i i 0.010 0.310 0.400 0.5*1 0.030 [*' r < * - jv. [';........ .'"'ri.V-' -." '.' r t rr *r:**Y*-- - r'.v *1' TVTrf`T ""Tf* t " f-- * r* f "Tr*1 * - r i t-trnrn rnTTfTfrmmtnmyrn iiwinrn wnrww. ;:jn amaKi riS *t t'nwr* v 'i-Av 'i^j'jt 'itji ;, *;Vv_ ,'-r - p* vv';:' p\*- * % : >;- -'* 4 * L .' ; \ vV : * ty. * * j i`>, . * *v. - #i i . r * - ' n , *\* -#J: - .r-'?r : , i - -.* t it, * .1*J ":l w-Kr* !* r> >',: ',;/ o ^ 'if z o-: r" "A1'* ^ a vi;? Z ^ M.. V.1 --( ja, .* * < i -*r i ' , -H O ^V-CM ' ' * Solvent Hanochloridei* BP (C*) Vapor preisure at 20'C (Torr) Diffusion coefficient at 25 *C (cm Vs ee) TABLE 1 (Continued) Voluno charcoal (!)' Oeltht charcoal (*)' Experimental breakthrouih times `it lot 99t (min) (atn) (In) . ;'i .! a *. ..' , : : :'-'; ' * m"..2*w .AJ-i'-, Heiiht. . .:;-./1|^>V**/,, wadasteorrbed " J ' h1'. :?* tit. solvent!adsorbed aatt *' 100% l1'*';f`p '*?' per wt. of carbon i. a Ml Mot MOOt (t/f) (l/l) (I/I) per t. f car(blo/o.nln.). s'tiTf-y ' m' V1'/ .... /:?, t'v ,fs;t.- ' g.7 ' , 'V'i Hethpl chloride Vinjrl chloride Ethp 1 ch lari de 2-Chloroprnpane Allpl ch lerlde t-Cbloropropane 2-CHIoro-I. ethyipropane l.Chlerohutane l-Chloro-2- ethyibutane l>Ch loropentana Chlorocyclopentano Chlorobeniene l*ChIoroheaane Chloratoluene 1-Chloroheptana >1--t(CChhlloerrooBeethyl)] heptane -2*.2 '13.9 12.1 15.1 **.S 4*.7 SO.I 77.5 15.7 101.4 111 112 114 > 5 159,2 1S9.2 i1s1r1.. 34*0 ' 2110 1110 410 100 277 0,1140" 0.099S1* 0.095011 ,o.oai9h 0.0975 0.0B20h 240 * 0.0737h 10.0 ' 0.074S1* 60.1 0.067Sh 23.0 0.06llh .- 0.0711 9.11 7,15 2.66 2.1 0.0747 0.0*llh . 0.0*1* 0(0S91h O.OSSJ" 141 147 141 141 141 146 147' 145 141 147 146 146 ISO iS.7 SS.7 56.1 56. S 55.5 55.1 0.05 3.1 5.6 26,1 10.5 24.5 0.7 6.6 10.7 35.0 44.6 34.0 57.0 55.1 17.4 .52.1 II.1 57.0 51.1 56.1 74.7 55.6 $5.1 ,77.5 107 55.1 77.1 70.3 96.6 106 . 131 95.1 14.6 46.1 11.7 109 106 141 161 145 194 197 , 211 205 119 0.0001 0.001 0.001 0.074 . <' r v..s 0.009 ' 0.016 0.0)4 0.026 0.010 (K107 0.003 0.112 0.076 0.105 0.114 0.111 0.011 ' 0.070 V>4 i4,i r,*' 0.041 0.167 0.104 * 0.096 0.0)1 0 :b40 , f1,. /* :r -1 O'. 10* ' 0.010 0.270 *n * *A I 0.010 0.265 0.241 0.117 9.301 i 0.320 ' 0.419 ; 0.110 ' 0.192 o.sas 6.001 -v+.ii Ai m . 0.322 0.471 0.170 .51* ' 0.429, 0.5*2. 0.574 0.611 0.050 r ? . . -'irA 0.449 0.501 ' 6.011' tVi-1 V-\(. * 0.605 0.7*1 V .0.OOS^gji;.1: \HW 1BJ ''`iiaMT.iSHSl**** :* V . '. 1 . '.I Cbt'orocj'clopentane Cblorobemene l-Chlorohemne o-Chlorotoluene 1 -Ch loroheptnn* S - (Ch lorome tlivl) heptane ---------- J ----------- -- m III 134.5 150.1 1S9.2 171. - 0.0711 9.11 0.0747 7.15 0.043]' 1.66 0.0615 2,2 0.0591 . 0.055 7 ---- :------: <rea * m ** t TsT7' ^0:3 nr s.irr ror* 146 55.6 77.S 106 lit 0.322 0.429 0.561^^ 0.01\ 146 55.1 107 m 70S 0.471 0.574 0.601 - 150 55.5 77. J 95.5 169 0.370 0.449 0.591 0.013 146 55.5 102 ff 122 192 0.514 0.605 0.741 , 0.005 150 SS.S 61.5. 101 143 0.437 `O.S3 I 0.625 - 0.013 V .-LI.' 148 55.7 63.4 60. S 183 0.374 t 0.465 0.614 , ,0.031 'rkii`Ul 'S!'uuir.> m TABLE 1 {Continued) '\, r.l# v-K ;' ' : ;* s.y'i1 yf` Solvent 8P {C*J Vapor pressure et 20*C Ctorr) lit f f us ion coefficient . ,it 2S*C 1 Volume chnrcoel (ml)* Heljht charcoal Cl) Experiment*] breakthrough time* t.iti t'l,o,,,t tlm (min) (min) (min) JSUa'itVMl Ht. solvent adsorbed ,at ^loot t'i S. i1V-' i perwt. of .carbon '___ f ,.,^6 ;'*V, [ t d t ' V i v?'5 4-i. I llt l10f *100.j'carbon1 1 f (*/*) Ci/i),. ii/i) ----... U/i) tr J, *.. < 1/; at:i * , ,A .'P; ;VV.J o a -1- ^ zo . "H :.. -> O ' aTf M03 .- . . 5 ^.,4 -4 -i ' J Plchloridts* Olchloronethane 40.1 trani-I,2-0ichloro- ethplen* 49 1,1'Dlebtoroethane 5^. 5 cls-l ,1-DIchloroathy1en* 59.1 1,2-D^ch loroetiTane^~>53.5 l,:>01chtoroprop*n 94.4 eis .trtns-1,3-Dichloropropene 101 1,4-Dlchlorobuttne 162 o-Otchtorobenien* 110.4 146 0.1037 263 151 . 0,0826h 0 .0919 141 . 60.1 42.3 0.082ttl 0.0907 0.0794 3.10 0.16 0.0763h 0.0C6611 0.064Sh Tr lehlorldes* Chloroform Hathyl chloroform Trichloroethylene 1,1,1-TrlcHloroethans 1^33-TrichJoropropn J 61.1 74 66.5 113.6 156 , 150.3 105 SI.6 17.5 1.1 0.0566 0.0794 0.0175 0,0791 0.0671h 144 145 143 144 144 145 147 146 146 i44 14 4 . ' 145 145 147 55.4 ld.l 15.6 63.7 55.7 55.5 33.0 23.3 50.3 124 40.1 225 55.3 55.3 55.6 29.8 42.6 16 5 <fnxiEi> 186 ' 65.0 90.3 200 0.034 o.osi Oiiot o'.ill 0.1217 0o..0o9o2i 0.il6 0.214 0.291 0.1*7. .0,16* ,0.06s '`V;*iS<. *afU.*i!.<, .'. . \ .. . o.isi: .0.117 j- o.oji ,/ a '"-M:1 i g rV'.i U.16B'' w,i* UeVe3j s'ji oiios'' Oi4S6 0.016 ** it 'V*:* *>;*v 56.7 55.6 57.3 55.6 56.2 54.1 56.1 85.5 110 10J 129 109 132 206 215 230 33.2 40.4 5S.3 52.4 174 56.0 19* 63.0 193 71.8 112 206 0.319 .0.401 i 0.505 0.637 01606 0.016 1 f Sii':;; ' - V.iS/.'t!, 0.7SS - . i 0.616 0.716 0.911 ' i> ,`- ' . ?' -* v ;* -"I'Xilj' . 0,156 .o.i*o;: 0.415- 01050 :: - 0.212 p.:.9(0.s30:o.oi..C-gf! 0.293 0.411 0.615 0.011 >, ^'iVv.nTiW.! .ft;/- V:' 0.377 o.56i 0,773 < o.o4i 56.:' in in in 0.641 . 0.754 .'0.91S r \'i: (PetMVlee) t^rwwjr.t.'T ,* ' ', `e-S.m.` ..* **i.*,r'**tf'^*/v '* Vftyp4he>ep 4,. :-A,y ,, .{ * X * .f r > T; * ;:v. ' v 1 :??>:.f:>p . ''"* > -y>: ' .** .v,, - <^:-.-. v, ;*.t i *. * .' '-'A . S t,W . J . Vv^| rr,< \ h: i>.`i>f^.,. .,:-.'.T.,fv| i.v' ,:-*P--`tHiVH.. Ji.'VI'*'-i'Vl '.T* 3'r`VW&^v Jit ^ v / y^srn^ffWirf^^ ------------ ir~ ^ ii ;i.i-- -------nrmm m-----1--in-mr-nTr iirrf t ^TrtirrrniiTiHwt*9 TABLE I (continued) Solvent `BP 1C*) Vepor pressure t IQ'C (Tore) Diffusion coefficient t 2S*C (e^fsecl Voluao chircoel (I)' Keiihtcharcoal (I)' Experimental breafcthrouth tinea *11 *10* * 09* (In) (ln) (in) Wt. solvent adsorbed *1* (I/I) *10* *100% (t/t) (l/l) _. *.1.0..0.| ,.a, carbon1 l/l) t; i-VVrJ; -- !*' Tetrachlorides1 Carbon tetrachloride 76.8 Perchloroethylene 111.1 1,1,1,1-Tet nchloroethane H 91.1 14.0 4.73 0.0*1 B 0.0797 0.0721 Pentachlorides* Pentachloroethane 161 - Acetates* Methyl acetate 1 ST. J 170.1 Vinyl acetate 71.5 91.1 Ethyl acetate Isopropyl acetate laoproponyl acetate Propyl acetate Allyl acetate 71,1 17.5 96 101.) 103, S 74.4 47,3 30.0 It. 9 ec-lutyl acetate Butyl acetate laopantyl acetate 1 It. S m.i HI.i 1.0 u 0.0673 0.0973 0.079Jh 0.0161 0.0770 0.071*1* 144 55.4 . . 77.0 90.0 147 0.473 0,545 0.677;. t' ' 1 - . -1 V.-.V V' 146 55.7 107 119 209 0,704 0*S35. 1.01 ; ' *V "> - 146 ,, 55.3 104 131 216 0. |09 1 't * - 'r , ' ' 7, 'V ' .O.Mli 1.07 r; ;V . ' r i'%.-.<V* /ir` V ** '. * t 4 145 56.1 91.0 117 , 11*7 0.741 0.914 1.13 / . . `.` 4 s f`. * ** ^ i\ i/y' it .. * ;* i , ; `.. '-) > 146 55.6 32.1 46.5 143.1 0.097 ^o.ni . o*au . o!o73 141 55.6 55.0 11.1 .235 0.11* Oi269 -0.191 0.006 r.J ;/ < v- 145 60.6 66.1 14.7 172 ' 0.21$ ", 0.167 0.350 0.001 146 55.6 64.5 5.6 166 0.262 0.339 ` 0.453 .0.036 : '.). JO" 145 57.1 B0.6 106 193 0,323 *i.400 0.507 MMhuaMOMHMeMHiOMllAldMMa^l /' . * * ' ' :1 / ? *' "'} i! ( ! * 1 . ' i\4 liopropyl acetate liopropenyl acetate Tropyl acetate Allyl acetate *ec-utyl acetate Butyl acetate 1Jopen ty1 acetate 17.5 96 101.J 10S.S 111.5 126,1 141.5 ,, V 10(4 47.3 30.0 24.9 > " S.O 3,6 UaVIOl 0,0770 O.07ISh 0.0765 0.071lh 0.0649 0.0672 o.boos'1 14* ,60.6 66.1 54.7 172 Jo\iTs~ 0.267, 0.3S0" 146 55.6 64.5 55.6 166 0.267 0.339 0.413 _ 0.0u\ 145 57,1 50.6 106 193 0.323 0.409 0.507 '--^V 145 55.9 75,5 99.0 164 0.315 0.392 0.507 0.020 145 145 56.1 55.9 75.5 95,6 52.6 101 246 164 0.299 0.351 0.369 O.S17 0.456 0.337 d.04S . /V- t'1..1 145 145 55.0 55.5 77.3 . 70.9 96.9 5 6.-3 226 177 0.361 0.366 0.443 0.595 0.447 0.564 0.023 . VE*. 1 0.020 -f.'* x.*i 4 - r*-f . "-V( 'r- = - V' .. o' * \ '* *2 - ; 1 r: i v V' r;':V ` :/; ' i* !' i' e>. ' r^-'i - :: :ii i ' 1 ' *?.+Z} `ivm'ifMa ,V 5, iM o ;*T ',^1 'In-' 7 Vi^OZ DO-,'lr,.1"1'' # ` i .' , 1a i To)1 o :*:>>>' " M J+i,. -4 a)! * ?i ~i S >i-->I I. - _ , \ /, J. e< \ = ' "* < Solvent Kcetates* Cent. 1,3<Dimethyl butpi acetate rentyl acetate llexyl'aeetate Ketonea^ Acetone 2>9utanone 2>Pentanone 3-Fentanone 4-Wethpl*2- pent anone HMltyl oxide Cyclopentencnt 2,4>reRtanedione l.lleptanone 2-llaptanone Cyclohexanone S-Hathyl-3- heptenene ICBP'J srs:*? (Terr) (cm /s.ee) 146.2 145.4 169 4 2,95 0,0S67h 0,9610 0.0S67h * 56.2 SP7 79.6 70.6 102.3 30.5 102.7 US. 5 26,5 f" It 129.7 ' 7,9 130.7 140,4 6.5. 147.3 151,2 2,5 155.6 5.4 159.5 *. 0.1049 0 .0903 0.0793 0,0 7 4 oh la 0.0677" 0.0 760 O.0T96h 0.07l7h 0.0625h 0.0 62 s'* 0.0T291' 1. 0,0555" TABLE I (continued) Volume charcoal (nl)* Wei (lit charcoal Experimental breakthrough timet Mi Moi *991 (mini (U) (nln) i K.iiht water . : ! UV i.Vr v/*?|i*I , . adiorfetd Ht. solvent adsorbed at t100. , L-JvK . ' >* rper wt. of carbon____ 'p*e,r *1<'rt, >, :I tvr- 5 et Ml 101 x100l ` carbon1 . (|/|) Ct/i) ,((/() ...U/(), vva: *r;.*.', y .'.'i 149 145 145 164 160 1S9 A 161 160 , 169 167 176 160 117 166 16$ 55.5 60.6 55.7 ' 72.6 55.5 67.0 76,0 57,3 55.3 60.5 37.1 46.0 66.0 51.9 94.4 55.0 104 121 51.4 * 55.1 93,5 114 96.1 lit 60.1 64.5 122 141 139 161 70.6 130 144 55.1 91.0 105 61.9 101 114 64.7 126 144 61,0 16,4 99.1 x yi a ; s >Y`.- 151 0,346 0,426 O.SU; 0.02S V *.\\ V.*! (. I 5 ;< V , 225 0,375 0.^4 ' 0.6l(, ,o.it ' i !*,;;uf- - ' ?-rt .s' 202 0,35$ 0.410,1 0.5| . ' ^ i;.`f I'jjlH ; :, 119 . 239 0.071 0,199 ............. it >' 0.09$, .0.13$ o.iisVo.ios V . / . - I ;ft f.i - f,r1: 01109 1>V ')' j * ^`C:r 0.05$ , * in,,(0V j 231 0.341 0.391-.0.4I3 ', 175 0.30S O.S 0l4 ^ ;y ... 211 0.367 o.4ift; o.sit O.0OT ' t 224 0.440 0.49SVO.$7I - 'ff 305 0.405 , 0.4600.SI* ' ; ` i 5';.Vf . i -,t : .. ' ''l ! 'V- ^ y 214 0.405 0^447'' b.5I7 ' .'.i* . . *; 156 0.396 o;4Sl-, 0.S4I o,oi4:1 -f'^1 . . i i'-wj 237 0.412 0.460 6.$60 o.oos ,tv.iy5 249 0.423 , rt llM ' ^ ti-'-J 111 0.359 Q j ' ,/ "``.'^**^ '. "'.*') ''? Y^ ! J * *'T^f^V *?'y|" ""T?"''':' j ^fiXSi\r3c ; Kt'^-KEEt*.'-'-- '..rrv'TT--' r - --'iif'*: . i ' " ''' ! -......... --.............. . . .'...i--ri.rr.i uo( mimwmniwgmwwiw> 1 ..; . < _,........... . ._i. ....... . .. _ .._........_ _ _'. *t4T; ,r- .;. ..** f.iJ -'fc ffT `. -V * g'15 V , i-t -'. bPp,`,#.>r * J / ' '-M; 1) ` 1. .' ' z'v,-'* *: ;- ` j.T.;* V VYY; if-v-i t ': 5*."y :;; i . * y :' -; i-T i;4 i-vj-2 u$ta Solvent Itetonal Cont. 3-Methyl- eyclohexanone Dltsobutyl ketone 4>Methylcyclo- haxanone BP , (C*) Vapor pressure at 20*C (Torr) Diffusion coefficient et 2S*C (c /sec) TABLE I (Conlinued) Volune cherconl Weight charcoal t*r '. 1 ' : * |; :.^ *1.4 tfr *Y* t . Weijht -/. .ij /;'M Sad sao reJadii1- ti1ap.!tvfmiIi Experlnental Kt. solvent adsorbed;' at it<r'i'\A breakthrough tinea --paj.ut^ of carbon `11. MOb 99% Mb (in) (Bln) (in) (f/f) *lo Moot carbon VY'-.-i.4* Cl/1) tr/i) ; : (|/B) -------------'rMlV- >*lA' i ft^rn;1 161 169.4 ' i. 171.3 - 0 ,0669h 0.0S54h 0.0669u 16 2 6315 101 123 216 0.395 0.472 0.595 *. 162 60.4 ' 70,1 83,3 m 0.369 ' 0.427 . .6.556. 172 6 7. b 111 126 245 0.463 . 0.520 0.560 0.099 -* v ;v.Tt-,, : V* -*!> ' ; V'-V** 0 "V* .Vi 9 2 <*.- X 1 3-H O,, . x A.r Cf sl . " Tl 3)-; A JI'I -l ithanes1 .Pantana 2,3-OinathyIbutana Itaxane Methylcyclopontane Cyclohexane Cyclehaxene 2,2,4-TrlBathyl-'* pentane Haptana Methyl cyclohexane 36.1 -si.o 61.7 71.1 80.7 13.3 ' 96,S 414 191 111 110 77.S 70.4 31.6 0.0842 0.0619*' 0.0731*' 0.0734h 0.0743*' 0 .0 763*' o^sne*1 0.0610" 0.0679" 166 167 160 164 161 1S9 . 161 62.6 63,5 55.0 . 66.7. 59.3 57.3 , 57.5 60,7 72. d 71.3 81.1 147 m 52.3 64.6 178 62.2 76.1 174 68.7 '82.3 179 85.1 100 19 3 , 0.155 0.179 0.228 0i216 o.m 0.241 0.300 0.220 ' 0.334 0.174 0.216 0.272 0.209 0.278 0.254 , 0l337 t ' r. 4 1 . c 0.313 0.40i 68.3 60,4 166 0.300' o.oii i i i i. ; 0.440 -i'as; ,--Ja s'C-V'.* 1. V; -.1 . V k|fcV' IJr ' , ;r7 , .V:: j;\: V-. if 'f v-1 V-'- M f ' r' i ', s, V * ' : V ;nY'4 ` ,r y h'^'t rr 3 //*. 1 ,VVC*J.S' \<* \ : y J * r.l-t'll&i .5'':-` -i'Sj *S "\,vv{ ** v\ / *? >- h'i 1 n b z> ? *.;: %Vi I a nj.v > n so y.' z -* i1 r-,- --T*>t *in Vv'?k5*jT?.C' . T *. V Cyclohexane Cyclohexane 7.7.4-Trioethylpan tine Heptane Methyl eye 1 ohexane 10,7 SJ.S 96.5 99.5 100.9 77.5 70.4 39.6 35.4 16 .J 0.074Jh 0.0 76 s'' O.OSiM*1 o.oiie1' 0.0679h 161 59. J 66.7 '12. J 179 0.216 159 57. J 15.6 100 19] 161 57.5 66.3 10.4 166 160 57.9 79; 2 19.t 191 160 5 7,5 69,S' 90.5 191 -H.1 V, m&t^j| ******* %*&&*** ^ TABLE t (Continued) voter J.' 1- y ti Solvent tP (C*) Vapor pressure at 20*C , (Torr) Diffusion eoeff lelent at 2S*C (cn^/see) Yolvae charcoal CD* beljht charcoal c*ib Experinental breakthrouth tinea (nin) (!>) (r ln> ;' Wt. folyant par t. of acdaarobrobne,di *lb` (I/'t) `mb `mob (i/i) (i/i) adsorbed' | par at. ` B- carbon*f Yr'j J-V-' | 2 .(/l)1 i*l Alkanes1 Cont. 1, 1,5 -Cyelohaptatrlene 1,3,5-Trlnethylheaane S-Ethylidene-2norbornena Cyelooetane Hors'nt Oacane 115.S 124.5 ' 147.5 ISO ISO 174 12.5 4.2 T 3.15 0.96 0,0742h 0,0559h 0.0644h 0.0639h 0.05S9h 0.0530h koines1 Methylmlne Oloathylaainr Xthylaolna. Itopropylanlne Prepyianina Olathylenina lutylsnln* Trlathylaolna 'Olpropylaolna Dllsopropytaolna -6.7 2160 6.7 1295 16.6 972 31.S 479 . 47.9 24 7 S5.S 191 77,S 75 . 69.4 46.2 110 11.2 110.3 - 0.1 3001' 0.107]'' 0.10J21' O.OI79h 0.0(79h 0.099) 0.0972 0,0754 0.0647h 0.0647*' 169 166 16S 172 168 164 161 164 161 160 172 160 162 160 170171 6J.4 121 137 246 64.2 67.6 90.0 166 67.4 w 70 j J * 63.5 57.7 96.5 101 221 96.8 US 220 76.2 69. S 196 70.1 91.5 156 51.5 . 12.4 IT.# #1.5 70.0 17.1 21.T #4 59.6 40.5 49.7 270 60,4 65.6 TS.t 194 65.5 90.0 lit 550 62.1 68.0 105 V' ' 63.9 110 125 279 59.1 11.1 91.0 174 61.2 93.0 105 126 67.0 77.0 97.1 its ' ; - \-l; ' r " f ` ` t ft ;t . 0.119 0.266 0.415 ; 0.516 ' 0,110 0.444 . 0.001,' J- p$I o.ooi U 0.341 0.545 0.193 0.526 0.597 0.497 \ 1 S v- f* 007}* M 0.027 0.140 0.116 0.193. 0.490 0.439 0.555 *'' (.'/J . r-.; ` 0.017 r, 1 0.015 0.014 0.010 0.041 0.010 0.050 ,*>:* *v 0.150 b Jy `1 1-: u; 0.291 a:*# 0.068 o.oti *0:179 . 0.261 .if Vi-v: 0.142 0.162 0.175 ' 0.116 0.180 0;117 . OtllS * 0.252 * v *f ` ' r 0.219 ' 0 .369 ' 0.1S1 o;ioo 0.270 0.312 ( 0.429 0.031 , 0.107 0.105 0.257 0.141 0.416 o.iio 0.4)9 0.191 0,170 ; 0.012 0.060 *" :*> 0.060 i. _ , `-IN V ^ r`.|.'>t<"\W^ir*'y,lyV tiv^vj>xi^j..mWi^'l^^vr,f>^^w,!Wtm,)ni,t|,W[W,W|W,i Ufcw.vn.w.^, . >r*mwiw.eiei.* iKWwfr4n*,H>>fM^* ,;.V -.*: r->'*|t*S$r-V'.'J -'V- ..:>*?- -, -> .' ?. V * *''4tVv^T;;$<;>'f*'^TA'J v/ / '* si''W*^!ASSK*iJMmOT3S^^ siflWCiSrflV" " l' rtwsif5'f>i W41*ews-Y'.hW* ri*v.vweArtsu .euniwr>irrfcir*>t*M>rcwwi f Is xn Jmmm .' " ij >'(', '.: !e,r; ;;,f''' '''-is'd'i ^CAY. v f, > ,V ; -1 .i| Solvent BP (C) Vepor pressure at IOC (tort) Diffusion coe,f,f.icr ient " ,C (cm /see) TABLE t (continued) Voluae charcoal (ml)- height chercoel (i) Experimental breakthrough tlaes cit `lot 99t (ain) (aln) (aln) ' ,. /," 'If ' * j * ,t* . H J jiVilJy,4.VMy.M' .i X*' * j '* y,\&L ?>& . v v jf.r .* 1 height * meter ... , I'!%> ' edsorbej 'fj;- i* of r Miht. solvent edsorbed t ,t.... .if?$!'& " . `lot `lOOt:, eerbon^V* (i/i) (i/i) . (i/tD)<* i ' f (1/1) '> ;;-a' ':-?{ ;l, 4 . 1 .1 . V* " ;: \ Amines Cont. Cyclohexyl amine 134 0^06641' 1*9 64.3 - 112 121 279 ' 0,112 If.431 0.5*4 , t '*.1. f\ i' v-*->fS 1 Olbutylaalne 159 Hlscellaneous l.l 0.0567** 164 64.6 75.5 14. 1 116 0.135 0.372 b . 410- 0.009 '{' -i, : - 'Xa V*' - *.. t *. *i 5 1 v'-'.-iv . ( , - ir; v.^ . ' ' '-f &? (, * r S|ilf V/' * ' i " - Ml 44 *. * r - o Nj -V-Jl'i ',i ~n a) 4 * 1a# , --f VP:)' Methyl iodide1 Acrylonitrile1 Dlbroneaethene1 Pyridine1 Eplchlorohydrln* 2>Methoxyethenol4 1;2-Dlbroooethane1 1-Nltropropene1 ; 2-tthoxyetlienol* ` Acetic anhydride . 42.4 33* 77.3 67,1 91.S 33 115.2 15.4 11*.9 12,5 124.4 ' 9.0 131.5 131.* 135.5 1.6 7.2 , 139.6 3.7 0,0900** 0.1059 0.012* 0,0124** 0.0121*1 0.0114 0.0140** 0.07llh 0.0711 0.075S1* 160 ' 160 160 160 146 146 161 1*0 141 ", 161 51.2 51.0 62.1 64.3 56.9 55.5 ^ 61.9 11.6 17. 7 94.5 41.5 61. 1 161 12 121 279 119 . 134- 292 15.5 no 211 ; 116 145 249 , 141 16 5 303 0,091. 0.09 2 0.1(7 I't'l a .lit 0,174 0,502 0.717 1.06 0.324' 0.360 0.460 0.301 0.352 0.317 0.431 0.561 e 6.540 0.94* ,l.O0>; 1.33* p% 0.016. , r\ -s r> .. 0.006 ` 0,01* m\\ |*-X < . A iV; . 0.014 } 1 ; t T . 0*096 s' .63.7 143 . 164 322 r . . 55.4 77.0' 133 ' 1 213 j". 1 61.0 ,-f xu ,; 13* ;>]' jtb ri 0.277 ,',0i426,;'.b.*93^ : j 1 *e4 . f. ' *rA *t *k?j * >* -V ' ,1 .V l ) V.1 v \ * '-S nr V- '' '1 ; * .S J: , t: - ^. ; `.l* Hr'1 t , :\- ` v">: f-l. .*! T,*1 \Lv Mv * 1 1-Nathoiyetatnel* 1,1-Dibroaoethane* 1-Hi tropropane 2-Ethoxyetlnnol* Acetic anhydride 124.4 131 .S 131.6 135.5 139.6 9.U 1.6 7.2 3.7 0.01(4 0.01401' 0, 07 11'' 0.0711 n. 0 7 s sll no S5.* JIfr 143 1*9 ` <eI ? r*WI*i*T *r> ' 161 61 .9 141 165 you 0.946 1.09 1.336 160 63.2 143 164 322 0.443 0.504 0.6: 141 55.4 77.0 123 213 0.277 0.426 0.593 HI 61.0 124 131 200 0.459 0.506 0.592 TABLE 1 (Continued) v :<! Viftl'&i r Solvent ip (C*) Vapor pleasure at 20*C (Torr) 01ffus Ion at 2S*C (caI/s ee) Hit celleneoua Cont. 2-Methonvethy 1eettle* Iroaobemene1 144.5 1S6 3.6 3.0 0.066611 0.0661h charcoal Cal)* 150 160 Experlaental charcoal el%- *10b *991 <*lb Cain) (In) (in) ,* ' SS.7 51.1 93.3 142 113.2 159 303 297 . ( .( Ht. solvent adsorbed par wt. of carbon *1% (g/1) t*101" t*1001,' (t/t),(*/!) ",t*r ' f '.`Vl.'S'| adsorbed' ', e v_*-1 at 1 mm'i j =f par wX tt. K,' 1 f ' . iy' Vk :' i"."ti.' P -.'fa *ti 1 0.431 . 0.521, 0.707! . - VW fH't'j* 0.149 0,940 1.126 ' . ' .* aj* * I .A 2*Et1io)tyethy I icitite1 156.3 2.0 0.06I91' 141 55.1 79.S 96.5 241 0.417 0.497 -0.6(9 ., * -.^v . * r 1 1 1 1 -- ' ^ 1 `' V`Vi,iW. 1'.*-, *Averaga voluaat for a eartrtdfa pair are 146.3 i 1.9 al for the Type 1 and 163.1 1 6.3 al for the Type I. : i i 'r.Wsi- ^Average wal|htt for a cartridge pair arc S6.1 * 1.2 g for the Type 1 and 62.2 3.9 g for the Typpe* 2* ? o''X Calculated froa ^Eftlaated froa HQC/24,1 10S *c. ; - (t^' 0.9 (t^ - tj;)] (HQCJ/26.1 10fi *c. *1/ Vi-:-' *Sea Ref. 4, "Data Ffoceialng," calculation of Hjt Calculated froa N 11,0 "total * V *Ustd Type 1 cartridges, h Calculated froa Gilliland's equation D?s - [0.0043T1 'S(l/H,,ir 1/|`lap1 'S^(vair .33 4 where v^r It 29.9 wl/aol and vyap Is calculated froarthe LeBas approximation (ate uti ivi- lltaad Type 2 cartrldgat. '!. r; ,* */.' i It .V; Jt.' -.jVm- ui '4, .r vihfr'S.}' \ ... !V. , * ` H -f*- ft t -.2 0.33 4 . i ' i ,* 1 , - * - \ 1, < J3 - j> . t M::-; 'J ' ; - -` T f .i';;j;i , ( ,. ; ..</ ' - ..;'' mVTi.'*i, !.',t : ` > y-- R1 's ,-Vi.;'yy {'W . :- r*U-!,v 1] : b [<.,'.;. r ' *., c s , 11 ;V ' < * v /v * 'j V M*.*.-V* to the upstream concentration) for each sol1 cartridge`breakthrough can be calculi vent is shown as a function of time. These from ji~ figures yield the complete adsorption history ;;.V from initial breakthrough to total cartridge V: saturation for each of the solvents and gases ' . ' " U iW-wwy ;-V. tb = MQC > V?. v-- -, - . '<- - ffiie tested. ^ :i" 'r ry. - V-- where/b " Initial cartridge breakthrou Table I helps summarize the data shown time (min)..' _ -* m '.jn Figs. 4 through 13. Here solvents are "j r arranged by classes, and within classes by ~ boiling pointy with the most volatile com~ . pound shown first The times to reach T %, 10%, and 99% breakthrough and the re. spedive weights adsorbed are shown for ;~ Vm -- molar volume bi me syitegjfi ' . temperature and pressure (24^v liters/mole at 20C,* 760 *tWojIrrjp^1 JV,P w = weight of solvreenntt ad*sor-bed - ^ f^jhe gram of activiated ccaarrbWon* (gm/gm). each solvent. ' Wt = weight of activated carbon^a This table'shows that, within each class of solvent, the most volatile solvent breaks through first. As the boiling points of the (gn)- ' M -- molecular weight of the con?^ '*. taminant (gm/mole). . solvents within a class increase, however, Q = airflow rate (liters/mb). . the trend eventually reverses. At some point C = upstream gas concentration*: - - the breakthrough time actually decreases (ppm). with rising solvent boiling points. This oc- V. curs for each class of solvent All the terms can be measured or calcu-^ lated except w. The weight of solvent ad- ' '% Table I also illustrates how the weight of sorbed is extremely difficult to predict, since^- f solvent adsorbed varies with the vapor pres it is a complex function of the nature of the * 0 \\ sure as well as the boiling point. Within adsorbent and solvent vapor. Therefore^' '~ each solvent class the weight adsorbed is equation 1 is useful only if the weight is: both an increasing function of the boiling determined experimentally. Estimations of V point and a decreasing function of the vapor the breakthrough time can be calculated,~~ pressure--the two being interrelated. This however, from the adsorption isotherm and' is shown to be the case for 1%, 10%, and the Mecklenburg equation. 100% breakthrough. These data can be The adsorption isotherm for microporous[ used, therefore, to approximate the weight adsorbents yields the maximum weight of? adsorbed of an untested solvent once its solvent adsorbed at total carbon saturation V ' class and boiling point or vapor pressure are known. Table I also gives the diffusion coefficients and can be calculated by .vs w. = pWt> exp j^--^-Pog <p,/p)]* J . (2)| and the activated carbon weights and vol umes needed in the theoretical calculation of the breakthrough times. It also shows the . -fei where w, = equilibrium'stadc adsorptive ca pacity per unit weight carbon 7^ I ^sNl weights of water adsorbed. Note the rela tively large amount of water adsorbed in connection with more volatile solvents, espe (gm/gm). p -- density of solvent (gm/cm5). ^ Wt -- total volume of adsorption ^ 'tZSf-'&.PP?'51 ^ 4 cially those that aTC miscible with water. Calculation o/ Breakthrough Times . space (cms/gm). B * microporosity constant for the -7 carbon. The ability to predict the cartridge break- . T = temperature (*K). . through mathematically for any solvent that* ' fi -- affinity coefficient of solvent va- V may be encountered would be useful. Initial . por for the activated carbon. '**; sf-rav.*-*?! * ft: TZZ?. . ^:s#^?3 k f _r!iV -' & . *- t - - % i . .\, V. DO 0781.48 CONFTOFNTTAl equilibrium partial pressure of coefficient is independent of the temperature cartridge breakthrough!' min). ' ;*3isS?-' - the solvent vapor. (torr). , - ' ~ : -***: `-V-. This adsorption isotherm bolds for any /'^nicroporous adsorbent and is valid only at and practically independent of the porosity. The fi term can be determined expert-'-jf mentally or approximated by: L. _** --' - volume at the system' temperatures below the critical temperature ature and pressure (24.^ V. ;`0f the vapor. The Wa and B terms are inter- p v Pt 'V M,p. ">-(3) ttole at 20C, 760 torr),I --plated and depend only on the nature of where v, v * molar volume for the un of solvent adsorbed pJjjS "the adsorbent. The affinity coefficient fi known and standard solvent of activiated carbon^ "characterizes the adsorption of a given vapor (cm/mole)., "> ` . with respect to another vapor selected as a P, Pt -- parachors for the unknown of activated carbojl *\ TABLE U Jar weight of the con-^. nt (gm/mole). .V Cartridge Characteristics and Test Conditions Used for Calculating Weight of Solvent Adsorbed, rate (liters/min). $L im gas concentration^ -n - n be measured or calculi ie weight of solvent ad^ Sf.' jii^11*- difficult to predict, siucejs from Adsorption Isotherm 'i - Cartridge type Parameter Density, p (gm/cros) Maximum adsorption space, We (cms/gm) Degree of porosity, B" - . Temperature, T (K) ` I ft 0.65 1.0 X IQ* 293 2 . ft 0.61 0.95 x 10* 293 :tion of the nature of the f; Affinity coefficient, y3 See Tables IV and V vent vapor. Therefore, v* ill only if the weight is ' mentally. Estimations of' Saturated vapor pressure, p, (torr) Solvent vapor pressure at 1000 ppm, p (torr) ' See Table I 0.76 Obtained experimentally from weight and volume measurements. 0.76 time can be calculated, adso'-'ion isotherm and .' juatk sotherm for microporous ' TABLE III Cartridge Characteristics and Test Conditions Used for Breakthrough Time Calculations* from Mecklenburg Equation he maximum weight of " Cartridge Type ! total carbon saturation Parameter 12 ted by j^Hog (p./p)]2 J (2) ; j* rium static adsorptive ca-_ ' per unit weight carbon ;* Weight of solvent adsorbed (w,) per weight of activated carbon (gm/gm) Carbon density, pc (gm/cm3) Cross-sectional area of carbon, A (cm-) Humber of cartridges tested, n Flow rate, Q (lilers/min) External surface, at (cmtygm) See Table I 0.375 32.1 ^ 2. 53.3 45 0.389 39.6 2 53.3 77 If!h n'* n). ^ fi: of solvent (gm/cm5).. 'olurae of adsorption^' cmVgrtt). arosity constant for the . Diameter of granule, d (cm) Viscosity of air-vapor stream, 17 (gm/cm-sec) Density of air-vapor stream, pa (gm/cm3) Breakthrough concentration. C* (ppm) Inlet concentration. C; (ppm) Molecular weight. M (gm/mole) 0.165 1.83X 1(H 1.2 X 10-* 10 1000 b 0.117 1.83 X10* 1.2 X HP* 10 1000 a Void volume. Vv (cms/sm) 0.42 0.38 iture (K). coefficient of solvent vathe activated carbon. ' > Cartridge volume, V (cm3) Diffusion coefficient at 25C..D (cm*/*ec) 70 See Table I *At 20C and 760 loir. ^Obtained from the Handbook of Chemistry and Physics, 80 7 smmi: ... 1 'mmV': i ' **'c'``S.* c- I- r-- i(nrric" (calcu lated ^ from Sugden's equa tion... .." periraental values ot w. are also shown * .'Tables IV-and V. Note that the sorption tile materials show the greatest deviA^ *In*tIy t solvent density for the un- from the calculated values. This is due nSr^ correct* Tcnown and standard solvent (gm/co5)^;'^'" ' .manly to the preferential adsorption 'of-tjjfl $ A* * water vapor present. In theory, the;^' weight ; molecular weights for the un- V '. sorption isotherm described by equatioj stlOO? known and standard solvent , (gm/mole). - * .' All the parameters needed to solve the adsorption isotherm are given in Tables I through V. Comparison of the actual ex- is valid only for a single vapor in air-sp bo^cve neglects competing adsorption by waterop- sdsorpt any other vapors. Even by expanding"!^ Jess. st adsorption isotherm to include multiple va?^" mated por systems, it is still difficult to predict "h? w. what extent highly polar materials such a?" The TABLE IV . ' Comparison of Calculated and Observed Adsorption Capacity of Type I Cartridges for Several Solvents* Adsorptive Capacity. wt Solvent ' Benzene . Toluene m-Xylene Affinity Coefficient, 0 1.00* 1.33* 1.38= Observed (gm/gm) 0.327 0.473 0.536 Calculated from Equation 2 fgm/gm) 0.408 0.507 0.540 Deviation from Observed <%) + 25 + 7.2 + 0.7 Methanol Ethanol Propanol n-Butanol n-Pentanol 0.40* 0.61* 0.84d 1.02d 1.22d 0.018 0.168 0.384 0.512 0.552 0.048 0.251 0.429 0.495 . 0.525 + 167 + 49 + 12 - 3.3 - 4.9 Methyl chloride Ethyl chloride I-ChJoropropane 1-Chlorobutane Chlorobenzene 0.56* 0.76* 0.91 = 1.09= 1.18= 0.008 0.048 0.196 0.391 0.562 0.016 0.129 0.293 0.426 0.669 + 100 + 169 + 49 + 9.0 + 19 Dichloromethane 1,2-Dichloroethane 1,4-Dichlorobutane o-Dichlorobenzene 0.66* 0-90= 1.28= 1.36= 0.101 0.456 0.755 0.911 0.216 0.555 0.720 0.851 ' + 114 + 22 - 4.6 - 6.6 Chloroform 0.86* 1,1,2-TrichIoroethane 1.08= 0.415 0.773 , 0.518 0.822 + 25 + 6.3 Carbon tetrachloride 0-96* Perchloroetbylene 1.21* 0!677 1.01 0.690 ' 0.965 + 1.9 - 4.5 Methyl acetate Ethyl acetate Propyl acetate Butyl acetate Pentyl acetate 0.89d 1.10* 1.30* 1.48d 1.63d 0.214 0.350 0.507 0.584 0.616 0.333 0.442 0.513 0.550 0.577 + 56 + 26 + 1.2 - 5.8 - 6.3 The equilibrium partial pressure . p, at 1000 ppm is 0.76 torr. The saturated vapor pressure. pa, is taken from Table I. Experimental values taken from ref. 6. Calculated from parachors using Sugden't equation. dCa)culated from equation 3 using molar volumes. ' t u*" where C. $ Cr pso & ml '3a M4-. -.'kq U1' >-Sf * ** -- ,V " *,*,** ;*' 1 , ' * V* '-.-.--i*'j,!t .ii. V4T! nOjft ^ater trial the more vqjg Sorption processes of organic vapors. Cur- greatest deviation? :I^e'ntly there is no satisfactory method of I Thi* is due pJJ^ ?jnrrection for this interference.*;*Vi- tferei...al adsorption of as was previously mentioned, w is the tsent. In theory, thejjjjlr ^^eight adsorbed at total saturation--that is, n described by equation^ \00% breakthrough. Initial breakthrough, r a single vapor in air; ^ %owever, occurs long before the equilibrium ng adsorption by water`adsorptive capacity is established. Neverthe- I. Even by expanding T'ijjcss, such breakthrough times can be esti- xm to include multiple va$ i still difficult to predict to* Jy polar materials such ^ Tnated from the Mecklenburg equation once 'iw, has been determined. %> The Mecklenburg equation states that - and pc ** carbon density (gm/cm*) A -- cross-sectional area of the adsor- " bent bed (cm*). . - `- V -- carbon volume (cm*). - . .-n = number of cartridges tested. ; Co = assault concentration (gm/liter). y V -,,z = bed depth (cm).-.* ac = specific surface area (cmVgm)." >d " diameter of granule (cm). G = mass velocity through cartridge . + (gm/cm2-sec). n -- viscosity of the air-gas stream (gm/cm-sec). opacity Deviation from Observed (%) + 25 + 7.2 + 0.7 + 167 + 49 + 12 - 3.3 - 4.9 1 + ,o9 + 49 + 9.0 + 19 + 114 + 22 - 4.6 - 6.6 25 6.3 1.9 4.5 56 26 1.2 5.8 6.3 jrr. The satu- 1000pcQVcPc 60An z = V/A Dio = 0.967D2* p* -- density of air-vapor stream (gm/cm*). D = diffusion coefficient (cmVsec). Cb = breakthrough concentration (ppm). ' Ci = assault concentration (ppm). Vc ~ void volume (cm*/gm). Equation 4 is generally useful only for Cb/Ci < 0.2--that is, for breakthroughs 'iv T-if = -iV *' 'Ck> Pm V srsy'm -M /, -M ."ti & 'lilt TABLE V Comparison of Calculated and Observed Adsorption Capacity of Type 2 Cartridges for Several Solvents* Adsorptive Capacity, w. Solvent Acetone 2-Butancne 2-Pcntanone 2-Heptanone Affinity Coefficient, (3 0.88b 1.10c 1.19' 1.57' " Observed (gm/gm) 0.135 0.295 0.483 0.560 Calculated from Equation 2 (gm/gm) 0.236 0.360 0.427 0.493 Deviation from Observed (%) + 75 +22 -12 -12 Pentane Hexane Heptane Nonane Decane 1.08b 1.295b 1.46b i.ss" 2.05" " 0.228 0.334 0.432 0.490 0.553 0.225 0.319 0.375 0.434 0.442 ' - 1.3 - 4.5 -13 -11 -20 Methylaminc Ethylamine Butylamine Dibutylamine 0.72" 0.91" 1.29" 1.25" 0.041 0.179 0.429 0.480 0.061 0.166 0.371 0.466 +49 - 7.3 -14 - 2.9 The equilibrium partial pressure, p, at 1000 ppm is 0.76 torr. The satu rated vapor pressure, p,. is taken from Table 1. "Experimental values taken from ref,"6. Calculated from equation 3 using molar volumes. "Calculated from parachors using Sugden* equation. l - . 14. * J k Tl *if" 4 t * l f v 7S..C *v 3*V &J * Jr tv* ^.77v-.sy--v--r-- ----- . , - s, `r ' 7-L ' -^ r ~ * r 7" r ` - ' .. J , imiM-- ,;r? - y.v <> - v1.' ^i vvif i^r. 1 1* :! - v.;.h : ,vW V ''P v !-'-/v . ; /.\Pl iP DO '078151 ' rV.^V^'cVri ---'r-x ' ' - OONFTDFNTT Al less tban 20%. The predicted and actual breakthrough ' times are compared in Table VI and VII. i=VTn general, the predicted times are somewhat V:xnore optimistic than those determined ex,!v perimentally. .This again can be explained !" : by water's tendency to occupy the available adsorption sites. Tables VI and VII show conclusively that approximate breakthrough times can indeed be calculated, but only if the activiated car bon is well characterized. .Approximately twenty-five variables must be known, how ever, before such calculations can be initi- a.ted.. . - - There have been attempts to'!') these calculations by relating the 'bjSv through time or weight adsorbed directj&5 a single property of the solvent such asTicS ing point, molecular weight, vapor pre*gfif| or diffusion coefficient. These oveisu^^S Ccations generally fail, however, many interrelated variables play a adsorption. ' ". *" Effect of Concentration In a preliminary investigation we'varied the concentration, from 125 to 2000 ppm e- K9 ! ? *****ii5*i - m 15/3 - ** - - <-, ' . '.. . - . .<> - i}- :^ ^ E5'2T>'*3Svt'* % v^+-Av**- > Ls* v#>*v# -^.r- - .':** - t TABLE VI Comparison of Predicted and Actual 1% Breakthrough Times, Type 1 Cartridges* Calculated from Mecklenburg Equation Material Benzene Toluene iw-Xylene Methanol Ethanol n-PropanoI n-BuianoI n-Pentanol Time Measured (min) 73.3 94.3 98.7 0.2 28.070.4 115 102 Using Experimental Weight Adsorbed (min) 74.2 89.1 82.0 10.9 67.6 115 120 104 Using Calculated Weight Adsorbed from Adsorption Isotherm (min) 92.6 95-5 82.6 29.1 101 128 116 99.2. Methyl chloride Ethyl chloride 1-Chloropropane 1-Chlorobutane Chlorobenzene Dichloromethane 1,2-Dicbloroe thane 1,4-Dicblorobutane o-Dichlorobenzene Chloroform 1,1.2-Trichloroclhane Carbon tetrachloride Perchloroethylene Methyl acetate Ethyl acetate #i*Propyl acetate n-Butyl acetate n-Pentyl acetate 0.05 5.6 24.5 72.3 107 10.6 54.0 108 109 33.2 71.8 77.0 107 32.8 - 66.8 78.8 . . 77.3 72.6 . 3.0 13.2 43.0 70.8 83.8 21.6 81.2 96.4 99.6 61.0 98.7 75.* 104 51.7 69.1 83.9 81.8 74.5 53 35.6 64.3 77.1 99.7 46.2 98.8 91.9 93.0 76.1 105 77.3 99.3 80.5 87.3 84.9 THU 69.8 Test conditions; 53.3 liters/min, 50% relative humidity, and 20*C. Cartridge characteristics are summarized in Tables II and III. .*r- A ..a. 'ir .v- -- --r * at "I m F si -- attempts to simplify^ bv. relating the break-"?1 - TABLE YD, Comparison of Predicted and Actual 1% Breakthrough - Timet, Type 2 Cartridges `Jr- Jwei( adsorbed directly to*j Calculated from Mecklenburg Equation 1 of the solvent such as boil^l m ntlar weight, vapor pressure ^'3 efficient. These oversimpli-^ % fail, however, since so? ~ *-- Material - . 1 w V - _ - Using M"` ,* .. . Zr* * " .Experimental ; 'Tune- Weight : Using Calculated Weight Adsorbed from . Measured Adsorbed Adsorption Isotherm (min) (min) (min) '7 td variables play a role in; Acetone 37.1 .58.3 . 102 2-Butanone' 81.9 > ioi 123 . * - ' 2-Pentanone 104 .. 137 . - 121 . itration 2-Heptanone 101 116 -102.. _ ; tary investigation we varied/? a, from 125 to 2000 ppm for rough . n-Pentsne n-Hexane n-Heptane n-Nonane /i-Decane Methylamine 60.7 52.3 78.2 76.2 70.8 12.4 77.6 93.7 103 89.4 90.3 33.6 76.6 89.5 89.1 79.2 72-2 50.0 . mburg Equation Etbylamine n-Butylamine 40.5 110 99.3 145 92.1 125 Ising Calculated Di-n-butlyamine 75.5 86.9 84.4 Weight Adsorbed from Adsorption - `Test conditions; 53.3 liters/min, 5086 relative humidity, and 20*C. Cartridge characteristics are summarized; in Tables II and HI. Isotherm (min) 92^6 95.5 benzene and from 50 to 2000 ppm for ace e tone, and measured the effect on service life. The characteristic S-shaped break 82.6 through curves for these solvents appear in 29.1 10* llllfi 99.2 5.9 35.6 Figures 14 and 15. Although the time to reach a given breakthrough increases as the concentration diminishes, the breakthrough time-concentration relationship is not in versely proportional as one might intuitively suspect. However, a logarithmic plot of the - 64.3 77.1 99.7 46.2 * 98.8 ^ 91.9 .* 93.0 76.1 * 105 ; 77.3 99.3 80.5 87.3 84.9 77.0 69.8 breakthrough time (for example, at 10%) as a function of the concentration yields the -ji ' linear relationship shown in Figure 16. The resultant empirical equations for the straight lines are; /lO percent = 1.4 X 104 X C/" 76 benzene flO peretnl = 1.1 X 105 X Cl~* * acetone for for where fio percent is the time in minutes to achieve a 10% breakthrough, and Ct is the. upstream assault concentration in parts per 1 million. These results conform to the basic 100 150 ZOO 250 300 350 400 4$0 Ttae -- aln Figure 14. Breakthrough curves for type 1 car tridges, at various conccnlations of benzene. Each cartridge pair contained 56.6 1.5 gm of acti vated carbon and was tested at a flow rate of 53.3 liters/min and 50% relative humidity. Summary We have examined the service lives of organic vapor respirator cartridges exposed to aromatics, alcohols, acetates, alkanes, ke tones, amines, and chlorinated materials. We assaulted the cartridges under standard ized conditions and monitored the down y. and 20"C. 11. Frcundlich equation and have been demon strated previously by Fraust and Hermann.* stream concentration to cartridge saturation. The standard test conditions included a $ol- v-- . i- - ., ^. . * -- 9 c-_ 100 - bon has a greater affinity for the less volatile *, materials. ' ' : V. ^ The relative humidity greatly influence**^ the amount of solvent vapor adsorbed, sig^ nificantly decreasing the activated carbon's^ affinity for volatile or water-soluble solvents':^ 'A brief investigation showed that the ef--^_ feet of . concentration on breakthrough tinted conforms to the basic Freundlich equation. *n fi t-*V H i Wit* fr 150 200 250 300 350 400 450 Tine--feln Figure 15. Breakthrough curves for type 2 car tridges at various concentrations of acetone. Each cartridge pair contained 60-5 2.9 gm of acti vated carbon and was tested at a flow rate of 533 liters/min and 50% relative humidity. 500 100 S -- i . 1111_____ i _!''_____ 50 100 200 500 1000 Concentration -- ppm Figure 16. The 10% breakthrough time as a function of concentration for benzene and acetone. vent concentration of 1000 ppm, 50% rela tive humidity, and a flow of 53.3 liters/min. Measured breakthrough times agreed reasonably with calculated values obtained from the adsorption isotherm and Mecklen burg equation. In general, the activated car- References 1. Ruch, W. E., G. O. Nelson, C. L. Lindeken^C R. E. Johnsen, and D.'J. Hodgkins: Respira- tor Cartridge Efficiency Studies: I. Eaperi-"V< mental Design, Amer. Ind. Hyg. Ass. 3. S3-'x-` 105 (1972). '-'js 2. Nelson, G. O.. and D. H. Hodgkins: Respirator Cartridge Efficiency Studies: 1L Preparation.^ of Test Atmospheres. Amer. Ind. Byg. Ass. J V JJ.T10 (1972). '.I; 3. Nelson, G. O., R. E. Johnsen, C. I_ Lindeken, 'V and R. D. Taylor: Respirator Cartridge Effi--' ciency Studies: III. A Mechanical Breathing -- Machine to Simulate Human Respiration, 'tt < -> Amer. Ind. Hyg. Ass. J. 33H45 (1972). ys 4. Nelson, G. O- and C. A. Harder. Respirator ' TM Cartridge Efficiency Studies: IV. Effects of . Steady-State and Pulsating Flow. Amer. Ind. $ Hyg. Ass. J. 33:191 (1972). 5. Smisek. M., and S. Cemy: Active Carbon, pp. 133-135, Elsevier. New York (1970). 6. Freedman, R. W., B. 1. Ferber, and A. M. Hartstein: Service Lives of Respirator Car tridges Versus Several Classes of Organic Va pors. Amer. Ind. Hyg. Ass. J. 34:55 (1973). 7. Perry. J. H.-(ed.): Chemical Engineerf Hand book, 3rd ed. pp. 538-539, McGraw-Hill, New York (1950). 8. Walker, P. L (ed.): Chemistry and Physics of Carbon, pp. 115-116, Dekker, New York (1966). *. 9. Fraust. C. L, and E. R. Hermann: The Ad-' sorption of Aliphatic Acetate Vapors onto Activated Carbon. Amer. Ind. Hyg, Ass. J. 30: ; 494(1969). \' Short Course The annual Short Course in Fundamentals of Industrial Hygiene will be presented at the Kettering Laboratory, University of Cincinnati, from October 14-27, 1974. The course, half lecture-half laboratory, will be conducted by the graduate faculty of the Department of Environmental 'f. i-' In 1 8* of ns er b! sB be *P a Pr sc D1 hi O' P* si OI is $600. For information contact HowJVd Ayer, Kettering Laboratory, 3223 Eden Avenue, Cincinnati, Ohio 45219. (513) 872-5708. 'M 't