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Artículos de revistas sobre el tema "Calcium catalysts"

Autor: Grafiati

Publicado: 25 de enero de 2025

Última modificación: 31 de julio de 2025

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1

Mazaheri, Hoora, Hwai Chyuan Ong, Zeynab Amini, et al. "An Overview of Biodiesel Production via Calcium Oxide Based Catalysts: Current State and Perspective." Energies 14, no. 13 (2021): 3950. http://dx.doi.org/10.3390/en14133950.

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Biodiesel is a clean, renewable, liquid fuel that can be used in existing diesel engines without modification as pure or blend. Transesterification (the primary process for biodiesel generation) via heterogeneous catalysis using low-cost waste feedstocks for catalyst synthesis improves the economics of biodiesel production. Heterogeneous catalysts are preferred for the industrial generation of biodiesel due to their robustness and low costs due to the easy separation and relatively higher reusability. Calcium oxides found in abundance in nature, e.g., in seashells and eggshells, are promising

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2

Stegner, Philipp C., Jonathan Eyselein, Gerd M. Ballmann, Jens Langer, Jochen Schmidt, and Sjoerd Harder. "Calcium catalyzed enantioselective intramolecular alkene hydroamination with chiral C2-symmetric bis-amide ligands." Dalton Transactions 50, no. 9 (2021): 3178–85. http://dx.doi.org/10.1039/d1dt00173f.

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Enantioselective catalysis with calcium catalysts is challenging due to facile loss of the chiral spectator ligand. Herein a series of bis-amide calcium catalysts with chiral binaphtalene bridges is introduced.

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3

Díaz-Muñoz, L. L., H. E. Reynel-Ávila, D. I. Mendoza-Castillo, A. Bonilla-Petriciolet, and J. Jáuregui-Rincón. "Preparation and Characterization of Alkaline and Acidic Heterogeneous Carbon-Based Catalysts and Their Application in Vegetable Oil Transesterification to Obtain Biodiesel." International Journal of Chemical Engineering 2022 (July 20, 2022): 1–13. http://dx.doi.org/10.1155/2022/7056220.

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This paper reports the preparation, evaluation, and comparison of alkaline and acidic heterogeneous carbon-based catalysts in the transesterification of safflower oil with methanol to obtain biodiesel. These catalysts were obtained from the pyrolysis of flamboyant pods and their functionalization and activation with potassium hydroxide, citric acid, tartaric acid, sulfuric acid, and calcium nitrate. Different routes for the preparation of these catalysts were tested and analyzed where the FAME formation was the target variable to be improved. Results showed that the catalyst prepared with pota

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4

Alsowayigh, Marwah M., Amal H. Alsehli, Fahad Alqahtani, et al. "Investigation of Calcium Phosphate Catalysts in Sodium Borohydride Methanolysis for Improved Hydrogen Production." Catalysts 14, no. 8 (2024): 512. http://dx.doi.org/10.3390/catal14080512.

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In this study, calcium-rich resource minerals such as brushite, tricalcium phosphate (TCP), and hydroxyapatite were tested as catalysts for the methanolysis of alkaline solutions of NaBH4 to generate hydrogen H2. The synthesis of calcium phosphate compounds was characterized by means of X-ray powder diffraction (XRD) and scanning electron microscopy (SEM). The hydrogen generation rate with the TCP catalyst (15,214 mL min−1 g−1) was higher than with the hydroxyapatite catalyst (12,437 mL min−1 g−1) and brushite catalyst (6210 mL min−1 g−1) for the methanolysis of 250 mg NaBH4 at 298 K using 25

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5

Li, Changqing, Xinyue Cui, Aili Wang, et al. "Direct Synthesis of Calcium Lactate through the Reaction of Glycerol with Calcium Hydroxide Catalyzed by Bimetallic AuCu/SiO2 Nanocatalysts." Catalysts 14, no. 5 (2024): 318. http://dx.doi.org/10.3390/catal14050318.

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Bimetallic AuCu/SiO2 nanosized catalysts were prepared using the wet chemical reduction technique. From among Au0.1–1.5Cu10/SiO2 catalysts, the Au0.5Cu10/SiO2 catalyst gave the highest yield of calcium lactate of 87% at a glycerol conversion of 96% when the reaction of glycerol with calcium hydroxide at a mole ratio of calcium hydroxide to glycerol of 0.8:1 was conducted under an anaerobic atmosphere at 200 °C for 2 h. The interactions between metallic Au0 and Cu0 nanoparticles facilitate calcium lactate formation. The simulation of glycerol consumption rate with an empirical power-function re

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6

Istadi, Istadi, Udin Mabruro, Bintang Ayu Kalimantini, Luqman Buchori, and Didi Dwi Anggoro. "Reusability and Stability Tests of Calcium Oxide Based Catalyst (K2O/CaO-ZnO) for Transesterification of Soybean Oil to Biodiesel." Bulletin of Chemical Reaction Engineering & Catalysis 11, no. 1 (2016): 34. http://dx.doi.org/10.9767/bcrec.11.1.413.34-39.

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<p>This paper was purposed for testing reusability and stability of calcium oxide-based catalyst (K<sub>2</sub>O/CaO-ZnO) over transesterification reaction of soybean oil with methanol to produce biodiesel. The K<sub>2</sub>O/CaO-ZnO catalyst was synthesized by co-precipitation method of calcium and zinc nitrates followed by impregnation of potassium nitrate. The fresh and used catalysts were tested after regeneration. The catalysts were characterized by Scanning Electron Microscopy (SEM), X-ray Diffraction (XRD), and BET Surface Area in order to compare the catal

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7

Suprapto, Suprapto, Tikha Reskiani Fauziah, Meiske S. Sangi, Titie Prapti Oetami, Imroatul Qoniah, and Didik Prasetyoko. "Calcium Oxide from Limestone as Solid Base Catalyst in Transesterification of Reutealis trisperma Oil." Indonesian Journal of Chemistry 16, no. 2 (2018): 208. http://dx.doi.org/10.22146/ijc.21165.

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CaO catalysts were synthesized from limestone by thermal decomposition and coprecipitation methods. The CaO and MgO reference catalysts were also synthesized for comparison. The catalysts were characterized by X-ray diffractometer (XRD) and the analysis result was refined by Rietica software. CaO catalyst obtained by coprecipitation method has higher purity of CaO and lower MgO content than those of calcined CaO. The catalysts were also characterized by Fourier Transform Infrared (FTIR) spectroscopy. FTIR spectra showed that the catalysts can be easily hydrated and carbonated in air. The catal

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8

Resitoglu, Ibrahim Aslan, Ali Keskin, Bugra Karaman, and Himmet Ozarslan. "Suppressing Calcium Deactivation in Selective Catalytic Reduction of NOx from Diesel Engines Using Antimony." Processes 13, no. 6 (2025): 1914. https://doi.org/10.3390/pr13061914.

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The selective catalytic reduction (SCR) of NOx emissions by hydrocarbons (HCs) using a silver (Ag)-based catalyst offers significant advantages over conventional SCR systems that rely on ammonia reductants and vanadium-based catalysts. However, the conversion rate of SCR is influenced by several factors, among which catalyst poisoning is a major concern. Toxic metals such as sodium (Na), potassium (K), magnesium (Mg), and calcium (Ca) can degrade catalyst activity and lead to deactivation. Poisoned catalysts suffer from reduced conversion rates and premature deactivation before reaching their

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9

Wang, Jian, and Yi Fan Zhang. "The Study of Divalent Metal Ion Catalysts on Phenol-Formaldehyde Resol Resins." Applied Mechanics and Materials 71-78 (July 2011): 818–21. http://dx.doi.org/10.4028/www.scientific.net/amm.71-78.818.

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The curing characteristic of phenol-formaldehyde resol resins catalyzed with magnesium hydroxide, calcium hydroxide and barium hydroxide was studied in this study.The effects of catalysts on chemical structure of phenol formaldehyde resin was investigated by fourier transform infrared.The results indicated that divalent metal ions catalysts played an important role influence both the cure rate and cure time.Phenol formaldehyde resin catalysed by diffierent catalysts showed diffierent addition of formaldehyde onto ortho positions of phenolic rings.The order of the divalent metal ions effectiven

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10

Garbarino, Gabriella, Federico Pugliese, Tullio Cavattoni, Guido Busca, and Paola Costamagna. "A Study on CO2 Methanation and Steam Methane Reforming over Commercial Ni/Calcium Aluminate Catalysts." Energies 13, no. 11 (2020): 2792. http://dx.doi.org/10.3390/en13112792.

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Three Ni-based natural gas steam reforming catalysts, i.e., commercial JM25-4Q and JM57-4Q, and a laboratory-made catalyst (26% Ni on a 5% SiO2–95% Al2O3), are tested in a laboratory reactor, under carbon dioxide methanation and methane steam reforming operating conditions. The laboratory catalyst is more active in both CO2 methanation (equilibrium is reached at 623 K with 100% selectivity) and methane steam reforming (92% hydrogen yield at 890 K) than the two commercial catalysts, likely due to its higher nickel loading. In any case, commercial steam reforming catalysts also show interesting

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11

di, Bitonto L., H.E. Reynel-Ávila;, D.I. Mendoza-Castillo, A. Bonilla-Petriciolet, C.J. Durán-Valle, and C. Pastore. "Synthesis, characterization and applications of carbon-based calcium catalysts deriving from avocado seeds for biodiesel production from waste cooking oil." Bulgarian Chemical Communications 51, Special Issue B (2019): 85–88. https://doi.org/10.34049/bcc.51.B.002.

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In this work, avocado seeds were successfully used as precursors to produce carbon-based calcium catalysts for biodiesel production. The catalysts were synthetized via precipitation method, by loading different amounts of calcium nitrate on carbonized supports obtained by pyrolysis under nitrogen flow of dried biomass. The effect of Ca loaded on the structure and the activity of the catalysts for biodiesel synthesis from sunflower oil with methanol was investigated. Results showed that supported catalyst loaded with 20%wt of Ca, efficiently promote the trans-esterification process (FAMEs conte

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12

Duban, García, Bustamante Felipe, Luz Villa Aída, and Alarcón Edwin. "Esterification of rosin with methyl alcohol for fuel applications." Revista Facultad de Ingeniería, Universidad de Antioquia, no. 100 (December 9, 2020): 10–20. https://doi.org/10.17533/udea.redin.20201214.

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Oleoresin is obtained via tapping of pine trees and as a by-product of Kraft process in the pulp industry. Because of its low production cost, it is an attractive source for biofuels. Oleoresin is composed mainly of rosin (around 80%, a solid mixture of isomeric abietic acids), and it cannot be used directly as fuel in engines. However, the methyl ester of rosin has lower boiling and melting points than rosin, and it is highly soluble in hydrocarbons. Esterification of rosin with methyl alcohol was evaluated over acid and basic heterogeneous catalysts in the presence of several solvents. In co

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13

Lee, Sungho, Jeyoung Ha, and Oi Lun Li. "Plasma Modification of Biomass-Based Starfish Catalysts for Efficient Biodiesel Synthesis." Nanomaterials 14, no. 15 (2024): 1313. http://dx.doi.org/10.3390/nano14151313.

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This study investigated biodiesel production via the transesterification of grapeseed oil with plasma-modified biomass-based catalysts originating from starfish. Dried starfish was first converted into magnesium and calcium oxide through heat treatment and then further modified by plasma engineering to improve the catalyst’s surface area and active sites via zinc addition. The Zn content was added via plasma engineering in the ratios of starfish (Mg0.1Ca0.9CO3): ZnO varying from 5:1, 10:1, to 20:1. The structure and morphology of the catalyst were confirmed through XRD, SEM, and XPS analysis.

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14

Balloi, Valentina, Manuel Antonio Diaz-Perez, Mayra Anabel Lara-Angulo, et al. "Metal–Organic Frameworks as Formose Reaction Catalysts with Enhanced Selectivity." Molecules 28, no. 16 (2023): 6095. http://dx.doi.org/10.3390/molecules28166095.

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The formose reaction is an autocatalytic series of aldol condensations that allows one to obtain monosaccharides from formaldehyde. The formose reaction suffers from a lack of selectivity, which hinders practical applications at the industrial level. Over the years, many attempts have been made to overcome this selectivity issue, with modest results. Heterogeneous porous catalysts with acid–base properties, such as Metal–Organic Frameworks (MOFs), can offer advantages compared to homogeneous strong bases (e.g., calcium hydroxide) for increasing the selectivity of this important reaction. For t

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15

Brutovský, Milan, Daniela Kladeková, Katarína Reiffová, and Adam Košturiak. "Vanadium-Phosphorus Catalysts Modified with Magnesium, Calcium and Barium." Collection of Czechoslovak Chemical Communications 62, no. 3 (1997): 392–96. http://dx.doi.org/10.1135/cccc19970392.

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Vanadium-phosphorus catalysts specially modified with promotors can ensure an efficient and selective oxidation of C4 hydrocarbons, even also that of butane to maleic anhydride. The catalysts with incorporated Mg, Ca or Ba ions provide a higher conversion of butane, yield of maleic anhydride, and selectivity for the latter compound than the unmodified catalyst. The conversion of butane and yield of maleic anhydride decrease with increasing basicity of the incorporated modifiers in the order: Mg, Ca, Ba, however, the selectivity of formation of maleic anhydride increases in the opposite order,

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16

Fayzullayev, N., K. Akmalaiuly, and A. Karjavov. "CATALYTIC SYNTHESIS OF A LINE BY ACETYLENE HYDRATION." SERIES CHEMISTRY AND TECHNOLOGY 2, no. 440 (2020): 23–30. http://dx.doi.org/10.32014/2020.2518-1491.19.

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Acetone is a valuable chemical product. It can be obtained by oxidative dehydrogenation of isopropyl alcohol, oxidation of propylene, decomposition of acetic acid and ethyl alcohol, oxidation of cymene and others. Among the known processes for the production of acetone, the most promising is the synthesis by hydration of acetylene in the presence of catalysts. The advantage of this method is the possibility of carrying out the process in existing plants for the production of acetic aldehyde. On the other hand, the process of simultaneously producing acetaldehyde and acetone under the influence

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17

Kesic, Zeljka, Ivana Lukic, Miodrag Zdujic, Ljiljana Mojovic, and Dejan Skala. "Calcium oxide based catalysts for biodiesel production: A review." Chemical Industry and Chemical Engineering Quarterly 22, no. 4 (2016): 391–408. http://dx.doi.org/10.2298/ciceq160203010k.

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Vegetable oils are mainly esters of fatty acids and glycerol, which can be converted to fatty acid methyl esters (FAME), also known as biodiesel, by the transesterification reaction with methanol. In order to attain environmental benignity, a large attention has been focused in the last decades on utilizing heterogeneous catalysts for biodiesel production instead the homogenously catalyzed transesterification of vegetable oil. The pure CaO or CaO mixed with some other metal oxide due to its low solubility in methanol, FAME and glycerol, low cost and availability is one of the most promising am

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18

Huang, Da Ming, Wei Wei Jiang, Lin Lin, et al. "Study on the Catalyst Performance on Cornus wisoniana Oil Catalytic Cracking Prepared Biological Fuel Oil." Applied Mechanics and Materials 477-478 (December 2013): 1457–63. http://dx.doi.org/10.4028/www.scientific.net/amm.477-478.1457.

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In our Research, we Used Cornus Wisoniana oil as Feedstock and the High Temperature Pyrolysis Kettle as the Reactor. Examine the Performance of Lanthanum Oxide, Zirconium Sulfate, Calcium Oxide and KF Loaded Catalyst on Cornus Wisoniana oil Catalytic Cracking Reaction. and through the SEM, XRD and FT-IR, Optimal Catalysts were Used to Characterize the Structure. the Results Showed that among KF Modified Catalyst KF Supported on Cao Produced Highest Yield of Bio-Fuel Oil from Cornus Wisoniana oil. when the Dosage of Catalyst Reached 1%, KF Impregnation Ratio of 40%, and Catalyst Calcination for

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19

Buasri, Achanai, Teera Sriboonraung, Kittika Ruangnam, Pattarapon Imsombati, and Vorrada Loryuenyong. "Utilization of Waste Enamel Venus Shell as Friendly Environmental Catalyst for Synthesis of Biodiesel." Key Engineering Materials 659 (August 2015): 237–41. http://dx.doi.org/10.4028/www.scientific.net/kem.659.237.

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Calcium oxide (CaO) is one of the most promising heterogeneous alkali catalysts since it is cheap, abundantly available in nature, and some of the sources of this compound are renewable (waste material consisting of calcium carbonate (CaCO3)). In this study, the waste enamel venus shell was used as the raw material for CaO catalyst. The calcination of bio-waste was conducted at 900 °C for 2 h. The raw material and the resulting CaO catalyst were characterized using X-ray diffraction (XRD), X-ray fluorescence (XRF), scanning electron microscopy (SEM) and the Brunauer-Emmett-Teller (BET) method.

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20

Bakhtadze, V., V. Mosidze, D. Lochoshvili, and M. Fajishvili. "ACTIVITY OF Al.Ca / MnOx.CoOy.Pd MANGANESE-COBALT-PALLADIUM CATALYST IN CO OXIDATION REACTION." Slovak international scientific journal, no. 89 (November 15, 2024): 8–10. https://doi.org/10.5281/zenodo.14167009.

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The activity of manganese-palladium, cobalt-palladium and manganese-cobalt-palladium catalysts supported on a modified alumina-calcium carrier was studied in the reaction of CO oxidation. It was shown that the mixed Mn.Co.Pd catalyst is more active than Mn. Pd and Co. Pd samples

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21

Al-asadi, Mohammed, and Norbert Miskolczi. "High Temperature Pyrolysis of Municipal Plastic Waste Using Me/Ni/ZSM-5 Catalysts: The Effect of Metal/Nickel Ratio." Energies 13, no. 5 (2020): 1284. http://dx.doi.org/10.3390/en13051284.

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This work is dedicated to the high temperature pyrolysis of municipal plastic waste using Me/Ni/ZSM-5 catalysts. Catalysts were synthetized by wet impregnation. In addition to nickel, synthetic zeolite catalysts contain calcium, ceria, lanthanum, magnesia or manganese. Catalysts were prepared and tested using 0.1, 0.5 and 2.0 Me/Ni ratios. Catalyst morphology was investigated by SEM and surface analysis. Higher concentrations of second metals can block catalyst pore channels due to the more coke formation, which leads to smaller surface area. Furthermore, the chemicals used for the impregnatio

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22

Wang, Bo, Xueyong Ding, Xiaofei Zhang, Tianhua Ju, and Shigang Li. "Effect of catalyst on tail gas during reduction of vanadium-titanium magnetite carbon-containing pellet." E3S Web of Conferences 267 (2021): 02046. http://dx.doi.org/10.1051/e3sconf/202126702046.

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Catalyst can enhance the reduction effect and promote the reduction of vanadium titanomagnetite. In this paper, the carbon-containing pellets of vanadium titanomagnetite were prepared by using highly volatile coal as the reducing agent under the background of a novel process of pre-reduction in the rotary kiln. The effects of CaO, CaCO3, B2O3 and borax (Na2B4O7·10H2O) on the tail gas characteristics of carbon-containing pellets in the prereduction process were studied by using a simulated rotary kiln and flue gas analyzer. The results showed that the enhanced reduction effect of boron catalyst

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23

Koesnarpadi, Soerja, Teguh Wirawan, Mukhamad Nurhadi, et al. "Oxidation of Styrene to Benzaldehyde Using Environmentally Friendly Calcium Sulfate Hemihydrate-Supported Titania Catalysts." Bulletin of Chemical Reaction Engineering & Catalysis 19, no. 4 (2024): 622–34. http://dx.doi.org/10.9767/bcrec.20224.

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This paper presents the synthesis and characterization of calcium sulfate hemihydrate (CSH)-supported titania (TiO2) catalysts and their application in the environmentally friendly oxidation of styrene to benzaldehyde using hydrogen peroxide (H2O2) as the oxidant. The study explores the catalyst's structure-activity relationship, emphasizing the importance of mesoporous materials for enhanced catalytic performance. The CSH-Titania catalysts were synthesized using fish bone-derived CSH as a support, which aligns with green chemistry principles. Characterization techniques such as Fourier Transf

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24

Syuhada, Ain, Mariam Ameen, Farooq Sher, et al. "Effect of Calcium Doping Using Aqueous Phase Reforming of Glycerol over Sonochemically Synthesized Nickel-Based Supported ZrO2 Catalyst." Catalysts 11, no. 8 (2021): 977. http://dx.doi.org/10.3390/catal11080977.

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The aqueous phase reforming (APR) of glycerol was studied using sonochemically synthesized 10%Ni-x%Ca/ZrO2 catalysts (where x = 0, 0.5, 3, and 5) for the production of value-added liquid products. The APR reaction was performed in a batch reactor under the following conditions: 20 bar, 230 °C 450 rpm, and 1 h of reaction time. The synthesized catalysts were characterized using XRD, FESEM, BET, and H2-TPR to observe the effect of Ca doping on the physio-chemical properties of the catalysts. The results revealed that, at higher Ca loading, the catalysts experienced serious particles’ agglomerati

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25

Buasri, Achanai, Nattawut Chaiyut, Vorrada Loryuenyong, Phatsakon Worawanitchaphong, and Sarinthip Trongyong. "Calcium Oxide Derived from Waste Shells of Mussel, Cockle, and Scallop as the Heterogeneous Catalyst for Biodiesel Production." Scientific World Journal 2013 (2013): 1–7. http://dx.doi.org/10.1155/2013/460923.

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The waste shell was utilized as a bioresource of calcium oxide (CaO) in catalyzing a transesterification to produce biodiesel (methyl ester). The economic and environmen-friendly catalysts were prepared by a calcination method at 700–1,000°C for 4 h. The heterogeneous catalysts were characterized by X-ray diffraction (XRD), X-ray fluorescence (XRF), scanning electron microscopy (SEM), and the Brunauer-Emmett-Teller (BET) method. The effects of reaction variables such as reaction time, reaction temperature, methanol/oil molar ratio, and catalyst loading on the yield of biodiesel were investigat

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26

Gaide, Ieva, Violeta Makareviciene, Egle Sendzikiene, and Kiril Kazancev. "Natural Rocks–Heterogeneous Catalysts for Oil Transesterification in Biodiesel Synthesis." Catalysts 11, no. 3 (2021): 384. http://dx.doi.org/10.3390/catal11030384.

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Some of the more recent methods to produce biodiesel are based on heterogeneous catalysis, which has the advantage of easy separation of catalyst from the final product. In this paper, the heterogeneous transesterification of rapeseed oil with methanol is studied. The aim of this work was to investigate the possibilities of using natural catalysts in biodiesel synthesis and to determine the optimal conditions for this process. After the evaluation of catalytic effectiveness of rocks containing calcium and magnesium carbonates, it was determined that dolomite is the most effective catalyst in h

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27

Dang, Kavisha, Navneet Kumar, Vimal Chandra Srivastava, Jinsub Park, and Mu Naushad. "Efficient Propylene Carbonate Synthesis from Urea and Propylene Glycol over Calcium Oxide–Magnesium Oxide Catalysts." Materials 16, no. 2 (2023): 735. http://dx.doi.org/10.3390/ma16020735.

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A series of calcium oxide–magnesium oxide (CaO–MgO) catalysts were prepared under the effects of different precipitating agents and using varied Mg/Ca ratios. The physiochemical characteristics of the prepared catalysts were analyzed using XRD, FE-SEM, BET, FTIR, and TG/DTA techniques. Quantification of basic active sites present on the surface of the CaO–MgO catalysts was carried out using the Hammett indicator method. The as-prepared mixed oxide samples were tested for propylene carbonate (PC) synthesis through the alcoholysis of urea with propylene glycol (PG). The effects of the catalyst c

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Diaz-Muñoz;, L.L., H.E. Reynel-Avila, Bitonto L. Di, D.I. Mendoza-Castillo, C. Pastore, and A. Bonilla-Petriciolet. "The potential use of calcium-doped flamboyant char as a heterogeneous catalyst in triglycerides transesterification." Bulgarian Chemical Communications Volume 51, Special Issue B (2019): 128–31. https://doi.org/10.34049/bcc.51.B.007.

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This study reports the synthesis of heterogeneous catalysts from flamboyant biomass and their evaluation on the transesterification reaction of safflower oil with methanol to produce biodiesel. The optimization of catalyst preparation conditions was performed. Results showed that the concentration of doping metallic specie was the main variable that affected the performance of flamboyant-based catalyst in the reactive system to obtain the biofuel where the highest formation of methyl esters was 93 %. Physicochemical characterization of the carbon-based catalysts was done with X-ray diffraction

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29

Guo, Yangyang, Xiaofei Xu, Hong Gao, Yang Zheng, Lei Luo, and Tingyu Zhu. "Ca-Poisoning Effect on V2O5-WO3/TiO2 and V2O5-WO3-CeO2/TiO2 Catalysts with Different Vanadium Loading." Catalysts 11, no. 4 (2021): 445. http://dx.doi.org/10.3390/catal11040445.

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Ca poisoning behavior is inevitable for high-calcium content flue gas, so V2O5-WO3/TiO2 (VWT) and V2O5-WO3-CeO2/TiO2 (VWCeT) catalysts with different vanadium content have been prepared and the Ca-doped catalysts are compared in this manuscript. The result shows Ce addition can both promote the NO conversion and the alkali resistance. Lower Ca addition for 0.1VWCeT catalyst promotes its oxidability and Ce modification is more suitable for low vanadium catalysts. The total acidity and the reducibility of catalysts decline after Ca doping, and the reducibility of the active species on catalysts

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30

Hindryawati, Noor, Daniel Daniel, Erwin Erwin, and Gaanty Pragas Maniam. "PREPARATION OF SPENT BLEACHING EARTH-SUPPORTED CALCIUM FROM LIMESTONE AS CATALYST IN TRANSESTERIFICATION OF WASTE FRYING OIL." Jurnal Bahan Alam Terbarukan 6, no. 1 (2017): 68–75. http://dx.doi.org/10.15294/jbat.v6i1.9860.

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An investigation was conducted on palm oil refinery waste-spent bleaching earth (POR-SBE), POR-SBE supported by calcium as catalysts for methyl esters production through transesterification process using waste frying oil. The catalysts showed longer lasting activity than the traditional alkali catalysts. The optimum conditions for the process were: Ca-POR-SBE catalyst amount 7 %; methanol to oil molar ratio 12:1; and a reaction duration is 4 h. The process was able to transesterify oil to methyl esters at 96.8 % conversion at 65 C. The catalysts were easily separated from the reaction mixture

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31

Turabjanov, Sadritdin Makhamatdinovich, Bakhytzhan Shilmirzaevich Kedelbaev, Gaffor Rakhmonberdiev, Komila Sadriddin kizi Ibragimova, and Khasan Irgashevich Kadirov. "DEVELOPMENT AND INVESTIGATION OF PROPERTIES OF MIXED CATALYSTS FOR VAPOR-PHASE HYDRATION OF ACETYLENE." Chronos 7, no. 11(73) (2022): 155–58. http://dx.doi.org/10.52013/2658-7556-73-11-44.

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In order to develop new catalysts for the synthesis of acetaldehyde by vapor-phase hydration of acetylene, new mono- and bifunctional catalysts based on cadmium, zinc, chromium, and iron compounds on supports were developed and their most important textural characteristics were studied. It was shown that zinc oxide and cadmium fluoride are bifunctional catalysts, in the presence of which acetaldehyde was synthesized with a yield of 69.0 — 70.0%. It has been established that the stability of their operation before regeneration exceeds more than 100 hours, i.e. 1.3 times more than industrial cad

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Çakırca, Emine E., Gizem N Tekin, Oğuzhan İlgen, and Ayşe N Akın. "Catalytic activity of CaO-based catalyst in transesterification of microalgae oil with methanol." Energy & Environment 30, no. 1 (2018): 176–87. http://dx.doi.org/10.1177/0958305x18787317.

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In this work, activities of modified dolomite catalysts using calcium acetate in the heterogeneously catalyzed transesterification of microalgae oil with methanol were investigated. Modified catalysts were prepared via wet impregnation method and calcined 850°C for 2 h. Reaction conditions were examined as the catalyst type, amount of catalyst, methanol/microalgae oil molar ratio, and reusability of the catalyst using the dolomite and modified dolomite catalysts. When investigated reusability of the modified dolomite catalyst in the transesterification of microalgae oil with methanol, catalyst

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33

Makepeace, Joshua W., Hazel M. A. Hunter, Thomas J. Wood, Ronald I. Smith, Claire A. Murray, and William I. F. David. "Ammonia decomposition catalysis using lithium–calcium imide." Faraday Discussions 188 (2016): 525–44. http://dx.doi.org/10.1039/c5fd00179j.

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Lithium–calcium imide is explored as a catalyst for the decomposition of ammonia. It shows the highest ammonia decomposition activity yet reported for a pure light metal amide or imide, comparable to lithium imide–amide at high temperature, with superior conversion observed at lower temperatures. Importantly, the post-reaction mass recovery of lithium–calcium imide is almost complete, indicating that it may be easier to contain than the other amide–imide catalysts reported to date. The basis of this improved recovery is that the catalyst is, at least partially, solid across the temperature ran

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34

REDDY, E. LINGA, A. PRABHAKARN, J. KARUPPIAH, N. RAMESHBABU, and CH SUBRAHMANYAM. "GOLD SUPPORTED CALCIUM DEFICIENT HYDROXYAPATITE FOR ROOM TEMPERATURE CO OXIDATION." International Journal of Nanoscience 11, no. 03 (2012): 1240004. http://dx.doi.org/10.1142/s0219581x12400042.

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Gold supported hydroxyapatite (HA) and calcium deficient hydroxyapatite (CDHA) was studied for the room temperature CO oxidation. Nanostructured gold catalyst has been prepared by deposition precipitation method, whereas HA was synthesized by microwave synthesis. Inorder to understand the influence of surface properties of HA, support HA was synthesized with different Ca/P ratios (1.67, 1.62, 1.57, 1.534 and 1.5). The gold supported catalysts were characterized by XRD, BET, ICP-OES and TEM. Typical results indicate that gold supported 1.57 HA shows higher activity compared to other HA catalyst

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35

Zheng, Yifan, Lin Gu, Yining Li, Jamal Ftouni, and Abhishek Dutta Chowdhury. "Revisiting the Semi-Hydrogenation of Phenylacetylene to Styrene over Palladium-Lead Alloyed Catalysts on Precipitated Calcium Carbonate Supports." Catalysts 13, no. 1 (2022): 50. http://dx.doi.org/10.3390/catal13010050.

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The quest for improved heterogeneous catalysts often leads to sophisticated solutions, which are expensive and tricky to scale up industrially. Herein, the effort to upgrade the existing inorganic nonmetallic materials has seldom been prioritized by the catalysis community, which could deliver cost-effective solutions to upgrade the industrial catalysts catalog. With this philosophy in mind, we demonstrate in this work that alloyed palladium-lead (Pd-Pb) deposited on novel precipitated calcium carbonate (PCC) supports could be considered an upgraded version of the industrial Lindlar catalyst f

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36

Begouin, Jeanne-Marie, and Meike Niggemann. "Calcium-Based Lewis Acid Catalysts." Chemistry - A European Journal 19, no. 25 (2013): 8030–41. http://dx.doi.org/10.1002/chem.201203496.

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37

Andiena, Resty Zama, Karna Wijaya, and Akhmad Syoufian. "Nanocatalysts of Sulfated Zirconia and Calcium Oxide/Zirconia for Microwave-Assisted Biodiesel Synthesis from Castor Oil." Materials Science Forum 1067 (August 10, 2022): 167–76. http://dx.doi.org/10.4028/p-4320g2.

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Nanocatalysts of sulfated zirconia (SZ) and CaO/zirconia for microwave assisted-biodiesel synthesis from castor oil have been successfully prepared. The aim of the research was to determine the effectiveness and the selectivity of catalysts in biodiesel production. The sulfated zirconia catalyst was prepared by the wet impregnation method while the calcium oxide/zirconia catalyst was prepared through the wet impregnation by microwave-assisted method. The catalysts were used for the esterification and transesterification reaction with the highest acidity and the basicity value of 7.16 mmol NH3

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38

Li, Suan, Zhenguang Sun, Qi Liu, Hang Ye, and Kunpeng Wang. "Self-catalysed hydrogenation of heavy oil and coal mixtures." Polish Journal of Chemical Technology 25, no. 2 (2023): 8–14. http://dx.doi.org/10.2478/pjct-2023-0011.

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Abstract Coal liquefaction and heavy oil processing have become the urgent need for national energy strategic technology reserves in China. However, the inactivation of solid catalysts in these processes is an inevitable problem. Therefore, a self-catalysed method was proposed. The properties of raw oil could be changed by adding a modifier, as it has the function of self-catalysis, and the additional catalyst is no longer needed. The effect of 200 ppm modifier on the hydrogenation of heavy oil and 500 ppm on the hydrogenation of coal and oil were investigated. The results showed that modifier

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39

Zotov, Yu L., D. M. Zapravdina, E. V. Shishkin, and Yu V. Popov. "Study of calcium-containing compounds as catalysts for the esterification of glycerol with higher carboxylic acids." Fine Chemical Technologies 18, no. 3 (2023): 175–86. http://dx.doi.org/10.32362/2410-6593-2023-18-3-175-186.

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Objectives. To investigate the catalytic activity of calcium-containing basic catalysts for the esterification of glycerol with higher carboxylic acids in order to develop a low-waste technology for the production of multifunctional additives, as well as to assess the possibility of using the reaction products for the processing of polyvinyl chloride.Methods. The consumption of oleic acid during synthesis was monitored using a titrimetric method of analysis with visual indication. The structure of the synthesized calcium-containing catalysts was confirmed by infrared spectroscopy; elemental an

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40

Ogunkunle, Oyetola, and Opeyeolu Timothy Laseinde. "Development of heterogeneous catalyst from assorted periwinkle snail shells for sustainable biodiesel synthesis." E3S Web of Conferences 430 (2023): 01230. http://dx.doi.org/10.1051/e3sconf/202343001230.

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Owing to the environmental friendliness of biodiesel compared to fossil fuels, its application in internal combustion engines has gained wide recognition. The biodiesel industry requires effective heterogeneous catalysts developed from agricultural biomass/residues due to their overall cost-effectiveness, recoverability, and reusability. Scientific reports on developing active heterogeneous catalysts from periwinkle snail shells for application in transesterification reactions are limited, as there is no evidence of stability test results for the catalyst’s structural and elemental composition

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41

Weissenberger, Tobias, Ralf Zapf, Helmut Pennemann, and Gunther Kolb. "Catalyst Coatings for Ammonia Decomposition in Microchannels at High Temperature and Elevated Pressure for Use in Decentralized and Mobile Hydrogen Generation." Catalysts 14, no. 2 (2024): 104. http://dx.doi.org/10.3390/catal14020104.

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We report an investigation of catalyst performance for the decomposition of ammonia under industrially relevant conditions (high temperatures of up to 800 °C and an elevated pressure of 5 bar) with further emphasis on their stability at high reaction temperatures. The catalysts were applied and tested as coatings in 500 µm wide channels of microreactors. Nickel-based catalysts were studied and compared to a ruthenium-based catalyst supported on SiO2. The effect of the support on the catalytic performance was investigated, and CeO2-supported nickel catalysts were found to exhibit the highest ac

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42

Sing Chong, Ngee, Francis Uchenna Okejiri, Saidi Abdulramoni, Shruthi Perna, and Beng Guat Ooi. "Evaluation of Shell-Derived Calcium Oxide Catalysts for the Production of Biodiesel Esters from Cooking Oils." Academic Journal of Chemistry, no. 61 (March 29, 2021): 20–27. http://dx.doi.org/10.32861/ajc.61.20.27.

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Due to the high cost of feedstock and catalyst in biodiesel production, the viability of the biodiesel industry has been dependent on government subsidies or tax incentives. In order to reduce the cost of production, food wastes including eggshells and oyster shells have been used to prepare calcium oxide (CaO) catalysts for the transesterification reaction of biodiesel synthesis. The shells were calcined at 1000 °C for 4 hours to obtain CaO powders which were investigated as catalysts for the transesterification of waste cooking oil. The catalysts were characterized by Fourier Transform infra

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43

Antunes, Isabel, Luís C. M. Ruivo, Luís A. C. Tarelho, and Jorge R. Frade. "Ca2Fe2O5-Based WGS Catalysts to Enhance the H2 Yield of Producer Gases." Catalysts 14, no. 1 (2023): 12. http://dx.doi.org/10.3390/catal14010012.

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Ca2Fe2O5-based catalysts were synthesized from siderite and calcite precursors, which were processed in the form of pelletized samples and tested as water gas shift catalysts. Catalytic tests were performed in a tubular reactor, at temperatures in the range 400–500 °C and with different H2O:CO ratios, diluted with N2; this demonstrates the positive impact of Ca2Fe2O5 on conversion of CO and H2 yield, relative to corresponding tests without catalyst. The catalytic performance was also remarkably boosted in a microwave-heated reactor, relative to conventional electric heating. Post-mortem analys

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44

Ali, Nur Afiqah, and Nozieana Khairuddin. "Biodiesel Production from Waste Cooking Oil using Heterogeneous CaO/Zn Catalyst: Yield and Reusability Performance." Chiang Mai Journal of Science 50, no. 6 (2023): 1–15. http://dx.doi.org/10.12982/cmjs.2023.070.

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Biodiesel is a r enewable, biodegradable, and non-toxic fuel derived from vegetable oils, animal fats, or recycled cooking oils. Biodiesel can be used as a direct replacement for diesel in diesel engines with minimal or no modification, and it has several advantages over conventional diesel. Eggshells, on the other hand, are composed mainly of calcium carbonate (CaCO3), a valuable resource for various industrial and agricultural applications. Improper disposal of eggshells can cause environmental pollution and discarding of eggshells in landfills takes up valuable space and emits potent greenh

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45

Dobosz, Justyna, Sylwia Hull, and Mirosław Zawadzki. "Catalytic activity of cobalt and cerium catalysts supported on calcium hydroxyapatite in ethanol steam reforming." Polish Journal of Chemical Technology 18, no. 3 (2016): 59–67. http://dx.doi.org/10.1515/pjct-2016-0049.

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Abstract In this paper, Co,Ce/Ca10(PO4)6(OH)2 catalysts with various cobalt loadings for steam reforming of ethanol (SRE) were prepared by microwave-assisted hydrothermal and sol-gel methods, and characterized by XRD, TEM, TPR-H2, N2 adsorption-desorption measurements and cyclohexanol (CHOL) decomposition tests. High ethanol conversion (close to 100%) was obtained for the catalysts prepared by both methods but these ones prepared under hydrothermal conditions (HAp-H) ensured higher hydrogen yield (3.49 mol H2/mol C2H5OH) as well as higher amount of hydrogen formed (up to 70%) under reaction co

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46

Kingkam, Wilasinee, Jirapa Maisomboon, Khemmanich Khamenkit, et al. "Preparation of CaO@CeO2 Solid Base Catalysts Used for Biodiesel Production." Catalysts 14, no. 4 (2024): 240. http://dx.doi.org/10.3390/catal14040240.

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The study investigated the use of CeO2 extracted from monazite with calcium oxide (CaO) as a solid catalyst for biodiesel production. The wet impregnation method was used to produce CaO@CeO2 mixed-oxide catalysts with 0–50 wt.% CaO. X-ray diffraction (XRD), Brunauer–Emmett–Teller (BET) surface area analysis, thermogravimetric analysis (TGA), and a Fourier transform infrared spectrometer (FTIR) was used to characterize the catalysts. In order to determine the optimal preparation conditions, the effect of different CaO compositions on the performance of CaO@CeO2 mixed-oxide catalysts was examine

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47

Alam, W. S., F. Abraar, V. Pramananda, and Z. Masyithah. "Synthesis of microalgae-based methyl ester using calcium glyceroxide catalyst derived from duck eggshells and crude glycerol in the n-hexane co-solvent system." IOP Conference Series: Earth and Environmental Science 1356, no. 1 (2024): 012114. http://dx.doi.org/10.1088/1755-1315/1356/1/012114.

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Abstract The synthesis of microalgae-based methyl ester has attracted the interest of researchers since microalgae have a high lipid content and can proliferate. Chlorella vulgaris, with its 63% lipid content on a dry basis, holds promise for methyl ester production. Heterogeneous catalysts, particularly calcium glyceroxide (Ca[O(OH)2C3H5]), play a crucial role in ester manufacturing due to their high catalytic activity. The synthesis of the calcium glyceroxide catalyst involves duck eggshells as a calcium source and crude glycerol. Optimal methyl ester production is achieved by employing n-he

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48

Chukwuemeke U, Wisdom, Ruth Oghenerukevwe Eyankware U, and Michael Chika Egwunyenga. "INVESTIGATION OF THE POTENTIAL OF WASTE BONES AS A CATALYST IN BIOFUEL PRODUCTION." Journal of Wastes and Biomass Management 5, no. 1 (2023): 15–21. http://dx.doi.org/10.26480/jwbm.01.2023.15.21.

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It has recently come to light that inappropriate waste management (particularly of animal bones) is a major contributor to environmental degradation on a global scale. Instead, it would be extremely beneficial to the economy if the bioeconomy civilization could find novel applications for these discards. Biodiesel’s output can be put to good use as a heterogeneous catalyst in the effective recycling of animal bone. Ca-based catalysts produced from discarded bones, have been extensively studied in the transesterification reaction due to their high catalytic activity and abundant feedstock. Calc

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Harder, Sjoerd. "From Limestone to Catalysis: Application of Calcium Compounds as Homogeneous Catalysts." Chemical Reviews 110, no. 7 (2010): 3852–76. http://dx.doi.org/10.1021/cr9003659.

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Buasri, Achanai, Tidarat Rattanapan, Chalida Boonrin, Chosita Wechayan, and Vorrada Loryuenyong. "Oyster andPyramidellaShells as Heterogeneous Catalysts for the Microwave-Assisted Biodiesel Production fromJatropha curcasOil." Journal of Chemistry 2015 (2015): 1–7. http://dx.doi.org/10.1155/2015/578625.

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Microwave-assisted biodiesel production via transesterification ofJatropha curcasoil with methanol using solid oxide catalyst derived from waste shells of oyster andPyramidellawas studied. The shells were calcined at 900°C for 2 h and calcium oxide (CaO) catalyst characterizations were carried out by X-ray diffraction (XRD), X-ray fluorescence (XRF), scanning electron microscope (SEM), and the Brunauer-Emmett-Teller (BET) surface area measurements. The effects of reaction variables such as reaction time, microwave power, methanol/oil molar ratio, and catalyst loading on the yield of biodiesel

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