The Effect of Sodium on the Catalytic Activity of ZnO-Al2O3/ZSM-5 and SnO-Al2O3/ZSM-5 for the Transesterification of Vegetable Oil with Methanol

In order to elucidate the effect of sodium on the activity of ZSM-5 supported metal oxides catalysts (ZnO-Al2O3/ZSM-5 and SnO-Al2O3/ZSM-5) for the transesterification of soybean oil with methanol, ZSM-5 supported metal oxides were prepared with and without sodium hydroxide by impregnation. The metal compositions of the ZSM-5 supported metal oxide catalysts and the metal concentrations dissolved from the catalysts to the methylester phase were measured by SEM-EDS and inductive coupled plasma spectroscopy, respectively. The catalytic activity of ZnO-Al2O3/ZSM-5 and SnO-Al2O3/ZSM-5 containing sodium did not originate from surface metal oxides sites, but from surface sodium sites or dissolved sodium leached from the catalyst surface

Structured ZSM-5/SiC foam catalysts for bio-oils upgrading

ZSM-5 zeolite coating supported on SiC foams was prepared by a precursor dispersion-secondary growth method and the resulting structured ZSM-5/SiC foam catalyst was used for the proof-of-concept study of catalytic bio-oils upgrading (i.e. deoxygenation of the model compounds of methanol and anisole) in reference to ZSM-5 catalyst pellets. A layer of ZSM-5 coating with inter-crystal porosity on SiC foams was produced by curing the zeolite precursor thermally at 80 °C. The use of SiC foam as the zeolite support significantly improved transport phenomena compared to the packed-bed using ZSM-5 pellets, explaining the comparatively good catalytic performance achieved by the structured ZSM-5/SiC foam catalyst. In comparison with the ZSM-5 pellets, the ZSM-5/SiC foam catalyst showed 100.0% methanol conversion (at the weight hourly space velocity, WHSV, of 8 h–1) and 100.0% anisole conversion (at WHSV =5 h−1) at the initial stage of the processes, while only about 3% were obtained for the ZSM-5 pellets, under the same conditions. Based on the comparative analysis of the characterisation data on the fresh and spent catalysts, the deactivation mechanisms of the ZSM-5/SiC and the ZSM-5 pellet catalysts were explained. The process intensification using SiC foam to support ZSM-5 improved the global gas-to-solid mass transfer notably, and hence mitigating the pore blocking due to the carbon deposition on the external surface of supported ZSM-5

Synthesis And Characterization Of Zeolite Membranes For Binary Gas Separation [QE391.Z5 T161 2007 f rb].

Tiga jenis membran zeolit MFI (ZSM-5 dan Silicalite-1) dengan kecacatan minimum telah disintesiskan dengan menggunakan cara yang berlainan. Membran tersebut adalah Silicalite-1 (Si/Al = ∞), Na-ZSM-5 (Si/Al = 25) and B-ZSM-5 (Si/B = 100). Three types of MFI zeolite membranes (ZSM-5 and Silicalite-1) with minimum defect were synthesized using different synthesis approach. These membranes were Silicalite-1 (Si/Al = ∞), Na-ZSM-5 (Si/Al = 25) and B-ZSM-5 (Si/B = 100)

Production of methyl ethyl ketone from biomass using a hybrid biochemical/catalytic approach

The recent demand for sustainable routes to fuels and chemicals has led to an increased amount of research in conversion of natural resources. A potential approach for conversion of biomass to fuels and chemicals is to combine biochemical and chemical processes. This research used microbial fermentation to produce 2,3-butanediol, which was then converted to methyl ethyl ketone by dehydration over a solid acid catalyst. The fermentation process was performed using the bacteria Klebsiella oxytoca (K.O). 2,3-butanediol then dehydrated to form methyl ethyl ketone on a solid acid catalyst, the proton form of ZSM-5, and heat. The goal was to determine the reaction kinetics of 2,3-butanediol dehydration over ZSM-5, and to demonstrate the hybrid biochemical/thermochemical approach for synthesizing chemicals from biomass. It was found that ZSM-5 produced methyl ethyl ketone with high selectivity (greater than 90%), and could convert fermentative 2,3-butanediol to methyl ethyl ketone. The reaction order of 2,3-butanediol dehydration was found to be slightly large than one, and an activation energy of 32.3 kJ/mol was measured

Sintesis ZSM-5 Menggunakan Silika Presipitasi dari Fly Ash Pabrik CPO

Palm fly ash is waste in the palm oil industry. Palm fly ash has high content of silica. ZSM-5 is one of synthetic zeolite which used as catalyst. It can be synthesized from silica and alumina using hidrothermal method. Source of silica that can be used to ZSM-5 synthesis are sodium silicate, gelled silica and precipitated silica. the purpose of this research is to synthesis ZSM-5 using precipitated silica hydrothermally. The result was analyzed using FTIR. ZSM-5 can be synthesized using precipitated silica hydrothermally. Based on infrared spectrum,the product synthesis shows four characteristic of ZSM-5 characters

Metán aktiválás új módszere: nemes fémmel promoveált Ga-HZSM-5 katalizátor alkalmazása N2O jelenlétében = Novel method in methane activation: noble metal modified Ga-HZSM-5 in the presence of N2O

H-ZSM-5 zeolitból kiindulva gallium ioncserével Ga/H-ZSM-5, valamint második fém (M- Fe, Co, Mo, Ag, Au) vegyületéből impregnálással egyfémes M/H-ZSM-5 és kétfémes M/Ga/H-ZSM-5 katalizátor sorozatot állítottunk elő. A mintákat XRF, XRD, XPS, TPR, TPD, TPSR, TPReact, NH3 lépcsőzetes termo-deszorpció (STD-NH3), Mössbauer spektroszkópia (Fe tartalmú minták esetén), TEM, valamint kinetikus módszerekkel vizsgáltuk. A Ga bevitel növeli a H-ZSM-5 savas centrumainak erejét és számát, a második fém hatására pedig a Ga/H-ZSM-5 erős savas centrumai pedig a M/Ga/H-ZSM-5 minták oxidációs centrumaivá generálódnak. A M/Ga/H-ZSM-5 katalizátorcsalád legjobb mintáin az N2O bontás, valamint a CH4+N2O reakció reaktánsainak 50 %-os konverziójának hőmérséklete 70-160 K-nel csökken a folyamat közismerten legjobb katalizátorához viszonyítva. N2O bomlásakor az erős redox centrumokon nitrogén és oxigén keletkezik. Az oxigén atomok kisebb hányada beépül a zeolit felületbe (Oa), nagyobbik része pedig rövid életű köztes állapotú atomi oxigén (nascent oxygen) formájában reagál a metánnal. Az N2O és CH4 közötti reakció összetett oxigén átviteli mechanizmus alapján megy végbe, amely szerint a N2O nem közvetlenül reoxidálja a katalitikusan aktív centrumokat, hanem MGa-OCH3 összetételű szpecieszekkel reagálva. A katalizátor szerkezetbe beépült Oa oxigén biztosítja a M/Ga/H-ZSM-5 minták kis hőmérsékletű (323-373 K) extra aktivitásának alapját. | Monometallic M/H-ZSM-5 and bimetallic M/Ga/H-ZSM-5 (M- Fe, Mo, Co, Ag, Au) catalysts were prepared by impregnation of H-ZSM-5 and H-ZSM-5 modified by Ga ion exchange, respectively, with M-precursor. The samples were investigated by XRF, XRD, XPS, TPR, TPD, TPSR, TPReact, stepped NH3 desorption (STD-NH3), Mössbauer spectroscopy (in case of Fe containing samples), TEM and kinetic methods. Introduction of Ga increases the strength and number of acidic sites in H-ZSM-5, on the effect of the second metal addition the strong acid centres of Ga/H-ZSM-5 transform into the strong redox sites of M/Ga/H-ZSM-5. On the best performing samples of the M/Ga/H-ZSM-5 catalyst family the temperature of the 50% conversion (T50) in N2O decomposition and CH4+N2O reaction is lower by 70 and 160 K, respectively, than that on the catalysts regarded recently as the most active in these processes. N2O decomposition on the strong redox sites produces nitrogen and oxygen. A smaller part of atomic oxygen is accommodated on the zeolite surface, the larger part of short life time transient atomic oxygen reacts with methane producing MGa-OCH3 species. The reaction between N2O and CH4 takes place via complex oxygen transfer mechanism. N2O does not reoxidize the reduced active sites directly, but reacting with the MGa-OCH3 species. The oxygen accommodated on the catalyst surface plays key role in the low-temperature (323-373 K) extra activity of M/Ga/H-ZSM-5

An Examination of Brønsted-Acid Sites in H-[Fe]ZSM-5 for Olefin Oligomerization and Adsorption

The adsorption and reaction properties of an Al-free H-[Fe]ZSM-5 were examined and compared to an H-[Al]ZSM-5 sample with the same site density. H-[Fe]ZSM-5 was shown to have Brønsted-acid sites in a concentration equal to the framework Fe concentration. Differential heats of adsorption for ammonia and pyridine were shown to be identical to that obtained in H-[Al]ZSM-5, with differential heats of ~150 kJ/mol for ammonia and 200 kJ/mol for pyridine. For H-[Al]ZSM-5, adsorption of either propylene or 1-butene at room temperature results in rapid oligomerization. TPD-TGA measurements of the oligomers in H-[Al]ZSM-5 show evidence for hydride-transfer reactions, in addition to simple oligomer cracking. By contrast, it is necessary to heat H-[Fe]ZSM-5 to 370 K for rapid oligomerization of propylene and oligomerization of 1-butene occurs only slowly at 295 K. TPD-TGA measurements of the oligomers in H-[Fe]ZSM-5 show no evidence for hydride-transfer reactions and H-[Fe]ZSM-5 forms much less coke than H-[Al]ZSM-5 during steady-state reaction in 1-butene at 573 K. Adsorption measurements of 1-butene on D-[Fe]ZSM-5 suggest that the protonated complexes of 1-butene are formed but that these are relatively stable towards reaction, implying that the carbocation transition states are relatively unstable

UJI KEASAMAN ZSM-5 HASIL SINTESIS DARI METAKAOLIN BANGKA TANPA CETAKAN ORGANIK

Zeolite Socony Mobile-5 (ZSM-5) merupakan jenis zeolit sintetis yang memiliki sifat asam sehingga sering digunakan sebagai katalis di bidang petrokimia dan petrolium. Agar dapat diketahui kemampuannya sebagai katalis, dilakukan uji keasaman ZSM-5 dengan metode adsorpsi piridina dan untuk menentukan karakteristik keasaman ZSM-5 terhadap pengaruh suhu kalsinasi. Uji keasaman ZSM-5 hasil sintesis dari metakaolin Bangka tanpa cetakan organik diperoleh dari pertukaran kation. Pada penelitian ini digunakan ZSM-5 sebanyak 6 sampel dengan variasi suhu dan perlakuan: ZSM-5 (1700C); ZSM-5 (1700C+peptin); ZSM-5 (1500C); ZSM-5 (1500C+CTAB); ZSM-5 (1200C); ZSM-5 (1200C+CTAB). Sampel ZSM-5 ditambah larutan CH3COONH4 0,5 M kemudian direfluks selama 3 jam dengan suhu 600C dan diaduk menggunakan magnetic stirrer dengan kecepatan 300 rpm. Setelah dipisahkan dari filtratnya, endapan yang diperoleh dikeringkan selama 24 jam dengan suhu 800C dan dikalsinasi pada suhu 5500C selama 10 jam. H-ZSM-5 yang diperoleh dianalisis menggunakan adsorpsi-desorpsi piridina dan dikarakterisasi menggunakan Fourier Transform Infrared (FTIR). ZSM-5 1200C menghasilkan total asam Lewis dan Brønsted terbesar yaitu 0.2027 mmol/gram. Dari hasil uji keasaman ZSM-5 hasil sintesis dari metakaolin Bangka tanpa cetakan organik dapat disimpulkan bahwa semakin tinggi suhu kalsinasi maka sifat keasaman ZSM-5 semakin menurun. Kata kunci: Keasaman ZSM-5, Adsorpsi-desorpsi piridina, Sisi asam Lewis and Brønste

Designing Hierarchical ZSM-5 Materials for Improved Production of LPG Olefins in the Catalytic Cracking of Triglycerides

LPG olefins (propene and butenes) are key building blocks in the petrochemical industry whose demand has been expanding steadily in recent years. The use of FCC (fluid catalytic cracking) units for conversion of triglycerides is a promising option for the future to boost production of LPG olefins. However, a need for innovative cracking catalysts is rising due to the different nature between petroleum and biomass-derived feedstocks. In this study, series of hierarchical ZSM-5 materials, namely, mesoporous ZSM-5, nanosized ZSM-5, and composite ZSM-5 were prepared, aiming to enhance the production of LPG olefins along with transportation fuels. Mesoporous ZSM-5 materials were synthesized by the postsynthetic modifications involving base treatment and subsequent acid washing, whereas nanosized ZSM-5 and composite ZSM-5 were synthesized by the direct-synthetic routes for a comparative purpose. The obtained materials were characterized by XRD, FTIR, N2 sorption, TEM, AAS, ICP-AES, and NH3-TPD, and their catalytic performance was assessed in the cracking of triolein as a representative of triglycerides under FCC conditions. It was found that the subsequent strong acid washing step of alkaline treated ZSM-5 for removal of aluminum debris and external acid sites is needed to improve the catalytic performance. The resulting mesoporous ZSM-5 material shows higher yields of the desired products, i.e., gasoline and LPG olefins than its parent, commercial ZSM-5 at the almost complete conversion (ca. 90 wt.%). The selectivity toward LPG olefins is also enhanced over all the hierarchical ZSM-5 materials, particularly high for composite ZSM-5 (ca. 94 wt.%). The improved diffusion and lowered acidity of the hierarchical ZSM-5 materials might be responsible for their superior catalytic performance. © 2019 Xuan Hoan Vu and Udo Armbruster