Vapor-Liquid Equilibria for HFCs + Propane

Transcription

1 Vor-Lqud Equlbr for HFCs + Proe Altertves Reserch Ceter Hyu Sg J, Byug Gwo Lee, De Ryook Yg, Jog Sug Lm * CFC Altertve Reserch Ceter, Evrometl d Process, KIST Chemcl Egeerg, Kore Uversty Chemcl Egeerg Sogg Uversty* *Corresodg uthor

2 Itroducto Ar codtog hs to use refrgerts d lthough there re my tyes of refrgerts, cludg r d wter, t s ecessry to use chemcls for resosof effcecy d ultmtely to coserve eergy. Hydrofluorocrbos (HFCs) re fmly of refrgerts tht hve bee secfclly develoed to rovde ltertves to CFCs d HCFCs. They hve my of the fvorble chrcterstcs of CFCs eseclly those of zero flmmblty d zero toxcty. However, HFCs re owerful greehouse gses tht re detfed the Kyoto Protocol. Ths c be doe ether by : mmsg lekge of HFC refrgerts to the lowest rctcl level or by usg low Globl Wrmg Potetl refrgerts such s mmo or HCs (hydrocrbos)

3 Itroducto R11(CCl 3 F) s sgle chlorofluorocrbo or CFC comoud. It hs hgh chlore cotet d ozoe deleto otetl (ODP) d hgh globl wrmg otetl (GWP). ODP = 1, GWP = 4000 R(CHClF ) s sgle hydrochlorofluorocrbo or HCFC comoud. It hs low chlore cotet d ozoe deleto otetl d oly modest globl wrmg otetl. ODP = 0.05, GWP = 1700 R134(CH FCF 3 ) s sgle hydrofluorocrbo or HFC com-oud. It hs o chlore cotet, o ozoe deleto otetl, d oly modest globl wrmg otetl. ODP = 0, GWP = 1300 R36e (CHF ( CHFCF 3 ) s sgle hydrofluorocrbo or HFC com-oud. Curretly, oe of the ledg cddtes to relce CFC-114 s R36e. ODP = 0, GWP = 100 R90(CH 3 CH CH) - Pure roe, hydrocrbo (HC) effcet turlly occurrg refrgert wth smlr roertes to R. ODP = 0, GWP = 3 Sde by sde comrso of se ce from 1979 d 003 Courtesy NASA

4 Purose of reserch Vor lqud equlbrum dt re requred s oe of the most mortt tyes of formto evlutg the erformce of refrgerto cycles d determg ther otml comostos. I the reset study, bled of roe d oflmmble HFCs refrgert re reduced both globl wrmg mct d flmmblty. I ths work, we mesured VLE dt for the bry mxture of Hydrofluorocrbos (HFCs HFCs) + roe t 73.15, 83.15, 93.15, , d K. Exermetl dt were correlted wth the Peg-Robso d Peg- Robso-Stryjek Stryjek Ver equto of stte usg the Wog-Sdler d Huro-Vdl mxg rules.

5 CSD EoS It ws foud tht the CSD-EoS hs bee demostrted to rereset the P-V-T roertes. Ths equto of stte s exressed s follows PV RT 1+ y + y = 3 y 3 ( 1 y) RT ( V + b) ) y b = V : molr volume 4V I cse of ure comoet, the temerture deedece of d b re rereseted by the followg forms: =α + ( α T α ) 0 ex 1 T b = β + 0+ β1t βt The coeffcet of α, 0, α1α equto (3) d β 0, β1, β equto (4) were cted from REFPROP 5.0

6 CSD EoS I the lcto of CSD-EoS to mxture, there exsts the effectve moleculr rmeters m d bm defed by usg the followg mxg rules: m = x x = 1 j= 1 j j b m = x x b = 1 j= 1 j j Whe = j, the vlue of d b re those of d b of the ure Comoets whch re determed by equto (3) d (4). The vlues of 1 d b 1 c be exressed s followg forms 1 1 ( )( ) 1 / f 1/ = b ( ) 3 1= b11 + b / The model volves the djustble bry rmeters, f 1, whch must be determed from exermetl dt. 8

7 PR EoS The VLE dt were correlted wth the Peg-Robso equto of stte, whch s exressed s follows RT P = V b V M M (V M ( T ) + b) + b(v M b) R T P c ( T ) = α ( T ) α [ 1 ] c ( T ) = + k ( 1 T / T ) c b= RT P c c k = ω ω

8 Mxg rule W-S mxg rule The Wog-Sder mxg rule ws used ths work to obt equto of stte rmeters for mxture from those of the ure comoets. Ths mxg rule for cubc equto of stte c be wrtte b m xx j j = E 1 A / CRT ( b / RT ) x [ ]( k ) 1 j j 1 ( b / RT ) = ( b / RT ) + ( b / RT ) / j RTb j b m m = x b + A C E where C s costt equl to for the PR-EOS used ths work, k j s bry tercto rmeter

9 NRTL model s excess Helmholtz free eergy model t fte ressure whch c be equted to low-ressure excess Gbbs free eergy A E RT = x j r x j x G r j G τ r j ( α τ ) d A /( RT ) G j = ex j j τ j = j where Gj s the locl comosto fctor for the NRTL model, τj s the NRTL model bry tercto rmeter, Aj= (gj-g), where gj s tercto eergy rmeter of the -j comoet, αj s ordomess rmeter d equl to 0.3 for the bry mxture Ivestgted here

10 Exermetl rocedure A cert mout of HFCs ws troduced to the cell. After the desred temerture ws cheved, the ressure of the ure comoet ws mesured. A roer mout of roe ws suled to the cell from chrgg cylder. Whe the equlbrum ws tted, ressure ws mesured. The comosto of the smles were mesured by mmedtely jectg them to the gs chromtogrh.

11 Result d Dscusso <VLE curve> P(MP) P(MP) x 1, y 1 HFC Proe Clc. wth CSD-EoS ( ) P-x-y dgrm for the HFC Proe system Exermetl dt t 73.15( ); 83.15( ); 93.15( ); ( ); ( ); 33.15K( ) x 1, y 1 HFC-7e + Proe Clc. wth RP-EoS usg W-S mxg( ) P-x-y dgrm for the HFC-7e + Proe system. Exermetl dt t 93.15( ); K( ). H F C s + r o e

12 Result d Dscusso <The zeotroc comosto wth ressure> 0.65 Azeotroc comosto (mole frcto) K K K K K K P(MP) HFC Proe Azeotroc comosto (mole frcto) 93.15K K P(MP) HFC-7e + Proe H F C s + r o e

13 Result d Dscusso <The zeotroc dt> T HFC roe x 1 P(MP) HFC-7e + roe x 1 P(MP) H F C s + r o e

14 Result d Dscusso <Devto of ΔP d Δy> P x 1 (HFC-143 mole frcto) y HFC Proe x 1 (HFC-143 mole frcto) 73.15( ); 83.15( ); 93.15( ); ( ); ( ); 33.15K( ). H F C s + r o e

15 Result d Dscusso <Devto of ΔP/P(%) d Δy> C 30C C 30C P/P(%) y 1 x 1 (roe mole frcto) HFC-7e + Proe x 1 (roe mole frcto) H F C s + r o e

16 cocluso The VLE of HFC-143 d HFC-7e wth roe system were used the PR EoS combed Wog-Sdler mxg rule d NRTL excess Helmholtz free eergy model d CSD EoS Ths mxg rule combed wth PR equto of stte d ctvty coeffcet model (NRTL) for the A ex term show very good correlto The vor-lqud equlbrum betwee mesured d clculted vlues (AAD-P(%)) for HFCs + roe from 73.15K to 33.15K d the devtos were less th 0.61% I ths temerture, zeotroc behvor hs bee foud HFCs + roe systems. H F C s + r o e