Hydroisomerization Reaction Research Articles

Direct synthesis of low-silica ZSM-48 zeolite via seed-assisted hydrothermal synthesis with 1,6-hexanediamine as template

ZSM-48 zeolite is characteristic of 10-member ring (10-MR) one-dimensional tubular channel structure and finds extensive applications in catalytic hydroisomerization reactions. Here we developed an efficient synthetic strategy for low-silica ZSM-48 zeolite with a SiO2/Al2O3 ratio at 30–176 via a seed-assisted hydrothermal synthesis method, overcoming the limit that 1,6-hexanediamine (HDA) template can only be used to synthesize high-silica (i.e., SiO2/Al2O3 ratio >200) zeolites. A two-step crystallization procedure coupled with zeolite seed-assisted synthesis strategy was enrolled to realize well crystallized ZSM-48 zeolites, in which the zeolite nuclei are sufficiently produced at the nucleation temperature at 100 °C for 24 h with the aid of zeolite seeds, and the zeolite growth is proceeded at the crystallization temperature at 160 °C for 48 h. The morphology and particle size of low-silica ZSM-48 zeolite have been manipulated by adjusting the synthetic parameters, such as the alkalinity and silicon source of aluminosilicate gel for zeolite, the crystallization manner (static or dynamic crystallization), as well as the presence of additive (i.e., sodium chloride). The as-synthesized ZSM-48 zeolite possesses a high acid content of 0.194 mmol/g, highlighting its potential as an excellent acidic support for hydroisomerization catalysts. The cost-effective and environmentally friendly synthesis strategy, which is anticipated to expand the application of alkylamine organic templates in the synthesis of low-silica ZSM-48 zeolite.

Shape selection of alkane hydroisomerization over one-dimensional zeolite supported Pt catalyst: Pt/ZSM-48 versus Pt/ZSM-22

Hydroisomerization of long-chain n-alkanes plays a vital role in petrochemical and coal chemical industries, because it can produce high-quality hydrocarbon fuels and lubricant base oils. ZSM-48 (0.56 × 0.53 nm) and ZSM-22 (0.57 nm × 0.46 nm) are characteristic of one-dimensional 10-member ring zeolites suitable for n-alkanes hydroisomerization reaction. Here, the effect of the structure difference between ZSM-48 and ZSM-22 zeolites on hydroisomerization is titrated by the isobutane and n-dodecane. The product distribution of hydroisomerization of isobutane to n-butane shows the reaction pathway on Pt/ZSM-48 and Pt/ZSM-22, in which the monomolecular hydroisomerization of isobutane is involved within the active sites in zeolite channels, while the polymerization-cracking bimolecular reaction occurs on the pore-mouth of zeolite. Pt/ZSM-48 zeolite, possessing larger channel and aperture size than those of Pt/ZSM-22, is more conducive to the diffusion of butane molecules and bimolecular polymerization. Therefore, the isobutane conversion (14 %) on Pt/ZSM-48 produces less C1+C2 (1.7 wt% vs. 3.4 wt%) and more C3+C5+C8 (19.2 wt% vs. 16.9 wt%). For the hydroisomerization of n-dodecane, the iso-dodecane selectivity of Pt/ZSM-48 (43.3 wt%) is significantly higher than that of Pt/ZSM-22 (12.4 wt%) at the similar n-C12 conversion (40 %). Compare with the isomers of Pt/ZSM-22, the mono-branched isomers with methyl near the middle of the chains and multi-branched isomers are more easily formed on Pt/ZSM-48, which is conducive to the “key-lock” catalysis mechanism. The larger pore size of ZSM-48 is conducive to n-C12 insertion into zeolite pores, methyl migration and isomer diffusion, and its adjacent pores are more compatible with double-branched isomers. In addition, a high selectivity of C4∼C5 alkanes (53.2 wt%) on Pt/ZSM-22 and a high selectivity of C6∼C9 alkanes (44.7 wt%) on Pt/ZSM-48 show obvious difference in cracking product distribution, implying different position of methyl groups in i-C12 isomers on Pt/ZSM-22 and Pt/ZSM-48 samples, respectively. The present comparison between Pt/ZSM-48 and Pt/ZSM-22 benefits the selection and development of one-dimensional zeolitesupported metal catalyst in a wide range of hydro-processing reactions.

Hydroisomerization catalysts with enhanced metal charge density prepared by a novel low temperature loading method

Bifunctional catalysts, consisting of metal and acid sites, can be applied in the alkane hydroisomerization reaction, and the process of dehydrogenation and hydrogenation at the metal sites can balance the isomerization and cracking routes, carbocation rearrangement at acidic sites affecting the hydroisomerization performance. Metals are traditionally prepared at high temperature which results in metal agglomeration. To address this drawback, a low-temperature method for catalyst loading is proposed. The method provides catalysts with smaller particle sizes and higher dispersion to prevent metal agglomeration. Specifically, when the loading capacity of metal Pt is 0.3 wt%, this method results in both single atoms and metal clusters within the catalyst. And the catalyst shows a balanced metal-acid function once capacity for Pt loading increased to 0.5 wt%. Moreover, the electron density of Pt following metal loading on g-C3N4 support increased, and the turnover frequency (TOF) of each metal site also increased with the rise of nPt/nA. Furthermore, it is noted that the catalyst prepared by low-temperature loading shows significant increased hydroisomerization activity and selectivity compared to those prepared with the traditional method, with an isomer yield of up to 68.2 %.

Tailored synthesis of plate-like SAPO-11 molecular sieve and its application in non-noble metal-supported catalyst for efficient hydroisomerization of long-chain n-alkanes

The tailored synthesis of plate-like SAPO-11 molecular sieve was achieved by introducing seed-surfactant directing agent into the synthesis system for the first time. The effects of morphological change of SAPO-11 molecular sieve on the physicochemical properties of SAPO-11 and the active phase properties of the catalyst were analyzed via a series of characterization techniques. The hydroisomerization of n-hexadecane was used as the model reaction to evaluate the catalytic performance of NiWS supported catalysts based on SAPO-11 molecular sieve with different morphologies. The plate-like SAPO-11 possessed better textural properties and acidity than pseudo-spherical SAPO-11. Meanwhile, the stacking number, dispersion and metal sulfidation degree of the active phase of sulfided NiW/SAPO-11-P were improved, and its high proportion of type II active phase optimized the metal–acid synergistic catalytic mechanism. Through tracking and analyzing the crystallization process of plate-like SAPO-11, the formation mechanism of plate-like SAPO-11 was investigated and revealed. The adsorption kinetics, diffusion behavior and catalytic kinetics of n-hexadecane on the catalysts were emphatically investigated. The optimized support structure and active phase properties improved the intrinsic catalytic activity and hydroisomerization reaction path priority of NiW/SAPO-11-P. It was found that the hydroisomerization reaction on NiW/SAPO-11-P was carried out under the reaction-limiting conditions, while the hydroisomerization reaction on NiW/SAPO-11-C was carried out under the reaction-controlling conditions. The effects of plate-like SAPO-11 on the activity stability of the catalyst was investigated, and the essential reasons for the differences in activity stability of the catalysts were revealed through comprehensively analyzing the coke formation difference and diffusion behavior difference. It is expected to provide reference for the tailored design of SAPO-11 molecular sieve with special morphology and the preparation of efficient hydroisomerization catalyst.

Hydroisomerization of n‐dodecane over ZSM‐48 with different metal properties

AbstractThe distance between the two active sites of a bifunctional catalyst (acid sites and metal sites) is critical for the hydroisomerization performance. However, the influences of the dehydrogenation/hydrogenation species (Pt or Ni) and the intimacy between the acid sites and the metal sites over the distribution of the isomers have rarely been investigated. Herein, the bifunctional catalysts were prepared by loading the hydrogenation component (Pt or Ni) on γ‐Al2O3 or HZSM‐48 zeolite separately and then mixing them with equal mass of HZSM‐48 molecular sieves and γ‐Al2O3, respectively. The hydroisomerization performance of n‐dodecane was investigated on a fixed‐bed reactor. The loading position of the metal can directly affect the activity of the hydroisomerization reaction. However, the distribution of the isomer products is not affected by the loading position and the metal type (Pt or Ni) obviously, and the middle‐positioned isomer is the main isomer product regardless of the position and the type of the metal. The catalysis results indicate that the isomerization of n‐dodecane mainly follows the “Key‐Lock” catalysis mode on HZSM‐48.

Experimental and Kinetic Study of the Catalytic Behavior of Sulfate-Treated Nanostructured Bifunctional Zirconium Oxide Catalysts in n-Heptane Hydroisomerization Reactions

In this study, a mono-functional ZrO2 nanomaterial was treated with sulfur and loaded with two different percentages of platinum metals (i.e., 0.5 and 1 wt%) to generate an acidic bi-functional Pt/SZrO2 nanocatalyst for the purpose of increasing the catalytic activity and selectivity together. This work aims to determine the least amount of the costly platinum metal that can be added to the catalyst to achieve the appropriate balance between the acidic and metallic sites. Both rapid deactivation of the super-acid nanaocatalyst and fast cleavage of the zero-octane n-heptane chain can consequently be prevented throughout the reaction. This can be achieved by accelerating the hydroisomerization reactions at a pressure of 5 bar to reach the highest selectivity towards producing the desired multi-branched compound in fuel. Several characterization techniques, including XRD, SEM, EDX, BET, and FTIR, have been used to evaluate the physical properties of the catalysts. The best reaction product was obtained at 230 °C compared to the other tested temperatures. The conversion, selectivity, and yield of reaction products over the surfaces of the prepared catalysts followed this order: 0.5 wt% Pt/SZrO2 > 1 wt% Pt/SZrO2 > 0.5 wt% Pt/ZrO2 > 1 wt% Pt/ZrO2 > SZrO2 > ZrO2. The highest conversion, selectivity, and yield values were obtained on the surface of the 0.5 wt% Pt/SZrO2 catalyst, which are 69.64, 81.4 and 56.68 wt%, respectively, while the lowest values were obtained on the surface of the parent ZrO2 catalyst, which are 43.9, 61.1 and 26.82, respectively. The kinetic model and apparent activation energies were also implemented for each of the hydroisomerization, hydrogenation/dehydrogenation, and hydrocracking reactions, which track the following order: hydroisomerization < hydrogenation/dehydrogenation < hydrocracking. The lowest apparent activation energy value of 123.39 kJ/mol was found on the surface of the most active and selective 0.5% Pt/SZrO2 nanocatalyst.

OSDA-free synthesis of FeZSM-22 zeolite from natural minerals for n-octane hydroisomerization

A seed-directed approach to synthesizing FeZSM-22 zeolite without organic structure directing agent (OSDA) was developed by using Fe-rich diatomite as all aluminum and iron sources. The FeZSM-22 zeolite with optimal crystallinity and purity can be obtained by systematically adjusting feed composition and synthesis conditions. Characterizations show that FeZSM-22 zeolite synthesized with OSDA-free owns high crystallinity, obvious thin needle-shaped morphology and high Bronsted/Lewis acid ratio. Significantly, when used for n-octane hydroisomerization reaction, its derived catalyst exhibits the best catalytic performance reflected by the highest selectivity to C8 isomers compared to the two reference catalysts prepared based on a Fe-containing and a Fe-free ZSM-22 synthesized through an OSDA-directed route from natural diatomite and conventional chemicals, respectively. This work provides an alternative route to sustainably synthesizing heteroatomic zeolites with high performance.

Pd–Pt promoted HPMo/UiO-66 acid catalyst for n-hexane hydroisomerization for higher quality and cleaner fuel production: Catalytic activity and kinetic modeling

The preparation of catalysts with adequate stability for the n-hexane hydroisomerization reaction is always a challenge in refineries. Therefore, in this work, the metal-organic framework UiO-66, heteropoly phosphomolybdic acid (HPMo), and bifunctional (Pd + Pt)/HPMo/UiO-66 samples were synthesized, characterized by experimental techniques, and tested in the n-hexane hydroisomerization reaction. As a result, the microporous (0.2%Pd+0.3%Pt)/30%HPMo/UiO-66 bifunctional catalyst exhibited an iso-hexane selectivity of 86% and n-hexane conversion of 72.1% after 36 h of reaction time. In addition, the Langmuir-Hinshelwood model was used to examine the kinetics of this reaction due to the inhibitory effect of hydrogen. The results provided an acceptable fit to the experimental data and allowed the determination of the kinetic parameters. Accordingly, the apparent activation energy of this bifunctional catalyst and the adsorption heats of hydrogen and n-hexane were calculated at 26.27, −16.12, and −7.82 kJ mol−1, respectively.

Regulate the mesopores and acidic structure of Pt/USY zeolite catalyst for improved performance in the hydroisomerization of phenanthrene to alkyl-adamantane

Adamantane-based high energy density fuels (HEDFs) play a key role in military and aerospace applications due to their high volumetric calorific value and high density. In the preparation of adamantane-based HEDFs by hydroisomerization of polycyclic aromatic hydrocarbons (PAHs) in coal tar, there is competition between cracking and ring-opening reactions. Therefore, USY zeolites were etched with NaOH solution to expand the mesoporous and regulate the acidity, inhibit the cracking reaction, and promote the ring-shift isomerization of perhydrophenanthrene (PHP) to alkyl-adamantane (AlA), increasing the yield of AlA from 19% to 32%. There are two processes in the conversion of PAHs to AlA, hydrogenation and ring-shift isomerization. Phenanthrene was first hydrogenated to PHP, then isomerized to alkyl-adamantane, the product distribution of alkyl-adamantanes with different side chains was discovered, part of the C14 alkyl-adamantanes cracked, and the hydroisomerization reaction of PHP occurred only on the outer surface or pore mouth of USY zeolite. It provides a new perspective for the hydroconversion of PAHs to HEDFs.

Effects of Aluminum Source with Different Properties on the Properties of Pd/SAPO-41 and its Catalytic Hydroisomerization Reaction

Aluminium source is one of the main factors affecting the physicochemical properties of SAPO-41.Silicoaluminophosphate molecular sieves-SAPO-41 were prepared via hydrothermal synthesis using di-n-butylamine (DBA) as templating agent, pseudo-boehmites, phosphoric acid and silica sol as aluminum, phosphorus and silicon sources respectively. Using XRD, N2 physical adsorption, SEM and Py-IR analysis media, the effects of aluminum sources on the crystal and pore structure, morphology, B-acid center strength of the prepared SAPO-41 molecular sieves. The catalytic hydroisomerization performance over Pd/SAPO-41 bifunctional catalysts were investigated. Pseudo-boehmite type has little effect on the crystal structure and chemical composition of SAPO-41 molecular sieve, but has different effects on its morphology, pore structure, B-acid strength of SAPO-41, and Pd dispersion on Pd/SAPO-41. The hydroisomerization conversion of n-decane over 0.5Pd/S41-A1 can reach 88.56 %, and the selectivity of isoparaffin can reach 90.88%.This work provides a reference for selecting an ideal aluminum source for the synthesis of SAPO-41.

Kinetics of Liquid-Phase 1-Butene Hydroisomerization over Pd/Al2O3 Catalysts

Liquid-phase 1-butene hydroisomerization to 2-butene is an important approach to utilize cheap and abundant C4 olefins (normally as by-products from refinery processes), and the reaction kinetics is critical to the development of its reactors and catalysts. Herein, kinetics experiments are performed to understand the characteristics of liquid-phase 1-butene hydroisomerization over a commercial Pd/Al2O3 catalyst, and three intrinsic kinetics models are proposed to describe the rates of the hydroisomerization and hydrogenation reactions. The results show that the selectivity toward 2-butene increases with temperature, indicating the hydrogenation reactions are suppressed due to the low partial pressure of hydrogen under high temperature. The fraction of hydrogen in reactants significantly affects 1-butene conversion and 2-butene selectivity, and thus, this effect should be included in kinetics models. Comparing the proposed power-law, dual-site Langmuir–Hinshelwood, and single-site Langmuir–Hinshelwood models, the single-site Langmuir–Hinshelwood model is the best in predicting the experiments, implying that hydroisomerization and hydrogenation reactions may occur at the same type of active sites under the reaction conditions in this work. The activation energies of the hydroisomerization reactions are lower than those of the hydrogenation reaction, and the adsorption enthalpy of butenes is smaller than that of hydrogen.

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).

Toward n-Alkane Hydroisomerization Reactions: High-Performance Pt-Al2O3/SAPO-11 Single-Atom Catalysts with Nanoscale Separated Metal-Acid Centers and Ultralow Platinum Content.

Long-chain n-alkane hydroisomerization reaction plays a vital role in petrochemical and coal chemical industries, which could produce high-quality hydrocarbon fuels and lubricant base oils for modern transportation and mechanical drive. However, minimizing precious metal usage while maintaining the catalyst performance remains a great challenge. Herein, a novel bifunctional catalyst toward n-alkane hydroisomerization reactions, Pt-Al2O3/SAPO-11 (Pt-A/S11) featuring nanoscale separated metal-acid active centers has been synthesized via a simple two-step procedure. In detail, Pt species was first loaded on the nanometer-sized alumina matrices through an incipient wetness impregnation method and then mixed with SAPO-11 molecular sieve to form the composite catalyst. Importantly, 0.015Pt-A/S11 catalyst with the ever-reported lowest Pt loading amount of 0.015 wt % exhibits an extraordinarily high isomer yield of 85.8% compared to previous published results and the traditional Pt-SAPO-11/Al2O3 (Pt-S11/A) catalyst accompanying with the direct contact between metal and acid sites (65.6%). It has been confirmed that the Pt species in 0.015Pt-A/S11 samples exist in single-atom form, leading to an excellent hydroisomerization performance. The possible reaction processes have been discussed to elucidate the exemplary catalytic performance of the synthesized Pt-A/S11 catalysts with nanoscale intimacy of metal-acid sites.

Novel design of lubricant-type vacuum distillation process for lube base oils production from hydrocracking tail oil

Dividing-wall columns (DWCs) are widely used in the separation of ternary mixtures, but rarely seen in the separation of petroleum fractions. This work develops two novel and energy-efficient designs of lubricant-type vacuum distillation process (LVDP) for the separation of hydroisomerization fractions (HIF) of a hydrocracking tail oil (HTO). First, the HTO hydroisomerization reaction is investigated in an experimental fixed-bed reactor to achieve the optimum liquid HIF by analyzing the impact of the operating conditions. A LVDP used for HIF separation is proposed and optimized. Subsequently, two thermal coupling intensified technologies, including side-stream (SC) and dividing-wall column (DWC), are combined with the LVDP to develop side-stream vacuum distillation process (SC-LVDP) and dividing-wall column vacuum distillation process (DWC-LVDP). The performance of LVDP, SC-LVDP, and DWC-LVDP are evaluated in terms of energy consumption, capital cost, total annual cost, product yields, and stripping steam consumption. The results demonstrates that the intensified processes, SC-LVDP and DWC-LVDP significantly decreases the energy consumption and capital cost compared with LVDP. DWC-LVDP further decreases in capital cost due to the removal of the side stripper and narrows the overlap between the third lube oils and fourth lube oils. This study attempts to combine DWC structure into the separation of petroleum fractions, and the proposed approach and the results presented provide an incentive for the industrial implementation of high-quality utilization of HTO through intensified LVDP.

Synthesis of ZSM-48 zeolites and their catalytic performance: a review

The synthesis and catalytic performances of ZSM-48 were summarized. ZSM-48 was mainly applied in cracking reactions, shape selective reaction, methanol to hydrocarbons and showed excellent catalytic performance in hydroisomerization reaction.

Advances in Catalytic Applications of Zeolite-Supported Metal Catalysts.

Zeolites possessing large specific surface areas, ordered micropores, and adjustable acidity/basicity have emerged as ideal supports to immobilize metal species with small sizes and high dispersities. In recent years, the zeolite-supported metal catalysts have been widely used in diverse catalytic processes, showing excellent activity, superior thermal/hydrothermal stability, and unique shape-selectivity. In this review, a comprehensive summary of the state-of-the-art achievements in catalytic applications of zeolite-supported metal catalysts are presented for important heterogeneous catalytic processes in the last five years, mainly including 1) the hydrogenation reactions (e.g., CO/CO2 hydrogenation, hydrogenation of unsaturated compounds, and hydrogenation of nitrogenous compounds); 2) dehydrogenation reactions (e.g., alkane dehydrogenation and dehydrogenation of chemical hydrogen storage materials); 3) oxidation reactions (e.g., CO oxidation, methane oxidation, and alkene epoxidation); and 4) other reactions (e.g., hydroisomerization reaction and selective catalytic reduction of NOx with ammonia reaction). Finally, some current limitations and future perspectives on the challenge and opportunity for this subject are pointed out. It is believed that this review will inspire more innovative research on the synthesis and catalysis of zeolite-supported metal catalysts and promote their future developments to meet the emerging demands for practical applications.

Effect of Tungsten Oxide Content in Pt/WO3-ZrO2 Catalysts on the Performance Characteristics of the Heptane–Benzene Mixture Hydroisomerization Reaction

Effect of Tungsten Oxide Content in Pt/WO3-ZrO2 Catalysts on the Performance Characteristics of the Heptane–Benzene Mixture Hydroisomerization Reaction

Hydroisomerization of n-hexadecane under mesoporous molecular sieve Pt/Al-SBA-15

1) Reduction of synthesis time of the Al-SBA-15 support. 2) The Pt/Al-SBA-15 catalyst was prepared by three different synthesis procedures. 3) Catalyst and support characterization by: XRPD, BET, NH3-TPD, SEM, TPR. 4) The Pt/Al-SBA-15 catalyst also presents low selectivity to cracked products. 5) The catalyst presented a 43% selectivity to the 7-methyl-pentadecane isomer. Oil derived products can be used effectively through the use of bifunctional catalysts in hydroconversion (hydroisomerization/hydrocracking) reactions. Therefore, the objective of this work was studying the n-hexadecane hydroisomerization using a bifunctional Pt/Al-SBA-15 catalyst, evaluating conversion and selectivity to mono branched products. The Al-SBA-15 support was synthesized by three different procedures, two described in literature, an innovator. The support was extensively characterized by several techniques. Pt was impregnated by incipient dry impregnation. The catalyst was characterized and activated. It was evaluated against the n-hexadecane isomerization in batch, 800 rpm, 280, 290 and 300 °C, and 55 bar, 0,052 grams of catalyst/ grams of reactant ratio. The conversion obtained was 100% for 30 h of reaction. The selectivity for mono-branched products obtained was 43% for all catalysts, remaining virtually constant with reaction time and temperature. Thus, this thorough work of bifunctional catalysts synthesis, characterization of the mesoporous support and application in hydroisomerization reactions, provides viable alternatives for the use of oil derived products in an efficient method.

Techno-Enviro-Economic Study of Hydrogenated Vegetable Oil Production from Crude Palm Oil and Renewable Hydrogen

From the perspective of technical, environment, and economics, hydrogenated vegetable oil (HVO) production with renewable hydrogen from biomass gasification (BG), geothermal electrolysis (GEO-E), and solar photovoltaic electrolysis (PV-E) is compared to steam methane reforming (SMR). The purpose of this study is to evaluate the energy efficiency, greenhouse gases emission factor, and production cost of HVO from various hydrogen production technologies. Production technologies are simulated using Aspen Plus ®. HVO is produced by hydrotreating and hydroisomerization reactions. The processes produce three main products: HVO, green naphtha, and bio-jet fuel. The feedstock used to produce hydrogen from BG is empty fruit bunch (EFB). Renewable electricity produced by geothermal combination of flash system and organic Rankine cycle (ORC) and solar photovoltaic (PV) with battery. Technical analysis is done by calculating the energy efficiency of overall system. Production cost of HVO is calculated by levelized cost of energy (LCOE). Life cycle analysis (LCA) is carried out to calculate CO2-eq intensity. The result shows that HVO production with SMR has the highest energy efficiency, 55.67%, which then followed by BG, 31.47%, PV-E, 9.34%, and GEO-E, 7.89%. The order of LCOE obtained from lowest to highest is HVO production from hydrogen produced by SMR (15.78/GJ-HVO), BG ($16.37/GJ-HVO), GEO ($22.83/GJ-HVO), and PV ($27.29/GJ-HVO). However, for CO2-eq intensity, the order is HVO productions with the hydrogen produced by GEO-E, PV-E, SMR, and BG are 1.63 kgCO2-eq/kg HVO, 1.86 kgCO2-eq/kg HVO, 5.57 kgCO2-eq/kg HVO, and 16.52 kgCO2-eq/kg HVO, respectively.

Blocking of Zeolite Pore by Loading Ni-Pt Nanoparticles for Maximization of Isomerization Selectivity

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 oC in steps of 50 oC 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.