Extraction of oleic acid from jojoba oil, soybean oil and olive oil Phase diagrams

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1 IndianJurnalfChemicalTechnlgy Vl.3, Nvember1996,pp Extractin f leic acid frm jjba il, sybean il and live il Phase diagrams JaimeWisniak*,AlexanderApelblat&Ahu-AkelKhaled epartmentfchemicalengineering,ben-gurianuniversityf thenegev.beer-shevar405,israel Received26ecember1995;accepted21May1996 imethylsulfxide, 2-cis-butene-l, 4-dil, 1, 2-butanedil, 2-prpanl, acetne, methanl, and acetamide, were cnsidered as ptential' extractants f fatty acids frm jjba, sybean and live ils, Ternary liquid-liquid phase diagrams at K, and the crrespnding distributin and selectivity cefficients f leic acid are reprted. Of the investigated slvents, nly dimethylsulfxide and methanl have the desirable extractin characteristics f distributin cnstant greater than I and high selectivity t serve as extractants f fatty acids. In a previus publicatin I, we have reprted experimental phase equilibrium data fr the extractin f leic acid frm sybean il and jjba il using N-methylfrmamide, dimethylfrmamide, frmamide, dimethylsulfxide (MS6), 1, 2-butanedil and 2-cis-butene-l, 4-dil, as the selective slvents, Our results have shwn that the effect f the structure f the il n mutual slubility is nt very large and that with slvents like frmamide, methylfrmamide and dimethyl frmamide and blcking f the amid grup with an increasing number f methyl grups results in increased mutual slubility. Out f the slvents tested, nly N-methylfrmamide and 1,2-butanedil exhibited distributin cnstants greater than 1 and high selectivity, and culd thus be cnsidered as ptential extractants f fatty acids. In the present wrk, the fllwing additinal new slvents were cnsidered as ptential extractants f fatty acids: imethylsulfxide, 2-cis-butene-l, 4-dil, 1, 2-butanedil, 2-prpanl, acetne, methanl, and acetamide, Results fr six systems with jjba il, three with 0 sybean il, and ne with live il are reprted here. Olive il has been included in rder t extend ur previus results n the nature f the il n the characteristics f the phase diagram. In all partitin experiments, leic acid (Ci~) served as a representative f fatty acids, quality and jjba il (Israel Jjba) were used in the partitin experiments, The bindal curves iri the ternary systems were determined by weighing methd in the fllwing manner: increasing amunts f leic acid were mixed with il-slvent slutins f knwn cmpsitin in a therm stated bath at K Turbidity f these slutins was determined using a Turner designs nephelmeter mdel , A sharp increase in turbidity indicated frmatin f a new liquid phase, The pertinent cexistence curves are reprted in Tables The distributin curves (tie-lines) were determined in separate experiments by preparing synthetic mixtures, cmpsitin f which fell within the tw-phase regin, and separating the phases after equilibrium was attained. Each phase was then titrated fr leic acid with standard s- Table I-Cexistence (bindal)curvein the leicacid (1)-jjba il(2)-dimethylsulfxide (3)systemat K OAU Experimental Prcedure All reagents used were f analytical grade and were used withut further purificatin. Cmmercially ay-ailable sybean il and live il f edible *Authr t whm crrespndence shuld be addressed.

2 300 INIAN 1. CHEM. TECHNOL., NOVEMBER 1996 Table 2-Cexistence (bindal) curve in the leic acid (1 )-jjba il (2)-2-cis-buten-l, 4-dil (3)"system at K (l.o ] ] dium hydrxide slutins. The tie lines were lcated using simultaneusly the leic acid cncentratin and the cexistence (bindal) curves. The results btained in Tables are the average f three determinatins. The verall errr is cnsidered t be less than 1% in the determinatin f the bindal curve and 3% in the determinatin f the tie lines. Table 3-Cexistence (bindal) curve in the leic acid (1 )-jjba il (2)-1, 2-butanedi] (3) system at K ] Table 4-Cexistence (bindal) curve in the leic acid (1 )-jjba il (2)-2-prpanl (3) system at K ] O.]708 O.] ] 0.02] ] ] : (1) Results and iscussin The experimental results fr the liquid-liquid phase equilibrium at K fr the ternary systems leic acid (1 )-il (2 )-slvent (3) are presented in Tables 1-16 and Figs 1-6. The data include experimental slubilities (cexistence curves), tielines, distributin cefficient and selectivity cefficient S, defined as: S= where w represents weight per cent.... (2)

3 SNIAK et af.: EXTRACTION OF OLEIC ACI 30t Table 7-Cexistence (bindai) curve in the leic acid (1) sybean il (2)-2-prpanl (3) system at K WJ As in ur previus wrk I, it was fund that the cexistence curves culd be accurately represented by the'extended Setchenw equatinz. Inw,=an+alw\+aZwz+a,zw,wz... (3) where Wi are the weight r mass fractins f cmpnents, ai the adjustable cefficients and + + w, = 1... (4) The cefficients f Eq. (3) were evaluated by an unweighed multivariate least squares methd and are reprted in Table 17 tgether with the pertinent cefficient f crrelatin. The equilibrium partitin f cmpnents between the il and slvent phases was determined by a simultaneus slutin f Eqs (3) and (4) and using the knwn dis-

4 302 INIAN 1. CHEM. TECHNOL., NOVEMBER 1996 Table 10--Cexistence (bindal) curve in the leic acid (1) live il (2)-methanl (3) system at K ~ tributin f leic acid (i.e., values f [Wt]il and [Wt]slvent as determined by titratin methd). ue t the small size f the hetergeneus regin n tie-lines were determined fr the systems where 2-prpanl and acetne were used as slvents. In ur previus publicatin I it was fund that the presence f an amid grup had ptential as an extractant f leic acid. Fr this reasn, additinal experiments were made using acetamide t explre the pssibility that the slid slvent wuld induce phase separatin. In this experimental series, slutins f leic acid and il f knwn cmpsitin were heated t 80 C and crystals f acetamide were added slwly with agitatin until the slid saturatin pint was attained. N liquid-liquid phase separatin was bserved. FigUres 1-6 can be used t analyze the effect f nature f the il (jjba, sybean and live) and f the slvent n the distributin f leic acid. The results may be summarized as fllws: 1- The effect f il structure n mutual slubi- Table ll--equilibrium partitin f cmpnents in the leic acid (1)-jjba il (2)-dimethylsulfxide (3) system (tie-lines) and distributin and selectivity cefficients f leic acid Oil w2s w W, phase Slvent phase Table 12-Equilibrium partitin f cmpnents in the leic acid (1)-jjba il (2)- 2-c~buten-l, 4-dil (3) system (tie-lines) and -distributin and selectivity cefficients f leic acid Oil S w w phase 0.25 Slvent phase Table 13- Equilibrium partitin f cmpnents in the leic acid ( 1)-jjba il (2)-1, 2-butanedil (3) system (tie-lines) and distributin and selectivity cefficients f leic acid Oil , S (l.o w2 w m phase 706 Slvent phase

5 SNIAK et al: EX1RAGnON OF OLEIC ACI 303 Table 14- Equilibrium partitin f cmpnents in the leic acid (1)-jjba il ('2)-methanl (3) system (tie-lines) and distributin and selectivity cefficients f leic acid (~2631 Oil phase W Slvent phase O.56Ofl s Table 15- Equilibrium partitin f cmpnents in the leic acid ( 1)-sybean il (2 }-methanl (3)' system (tie-lines) and distributin. and selectivity cefficients f leic acid Oil phase Slvent phase S O,() Tab]e 16-Equi]ibrium partitin f cmpnents in the leic acid (I)-live il (2}-methanl (3) system (tie-lines) and distributin and selectivity cefficients f leic acid Oil phase Slvent phase S ] WJ ( wi ,0972 WJ Slvent ] ' al ,3.51 z ] Om (1.064 (J.(J (J.()52 ( (J.(J49 a" Table 17-Cefficients f the Setchenv Eq. (]) (J) =jjha il, (J) = syhean il, (0) = live il. (2) = the hindal curve fr MSO and methanl was: In w! = a" + a, w, + a, w, + al., W,. lhy is nt very appreciable, althugh in general, sybean il is mre sluble. One interesting feature is shwn in Fig. 1 where the slvent is MSO. The system with jjba il is slutrpic, that is, the tie-lines change directin with cncentratin, and, in additin, the tie-lines fr sybean il run partially in ppsite directin as thse f jjba il. This means that the extract phases fr sybean il have a smaller cncentratin f leic acid than the raffinate phases. 2-Acetne and 2-prqpanl shw near cmplete slubil~tywith sybean and jjba ils. 3-In the case f mn-alchls like methanl and-2-prpanl the increase in chain length appears t be increasing the mutual slubility. 4-Mn-alchls like methanl and 2-prpanl shw a higher slubility range than dialchls like 2-ci~butene-l, 4~diland 1, 2-butanedil. 5-With di-alchls (2-ci~butene-l, 4-dil and 1, 2-butanedil) the mutual slubility is very lw,

6 304 INIAN J. CHEM. TECHNOL., NOVEMBER 1996 cnsequently separatin is very pr since all tielines g thrugh the slvent apex. 6-Frm the distributin cefficients f leic acid in the different il-slvent systems that ap OLEIC ACIO -- SOY8EAN ---- JOJ08A OIL' v t"" v v v u v V / u "\.+,----"'- \.OMSO Fig, I-Phase equilibrium diagram fr the system:: ( X ) leic acid +jjba il + MSO and (.) leic acid + sybean il + MSO. Nt all the tie-lines are shwn. pear in Tables 11-16, it can be seen that with the exceptin f MSO and methanl, the partitin f leic acid between the il and the slvent is characterized by rather lw distributin' cefficients. Frm the practical pint f view, the lwer the distributin cefficient, the larger the vlume f extractant that will be needed fr a given percentage remval f fatty acids. On the ther hand, hwever, the selectivity cefficients S f leic acid in jjba il, sybean il, and live il have the highest values in the regin f lw fatty acid cntent, which is the regin f industrial imprtance. The selectivity cefficients decrease rapidly with the increase f leic acid cncentratin in the il phase. Taking int accunt the values f distributin and selectivity cefficients, it seems that f the tested slvents nly dimethylsulfxide and methanl meet the necessary requirements (distributin cnstant greater than 1 and high selectivity) t serve as extractants Hatty acids. 7-Additin f acetamide des nt induce phase separatin. S-In all cases studied, the Setchenw mdel predicts the SOlubilitycurve fairly well. OlEIC ACI -- SOYBEAN ---- JOJOBA Oil HIS-BUTENE -U-IOl Fig. 2-Phase equilibrium diagram fr the systems: (x) leic acid +jjba il + 2-cis-butene-l, 4-diland (.) leic acid + sybean il + 2-cis-butene-l, 4-dil. Nt all the tie-lines are shwn.. 1 ~,l J J!~!,,~:11 ',t: U!~I~I~,I 1"1

7 SNIAK et al.: EXTRACTION OF OlEIC ACI 305 OLEIC ACI OLEIC ACI ijoba Oil K --+--"" *... y/ " '.... "",.{ ' '...., -. t/ _- ~ " /-/ "... ~ ,A-" >i --,~--~ ;:::~~~~~ '", :::, Fig. 3-Phase equilibrium diagram fr the system~: leic acid +jjba il + 1, 2-butanedil. Nt au the tie-lines are shwn Oil' v v ~ V V V " v ~" AcnOIlE Fig. 5-Phase equilibrium diagram fr the systems: (X) leic acid +jjba il +acetne and ( ) leic acid + sybean il + acetne OlEIC ACI OlElC,ACI SOYBEAN --- JOJOBA -- OLIVE Oil 2-PROPANOl Oil METHUOI Fig. 4-Phase equilibrium diagram fr the systems: ( x ) leic acid +jjba il + 2-prpanl and (.) leic acid + sybean il + 2-prpanl. Fig. 6-Phase ~uilibrium diagram fr the systems: (x) leic acid +jjba il + methanl, ( )leic acid + sybean il + methanl, and (*) leic add + live il + methanl. Knwledge f the phase diagram and the pertinent tie-lines allws calculatin f the number f theretical stages necessary fr the desired reductin in the cncentratin f the fatty acid 3. Acknwldgement Jjba Israel dnated the jjba il. References 1 Apelblat A, Zaharskin T, Wisniak J & Krngld E, JAm Oil Chemists Sc, 73 (1996) Marcus Y & Keretes A S, In Exchange and Slvent Extractin f Metal Cmplexes(Wiley-interscience, Lndn), Per!)' R H & Green, Perry's Chemical Engineers Handbk, 6th ed (McGraw-Hill, New Yrk), 1984.

M.J. Guthriel, D.G. Wagner2

EFFECT OF SUPPLEMENTAL PROTEIN OR GRAIN ON INTAKE AND UTILIZATION OF MEDIUM QUALITY PRAIRIE HAY BY STEERS M.J. Guthriel, D.G. Wagner2 and D.C. Weakley3 Stry in Brief Sixteen 1,053 lb tw-year-ld Herefrd