HY Catalyst Research Articles

Catalytic Conversion of 2‐Phenethyl Phenyl Ether and 2‐Phenoxy‐1‐Phenyl Ethanol Over ZSM‐5, Y and Beta Zeolites

AbstractCatalytic conversion of 2‐phenoxy‐1‐phenyl ethanol (PPE‐OH) and 2‐phenethyl phenyl ether (PPE) was conducted in an autoclave reactor using Faujasite zeolite (HY), Beta zeolite (HBEA), and Zeolite Socony Mobil‐5 (HZSM‐5) with medium and large pore channels. All catalysts were thoroughly analyzed using various techniques like FT‐IR, N2 physisorption, XRD, SEM‐EDX, NH3‐TPD, ICP spectroscopy, and thermogravimetric analysis (TGA). The results showed that HBEA and HY catalysts, with their larger pore channels and sizes, exhibited excellent activity in breaking the ether bond of PPE‐OH. HBEA and HY zeolites exhibited almost full conversion of PPE‐OH at 240 °C and 1 h, and HZSM‐5 zeolite obtained only 47% conversion of PPE‐OH at the same condition. The cleavage of the ether bond of β‐O‐4 linkage was performed over HBEA and HY zeolites better than HZSM‐5 zeolite. Moreover, high‐strong acid sites of HBEA zeolite favored breaking PPE at 240 °C and 1 h, and PPE did not convert over HY and HZSM‐5 zeolites at the same condition. These findings highlight the crucial role of pore size and channels and the acidity of catalysts for converting large molecules like lignin. This study provides valuable insights into using zeolite catalysts for breaking down the β‐O‐4 linkage in lignin.

Microwave-assisted pyrolysis of low-density polyethylene (LDPE)to value-added products over HY, HZSM-5 and Hβ catalyst

To reduce carbon emissions, environmental pollution, and to improve the circular economy, a microwave (MW) assisted pyrolysis of low-density polyethylene (LDPE)was carried out to yield valuable products such as aromatics, hydrogen, ethylene, and propylene gas. All three catalysts HY, HZSM-5 and Hβ were used as in-situ catalysts. Catalytic pyrolysis with HY, HZSM-5, and Hβ exhibited a lower liquid yield compared to non-catalytic pyrolysis. Gaseous fraction was mainly comprised of hydrogen, methane, ethylene, ethane, propylene, propane, and butane. It was found that methane (30.77 vol%) and hydrogen (55.24 vol%) were dominating gaseous products at 400 °C and 450 °C respectively using HY to LDPE ratio of 1:10. Whereas HZSM-5 facilitates formation of methane (65.94 vol%) at 400 °C and Ethylene (43.55 vol%) at 550°C. Hβ contributes to formation of alkanes and aromatics and gaseous products consist of majorly C3-C4 hydrocarbon gases which consist of 69.35 % propylene at 450°C. No sign of catalyst deactivation was observed even after 3 repetitive cycles.

Enhancement of ethylene selectivity in chemical looping oxidative dehydrogenation of ethane using manganese-based redox catalysts supported on HY zeolite

As the crucial role of zeolite catalysts becomes increasingly prominent in refining and petrochemical industries, this study introduces a novel application of xMn / HY catalysts in ethane catalytic dehydrogenation via Chemical Looping Oxidative Dehydrogenation (CL-ODH). The synergistic effect of manganese oxides on the HY framework and a moderate amount of acidic sites within the catalyst facilitates the cleavage of C-H bonds and the desorption of olefins, which are vital for advancing ethane CL-ODH. We identified the reasons for maintaining high ethylene selectivity using advanced characterization techniques such as XRD, SEM, TEM, BET, H2-TPR, NH3-TPD, and Py-IR. Notably, under optimized conditions at 700 °C with a gas time-space velocity (GHSV) of 1800 mL·h−1·g−1, the 3Mn/HY catalyst achieved approximately 97.1 % selectivity for ethylene and a 22.7 % conversion of ethane. These findings present a scalable route for ethylene production, showcasing significant industrial relevance by potentially reducing energy costs and improving yield.

Two-stage pyrolysis for effective tobacco stem utilization and tar reduction

Tobacco stem (TS) is a waste product of tobacco industry that cannot be directly disposed of due to regulatory concerns. This study explored a two-stage pyrolysis for modifying the TS structure, rendering it unusable for tobacco products, while preserving potassium and nitrogen in the char for agricultural use as fertilizer. Furthermore, the study aimed to minimize the production of harmful tar by in-situ converting heavy volatiles into gases. The effects of first-stage pyrolysis temperature (400 – 650 °C), second-stage temperature (600 – 800 °C) and various catalysts (β(60 H), HY, HZSM-5 and TiO2) on product distributions and properties were studied. Elemental analysis, FTIR, XRF and ICP-MS were employed to assess the retention of potassium and nitrogen in the char. The results show that under optimal conditions (450 ℃ for pyrolysis and 800 ℃ for cracking), a 40.3 wt% char yield with 93.0 wt% potassium and 50.3 wt% nitrogen retention, 1.8 wt% tar yield and 34.6 wt% gas yield were achieved. The two-stage pyrolysis established a staged temperature profile within the reactor, decoupling the “primary pyrolysis” of TS from the “secondary reaction” of volatiles. In comparison to one-stage pyrolysis, this approach reduced tar production by 89.9% and increased gas production by 51.6%. The use of HZSM-5 and HY catalysts further reduced tar yields by up to 30.9%. This innovative process altered TS structure, retained crucial nutrients in the char, significantly reduced tar content, and mitigated harmful substances such as nicotine and phenols, offering a sustainable solution for tobacco waste management.

Catalytic fractionation of Palm Kernel shell with Co and Cu over zeolite HY catalysts

Lignocellulosic biomass has the potential to be transformed valuable chemicals. This study extracted lignin from palm kernel shell with liquid phased oxidative fractionation in the presence of Co and Cu loaded over Zeolite HY catalysts. The oxidative fractionation was conducted at temperatures ranging from 140 °C to 180 °C, with various reaction times of 2–4 h. The GCMS analysis identified various products from the oxidative conversion including phenol derivatives (Butylated hydroxytoluene, 1,2-Benzenediol, etc.), phenolic aldehydes (Vanillin, Syringaldehyde, p-hydroxybenzaldehyde, etc.), and carboxylic acids (p-hydroxybenzoic acid, vanillic acid etc.). At a reaction temperature of 180 °C with a 2 h reaction time, Co/Zeolite HY catalyst yielded 9.81% and Cu/Zeolite HY catalyst yielded 13.53% for phenol derivatives. The optimal yield of lignin-derived compounds was achieved with a 5 wt% catalyst loading in the context of biomass weight, particularly with a 10% metal loading of Co and Cu over Zeolite HY support. Additionally, the total yield of lignin-derived compounds obtained was 32.85% for 10%Co/Zeolite HY and 23.89% for 10%Cu/Zeolite HY, catalysts respectively. This research displays incorporating metals into zeolite support subsequently boosts their catalytic efficiency in lignin oxidation.

Polyethylene Upgrading to Liquid Fuels Boosted by Atomic Ce Promoters

AbstractHydrocracking catalysis is a key route to plastic waste upgrading, but the acid site‐driven C−C cleavage step is relatively sluggish in conventional bifunctional catalysts, dramatically effecting the overall efficiency. We demonstrate here a facile and efficient way to boost the reactivity of acid sites by introducing Ce promoters into Pt/HY catalysts, thus achieving a better metal‐acid balance. Remarkably, 100 % of low‐density polyethylene (LDPE) can be converted with 80.9 % selectivity of liquid fuels over the obtained Pt/5Ce‐HY catalysts at 300 °C in 2 h. For comparison, Pt/HY only gives 38.8 % of LDPE conversion with 21.3 % selectivity of liquid fuels. Through multiple experimental studies on the structure‐performance relationship, the Ce species occupied in the supercage are identified as the actual active sites, which possess remarkably‐improved adsorption capability towards short‐chain intermediates.

Catalytic co-pyrolysis of coffee grounds and polyethylene: A comparison of HZSM-5 and HY

The effects of the HZSM-5 and HY catalysts on the co-pyrolysis performance and product distribution of coffee grounds and polyethylene (CP73) were characterized via thermogravimetric analyzer with Fourier transform infrared spectroscopy and pyrolysis–gas chromatography-mass spectrometry. The addition of HZSM-5 and HY facilitated the decomposition of CP73 and reduced its residual content. HY-catalyzed CP73 (CP73/HY) exhibited the lower residual content, with a 9.09 % decrease, than did CP73 (eliminating the influence of the mixing ratio). The addition of the catalysts did not enhance the pyrolysis performance of CP73; however, an increase in the mean decomposition rate promoted its decomposition. The addition of the catalysts significantly reduced the activation energy of CP73 to varying degrees. The maximum reduction in the activation energy occurred with CP73/HY, from 218.58 kJ/mol for CP73 to 191.86 kJ/mol. The addition of HY and HZSM-5 produced up to 35.94 % and 46.43 % aromatics, respectively, relative to that of CP73. In particular, CP73/HZSM-5 generated a higher quantity of monocyclic aromatics, whereas CP73/HY produced a greater amount of alkylbenzenes than did CP73. This study provides actionable insights into the practical implementation of the catalytic co-pyrolysis of biomass and plastics.

Impact of Low-Temperature Water Exposure and Removal on Zeolite HY.

Aqueous-phase postsynthetic modifications of the industrially important Y-type zeolite are commonly used to change overall acid site concentrations, introduce stabilizing rare-earth cations, impart bifunctional character through metal cation exchange, and tailor the distribution of Brønsted and Lewis acid sites. Zeolite Y is known to undergo framework degradation in the presence of both vapor- and liquid-phase water at temperatures exceeding 100 °C, and rare-earth exchanged and stabilized HY catalysts are commonly used for fluidized catalytic cracking due to their increased hydrothermal resilience. Here, using detailed spectroscopy, crystallography, and flow-reactor experiments, we reveal unexpected decreases in Brønsted acid site (BAS) density for zeolite HY following exposure even to room-temperature liquid water. These data indicate that aqueous-phase ion-exchange procedures commonly used to modify zeolite Y are impacted by the liquid water and its removal, even when fractional heating rates and inert conditions much less severe than standard practice are used for catalyst dehydration. X-ray diffraction, thermogravimetric, and spectroscopic analyses reveal that the majority of framework degradation occurs during the removal of a strongly bound water fraction in HY, which does not form when NH4Y is immersed in liquid water and which leads to reduced acidity in HY even when dehydration conditions much milder than those typically practiced are employed. Na+-exchanged HY prepared via room-temperature aqueous dissolution demonstrates that Brønsted acid sites are lost in excess of the theoretical maximum that is possible from sodium titration. The structural impact of low-temperature aqueous-phase ion-exchange methods complicates the interpretation of subsequent data and likely explains the wide variation in reported acid site concentrations and catalytic activity of HY zeolites with high-Al content.

One-pot glycerol conversion to acrylic acid catalyzed by Cu modified HY zeolite synthesized from natural resources and pro-analytical precursor

The conversion of glycerol to acrylic acid was carried out by the one-pot process method. The catalyst used in this conversion is Cu-modified HY zeolite synthesized using pro-analytical precursors and alternative precursors from natural resources i.e., Indonesian natural zeolite and kaolin. The crystal structure and physicochemical properties of catalysts were determined by various characterization techniques such as XRD, FTIR, SEM-EDX, TEM, SAA, and TPD-NH3. Based on XRD analysis, it shows that HY and CuHY, both from synthetic and alternative precursors, are confirmed to have typical peaks of Y zeolite. EDX mapping images show a uniform distribution of Cu on the HY surface. In addition, the TEM analysis also shows uniform particle size distribution. The results of catalytic glycerol conversion show that Cu-modified HY catalysts give a higher acrylic acid yield than HY. The results also show that the highest yield of acrylic acid was obtained in 27.5% and 25.8% at a dehydration time of 3 h using pro-analytical and natural resources CuHY catalyst, respectively. The Cu-modified HY catalysts having weak acid sites show the best catalytic activity in the conversion of glycerol to acrylic acid.

Iron-Locked Hydr(oxy)oxide Catalysts via Ion-Compensatory Reconstruction Boost Large-Current-Density Water Oxidation.

Nickel-iron based hydr(oxy)oxides have been well recognized as one of the best oxygen-evolving catalysts in alkaline water electrolysis. A crucial problem, however, is that iron leakage during prolonged operation would lead to the oxygen evolution reaction (OER) deactivation over time, especially under large current densities. Here, the NiFe-based Prussian blue analogue (PBA) is designed as a structure-flexible precursor for navigating an electrochemical self-reconstruction (ECSR) with Fe cation compensation to fabricate a highly active hydr(oxy)oxide (NiFeOx Hy ) catalyst stabilized with NiFe synergic active sites. The generated NiFeOx Hy catalyst exhibits the low overpotentials of 302 and 313mV required to afford large current densities of 500 and 1000mA cm-2 , respectively. Moreover, its robust stability over 500h at 500mA cm-2 stands out among the NiFe-based OER catalysts reported previously. Various in/ex situ studies indicate that the Fe fixation by dynamic reconstruction process can reinforce the Fe-activated effect on the OER amenable to the industrial-level large current conditions against the Fe leakage. This work opens up a feasible strategy to design highly active and durable catalysts via thermodynamically self-adaptive reconstruction engineering.

Efficient Pyrolysis of Low-Density Polyethylene for Regulatable Oil and Gas Products by ZSM-5, HY and MCM-41 Catalysts

In this research, catalytic cracking of low-density polyethylene (LDPE) has been carried out in the presence of three kinds of typical molecular sieves, including ZSM-5, HY and MCM-41, respectively. The effects of different catalysts on the composition and quantity of pyrolysis products consisting of gas, oil and solid material were systematically investigated and summarized. Specially, the three kinds of catalysts were added into LDPE for pyrolysis to obtain regulatable oil and gas products (H2, CH4 and a mixture of C2–C4+ gaseous hydrocarbons). These catalysts were characterized with BET, NH3-TPD, SEM and TEM. The results show that the addition of MCM-41 improved the oil yield, indicating that the secondary cracking of intermediate species in primary pyrolysis decreased with the case of the catalyst. The highest selectivity of MCM-41 to liquid oil (78.4% at 650 °C) may be attributed to its moderate total acidity and relatively high BET surface area. The ZSM-5 and HY were found to produce a great amount of gas products (61.4% and 67.1% at 650 °C). In particular, the aromatic yield of oil production reached the maximum (65.9% at 500 °C) when the ZSM-5 was used. Accordingly, with the three kinds of catalysts, a new environment-friendly and efficient recovery approach may be developed to obtain regulatable and valuable products by pyrolysis of LDPE-type plastic wastes.

Resource recovery from discarded COVID-19 PPE kit through catalytic fast pyrolysis

During the COVID-19 pandemic, the world saw an exponential surge in the production of Personal Protective Equipment (PPE) kits, which eventually got discarded in the biomedical waste stream. In this study, thirteen different polymer samples from the PPE kit were collected and characterized using Fourier transform infrared spectrometer, thermogravimetric analysis, and analytical pyrolysis-gas chromatograph/mass spectrometry. The characterization data showed that about 94 % by mass of components were made of only three polymers, viz. polypropylene (PP, 75.6 wt %), polyethylene terephthalate (PET, 12.5 wt %), and polycarbonate (PC, 6 wt %). The analytical pyrolysis of the PPE coverall suit (PP) yielded mainly alkenes containing 2,4-dimethyl-1-heptene as the major compound with 17 wt % yield at 600 °C. The pyrolysates from face shield (PET) were rich in benzoic acid (5.8 wt %) and acetophenone (4.8 wt %), while those from safety goggles (PC) were rich in phenol (17.6 wt %) and p-cresol (12.4 wt %) at 600 °C. HZSM-5 and HY zeolites were used for the catalytic upgradation of pyrolysates especially from PP, PET and PC. The temperature and feed-to-catalyst ratio were optimized by performing catalytic fast pyrolysis experiments at 500 °C, 600 °C and 700 °C with different feed-to-catalyst ratios 1:2, 1:4, and 1:6 (w/w). The yield of aromatic hydrocarbons, viz., BTEX (benzene, toluene, ethylbenzene, xylenes) and naphthalene, was maximum (∼25.7 wt %) from PP coverall when HY catalyst was used at 600 °C and 1:6 (w/w) loading. In the case of PET face shield, the total yield of BTEX, naphthalene and biphenyl was maximum (27.9 wt %) at 600 °C and 1:4 (w/w) of HZSM-5, while in the case of PC goggles, it was maximum (18.6 wt %) at 700 °C and 1:4 (w/w) of HY. This study shows that the entire PPE kit can be valorized via catalytic fast pyrolysis to generate petrochemical products and platform molecules like monoaromatic hydrocarbons at high selectivities.

Bifunctional CaCO3/HY Catalyst in the Simultaneous Cracking-Deoxygenation of Palm Oil to Diesel-Range Hydrocarbons

Palm oil is a promising raw material for biofuel production using the simultaneous catalytic mechanism of the bifunctional cracking-deoxygenation reactions. Through the cracking-deoxygenation process, the chains of palmitic acid and oleic acid in the palm oil were converted to diesel-range hydrocarbons. The combination effects of CaCO3 and HY zeolite enhanced the bifunctional catalytic cracking-deoxygenation of palm oil into biofuel, because of the increasing acid and basic sites in the catalysts due to the synergistic roles of CaCO3 and HY. The introduction of CaCO3 on HY zeolite generated both a strong acid and strong basic sites simultaneously on the designed catalyst, which supports the bifunctional mechanisms of hybrid cracking-deoxygenation, respectively. The CaCO3 impregnated on the HY catalyst has a synergistic and bifunctional effect on the catalyst supporting cracking-deoxygenation reaction mechanisms as mentioned previously. The deoxygenation reaction required the bifunctional strong acid and strong basic sites on the CaCO3/HY catalyst through decarboxylation, decarbonylation, and hydrodeoxygenation reaction mechanisms. Meanwhile, the cracking reaction pathway was supported by the strong acid sites generated on the CaCO3/HY catalyst. In other words, the high acidity strength promotes diesel selectivity, whereas the high strength of basicity leads to the deoxygenation reaction.

Constructing optimally hierarchical HY zeolite for the synthesis of high-energy-density tricyclic hydrocarbon fuel

In this work, a tricyclic fuel possessing high energy density and low freezing point has been synthesized via directional alkylation of naphthalene with cyclohexene. A hierarchical HY zeolite with well-defined micro/mesoporous framework was prepared by an alkali-treatment method to efficiently catalyze the reaction. Both porosity and acidity of HY zeolite were optimized by tuning NaOH concentration to maintain the active acid sites and increase their accessibility. The optimally hierarchical HY catalyst (0.5 HY) exhibited higher catalytic activity and good recycling stability. As a result, the tricyclic fuel was produced in high yield, which possesses an energy density of 42.38 MJ/L and a freezing point of < -75 °C. This work provides a straightforward reaction route and an efficient catalyst for the production of a high energy density tricyclic fuel using readily available raw materials.

Improving the stability of La-exchanged zeolite Y catalysts in the vapor-phase isomerization of endo-tetrahydrodicyclopentadiene by co-feeding steam

• La 3+ exchanged zeolite Y is more effective than HY catalyst for isomerizing endo-THDCPD to its exo isomer in vapor phase. • LaY catalyst has more Brönsted acidity and more moderate acid sites than HY catalyst. • Deactivated LaY catalyst could be completely recovered after calcination in air. • Improved stability of LaY catalyst was observed in the presence of a small amount of steam. The activities of La-exchanged zeolite Y (LaNaY) catalysts were investigated and compared with that of HNaY catalyst for the vapor-phase isomerization of endo-tetrahydrodicyclopentadiene (endo-THDCPD) to exo-THDCPD. HNaY and LaNaY catalysts were characterized by means of X-ray diffraction (XRD), nitrogen adsorption, NH 3 -TPD, pyridine-adsorbed Fourier Transformation Infrared Spectroscopy (FTIR). The LaNaY catalysts with La loading of 2-5 wt% showed better catalytic performance than the HNaY catalyst. All catalysts deactivated gradually with number of run. The activity of the deactivated LaNaY catalyst could be completely recovered after calcination in air for 4 h at 550 °C. The effect of steam co-feeding on the stability of the LaNaY catalyst was investigated. The results show that the stability of the LaNaY catalyst was improved by co-feeding steam compared to those in the absence of steam, which was attributed to the replacement of adamantane adsorbed on the active sites of the catalyst by competitive adsorption of water. In the presence of 5 % steam, the effect of temperature on the stability of the LaNaY catalyst was also studied. A high and stable activity was observed at 185 °C.

Experimental and Kinetic Study of the Effect of using Zr- and Pt-loaded Metals on Y-zeolite-based Catalyst to Improve the Products of n-heptane Hydroisomerization Reactions

The escalating cost of Pt metal has prompted researchers to incorporate other metals into Pt/catalysts to reduce the amount of Pt. In this work, several bimetallic Pt-Zr/HY-zeolite catalysts were prepared by incorporating small amounts of the inexpensive Zr into the Pt/HY-zeolite to form an active and selective catalyst. Results showed that although half of the required platinum metal was used, the catalytic activity of the prepared Pt-Zr/HY bimetallic catalyst was higher than that of the monometallic (Pt or Zr)/HY catalysts, as a result of the improved Lewis acidity of that catalyst that resulted from the addition of the Zr metal; additionally, the branched alkanes' yield also increased. The optimum catalyst was bimetallic, containing 0.5 wt% Pt + 0.5 wt% Zr, which achieved the highest yield of isomers at 70.2 mol%, along with 82.61 and 84.98 mol% for conversion and selectivity, respectively, under 1 MPa and 250°C reaction conditions. In addition, the hydroisomerization reaction kinetic model was achieved, giving good predicted results in agreement with the experimental calculations, with an acceptable relative error. It was found that lower activation energies (about 44.5 kJ/mol) were needed for olefin hydrogenation to iso-paraffins, while higher activation energies were required for i-paraffin hydrocracking (about 138.1kJ/mol).

Detailed understanding on thermodynamic and kinetic features of phenanthrene hydroprocessing on Ni‐Mo/HY catalyst

AbstractPhenanthrene hydrogenation is a key reaction for improving the quality of gasoline and diesel. Herein, we conduct detailed thermodynamic and kinetic analyses for phenanthrene hydrogenation on a Ni‐Mo/HY catalyst. We establish a comprehensive reaction network for phenanthrene hydrogenation, and calculate equilibrium constant, rate constant, adsorption constant, activation energy barrier, and reaction energy for each step in the reaction network. All of the steps in the reaction network are revealed to be exothermic. A kinetic model with 28 parameters is constructed for phenanthrene hydrogenation. The deviation of the product yields calculated by the kinetic model from those obtained in experiments is less than 4.5%, indicating the reasonability and accuracy of the kinetic model. The most favorable pathway for phenanthrene hydrogenation is demonstrated to be phenanthrene → tetrahydrophenanthrene → sym‐octahydrophenanthrene → 5,6‐butyl‐tetrahydronaphthalene → tetralin. These results are helpful for efficiently tuning catalyst properties and optimizing reaction conditions for enhancing phenanthrene hydrogenation.

Analysis of CaCO3 Impregnation on HY Zeolite Surface Area, Pore Size, and Activity in the Catalytic Cracking of Palm Oil to Biofuels

Fossil energy sources are currently decreasing, requiring the development of alternative energy sources. Vegetable oil is a raw material for alternative renewable energy supplies. This study produced biofuels from vegetable oil using calcium carbonate (CaCO3)-impregnated HY catalysts. In addition, this study aimed to investigate the effect of CaCO3 impregnation on the surface area and the catalytic activity of catalysts in the palm oil cracking process to produce biofuels. The HY catalyst was modified by the wet impregnation method in 5 wt% CaCO3 solution and was further calcined at 550°C for three h. Furthermore, the catalysts were tested in a continuous fixed-bed catalytic reactor at 450°C. The catalyst properties were characterized using Brunauer–Emmett–Teller (BET) surface area, Barrett–Joyner–Halenda (BJH) for pore size distribution, and X-Ray Diffraction (XRD) for crystal structure and phases. The results showed that the addition of CaCO3 decreased surface area and pore volume; however, the pore size increased, which resulted in the production of heavy hydrocarbons. Interestingly, the introduction of CaCO3 enhanced the yield of Organic Liquid Product (OLP) and diesel-range hydrocarbons selectivity to reach 79.09% and 30.54%, respectively. Furthermore, the introduction of CaCO3 increased deoxygenation activity.

Role of zeolite properties in bio-oil deoxygenation and hydrocarbons production by catalytic cracking

A comparison between the behavior of Y and ZSM-5 zeolites having the same Si/Al ratio was established in the catalytic cracking of bio-oil for producing fuels and platform chemicals. The catalysts were prepared by agglomerating each zeolite with a mesoporous γ-Al2O3 matrix. Properties of the zeolites and the catalysts were characterized by N2 ads/desorption, SEM-EDX, pyridine-FTIR, tBA-TPD, and NH3-TPD techniques. The experiments were conducted in a continuous two-step catalytic cracking system (TS-CC) at 450 °C. Both catalysts are highly selective to C5-C12 hydrocarbons, with a composition strongly affected by the porous structure and acidity of the zeolite. The HZSM-5 catalyst (high acid strength and Brønsted/Lewis ratio) promotes cracking and deoxygenation reactions that lead to C2−C4 olefins which condensate into aromatics, yielding 9% of 1-ring aromatics (3% BTX) and 4% of naphthalenes for a feed conversion of 85%. These reactions are less favored over the HY catalyst, which promotes olefins oligomerization and hydrogen-transfer reactions, yielding 14% of highly aliphatic gasoline (> 30% linear paraffins) and 5% of C13−C20 diesel fraction (> 90% long chain paraffins). The remaining upgraded bio-oil obtained with both catalysts is composed of light oxygenates, with ketones, acids and esters as main components and low concentration of phenolic compounds.

Comparison of cracking activity of the core-shell composite MCM-41/HY & MCM-48/HY catalysts in the synthesis of organic liquid fuel from Mahua oil

A synergistic catalyst was architectured using the hydrothermal crystallization method. Mesoporous material with pore diameter less than 20 nm was grown on the microporous Zeolite HY. The catalysts were characterized by XRD, ICP-OES, BET, TPD, SEM and TEM techniques. The SEM picture portrayed excellent core – shell morphology and TEM analysis corresponded to the XRD reports. Mahua oil was cracked in a pilot scale reactor over the synthesized catalysts at an optimized reaction condition (Temperature: 400 οC; WHSV: 4.6 h−1). The gaseous and liquid products of reaction were analyzed by Residual Gas analyzer and GCMS respectively. The NMR spectral analysis of fuel showed low traces of aromatics. The produced fuel was analyzed for its significant properties like calorific value, fire point, flash point and viscosity.