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008 121205t2012 my a f m 000 0 eng d
020 _aTHE0002114(Local)
039 9 _a201905131641
_byusri
_c201710161550
_daishah
_c201212051144
_dida
_c201212051122
_dida
_y201212051119
_zida
040 _aUMP
090 _aQD281.H8 S25 2012 rs Thesis
100 0 _aSalimah Shafii
245 1 4 _aThe effect of preparation methods condition on the activity of palladium and platinum catalysts towards hydrogenation of palm olein /
_cSalimah Shafii
260 _aKuantan, Pahang :
_bUMP,
_c2012
300 _axix, 132 p. :
_bill. ;
_c30 cm. +
_e1 CD-ROM
502 _aThesis (Master of Science in Industrial Chemistry) -- Universiti Malaysia Pahang - 2012
504 _aBibliography : p. [107]-113
520 3 _aThe hydrogenation of vegetable oils is an important practice in the modification of fats and oils especially to increase the stability of the oil. Highly unsaturated oil is susceptible to autoxidation, thermal decomposition and other reactions that affect the quality and flavor. Consequently, it is desired to partially hydrogenate the oil to improve shelf life. Another reason to hydrogenate vegetable oils is to improve its utility. The effect of ultrasonic irradiation (US) and microwave (MW) on the preparation of mono- and bimetallic Pd and Pt were compared with the conventional heating (CH) method. Besides that, their activities for the hydrogenation reaction of palm olein were also reported. The Pd, Pt and PdPt nanoparticles stabilized with polyvinylpyrrolidone (PVP) were prepared with molar ratio of PVP to metal of 40:1. Small size particles that are highly dispersed were obtained after 2, 10 and 40 min under MW for Pd, PdPt and Pt colloidal nanoparticles respectively. The average particles size for Pd, Pt and PdPt was 1.24, 1.03 and 1.05 nm respectively. Meanwhile US also enhanced the reduction process, where reduction process completed after 5, 30, and 60 min for Pd, Pt and PdPt nanoparticles. However, large particle sizes were obtained under ultrasonic irradiation.The Pdnanoparticles have bimodal distribution with average sizes of 1.37 and 2.68nm.The Pt and PdPt nanoparticles have only one distribution with average particles size of 1.42 and 1.28nm respectively. Whereas, CH method with takes 3 hours has produced Pd, Pt and PdPt with particles sizes of 0.99, 1.20 and 1.23nm. The XRD analysis has strengthen the TEM result obtained, where broad peak obtained described small particles produced. From the XRD data, particles sizes were also re-calculated by using the Scherer equation and compared with the TEM result. It has shown that, the particles sizes calculated using the Scherer equation are slightly higher than that of the TEM result. Based from the XPS analysis, surface compositions of Pd and Pt show that PdPt(CH) and PdPt(MW) catalyst were in core-shell structure, meanwhile PdPt(US) was in alloy formation.The hydrogenation reaction of palm olein was conducted under ambient temperature and pressure with the molar ratio of palm olein to catalyst of 25000:1. The result shows that Pd(CH), Pt(MW), and PdPt(MW) catalysts achieved higher linoleate conversion. The conversion of linoleate, elaidate selectivity and iodine values (IVs) are increased in order of Pt<PdPt<Pd. Elaidate selectivity for Pd, Pt, and for PdPt catalysts (includedprepared under CH, MW, and US) were at range 52-56%, 3.5-8%, 4.4-13.4% respectively. The IVs for Pd nanoparticles are slightly decreased from 57 to range of 41-43 after 180 min reaction time. On the other hand, IVs for Pt and PdPt shows highly decreased from 57to minimum values of to 38 and 39 respectively. The hydrogenation reaction under ultrasonic irradiation has enhanced the catalytic reactivity. Statistical analyses had proved that different types of catalyst, method of catalyst prepared and reaction conditions give a significant effect on the composition of linoleate, oleate, elaidate and stearate.
650 0 _aHydrogenation
650 0 _aCatalysis
650 0 _aOils and fats, Edible
856 4 0 _uhttp://ecollib.ump.edu.my/24624/
_zLibrary access only
999 _aVIRTUA40
_c3677
_d3683
999 _aVTLSSORT0080*0200*0400*0900*1000*2450*2600*3000*5020*5040*5200*6500*6501*6502*8560*9992