Chemo-catalytic Esterification and Transesterification over Organic Polymer-Based Catalysts for Biodiesel Synthesis

2019 ◽  
Vol 23 (20) ◽  
pp. 2190-2203 ◽  
Author(s):  
Heng Zhang ◽  
Chunbao (Charles) Xu ◽  
Kaichen Zhou ◽  
Song Yang
Keyword(s):  
Active Sites ◽  
Heterogeneous Catalysts ◽  
Organic Polymer ◽  
Catalytic Systems ◽  
Solid Catalysts ◽  
Catalytic Materials ◽  
Oil Resources ◽  
Biodiesel Synthesis ◽  
Esterification Reactions ◽  
Hydrophilicity And Hydrophobicity

The major sources of fuels in today's world predominantly come from traditional fossil resources such as coal, petroleum and natural gas, which are limited and nonrenewable. Meanwhile, their consumption releases large undesirable greenhouse gas and noxious gases. Therefore, the development of renewable and sustainable feedstocks to replace traditional fossil resources has attracted great interest. Biodiesel, mainly produced through esterification and transesterification reaction from renewable oil resources using acids and bases as catalysts, is deemed as a green and renewable biofuel that shows enormous potential to replace fossil diesel. Compared to homogeneous catalytic systems, the development of efficient and stable heterogeneous catalysts is vital to synthesizing biodiesel in an efficient and green manner. Among the developed solid catalysts, organic polymer- based catalytic materials are an extremely important topic, wherein distinct advantages of higher concentration of active sites and better stability of active groups are associated with each other. In this review, effective catalytic valorization of sustainable feedstocks into biodiesel via transesterification and esterification reactions mediated by functionalized organic polymer-based catalysts is discussed. Special emphasis has been given to the synthetic routes to the versatile organic polymers-based catalytic materials, and some other interesting catalytic roles derived from physicochemical property, like adjustable hydrophilicity and hydrophobicity along with swelling property in transesterification and esterification, are also illustrated.

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 Concluding remarks: progress toward the design of solid catalysts

2016 ◽  
Vol 188 ◽  
pp. 591-602 ◽  
Author(s):  
Bruce C. Gates
Keyword(s):  
Heterogeneous Catalysts ◽  
Performance Testing ◽  
Catalyst Design ◽  
Rapid Progress ◽  
Catalyst Structure ◽  
Solid Catalysts ◽  
Catalytic Materials ◽  
Fundamental Understanding ◽  
Scientists And Engineers ◽  
And Performance

The 2016 Faraday Discussion on the topic “Designing New Heterogeneous Catalysts” brought together a group of scientists and engineers to address forefront topics in catalysis and the challenge of catalyst design—which is daunting because of the intrinsic non-uniformity of the surfaces of catalytic materials. “Catalyst design” has taken on a pragmatic meaning which implies the discovery of new and better catalysts on the basis of fundamental understanding of the catalyst structure and performance. The presentations and discussion at the meeting illustrate the rapid progress in this understanding linked with improvements in spectroscopy, microscopy, theory, and catalyst performance testing. The following text includes a statement of recurrent themes in the discussion and examples of forefront science that evidences progress toward catalyst design.

scholarly journals Reflections on the value of electron microscopy in the study of heterogeneous catalysts

2017 ◽  
Vol 473 (2197) ◽  
pp. 20160714 ◽  
Author(s):  
John Meurig Thomas
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
Active Sites ◽  
Heterogeneous Catalysts ◽  
Three Dimensions ◽  
Single Atom ◽  
Catalyst Characterization ◽  
Solid Catalysts ◽  
Valence States ◽  
Ac Transmission

Electron microscopy (EM) is arguably the single most powerful method of characterizing heterogeneous catalysts. Irrespective of whether they are bulk and multiphasic, or monophasic and monocrystalline, or nanocluster and even single-atom and on a support, their structures in atomic detail can be visualized in two or three dimensions, thanks to high-resolution instruments, with sub-Ångstrom spatial resolutions. Their topography, tomography, phase-purity, composition, as well as the bonding, and valence-states of their constituent atoms and ions and, in favourable circumstances, the short-range and long-range atomic order and dynamics of the catalytically active sites, can all be retrieved by the panoply of variants of modern EM. The latter embrace electron crystallography, rotation and precession electron diffraction, X-ray emission and high-resolution electron energy-loss spectra (EELS). Aberration-corrected (AC) transmission (TEM) and scanning transmission electron microscopy (STEM) have led to a revolution in structure determination. Environmental EM is already playing an increasing role in catalyst characterization, and new advances, involving special cells for the study of solid catalysts in contact with liquid reactants, have recently been deployed.

scholarly journals Metal-Organic Frameworks as Versatile Heterogeneous Solid Catalysts for Henry Reactions

Molecules ◽  
2021 ◽  
Vol 26 (5) ◽  
pp. 1445
Author(s):  
Francisco G. Cirujano ◽  
Rafael Luque ◽  
Amarajothi Dhakshinamoorthy
Keyword(s):  
Active Sites ◽  
Heterogeneous Catalysts ◽  
Final Section ◽  
Metal Organic Frameworks ◽  
Henry Reaction ◽  
Solid Catalysts ◽  
Wide Range ◽  
Metal Organic ◽  
Materials Used ◽  
Heterogeneous Solid

Metal–organic frameworks (MOFs) have become one of the versatile solid materials used for a wide range of applications, such as gas storage, gas separation, proton conductivity, sensors and catalysis. Among these fields, one of the more well-studied areas is the use of MOFs as heterogeneous catalysts for a broad range of organic reactions. In the present review, the employment of MOFs as solid catalysts for the Henry reaction is discussed, and the available literature data from the last decade are grouped. The review is organized with a brief introduction of the importance of Henry reactions and structural properties of MOFs that are suitable for catalysis. The second part of the review discusses the use of MOFs as solid catalysts for the Henry reaction involving metal nodes as active sites, while the third section provides data utilizing basic sites (primary amine, secondary amine, amides and urea-donating sites). While commenting on the catalytic results in these two sections, the advantage of MOFs over other solid catalysts is compared in terms of activity by providing turnover number (TON) values and the structural stability of MOFs during the course of the reaction. The final section provides our views on further directions in this field.

scholarly journals A Review on Metal-Organic Frameworks as Congenial Heterogeneous Catalysts for Potential Organic Transformations

2021 ◽  
Vol 9 ◽  
Author(s):  
Kranthi Kumar Gangu ◽  
Sreekantha B. Jonnalagadda
Keyword(s):  
Active Sites ◽  
Heterogeneous Catalysts ◽  
Metal Organic Frameworks ◽  
Value Added ◽  
Biological Molecules ◽  
Full Potential ◽  
Organic Transformations ◽  
Solid Catalysts ◽  
Metal Organic ◽  
Catalytic Active Sites

Metal-organic frameworks (MOFs) have emerged as versatile candidates of interest in heterogeneous catalysis. Recent research and developments with MOFs positively endorse their role as catalysts in generating invaluable organic compounds. To harness the full potential of MOFs in value-added organic transformation, a comprehensive look at how these materials are likely to involve in the catalytic processes is essential. Mainstays of MOFs such as metal nodes, linkers, encapsulation materials, and enveloped structures tend to produce capable catalytic active sites that offer solutions to reduce human efforts in developing new organic reactions. The main advantages of choosing MOFs as reusable catalysts are the flexible and robust skeleton, regular porosity, high pore volume, and accessible synthesis accompanied with cost-effectiveness. As hosts for active metals, sole MOFs, modified MOFs, and MOFs have made remarkable advances as solid catalysts. The extensive exploration of the MOFs possibly led to their fast adoption in fabricating new biological molecules such as pyridines, quinolines, quinazolinones, imines, and their derivatives. This review covers the varied MOFs and their catalytic properties in facilitating the selective formation of the product organic moieties and interprets MOF’s property responsible for their elegant performance.

scholarly journals Fly Ash-Based Geopolymers as Sustainable Bifunctional Heterogeneous Catalysts and Their Reactivity in Friedel-Crafts Acylation Reactions

Catalysts ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 372 ◽  
Author(s):  
Mohammad I. M. Al-Zeer ◽  
Kenneth J. D. MacKenzie
Keyword(s):  
Fly Ash ◽  
Active Sites ◽  
Heterogeneous Catalysts ◽  
Coal Fly Ash ◽  
Solid Catalysts ◽  
Redox Sites ◽  
Redox Active ◽  
Porous Architecture ◽  
Acidic Sites ◽  
Catalytic Reactivity

This study presents the synthesis, characteristics and catalytic reactivity of sustainable bifunctional heterogeneous catalysts derived from coal fly ash-based geopolymer, particularly those with a high Ca content (C-class) fly ash. The developed catalysts were synthesized at room temperature and pressure in a simple ecologically-benign procedure and their reactivity was evaluated in the Friedel-Crafts acylation of various arenes. These catalysts can be produced with multilevel porous architecture, and a combination of acidic and redox active sites allowing their use as bifunctional catalysts. The acidic sites (Lewis and Brønsted acidic sites) were generated within the catalyst framework by ion-exchange followed by thermal treatment, and redox sites that originated from the catalytically reactive fly ash components. The developed catalysts demonstrated higher reactivity than other commonly used solid catalysts such as Metal-zeolite and Metal-mesoporous silicate, heteropolyacids and zeolite imidazole frameworks (ZIF).

scholarly journals Heterogeneous Catalysts for the Conversion of Glucose into 5-Hydroxymethyl Furfural

Catalysts ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 861
Author(s):  
Christiaan H. L. Tempelman ◽  
Ryan Oozeerally ◽  
Volkan Degirmenci
Keyword(s):  
Lignocellulosic Biomass ◽  
Active Sites ◽  
Heterogeneous Catalysts ◽  
Supported Catalysts ◽  
Metal Organic Frameworks ◽  
Reaction Conditions ◽  
Catalytic Systems ◽  
Hydroxymethyl Furfural ◽  
Potential Applications ◽  
Metal Organic

Lignocellulosic biomass, a cheap and plentiful resource, could play a key role in the production of sustainable chemicals. The simple sugars contained in the renewable lignocellulosic biomass can be converted into commercially valuable products such as 5-hydroxymethyl furfural (HMF). A platform molecule, HMF can be transformed into numerous chemical products with potential applications in a wide variety of industries. Of the hexoses contained in the lignocellulosic biomass, the successful production of HMF from glucose has been a challenge. Various heterogeneous catalysts have been proposed over the last decade, ranging from zeolites to metal organic frameworks. The reaction conditions vary in the reports in the literature, which makes it difficult to compare catalysts reported in different studies. In addition, the slight variations in the synthesis of the same material in different laboratories may affect the activity results, because the selectivity towards desired products in this transformation strongly depends on the nature of the active sites. This poses another difficulty for the comparison of different reports. Furthermore, over the last decade the new catalytic systems proposed have increased profoundly. In this article, we summarize the heterogeneous catalysts: Metal Organic Frameworks (MOFs), zeolites and conventional supported catalysts, that have been reported in the recent literature and provide an overview of the observed catalytic activity, in order to provide a comparison.

scholarly journals A Review on Application of Heterogeneous Catalyst in the Production of Biodiesel from Vegetable Oils

2017 ◽  
Vol 4 (2) ◽  
pp. 142-157 ◽  
Author(s):  
A.S. Yusuff ◽  
O.D. Adeniyi ◽  
M.A. Olutoye ◽  
U.G. Akpan
Keyword(s):  
Heterogeneous Catalyst ◽  
Heterogeneous Catalysts ◽  
Biodiesel Production ◽  
Comprehensive Overview ◽  
Solid Catalysts ◽  
Heterogeneous Catalytic ◽  
Catalytic Materials ◽  
Before And After ◽  
Catalyzed Reactions

Biodiesel has been considered as one of the interesting alternative and environmentally benign fuels. The development of environmental friendly heterogeneous catalyst for the esterification/transesterification process seems to be promising route and the reason why it is more preferred to conventional homogeneous and enzymatic catalyzed reactions is discussed. However, investigation on heterogeneous catalyst for biodiesel production is extensively carried out based on previous research studies. In order to reduce cost of biodiesel production, evaluation and characterization of heterogeneous catalytic materials before and after its preparation provide facts on the process that have significant impact on the desired activity and selectivity properties. This review study provides a comprehensive overview of common process techniques usually employ in producing biodiesel. Different materials that serve as sources of heterogeneous catalysts to transesterify oils or fats for production of biodiesel with emphasis on selection criteria of solid catalytic materials are also highlighted. The potential heterogeneous catalyst that could be derived from anthill, various methods of preparing solid catalysts, as well as reusability and leaching analysis are discussed in details

scholarly journals Biodiesel production from alternative raw materials using a heterogeneous Low Ordered Biosilicified Enzyme as biocatalyst

2020 ◽  
Author(s):  
Gabriel Orlando Ferrero ◽  
Edgar Maximiliano Sánchez Faba ◽  
Griselda Alejandra Eimer
Keyword(s):  
Active Sites ◽  
Heterogeneous Catalysts ◽  
Raw Materials ◽  
Biomass Conversion ◽  
High Water ◽  
Raw Material ◽  
Biodiesel Production ◽  
Waste Frying Oil ◽  
Solid Catalysts ◽  
Pork Fat

Abstract Background: Nowadays, as an alternative to the production of fuels and chemicals from the fossil platform, renewable feedstocks are widely investigated. For biomass conversion, a new generation of catalysts with specific characteristics such as high activity and selectivity, easy recovery and reusability is necessary. The design of highly efficient and stable heterogeneous catalysts represents a challenge in this field, mainly to overcome current energy and environmental issues. The combination of enzymatic and heterogeneous inorganic catalysis generates an unprecedented platform that combines the advantages of both. Among the techniques for producing solid catalysts, enzymatic mineralization with an organic silicic precursor to obtain hybrid biocatalysts (biosilicification) is highlighted. This technique can provide exceptional stability to the biocatalyst in drastic conditions of use.Results: Then, under these criteria, this work presents the one-step synthesis of a solid enzymatic catalyst, denominated Low Ordered Biosilicified Enzyme (LOBE) due to their structural properties. Pseudomonas Fluorescens lipase forms aggregates that are contained in the heart of a silicon-covered micelle, providing active sites with the ability to process different raw materials (commercial sunflower and soybean oil, Jatropha excisa oil, waste frying oil, residual soybeans, and pork fat) to produce first and second generation biodiesel. Obtaining yields between 81 and 93% by weight depending on the used raw material.Conclusions: Therefore, refined, non-edible and residual oils (with high water and free fatty acid contents) can be transformed into biodiesel through LOBE catalysts with commercial ethanol as co-substrate.

scholarly journals Calcium oxide based catalysts for biodiesel production: A review

2016 ◽  
Vol 22 (4) ◽  
pp. 391-408 ◽  
Author(s):  
Zeljka Kesic ◽  
Ivana Lukic ◽  
Miodrag Zdujic ◽  
Ljiljana Mojovic ◽  
Dejan Skala
Keyword(s):  
Vegetable Oil ◽  
Heterogeneous Catalysts ◽  
Low Cost ◽  
Methyl Esters ◽  
Biodiesel Production ◽  
Complex Catalyst ◽  
Solid Catalysts ◽  
Base Catalysts ◽  
Biodiesel Synthesis ◽  
Mild Temperature

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 among the proposed heterogeneous catalysts. Solid catalysts which contain CaO usually fulfill a number of important requirements, such as high activity at mild temperature, marginal leaching of Ca cations, long life activity, reusability in transesterification of vegetable oil and easy recovery from the final products of transesterification (FAME and glycerol). This review is focused to the recent application of pure CaO or CaO in complex catalyst structure and their use as heterogeneous base catalysts for biodiesel synthesis and suitability for industrial application.

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