I I IIGPI ! d 1 1 N o 4 { D d e m b s 1 0 1 0 ) 4 7 5 7 E'XCESS VOLUMES OF HEAVYOIL- STOCKS MIXTURES + (KEROSENE OR XYLENE) AT3O3 ( Haidr M Ar aamarc ch.n ical Engi.e*ii s Depadmenr.CoLLaEeofEigireenng,Nsnain Lrn ve6i! Baghdad l'aq Binaq nirturesofrhree, heaq oil-$ocks had been subj'cred to deisiry mersEmena The d a e h a d b e e ; . c q u i E d o n i h e v o h m e n i c b c h o v i o r o l r h e s e s v s l e m s T h o h e a v v o i l $ ' c k s u $ d w e r e of good vlrity, n;mely'10 stock.60 srock, and 150 slock 40 siock is $e lighre$ one *ith'APl s,;it] 33.7;hib 60 st."k is middle qpe and 150 $ock is heavvone *ilh "APl gmvitv2?7 afd i3.s resp€dively srocks *ith Kerosctre o' xvlBnd rbrm non ideal mirt'rcs' for *hich etccs volume;an be posirive o. negative Mixlures ofheavv oilsrocks wilh parafinic soike (keroscne) shoB negarile ;rc*s volume. while, aronatic rinss rcstrlls a lower posirive exce$ volume as shown i;xybDe when bledding wnh 40 stock and 60 stocl br( a negdrivc excess vohrme *hen blending with 150 stock The gruvirv ofoil-$ocks has an efle'r 'i exce$ voluDre shen the or! stocks;piked with Kemsenc or Xrlene Those,40 $ock !srvpical lighr rype resuhed in minmum negdiv;exd$ volumeof_21s, qhen ir was lPikcd rvith rhc kercsene while the spikedhe'vvo'l * o _ c * w i r t , l c o s e r e g a v e a - * i n u m e x c e $ v o l u m e d f - l l 2 ' f h c R e d l i c h - K i s t e r e q u r i o D w d s used ro nr r]t exces volume valLLes, ard rhecoetlicients aid e$imate olnE nandatd eror lalues Key*ords: E:ce$ Volufre, MixingBehuior, TD ofmixinC INTRODUCT'ION Thc mixing ol difercnl dompounds gives rhc to sol0tions thar generallv do n't behave idcally Thc devialion fiom ideaLirv is exnrescd by mmY thermodYradic p'openies- panicula.ly aclirirv coclncienb and exce* or residual popenies [l]. Erc($ fiennodlnamic propcfies are useful in ihe $ud) ol molecular interactions und amneencnis [2]. In poniculf. thev reflect tlE intemclions rhd take place betwecn so!ure tu vatu-"'aJ Heaq ott solute. solute solvetrt, and soLvenr - sd!vcnr species []1.Ii seneral, posilive cxcc$ volumes may be due to compensarion betw*n strong like inienclions Guch as th.se prcsenl in alehols) and equally unlike H-bond inreractio.s (such as lho* presni between alcohol rnd dhs) [],41. Ncsative cxce$ v.lume will occur when thc unhke inlerutions prevlil oler selfasociation ll,3l. Binary mixlures m an ,mponanr crds ofsolvcnts and solutions, snJ the behari.r ol rhen p[ysicaL propeilies is nill unclear [s] J. rhe blending ol penoleun com0onents halins dillerent physical popcrties, exces volLrmes occu. becduse lhe mmponenh do nor Lrm idcal soldrions ln an ideal soluton, the toul solulion volume is eqdal to the sum ol the lolumes oflhe componetrts l. oiler lor r $lurion ro aPproach idealitv, the n,olectrlcs of the matoiah blended tqethcr rnl$ be simil$ in sizc, shape. and propetiss ,f thc nature of $c comPnenls diffen atpftciably, then dcviation ftom ideal bchavior Day be cxpected. Thh devirlon nay be eitherp.sirive or negdrivq lhar is. rhe total volume may incrersc or decrease q[en dE componenls arc blendcd [3] Theblending of oil e.cks results in volume chatges, caused by rhc notr-ideal behlvior of oil systems as compared wirh thc calculated idell volume. Sinca thc oil indust! uses volune meosurcDrent in its balan.cs, ihe apparent dhcEpancies in marerid fray cius financial compliciiions- which in so'ne cas.s hove rcd Thc e\ces rolume behavior ol healt oil_ nocks mixtures is inporbnt. Since only small amo! ofdalabase tr€s publhhcd, especiallv on minurcs of hedly oilslocks Nith puF hldbcrbons. WhilE little eudiss were pubLished on mixtures of difterent tl'*s ol A lulL unde*landing of iherdodyilmic an'l knspon pr.pcnies of bin.ry liquid slicms k e$ential in many chcmical engineering pro.o$cs such s desiS! calouhtion, heat nansfer, mas tansfdr. nuid flo*. rnd so tirnh l7l we havc slarted n rcsearch progdn of the ercess propenies of nixtu.es conraining (hcavy oilstocks + spiket. ln this No* $c have rep.hed cxperimenr.l data such as dersiq over the whoLe nisc of composition The pEsentrvolk was in ve{ig.rcd lo evalLLnlc rhe lolumenic behavior of blends ol the he.vroilslocks. Fu hereim.f rhe workrvas ro investigare rhe eifecr ol hydrccarbons spikes such as kerosens and rylen€ od the exes volume of these mixtures. Three heal} oil sidcks $erc obraLnc,l lnm al Dunr Rclinery, namelt 40 slock, 60 siock, and 150 $ek. 40 (ock is the lighrcst one rvid i,^PI SEvii] il.69r'hile 60 nock is middle rype and 150 srock is hearl one. wrtrr "APl grvny 27.74 dd 23.79 respectvely The main propenics oloil nocks (10 stock, 60 stock, lnd 150 stock) were measured in al_ Ddra Rcllnery Labostories accordine to Afl and ASTM sDecilic.rion, as listed inlable l. rcPE!or.t1 N04 1o&ember r0t0) siopper widr a surfacht cleani4 fluid (gasoline), lhen witn acctone and dried Ensuing rh.r aU renoved by drying wiln a curcnt hol air pa$ing slowl] rhrough the Pyknometer and sropper capillary. Wiping lhe ou$ide ol Pyknomelor and stopper with a olean, lint-lree cbln. Nomally Pyknomeler oleaed b, using (ga$line and a@lone), ond died. All thc density medurencnts were caried od at RESULTS AND DISCUSSION The excest rhcmodynamic propen'es suoh as excess volumes olmixtures of hetvy oi lstocks lre coi sidenble i ntercst in lhe fi eld of tmnsp.rlation. Usually lighr oil-slock blended wilh Dediufr dd ako wi$ heavy oil- srdck to sath8 such specificdion lbr lubiicatina oil and anoder uses. Although lhese trslmenl have led to consideFbLe insicht inlo themodrn.mi. behavior ofrhesc mixtures. But lhcse blending led mostly lo Kerosene w6 uscd as pelrcleum fiaclio. io nudy the erces lolune phenomem of hearl oil srocks. This lmction was supplied by al- Dufr Refincry, while lhe xylenc w6 supplied tom MERCK Company, Gemdy. The neihod olmilng proces *as tchieved b) electidrl nircr al room lerlpedtdre (20- 25 "C), Densn, measuremenls sas made immediotely, after prepaing lhe mixtures ro avoid deposir f.rnarion or uporizing lhe lighr ends. All densily canied out dt ahospherio presurc. The following mixlures *ere prepaEd in rhis Three heavy oil-stooks binary mixlurs oler a mnge of weisht peEenr (0-100) al tenpedue 30'c. - Binary nixrlres of heovy oil stocks with spikes {keosene + xylene). over a raige of rcighl percent (0-100) at Densiry deleminalion of heavy oil-docks, spikes and their blends were canied outusng Pyknometer having a size of 50 cmr a@ording to the sland ard methods (IP I 9 l]) r3). The Pyknometer w.s placed in a *arer bath rype (.,ulabo F25) as show! in Fig. I which was capable of mainuining the teoperalurc wi$in + 0.1 !C ofthe selecled temperarurc. Thoouehly cleanins the Pyknometer and I - u.*vo u No.{D4enbq20r0) Table 2: Exce$ voluneofbinery synefrs: or Si@k ,10 wilh Slook 60 Table 3i Exce$ voLuheofbinar] sr$cmsi.f Stock'10 wilh Sloek 150 The heavy oil-slocks used *ere ol good varity, namely 40 $ock, 60 $ock, and 150 nock. 40 $ock is the lighrest one *hh 'API grivitt 33.7 *hile 60 $ock is middle tvpe and l5O nock is heovy onc. with 'API Cnvirv 27.7 and 23.3 respectivcly. Thre binary mixrures of heavy oil stocks have bcer made. Thc volumetic behaviot of thc binary mirtures of heavy oilnocks *i$ dilleEnt densities volume *as calculatcd by rhe linear expre$i.n in tems of ma$ fraclion ol bLendins componenr as tbllo*s [9] P ! + , . t P l - p 9 | a i p i Excss volume isdenned by the c'iualron: where /'s is lhe actu.l speoific volume. which is equal to l/pi" in cnr/kc lnd l.* G rhs measurcd densny ir *Sr',,r' Exce$ volunes lor binary heavl oil-stooks nixrltusare sumdarized in rables 2,3 and4 lfrhe dala in the fom ol erce$ volumes aE plofted again$ nas liacrion of refsrence compoDenls, snooth cudes arc obrained as shoqn in igure 2 The cudes p!$ rhrougi zerc !r 0 wt% and 100 wt% reference cdnponent, whilc rhe m.ximum exce$ volume occur at, or closc to, mds iaclion ol 0.5. indicarjng thar vt at lhis point should b€ good indicalorofrhc moLecular inleEotions rn V ^ , ' Excss volune are positive ror Gtock a0 + srock 60), and Gtock 60 + sock ls0) mixrrres over lhe mas lnction dnge, as sho*n in Fig 2 . As onc can se ftom Fig. 2lhe doived vllues af V! lor fie nock,10 + siock 150 mixlures ar very hieh (mdimallalue krboutt4.752 rcE vor ! No.4 (D{enber2010) cmr/ks ) and neeative over lhe qhole cornposilion range. V" ouryes are alnosl symnelrio *ilh rhe mdidun at 0.5 ma$ lracrio.s. Thn negarils sx€$ volume (shrinka8e) cone frcn the chmses in self asecistion (inte! or intramoleoulat and physical inlemotion (van der wals intenction and dipol+