البحث — المستودع الرقمي العراقي

المستخلص: الزيولايت النانوي - المتبلور بنوعين تم تصنيعهما ووصف خصائصيهما، النوع الاول يحتوي على ويحتوي على ZSM - 5/MCM - والاخر من نوع المركب 41 ZSM - مسام مايكروية ويسمى 5 05 نانومتر(. - نوعين من المسام ,المايكروية )اقل من 2 نانو متر( ومسام متوسطة ) 2 اجريت عم | Nanocrystalline ZSM - 5 zeolite and micro - mesoporous ZSM - 5/MCM - 41 composite zeolite were synthesized by hydrothermal treatment - conventional method. For ZSM - 5 two compositions were under investigation with different silica to alumina ratio of 86 and 68. Study of principal variables affecting the characterisics of synthesized zeolites were investigated in both aspects concerning chemical and process variables. Micro - mesoporous ZSM - 5/MCM - 41 composite zeolite were synthesized using alkaline treatment method and two step crystallization.Loading of synthesized zeolites with transition metals copper, cobalt, and ceria were conducted by impregnation.All zeolites products were characterized by X - ray diffraction (XRD), Atomic force microscopy (AFM), Fourier Transform infrared (FTIR), Brunauer - Emmet - Teller (N2 adsorption - desorption isotherm), Scanning electron microscopy (SEM), Transmission electron microscopy (TEM), X - ray fluorescence (XRF), and Thermogravemetric analysis/differential scanning calorimetry (TGA/DSC).XRD - patterns for ZSM - 5 showed, at different temperature ranging from (150 - 180 oC) and time of crystallization from 48 - 96h, that ZSM - 5 phase is the only obtained in almost all samples and the peaks at angle 2?= 7 ? 9o and 2?= 22.5 - 24.4o are typical. XRD - patterns for ZSM - 5/MCM - 41 identified by the 3 peaks in 2? < 10o and still having the peaks of ZSM - 5.AFM reports for both zeolites, ZSM - 5 and ZSM - 5/MCM - 41 indicated that a nano - level size of about 50 nm has been got. FTIR results showed that for ZSM - 5, the peaks near bands 3400, 1080, 800, 550, 450 cm - 1 have been clearly obtained. For ZSM - 5/MCM - 41 showedthe shifting of band at 1100 cm - 1 accompanied with a decrease of intensity in bands near 440 - 450 cm - 1.BET surface area results for ZSM - 5 samples showed a value of 320 - 380 m2/g and pore volume of 0.2 cm3/g. BET surface area for ZSM - 5/MCM - 41 showed an average value of 612 m2/g and pore volume of 0.5421 cm3/g.TEM images revealed that the loading of transition metals of copper and cobalt on both types of zeolite catalysts are distributed well on the surface of zeolite and on nano - level size.Biodiesel production, using prepared catalysts were conducted by esterification and transesterification by oleic acid and sunflower oil respectively with ethanol and methanol.Batch heterogeneous esterification process gave medium conversion of 69%. Semi - batch heterogeneous esterification gave better conversion of about 85%. The effect of both catalysts (Cu - ZSM - 5 and Co - Cu - ZSM - 5/MCM - 41) were similar and gave increase in conversion between 11 - 13%.Transesterification heterogeneous batch process using base - catalyzed (Ce - Na - ZSM - 5) and acid catalyzed heterogeneous transesterification (HZSM - 5), using sunflower oil and methanol showed a yield of 26% and 33% respectively relative to oil.