The Conversion of Light Naphtha Into Aromatics by Using Promoted Zeolite Catalysts

1989 ◽  
Vol 42 (12) ◽  
pp. 2095 ◽  
Author(s):  
G Berti ◽  
JE Moore ◽  
L Salusinszky ◽  
D Seddon

Zeolites of the ZSM-5 family are poor for converting liquid paraffins into aromatics, but commercially available H-ZSM-5 can be effectively promoted with zinc or gallium. A gallium-promoted zeolite was used for the conversion of pentane and a natural-gas condensate into aromatic-rich liquid products. Optimum performance was obtained at temperatures of 475�C and weight-hourly space velocity of 1 h-1. The aromatic products were principally benzene, toluene and xylene, with the benzene content increasing with increasing conversion temperature. Operation of the catalyst at high severity (high temperature, low space velocity) produced a liquid product containing over 90% of aromatics. Lower severity produced less aromatics but higher overall liquid yield.

Catalysts ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. 617 ◽  
Author(s):  
José Faustino Souza de Carvalho Filho ◽  
Marcelo Maciel Pereira ◽  
Donato Alexandre Gomes Aranda ◽  
João Monnerat Araujo Ribeiro de Almeida ◽  
Eduardo Falabella Sousa-Aguiar ◽  
...  

The ethanol conversion into hydrocarbons (light olefins and aromatics) using alkali-treated HZSM-5 with different SiO2/Al2O3 ratios (23, 38, and 53) zeolites was evaluated. The desilicated SAR 38 zeolite exhibited significant growth on the external surface area (61–212 m2/g) and the mesopore volume (0.07–0.37 cm3/g) without significate reduction on XRD crystallinity (93%). All catalysts were active on the ethanol conversion into hydrocarbons. At the same set of variables, the alkali-treated HZSM-5 zeolites showed a better conversion and a high selectivity to C4–C9 hydrocarbons when compared to the parent microporous zeolites. Only the parent HZSM-5 zeolite (SAR 53) was chosen for the statistical study using the standard response surface methodology in combination with the central composite design. It was found that maximum BTEX (benzene, toluene, ethylbenzene, and xylenes) and minimum ethylene production were reached for the following conditions: temperature 450 °C, pressure 20 bar, and WHSV (weight hourly space velocity) 5 h−1.


Energies ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 8497
Author(s):  
Jakub Frątczak ◽  
Nikita Sharkov ◽  
Hector De Paz Carmona ◽  
Zdeněk Tišler ◽  
Jose M. Hidalgo-Herrador

Clean biofuels are a helpful tool to comply with strict emission standards. The co-processing approach seems to be a compromise solution, allowing the processing of partially bio-based feedstock by utilizing existing units, overcoming the need for high investment in new infrastructures. We performed a model co-processing experiment using vacuum gas oil (VGO) mixed with different contents (0%, 30%, 50%, 70%, 90%, and 100%) of rapeseed oil (RSO), utilizing a nickel–tungsten sulfide catalyst supported on acid-modified phonolite. The experiments were performed using a fixed-bed flow reactor at 420 °C, a hydrogen pressure of 18 MPa, and a weight hourly space velocity (WHSV) of 3 h−1. Surprisingly, the catalyst stayed active despite rising oxygen levels in the feedstock. In the liquid products, the raw diesel (180–360 °C) and jet fuel (120–290 °C) fraction concentrations increased together with increasing RSO share in the feedstock. The sulfur content was lower than 200 ppm for all the products collected using feedstocks with an RSO share of up to 50%. However, for all the products gained from the feedstock with an RSO share of ≥50%, the sulfur level was above the threshold of 200 ppm. The catalyst shifted its functionality from hydrodesulfurization to (hydro)decarboxylation when there was a higher ratio of RSO than VGO content in the feedstock, which seems to be confirmed by gas analysis where increased CO2 content was found after the change to feedstocks containing 50% or more RSO. According to the results, NiW/acid-modified phonolite is a suitable catalyst for the processing of feedstocks with high triglyceride content.


2017 ◽  
Vol 6 (3) ◽  
pp. 201 ◽  
Author(s):  
A.V. Vosmerikov ◽  
G.V. Echevsky ◽  
L.L. Korobitsyna ◽  
N.V. Arbuzova ◽  
L.M. Velichkina ◽  
...  

<p>The conversion of methane into benzene, toluene and naphthalene at the reaction temperature of 750 °C and gas hourly space velocity (GHSV) of 500-1500 h<sup>-1</sup> over zeolites modified via impregnation with ammonium heptamolybdate and mechanical mixing with Mo oxide and nanopowder is studied under non-oxidative conditions. It has been established that the highest methane conversion per one run and maximal yield of aromatic hydrocarbons are reached for the sample containing 4.0 mass.% the Mo nanopowder. The stability of Mo-containing zeolite catalysts in the process of methane dehydroaromatization at different GHSV has been studied and a characteristic presence of the induction period caused by the formation of active Mo forms both on the external surface and into the zeolite channels has been established. Both the duration of induction period and stable catalyst operation are decreasing with increasing of GHSV. It was demonstrated that acidic properties of a Mo-containing zeolite catalyst depend on the Mo concentration and method of its introduction.</p>


2012 ◽  
Author(s):  
Tirena Bahnur Siregar ◽  
Nor Aishah Saidina Amin

Peretakan bermangkin minyak kelapa sawit kepada gasolin menggunakan H–ZSM–5 dan H–Beta dijalankan pada tekanan atmosfera dan kadar alir mengikut berat 2.5 jam–1. Suhu tindak balas ditetapkan dalam julat 450°C to 525°C. Mangkin yang dikalsinkan telah dicirikan menggunakan teknik pembelauan sinar X, penjerapan piridina–spektrofotometri inframerah dan penjerapan nitrogen. Hasil cecair dan gas dianalisis menggunakan kromatografi gas (FID) dan (TCD). Peningkatan suhu tidak balas meninggikan penukaran minyak kelapa sawit. Penukaran minyak kelapa sawit dan kepemilihan gasolin tertinggi diperolehi dengan mangkin H–ZSM–5, masing–masing ialah 96.12% berat dan 29.92% berat. Walaupun penukaran minyak kelapa sawit dan kepemilihan gasolin untuk kedua–dua mangkin adalah tinggi, tetapi H–ZSM–5 menunjukkan hasil yang lebih baik berbanding H–Beta pada semua suhu. Gasolin yang dihasilkan menggunakan H–ZSM–5 mempunyai kandungan naftena yang tinggi, diikuti oleh isoparafin, olefin, aromatik dan sedikit paraffin, manakala gasolin yang terhadil menggunakan H–Beta mengandungi olefin, naftena, paraffin dan aromatik. Hasil sampingan utama adalah gas yang terdiri daripada komponen C1–C3 menggunakan H–ZSM–5 dan C3–C4 menggunakan H–Beta Kata kunci: Zeolit; H–ZSM–5; H–Beta; peretakan; minyak kelapa sawit; gasolin The catalytic cracking of palm oil to gasoline over H–ZSM–5 and H–Beta was studied in fixed bed reactor operated at atmospheric pressure and weight hourly space velocity (WHSV) of 2.5 h–1. The reaction temperature was varied between 450°C to 525°C. The calcined catalysts were characterized using X–Ray Diffraction (XRD), Pyridine Adsorption–Infrared Spectrophotometry (Py–IR) and Nitrogen Adsorption (NA) methods. The liquid and gaseous products were analyzed using (FID) and (TCD) gas chromatography respectively. Increase in reaction temperature led to higher palm oil conversion. The highest conversion and gasoline selectivity obtained at 525°C were 96.12 wt% and 29.92 wt% respectively with H–ZSM–5. Although the conversion and the gasoline selectivity of both catalysts was high, but H–ZSM–5 performed better than H–Beta at all temperature range. Gasoline produced using H–ZSM–5 consisted mainly of naphthenes beside isoparaffins, olefins, aromatics and a small amount of paraffins, while the gasoline obtained by using H–Beta contained olefins, naphthenes, paraffins and aromatics. Gas was the major side product, which consisted mainly of C1–C3 for using H–ZSM–5 and C3–C4 compounds for using H–Beta. Key words: Zeolite; H–ZSM–5; H–Beta; cracking, palm oil; gasoline


Author(s):  
Sriatun Sriatun ◽  
Heru Susanto ◽  
Widayat Widayat ◽  
Adi Darmawan

NiO/silica-rich zeolite catalysts were used for coconut oil hydrocracking. The catalyst was prepared with a mixture of Na2SiO3, Al(OH)3, NaOH, and quaternary ammonium surfactants. The surfactant was varied of types like as tetrapropylammonium bromide (TPAB) and cetyltrimethylammonium bromide (CTAB). The acidity of the silica-rich sodalite zeolites enhances with the increase in nickel oxide added through a wet impregnation. The hydrocracking process was carried out by a semi-batch method. Liquid products were analyzed using GC-MS. The results showed that the addition of surfactants increased the catalyst surface area and acidity. Meanwhile, the presence of nickel oxide increases the acidity of the catalyst. The hydrocracking results showed an increase in gas products when the surface area was high, i.e., 23.781% in silica-rich sodalite zeolite without template (Z), 32.68% in silica-rich sodalite zeolite with tetrapropylammonium (ZTPA), and 39.673% in silica-rich sodalite zeolite with cetyltrimethylammonium (ZCTA). The presence of NiO increased the liquid product and the selectivity of the bioavtur fraction (C10-C15), where the highest percentage of liquid product was 60.07% at NiO/ZTPA.


2017 ◽  
Vol 68 (1) ◽  
pp. 116-120
Author(s):  
Iuliean Vasile Asaftei ◽  
Neculai Catalin Lungu ◽  
Lucian Mihail Birsa ◽  
Ioan Gabriel Sandu ◽  
Laura Gabriela Sarbu ◽  
...  

The conversion of n-heptanes into aromatic hydrocarbons benzene, toluene and xylenes (BTX), by the chromatographic pulse method in the temperature range of 673 - 823K was performed over the HZSM-5 and Ag-HZSM-5 zeolites modified by ion exchange with AgNO3 aqueous solutions. The catalysts, HZSM-5 (SiO2/Al2O3 = 33.9), and Ag-HZSM-5 (Ag1-HZSM-5 wt. % Ag1.02, Ag2-HZSM-5 wt. % Ag 1.62; and Ag3-HZSM-5 wt. % Ag 2.05 having different acid strength distribution exhibit a conversion and a yield of aromatics depending on temperature and metal content. The yield of aromatic hydrocarbons BTX appreciably increased by incorporating silver cations Ag+ into HZSM-5.


2012 ◽  
Vol 531 ◽  
pp. 263-267 ◽  
Author(s):  
Hong Hua Zhang ◽  
Yi Min Cao ◽  
Muhammad Usman ◽  
Li Jun Li ◽  
Chun Shan Li

The effect of phosphorus catalysts for hydrogenation reactions were studied in this work. Different catalysts supported on γ-Al2O3 containing phosphorus (WNiP/γ-Al2O3, MoNiP/γ-Al2O3, WMoNiP/γ-Al2O3 and WMoCoP/γ-Al2O3) were prepared through ultrasonic-assisted impregnation and temperature-programming methods. The catalytic hydrotreating reaction are under the reaction conditions of PH2=9MPa, Thf=370oC, space velocity=0.5h-1, and H2/oil ratio=1400. Gasoline (≤180oC) and diesel (180–360oC) are separated from the liquid product. The fractions were characterized by Elemental analysis, FTIR, KY3000 S/N and GC-MS analysis. Though analysis of test results, it can be concluded that the WNiP/γ-Al2O3 is the excellent hydrotreating catalyst in this series at this reaction condition.


Catalysts ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1362
Author(s):  
Boris N. Kuznetsov ◽  
Sergey V. Baryshnikov ◽  
Angelina V. Miroshnikova ◽  
Aleksandr S. Kazachenko ◽  
Yuriy N. Malyar ◽  
...  

For the first time, the fractionation of birch wood into microcrystalline cellulose, xylose and methoxyphenols is suggested based on the integration of alkali-acid pretreatments and hydrogenation in ethanol over a bifunctional Ru/C catalyst. It is established that removal of hemicelluloses during pretreatments of birch wood influences the yields of the liquid, gaseous and solid products of the non-catalytic and catalytic hydrogenation of pretreated samples in ethanol at 225 °C. The bifunctional Ru/carbon catalyst affects in different ways the conversion and yields of products of hydrogenation of the initial and acid- and alkali-pretreated birch wood. The most noticeable influence is characteristic of the hydrogenation of the acid-pretreated wood, where in contrast to the non-catalytic hydrogenation, the wood conversion and the yields of liquid products increase but the yields of the solid and gaseous products decrease. GC-MS, gel permeation chromatography and elemental analysis were used for characterization of the liquid product composition. The molecular mass distribution of the liquid products of hydrogenation of the initial and pretreated wood shifts towards the low-molecular range in the presence of the catalyst. From the GC-MS data, the contents of monomer compounds, predominantly 4-propylsyringol and 4-propanolsyringol, increase in the presence of the ruthenium catalyst. The solid products of catalytic hydrogenation of the pretreated wood contain up to 95 wt% of cellulose with the structure, similar to that of microcrystalline cellulose.


2019 ◽  
Vol 19 (3) ◽  
pp. 703 ◽  
Author(s):  
Siti Jamilatun ◽  
Budhijanto Budhijanto ◽  
Rochmadi Rochmadi ◽  
Avido Yuliestyan ◽  
Arief Budiman

With a motto of preserving nature, the use of renewable resources for the fulfillment of human needs has been seen echoing these days. In response, microalgae, a water-living microorganism, is perceived as an interesting alternative due to its easy-to-cultivate nature. One of the microalgae, which possess the potential for being the future source of energy, food, and health, is Spirulina plantesis. Aiming to identify valuable chemicals possibly derived from it, catalytic and non-catalytic pyrolysis process of the residue of S. plantesis microalgae has been firstly carried out in a fixed-bed reactor over the various temperature of 300, 400, 500, 550 and 600 °C. The resulting vapor was condensed so that the liquid product consisting of the top product (oil phase) and the bottom product (water phase) can be separated. The composition of each product was then analyzed by Gas Chromatography-Mass Spectrometry (GC-MS). In the oil phase yield, the increase of aliphatic and polyaromatic hydrocarbons (PAHs) and the decrease of the oxygenated have been observed along with the increase of pyrolysis temperature, which might be useful for fuel application. Interestingly, their water phase composition also presents some potential chemicals, able to be used as antioxidants, vitamins and food additives.


2017 ◽  
Vol 42 (1) ◽  
pp. 23-29
Author(s):  
Hua Song ◽  
Shengnan Li ◽  
Hualin Song ◽  
Feng Li ◽  
Huapeng Cui

A number of Zn–S2O82–/ZrO2–Al2O3 (Zn( x)–SZA) catalysts with different Zn mass fractions were synthesised and characterised by using X-ray diffraction, the Brunauer–Emmett–Teller method, and H2 temperature-programmed reduction. The structure and isomerisation performance of Zn( x)–SZA catalysts were studied using n-pentane as a probe reaction. The results showed that a pure tetragonal ZrO2 phase was formed on Zn( x)–SZA, and the ZrO2 crystallite sizes of the tetragonal phase increased in the order: Zn(0.5)–SZA < Zn(1.0)–SZA < Zn(1.5)–SZA < Zn(2.0)–SZA < SZA. Zn can strengthen the interaction between persulfate ions and the support, promote the formation of stronger acidity, lead to a better dispersion of sulfate ions on the surface, and improve the redox performance of the catalysts. The Zn(1.0)–SZA catalyst exhibited the best catalytic activity for n-pentane isomerisation. At a temperature of 170 °C, a reaction pressure of 2.0 MPa, a molar H2/ n-pentane ratio of 4:1, and a weight hourly space velocity of 1.0 h−1, the isopentane yield reached 58.0%.


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