scholarly journals Probing the Catalytic Efficiency of Supported Heteropoly Acids for Esterification: Effect of Weak Catalyst Support Interactions

2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Ali Alsalme ◽  
Aliyah A. Alsharif ◽  
Hamda Al-Enizi ◽  
Mujeeb Khan ◽  
Saad G. Alshammari ◽  
...  
Keyword(s):  
Acetic Acid ◽  
Active Sites ◽  
Catalyst Support ◽  
Supported Catalyst ◽  
Catalytic Efficiency ◽  
Biodiesel Production ◽  
Effect Of Temperature ◽  
Heteropoly Acids ◽  
Catalyst Loading ◽  
Esterification Activity

Supported heteropoly acids are an interesting class of solid acid catalysts which possess flexible structure and super acidic properties essentially required for the oil-based biodiesel production. In this study, a series of catalysts containing 25 wt.% of heteropolytungstate (HPW) supported on various clays or SiO2 were prepared, and their catalytic efficiency was evaluated for esterification of acetic acid with heptanol. The as-prepared catalysts were characterized by various techniques including FT-IR spectroscopy, thermogravimetric analysis, X-ray diffraction, scanning electron microscopy, and BET. The catalytic efficiency of both bulk and supported HPW catalysts for the esterification activity strongly depends on the type of support and amount of catalyst; the bulk HPW catalyst and the catalyst supported by kaolinite with 25 wt.% of HPW exhibited highest activity. In order to study the effect of temperature on conversion, all the catalysts were subjected to different reaction temperatures. It was revealed that esterification activity of both bulk and supported HPW catalysts strongly depends upon the temperature variations of the reaction. Besides, the effect of leaching of active sites on the catalysts performance for biodiesel production was also evaluated by inductively coupled plasma studies (ICP). The kaolinite-supported catalyst (25% HPW/kaolinite) demonstrated higher amount of leaching which is also confirmed by the significant decrease in its catalytic activity when it is used for the second time. However, the higher activity demonstrated by HPW/kaolinite maybe because of some homogeneous reaction indicating a weak catalyst support interaction (WCSI) resulting in the leaching of the catalyst during the test. Furthermore, the effects of other reaction variables such as catalyst loading and reaction time on the conversion of acetic acid were also studied.

Biodiesel Production Using Mixed Solid Catalysts

2013 ◽  
Vol 824 ◽  
pp. 451-458
Author(s):  
A.K. Temu
Keyword(s):  
Active Sites ◽  
Heterogeneous Catalysts ◽  
Biodiesel Production ◽  
Environmentally Benign ◽  
Catalyst Loading ◽  
Yield Data ◽  
Continuous Processes ◽  
Solid Catalysts ◽  
Base Catalysts ◽  
Astm D6751

One of the disadvantages of homogeneous base catalysts in biodiesel production is that they cannot be reused or regenerated because they are consumed in the reaction. Besides, homogeneous catalysed process is not environmentally friendly because a lot of waste water is produced in the separation step. Unlike homogeneous, heterogeneous catalysts are environmentally benign, can be reused and regenerated, and could be operated in continuous processes, thus providing a promising option for biodiesel production. This paper presents catalytic activity of single and mixed solid catalysts in production of biodiesel from palm oil using methanol as well as ethanol at atmospheric pressure. The catalysts used are CaO, K2CO3, Al2O3, and CaO/K2CO3, CaO/Al2O3, K2CO3/Al2O3 mixtures. Results show that methanol is a better reactant with biodiesel yield ranging from 48 to 96.5% while ethanol gives yields ranging from 20 to 95.2%. The yield data for single catalysts range from 20 to 89.2% while that for mixed catalysts range from 52 to 96.5% indicating improvement in the activity by mixing the catalysts. The study also shows that biodiesel yield increases with catalyst loading which emphasizes the need for sufficient number of active sites. The properties of biodiesel produced compares well with ASTM D6751 and EN 14124 biodiesel standards.

scholarly journals Significance of the structural properties of CaO catalyst in the production of biodiesel: An effect on the reduction of greenhouse gases emission

2014 ◽  
Vol 68 (4) ◽  
pp. 399-412 ◽  
Author(s):  
Radomir Ljupkovic ◽  
Radoslav Micic ◽  
Milan Tomic ◽  
Niko Radulovic ◽  
Aleksandar Bojic ◽  
...  
Keyword(s):  
Greenhouse Gases ◽  
Structural Properties ◽  
Active Sites ◽  
Biodiesel Production ◽  
Catalyst Loading ◽  
Biodiesel Fuel ◽  
Atmospheric Conditions ◽  
Complete Replacement ◽  
Short Contact Time ◽  
Surface Basicity

The influence of the physicochemical properties of a series of CaO catalysts activated at different temperatures on the biodiesel production was investigated. These catalysts show dissimilar yields in the transesterification of triglycerides with methanol. We have found significant relationships between structural properties (the type of the pore system, the typical CaO crystal phase and the sizes of crystallites (up to 25 nm), the minimal weight percentage of CaO phase, the total surface basicity and potential existence of two types of basic active sites) of CaO prepared and activated by means of thermal treatment at highest temperature and catalytic efficiency. Benefits of this catalyst are short contact time, standard operating temperature and atmospheric conditions, relatively low molar ratios and small catalyst loading. These all together resulted in a very high biodiesel yield of high purity. The properties of different biodiesel (obtained with the use of the prepared CaO catalyst) blends with different diesel and biodiesel ratios indicate that the higher the fraction of biodiesel fuel the better the achieved fuel properties according to the EU standards. A significant reduction of CO2 and CO emissions and only a negligible NOx increase occurred when blends with an increased biodiesel portion was used. The use of biodiesel derived blends, and the eventual complete replacement of fossil fuels with biodiesel as a renewable, alternative fuel for diesel engines, would greatly contribute to the reduction of greenhouse gases emissions.

scholarly journals Biodiesel Production from Reutealis Trisperma Oil Using KOH Impregnated Eggshell as a Heterogeneous Catalyst

Energies ◽  
2019 ◽  
Vol 12 (19) ◽  
pp. 3714
Author(s):  
Kusmiyati Kusmiyati ◽  
Didik Prasetyoko ◽  
Siwi Murwani ◽  
Muthiah Nur Fadhilah ◽  
Titie Prapti Oetami ◽  
...  
Keyword(s):  
Heterogeneous Catalyst ◽  
Active Sites ◽  
Fluorescence Analysis ◽  
Solid Particles ◽  
Biodiesel Production ◽  
Molar Ratio ◽  
Catalyst Loading ◽  
Infrared Spectrometry ◽  
Catalyst Characterization ◽  
Molar Ratios

This research paper describes the synthesis of a heterogeneous catalyst (Potassium hydroxide (KOH)-impregnated eggshell) from waste chicken eggshell using the wet impregnation technique. In this experiment, the catalyst was derived from eggshell that was calcined at 800 °C for 5 h. It was impregnated with KOH at various KOH concentrations (10%, 15%, 20%, and 25%). The best catalyst was obtained by eggshell impregnated with 20% KOH concentration. This result was supported by the analysis of the catalyst characterization using Fourier-transform infrared spectrometry (FT-IR), which showed that the catalyst contained CaCO3 and CaOH groups. X-ray fluorescence analysis (XRF) was also used to analyze the types of mineral contained in the catalyst, including calcium, potassium, sulfur, and other impurities. It revealed that the optimum minerals were found in the KOH-impregnated eggshell (20%) catalyst of 94.42% calcium, 5.06% potassium, and a small amount of other impurities. These optimum minerals serve as active sites to increase the biodiesel yield. Scanning electron microscopy (SEM) showed that the catalyst samples appear as small, spherical, homogenous, and solid particles. The catalytic activity was investigated by the transesterification of Reutalism trisperma oil in various types of catalyst (KOH-impregnated eggshell, eggshell, and KOH-impregnated CaO), percentages of catalyst loading (weight of 1%, 3%, 5%, 7%, and 10%) and molar ratios (methanol to oil of 6:1, 8:1, 10:1, 12:1, and 15:1) for 60 min at 60 °C. The result indicated the optimum catalyst loading was 5 wt% with an 84.57% biodiesel yield. While the best molar ratio was 12:1 (methanol:oil) with a 97.95% biodiesel yield. The optimum condition was gained using a molar ratio of 12:1, 5 wt% catalyst loading, and KOH-impregnated eggshell with a 94% biodiesel yield.

scholarly journals Proses produksi triasetin dari gliserol dengan katalis asam sulfat

2018 ◽  
Vol 12 (1) ◽  
pp. 192
Author(s):  
W Widayat ◽  
Hantoro Satriado ◽  
A Abdullah ◽  
Ika Windrianto K. Handono
Keyword(s):  
Acetic Acid ◽  
Sulfuric Acid ◽  
Production Process ◽  
Raw Materials ◽  
Batch Process ◽  
Biodiesel Production ◽  
Effect Of Temperature ◽  
Esterification Reaction ◽  
Glycerol Conversion ◽  
Acid Esterification

Triacetin production process from glycerol using sulfuric acid as catalyst.Glycerol can be produced from biodiesel production process with transesterification reaction. Glycerol of this reaction, not fully utilized as raw materials or as chemial products. Triacetate is a product of the esterification reaction of glycerol with acetic acid. Triacetate can be used for food and non-food. The objective of this study was to study the effect of temperature and the ratio of reactants on glycerol conversion on triacetate production process. The experiments were carried in batch process and total volume of glycerol and acetic acid 600 mL, stirring speed of 100 rpm and catalyst of sulphuric acid was 5 %-w glycerol based. The results of the qualitative analysis by means of FTIR confirmed there is Triacetate as product. Increasing of ratio molar of glycerol to acetic acid increased of glycerol conversion. The similar result obtained for temperature. The glycerol conversion was 67.6% and selectivity of triacetate 25%, where obtained using the reaction condition: mole ratio of glycerol to acetic acid 1:7, temperature 120 oC and 50 minutes.Keywords: glycerol, acetate acid, esterification, triacetin, glycerol conversion AbstrakGliserol dapat dihasilkan dari proses produksi biodiesel dari proses transesterifikasi. Gliserol dari proses ini, belum dimanfaatkan secara maksimal sebagai bahan baku maupun sebagai produk jadi. Triasetin atau gliserol triasetin merupakan produk reaksi esterifikasi gliserol dengan asam asetat. Kegunaan triasetin cukup banyak baik untuk keperluan bahan pangan maupun non pangan. Penelitian ini bertujuan untuk mempelajari pengaruh temperatur dan perbandingan reaktan terhadap konversi gliserol dalam proses produksi triasetin. Percobaan dilakukan dengan proses curah, dimana volume total gliserol dan asam asetat sebesar 600 mL, kecepatan pengadukan 100 rpm dan katalis asam sulfat adalah 5 %-b gliserol. Hasil analisis kualitatif dengan alat FTIR menunjukkan adanya produk triasetin, dimana kesesuaian dengan bahan standar triasetin cukup tinggi. Peningkatan perbandingan gliserol dengan asam asetat akan meningkatkan konversi gliserol. Demikian juga dengan peningkatan temperatur juga akan meningkatkan konversi gliserol. Hasil yang terbaik diperoleh pada perbandingan mol pereaksi gliserol dan asam asetat 1:7 temperatur 120 oC, waktu 50 menit dengan nilai konversi sebesar 67,6% dan selektivitas sebesar 25%. Kata kunci: gliserol, asam asetat, esterifikasi, triasetin, konversi gliserol

Ionic Liquids as Catalysts for the Acetylation of Camphene

2017 ◽  
Vol 743 ◽  
pp. 355-359
Author(s):  
Svetlana A. Popova ◽  
Irina Yu. Chukicheva
Keyword(s):  
Acetic Acid ◽  
Ionic Liquids ◽  
Ion Exchange Resin ◽  
Effect Of Temperature ◽  
Molar Ratio ◽  
Catalyst Loading ◽  
Esterification Reaction ◽  
The Face ◽  
Environmental Requirements ◽  
Acid Catalyzed

[bnmim]HSO4 and [bnpy]HSO4 are active and environmentally friendly catalysts for the acetylation of camphene with acetic acid. The reaction provides isobornyl acetate with 100% selectivity and 72-86% yield. The effect of temperature, molar ratio camphene/acetic acid, and catalyst loading were investigated. The catalyst can be reused four times without loss of activity. Isobornyl acetate is an important fine chemical and has been used in the field of fragrance, medicine, organic synthesis and cosmetics [1]. It is an intermediary in the synthesis of camphor [2]. Usually it is prepared by an acid-catalized reaction of camphene with acetic acid or acetic anhydride. But this process has serious drawbacks such as the corrosion of equipment, non-recyclability of the catalyst and serious environmental pollution. In the face of increasing environmental requirements, the use of such catalysts becomes unacceptable. Therefore many studies have recently focused on the development of "clean" (green) processes for the production of terpene derivatives with high selectivity. For this purpose, heteropolyacids [3, 4], zeolites [5, 6], solid acid catalysts [7, 8], ion-exchange resin [9-11] were used as catalysts for synthesizing terpene esters. However, these catalysts have drawbacks such as a large ratio of catalyst/substrate, fast deactivation and a selectivity that leaves much to be desired. In the recent years ionic liquids (IL) have been investigated by many researchers as catalysts for different reactions. Due to its low volatility, negligible vapor pressure, reasonable thermal stability, outstanding recyclability and reusability, ionic liquids may be a viable alternative to widely applicable catalysts in the processes of modern synthetic chemistry, the green chemistry [12]. The improvement of the versatility of ionic liquids was achieved by creating acidic functionalized ionic liquids and combining the properties of a reagent and solvent [13]. A number of such ionic liquids were synthesized and successfully applied in the esterification reaction [14-17]. Received that the structure of the IL cation determines the direction of the rearrangement of terpene, whereas the nature of the anion affects the selectivity of the reaction [18, 19]. In the present work, we report the acetylation of camphene with acetic acid catalyzed by imidazolium and pyridinium ionic liquids (Scheme 1). The influence of various reaction parameters, such as the temperature, the molar ratio of camphene/acetic acid and catalyst loading, on the activity of the most active catalyst is also studied.

Revisiting Glycerol Esterification with Acetic Acid over Amberlyst-35 via Statistically Designed Experiments: Overcoming Transport Limitations

2019 ◽  
Author(s):  
Víctor Gabriel Baldovino Medrano ◽  
Karen V. Caballero ◽  
Hernando Guerrero-Amaya
Keyword(s):  
Acetic Acid ◽  
Active Sites ◽  
Batch Reactor ◽  
Catalyst Particle ◽  
Experimental Designs ◽  
Particle Sizes ◽  
Turnover Rates ◽  
Designed Experiments ◽  
Different Temperatures ◽  
Glycerol Esterification

Turnover rates for glycerol esterification with acetic acid over Amberlyst-35 were measured under different temperatures, reactants and active sites concentrations, and catalyst particle sizes. Data were collected in a batch reactor. Experiments were done following a sequence of factorial experimental designs.

Efficient Production of Biodiesel Catalyzed by Acidic Nanoporous Carbon Materials：A Review

2020 ◽  
Vol 16 ◽  
Author(s):  
Anping Wang ◽  
Heng Zhang ◽  
Hu Li ◽  
Song Yang
Keyword(s):  
Pore Structure ◽  
Active Sites ◽  
Catalytic Performance ◽  
Nanoporous Carbon ◽  
Biodiesel Production ◽  
Efficient Production ◽  
Fossil Energy ◽  
Catalytic Materials ◽  
High Acid ◽  
Carbon Based

Background: With the gradual decrease of fossil energy, the development of alternatives to fossil energy has attracted more and more attention. Biodiesel is considered to be the most potent alternative to fossil energy, mainly due to its green, renewable and biodegradable advantages. The stable, efficient and reusable catalysts are undoubtedly the most critical in the preparation of biodiesel. Among them, nanoporous carbon-based acidic materials are very important biodiesel catalysts. Objective: The latest advances of acidic nanoporous carbon catalysts in biodiesel production was reviewed. Methods: Biodiesel is mainly synthesized by esterification and transesterification. Due to the important role of nanoporous carbon-based acidic materials in the catalytic preparation of biodiesel, we focused on the synthesis, physical and chemical properties, catalytic performance and reusability. Results: Acidic catalytic materials have a good catalytic performance for high acid value feedstocks. However, the preparation of biodiesel with acid catalyst requires relatively strict reaction conditions. The application of nanoporous acidic carbon-based materials, due to the support of carbon-based framework, makes the catalyst have good stability and unique pore structure, accelerates the reaction mass transfer speed and accelerates the reaction. Conclusion: Nanoporous carbon-based acidic catalysts have the advantages of suitable pore structure, high active sites, and high stability. In order to make these catalytic processes more efficient, environmentally friendly and low cost, it is an important research direction for the future biodiesel catalysts to develop new catalytic materials with high specific surface area, suitable pore size, high acid density, and excellent performance.

Catalytic Neutralization of Naphthenic Acid from Petroleum Crude Oil by Using Cerium Oxide Catalyst and 2- Methylimidazole in Polyethylene Glycol

2020 ◽  
Vol 13 ◽  
Author(s):  
Norshahidatul Akmar Mohd Shohaimi ◽  
Norfakhriah Jelani ◽  
Ahmad Zamani Ab Halim ◽  
Nor Hakimin Abdullah ◽  
Nurasmat Mohd Shukri
Keyword(s):  
Polyethylene Glycol ◽  
Crude Oil ◽  
Cerium Oxide ◽  
Active Sites ◽  
Naphthenic Acid ◽  
Naphthenic Acids ◽  
Catalyst Loading ◽  
High Concentration ◽  
Oil Refineries ◽  
Al2o3 Catalyst

: The presence of relatively high naphthenic acid in crude oil may contribute to the major corrosion in oil pipelines and distillation units in crude oil refineries. Thus, high concentration Naphthenic Acids crude oil is considered tobe of low quality and is marketed at lower prices. In order to overcome this problem, neutralization method had been developed to reduce the TAN value in crude oil. In this study, crude oil from Petronas Penapisan Melaka was investigated. The parameters studied were reagent concentration, catalyst loading, calcination temperature and reusability of the potential catalyst. Basic chemical used were 2- methylimidazole in polyethylene glycol (PEG 600) with concentration 100, 500 and 1000 ppm. Cerium oxide-based catalysts supported onto alumina prepared with different calcination temperatures. The catalyst was characterized by using Brunauer-Emmett-Teller (BET), Fourier Transform Infrared Spectroscopy (FTIR) and Thermogravimetry Analysis-Differential Thermal Gravity (TGA-DTG) to study physical properties of the catalyst. The Ce/Al2O3 catalyst calcined at 1000°C was the best catalyst due to larger surface area formation which lead to increment of active sites thus will boost the catalytic activity. The result showed that the Ce/Al2O3 catalyst meet Petronas requirement as the TAN value reduced to 0.6 mgKOH/g from original TAN value of 4.22 mgKOH/g. The best reduction of TAN was achieved by using catalyst loading of 0.39% and reagent of 1000 ppm.

scholarly journals Investigation of Gas Diffusion Electrode Systems for the Electrochemical CO2 Conversion

Catalysts ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 482
Author(s):  
Hilmar Guzmán ◽  
Federica Zammillo ◽  
Daniela Roldán ◽  
Camilla Galletti ◽  
Nunzio Russo ◽  
...  
Keyword(s):  
Carbon Capture ◽  
Active Sites ◽  
Co2 Reduction ◽  
Gas Diffusion ◽  
Gas Diffusion Electrode ◽  
Catalyst Loading ◽  
Co2 Conversion ◽  
Atmospheric Conditions ◽  
Electrochemical Co2 Reduction ◽  
Liquid Products

Electrochemical CO2 reduction is a promising carbon capture and utilisation technology. Herein, a continuous flow gas diffusion electrode (GDE)-cell configuration has been studied to convert CO2 via electrochemical reduction under atmospheric conditions. To this purpose, Cu-based electrocatalysts immobilised on a porous and conductive GDE have been tested. Many system variables have been evaluated to find the most promising conditions able to lead to increased production of CO2 reduction liquid products, specifically: applied potentials, catalyst loading, Nafion content, KHCO3 electrolyte concentration, and the presence of metal oxides, like ZnO or/and Al2O3. In particular, the CO productivity increased at the lowest Nafion content of 15%, leading to syngas with an H2/CO ratio of ~1. Meanwhile, at the highest Nafion content (45%), C2+ products formation has been increased, and the CO selectivity has been decreased by 80%. The reported results revealed that the liquid crossover through the GDE highly impacts CO2 diffusion to the catalyst active sites, thus reducing the CO2 conversion efficiency. Through mathematical modelling, it has been confirmed that the increase of the local pH, coupled to the electrode-wetting, promotes the formation of bicarbonate species that deactivate the catalysts surface, hindering the mechanisms for the C2+ liquid products generation. These results want to shine the spotlight on kinetics and transport limitations, shifting the focus from catalytic activity of materials to other involved factors.

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