Hasil Pencarian  ::  Simpan CSV :: Kembali

"[Preparasi zeolit berpori hierarki dari klinoptilolit Kalianda Lampung berhasil dilakukan dengan metode tandem acid-base treatments. Material zeolit alam berpori mikro dimodifikasi dengan menyatukan dua metode yang biasa dilakukan untuk mengubah ukuran mikropori zeolit menjadi mesopori, yaitu perlakuan asam (dealuminasi) dan perlakuan basa (desilikasi). Perlakuan asam diharapkan dapat meningkatkan rasio Si/Al sebagai hasil dari penurunan kadar Al, kemudian dilakukan perlakuan basa yang bertujuan untuk melarutkan sebagian atau menyeimbangkan kadar Si dan mengarahkan pembentukan mesopori dalam kerangka zeolit. Karakterisasi terhadap klinoptilolit raw dan hasil perlakuan asam-basa digunakan instrumen AAS, XRD, FTIR, dan BET surface area. Berdasarkan penelitian, Z-A4B1 memiliki sisi aktif yang cukup besar yang dapat berperan menjadi adsorben ion logam berat Cu(II) yang lebih baik karena kapasitas adsorpsi Z-A4B1 ini 4 kali lipat lebih tinggi daripada kapasitas adsorpsi dari klinoptilolit raw pada waktu optimum dan konsentrasi awal Cu(II) 300 ppm. Nilai KTK Z-A4B1 adalah sebesar 33,27 mg/g yang setara dengan 104,78 meq/100 g zeolit, sedangkan nilai KTK klinoptilolit raw adalah sebesar 72,19 meq/100 g zeolit. Adapun isoterm adsorpsi yang paling sesuai untuk menjelaskan mekanisme adsorpsi Cu(II) pada klinoptilolit berpori hierarki Z-A4B1 adalah model isoterm adsorpsi Freundlich.;Hierarchical zeolites are prepared from Kalianda Lampung clinoptilolite by tandem acid-base treatments. Natural zeolites that are micropore intrinsicly was modified with two familiar methods that mostly used to change micropore size zeolite into hierarchical zeolite; acid treatment (dealumination) and base teratment (desilication). Acid treatments can increase Si/Al ratio of clinoptilolite because of Al content decreasing, then base treatment can balance Si content and aim the mesopore formation in zeolite frameworks. Intensive characterizations of both raw and modified clinoptilolites are conducted using XRD, AAS, FTIR, and BET surface area measurement. In this research, Z-A4B1 has more active sites to adsorb Cu(II) ions because the adsorption capacity of Z-A4B1 is up to 4-fold higher than the adsorption capacity of raw clinoptilolite at its optimum contact time and initial Cu(II) concentration 300 ppm. The CEC of Z-A4B1 is 33.27 mg/g that equals to 104.78 meq/100 g zeolite, besides CEC of raw clinoptilolite is 72.19 meq/100 g zeolite. Therefore, adsorption isoterm that fit to explain the adsorption Cu(II) mechanism at hierarichal zeolite Z-A4B1 is Freundlich isoterm adsorption model., Hierarchical zeolites are prepared from Kalianda Lampung clinoptilolite by tandem acid-base treatments. Natural zeolites that are micropore intrinsicly was modified with two familiar methods that mostly used to change micropore size zeolite into hierarchical zeolite; acid treatment (dealumination) and base teratment (desilication). Acid treatments can increase Si/Al ratio of clinoptilolite because of Al content decreasing, then base treatment can balance Si content and aim the mesopore formation in zeolite frameworks. Intensive characterizations of both raw and modified clinoptilolites are conducted using XRD, AAS, FTIR, and BET surface area measurement. In this research, Z-A4B1 has more active sites to adsorb Cu(II) ions because the adsorption capacity of Z-A4B1 is up to 4-fold higher than the adsorption capacity of raw clinoptilolite at its optimum contact time and initial Cu(II) concentration 300 ppm. The CEC of Z-A4B1 is 33.27 mg/g that equals to 104.78 meq/100 g zeolite, besides CEC of raw clinoptilolite is 72.19 meq/100 g zeolite. Therefore, adsorption isoterm that fit to explain the adsorption Cu(II) mechanism at hierarichal zeolite Z-A4B1 is Freundlich isoterm adsorption model.]"

"Sintesis zeolit ZSM-5 berhasil disintesis dari zeolit alam Bayat- Klaten dengan menggunakan metode fragmentasi sistem submolten yaitu dengan memecah kerangka zeolit menjadi monomernya dalam suasana basa pada suhu 250oC. Sebelum fragmentasi, satu bagian zeolit dilakukan metode dealuminasi dan yang lain tanpa dealuminasi. Karakterisasi dengan FTIR, XRD dan EDX menunjukkan bahwa fragmentasi berhasil dilakukan, dimana struktur zeolit rusak dan pita inframerah karena AlO4 dan SiO4 muncul. Sintesis ZSM-5 dilakukan secara hidrotermal menggunakan tetrapropylammonium hydroxide TPAOH sebagai agen pengarah struktur pori dan penambahan LUDOX suspensi silika 40 dalam air dan tetraethyl orthosilicate TEOS . Karakterisasi XRD menunjukkan bahwa bahan yang disintesis dengan LUDOX memiliki struktur zeolit ZSM-5 dengan kristalinitas tinggi yaitu pada ZSM-5 1 , ZSM-5 3 dan ZSM-5 5 . Pencitraan dengan SEM menunjukkan karakteristik kristal heksagonal ZSM-5 pada semua hasil sintesis. Analisis luas permukaan BET menunjukkan luas permukaan khas zeolit mikropori, 262 m2 / g ; 102 m2 / g ; 278 m2 / g ; 185 m2 / g ; 309 m2 / g ; 183 m2 / g dan diameter pori 1,852 nm; Menunjukkan bahwa Zeolit ZSM-5 yang diperoleh berukuran mikropori. Rasio Si / Al tinggi diperoleh pada ZSM-5 1 , ZSM-5 3 dan ZSM-5 5 yaitu 18,15 dan 23. Hasil ini menunjukkan bahwa zeolit alam Bayat-Klaten dapat digunakan sebagai sumber silika dan alumina untuk ZSM-5 kristal tinggi dengan rasio Si / Al medium dan memiliki stabilitas termal yang baik. Dengan demikian, bahan ini berpotensi untuk diuji sebagai katalis hydrocracking fluida.

---

Synthesis of ZSM 5 zeolite was conducted using natural zeolite of Bayat Klaten by employing fragmentation method of submolten system through breaking zeolite framework into its monomer in alkaline condition at 250oC. Prior to fragmentation, one part the zeolite was treated with dealumination, the other without dealumination, labeled as ZSM 5 a and ZSM 5 wa, respectively. Characterization with FTIR, XRD and EDX show that the fragmentation was successful, in which the structure of zeolite was damaged and the infrared bands due to AlO4 and SiO4 appeared. The synthesis of ZSM 5 was performed hydrothermally using tetrapropylammonium hydroxide TPAOH as a directing agent of pore structure and addition of LUDOX 40 silica suspension in water and tetraethyl orthosilicate TEOS . The XRD characterization shows that the material synthesized with LUDOX has ZSM 5 zeolite structure with high crystallinity that is on ZSM 5 1 , ZSM 5 3 and ZSM 5 5 . Imaging with SEM shows the characteristics of the ZSM 5 hexagonal crystals in all the synthesis results. Analysis of BET surface area shows typical surface area of micropore zeolite, 262 m2 g 102 m2 g 278 m2 g 185 m2 g 309 m2 g 183 m2 g and pore diameter 1.852 nm Shows that ZSM 5 Zeolite obtained is micropore size. High Si Al ratio is obtained on ZSM 5 1 , ZSM 5 3 and ZSM 5 5 18, 15 and 23. These results indicate that Bayat Klaten natural zeolite can be used as silica and alumina source for high crystalline ZSM 5 with medium Si Al ratio and having good thermal stability. Thus, these materials are potential to be tested as fluid hydrocracking catalyst."