• Korean Chemical Engineering Research
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• v.53 no.1
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• pp.116-120
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• 2015

Synthesis of butenes through dehydration of 2-butanol was investigated over HY zeolite catalysts. 2-Butanol dehydration reaction was carried out in a fixed bed catalytic reactor. 2-Butanol conversion was increased with increase of $Si/Al_2$ ratio of HY zeolite catalysts, which can be ascribed to increase of acid strength with increase of $Si/Al_2$ ratio. Selectivities to 1-butene, trans-2-butene, and cis-2-butene were not greatly influenced by the change of the $Si/Al_2$ ratio of HY zeolite. As a result, it was advantageous to use a HY zeolite catalyst with 60 $Si/Al_2$ ratio for maximizing the yield of 1-butene in the dehydration of 2-butanol. The optimal reaction temperature for maximizing the yield of 1-butene was $250^{\circ}C$ over HY (60) catalyst.

• Clean Technology
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• v.9 no.3
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• pp.125-132
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• 2003

Activity improvement of Ni metal catalysts for carbon dioxide reforming was studied using HY-zeolite as the main supporter. As the reaction temperature increased, $CH_4$ and $CO_2$ conversions increased, and conversions higher than 80% was obtained above $700^{\circ}C$. As the Ni loading increased, the catalyst activity increased, and the highest activity was shown for the Ni loading of 13wt%. The HY-zeolite support showed the highest intial conversions of $CH_4$ and $CO_2$, but it showed faster deactivation than a ${\gamma}-Al_2O_3$ support. Nevertheless, it maintained the $CH_4$conversion higher than 80% after 24 hr reaction. The effect of promoters such as Mg, Mn, K, and Ca was also studied. It was observed that the Mg promotor exhibited the highest catalyst activity and less deactivation compared with Mn, K and Ca. After 24hr reaction, The optimum Mg content was found to be 5wt%.

• Journal of Energy Engineering
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• v.8 no.2
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• pp.248-255
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• 1999

Catalytic cracking of pyrolysed waste lubricating oil over solid acid catalysts (HY zeolite, ${\beta}$-zeolite, HZSM-5) has been carried out in a micro-fixed bed system. The feed oil for catalytic activity tests has been prepared by thermal cracking of waste lubricating oil under the reaction conditions of 480$^{\circ}C$, 60 min. Optimum reaction conditions for the maximum light oil yields($\_$21/) were WHSV(weight hourly space velocity)=1 at 375$^{\circ}C$. The amounts of total and strong acid sites appeared to be the largest in ${\beta}$-zeolite as determined by NH$_3$, TPD. It is seen that the catalytic activity order, in terms of the light fuel oil ($\_$21/) production, were HY zeolite)${\beta}$-zeolite>HZSM-5. Also, coke formation followed the same order. The highest activity in HY zeolite may be attributed from the fact that it has supercages facilitating the easy diffusion of larger molecules and also the effectiveness of the acid sites for cracking within the pore. This fact could be confirmed by the coke formation characteristics.

• Applied Chemistry for Engineering
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• v.24 no.3
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• pp.291-298
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• 2013

Conjugated linoleic acid methylester was synthesized through isomerization of linoleic acid methylester by using heterogeneous catalysts. As for heterogeneous catalysts, Ni supported zeolite type catalysts were used. H zoelite Y (HY) were ion exchanged with KCl aqueous solution to synthesize K zeolite Y (KY), and with impregnation method, Ni supported zeolite catalysts were synthesized. Catalysts were used after pre-treatment by using hydrogen. HY catalysts showed a high conversion at low temperatures; but a low selectivity for conjugation reaction. KY catalysts showed a low conversion at low temperatures; but a similar conversion with HY catalysts at high temperatures while a high selectivity at low temperatures. As a result, 4 wt% Ni/KY720 recorded the high conjugation yield of 63.4% at 220.

• Applied Chemistry for Engineering
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• v.29 no.2
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• pp.185-190
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• 2018

The dimer of bicyclo [2.2.1] hepta-2,5-diene (norbornadiene) can be used as a high-energy-density fuel. The purpose of this study is to investigate the effect of Co loading on the acid properties of HY zeolite catalyst and the catalytic activity in norbornadiene dimerization. When the cobalt was loaded on the HY zeolite catalyst, the amount of acid sites did not change, but the acid strength weakened. This can be attributed to the decrease in $Br{\ddot{o}}nsted$ acid site and the increase in Lewis acid site. The norbornadiene conversion and yield of norbornadiene dimer over the Co/HY catalyst showed higher than those over the HY zeolite catalyst. The higher activity of the Co/HY catalyst can be ascribed to the higher amount of Lewis acid sites over the Co/HY catalyst. Density and calorific values of the norbornadiene dimer prepared by using the Co/HY catalyst agreed well with the known values in the literature. It was confirmed that the norbornadiene dimer prepared in this study can be used as a high-energy-density fuel.

• Applied Chemistry for Engineering
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• v.25 no.1
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• pp.66-71
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• 2014

Synthesis of exo-tetrahydrodicyclopentadiene (exo-THDCPD) through the isomerization of endo-tetrahydrodicyclopentadiene (endo-THDCPD) was investigated over HY zeolite catalysts. Conversion of endo-THDCPD increased with the increase of $Si/Al_2$ ratio of HY zeolite catalysts, which can be attributed to increase of acid strength with increase of $Si/Al_2$ ratio. Yield of exo-THDCPD, however, was the highest over HY with $Si/Al_2$ ratio of 30, because the production of cyclopentadiene and oligomers was minimized. The optimal reaction temperature was $180^{\circ}C$ because the higher reaction temperature increased the production of by-products. The yield of exo-THDCPD also increased with the amount of the catalyst in feed. In the isomerization reaction of endo-THDCPD using the HY zeolite catalysts, it was confirmed that the internal diffusion resistance in the pore of catalysts would have more significant effects on the reaction activity than that of the external diffusion resistance of catalysts.

• Korean Chemical Engineering Research
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• v.58 no.4
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• pp.658-664
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• 2020

Zeolite HY is wet impregnated with Ni (0.1, 0.3, 0.4, 0.5 wt%), Pt (0.1 wt%) and reduced in presence of hydrogen to form nanosized particles of Ni and Pt. All the catalysts were characterized by XRD, TEM, ESCA, NH₃-TPD, Pyridine adsorbed FT-IR and BET. Characterization results confirm that the Ni and Pt fractions effectively rehabilitated the physio-chemical properties of the zeolite HY catalysts. Further, all the reduced catalyst were screened with hydroisomerization of m-xylene at LHSV = 2.0 h^-1 in the temperature range 250-400 ℃ in steps of 50 ℃ in hydrogen atmosphere (20 ml/g). The addition of Ni to Pt catalyst increases hydroisomerization conversion, as well as maximizes p-xylene selectivity by restricting the pore size. The increasing trend in activity continues up to 0.3 wt% of Ni and 0.1 wt% Pt addition over zeolite HY. The increasing addition of Ni increases the total number of active metallic sites to exposed, which increases the metallic sites/acid sites ratio towards the optimum value for these reactions by better balance of synergic effect for stable activity. The rate of deactivation is pronounced on monometallic catalysts. The results confirm the threshold Ni addition is highly suitable for hydroisomerization reaction for product selectivity over Ni-Pt bimetallic/support catalysts.

• Korean Chemical Engineering Research
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• v.54 no.5
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• pp.712-718
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• 2016

Platinum catalysts supported on the mesoporous material synthesized from Y zeolite were applied to synthesis of jet-fuel through n-octadecane hydroupgrading. The mesoporous aluminosolicate, $MMZ_{HY}$ was synthesized using Y zeolite as its framework source. The effect of the addition of Mg to $Pt/MMZ_{HY}$ catalyst for n-octadecane hydroupgrading was investigated. Catalyst characterization was performed with X-ray diffraction, $N_2$ adsorption, temperature-programmed reduction in hydrogen flow, temperature-programmed desorption of ammonia, and infrared spectroscopy of adsorbed pyridine. The high yield of jet-fuel over the $PtMg(2.0)/MMZ_{HY}$ can be attributed not only to the higher dispersion of Pt metal and higher reducibility, but also the higher amount of acid sites and higher strength of acid sites. The selectivity to iso-paraffin in the jet-fuel fraction could be reached above 80% over the optimized $PtMg/MMZ_{HY}$ catalyst.

• Bulletin of the Korean Chemical Society
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• v.25 no.11
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• pp.1726-1728
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• 2004

• Journal of the Korean Society of Safety
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• v.6 no.3
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• pp.5-11
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• 1991

To remove NO from flue gas, a direct decomposition method to $N_2$ and $O_2$ was investigated by using copper / zeolite catalyst. The copper ion-exchanged HY type zeolite has high activity on NO decomposition. The decomposition activity was increased with the increase of ion-exchange level, contacting time and reaction temperature in the range of 30$0^{\circ}C$ -50$0^{\circ}C$ , and decreased with the oxygen addition.