ChemInform Abstract: Deactivation of Solid Catalysts in Liquid Media: The Case of Leaching of Active Sites in Biomass Conversion Reactions

ChemInform ◽  
2015 ◽  
Vol 46 (40) ◽  
pp. no-no
Author(s):  
Irantzu Sadaba ◽  
Manuel Lopez Granados ◽  
Anders Riisager ◽  
Esben Taarning
Keyword(s):  
Active Sites ◽  
Biomass Conversion ◽  
Liquid Media ◽  
Solid Catalysts

scholarly journals Deactivation of solid catalysts in liquid media: the case of leaching of active sites in biomass conversion reactions

2015 ◽  
Vol 17 (8) ◽  
pp. 4133-4145 ◽  
Author(s):  
Irantzu Sádaba ◽  
Manuel López Granados ◽  
Anders Riisager ◽  
Esben Taarning
Keyword(s):  
Liquid Phase ◽  
Active Sites ◽  
Biomass Conversion ◽  
Liquid Media ◽  
Solid Catalysts ◽  
Specific Focus ◽  
Catalytic Processes

This review is aimed to be a brief tutorial covering the deactivation of solid catalysts in the liquid phase, with specific focus on leaching, which can be especially helpful to researchers not familiarized with catalytic processes in the liquid phase.

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.

Physicochemical and Catalytic Properties of Spinels Formed by Solid-Solid Interaction Between Fe2O3and V2O5

1996 ◽  
Vol 61 (8) ◽  
pp. 1131-1140 ◽  
Author(s):  
Abd El-Aziz Ahmed Said
Keyword(s):  
Vanadium Oxide ◽  
Active Sites ◽  
Catalyst Surface ◽  
Catalytic Properties ◽  
Flow System ◽  
Oxide Catalysts ◽  
X Ray Diffraction ◽  
Selective Catalyst ◽  
X Ray ◽  
Solid Catalysts

Vanadium oxide catalysts doped or mixed with 1-50 mole % Fe3+ ions were prepared. The structure of the original samples and those calcined from 200 up to 500 °C were characterized by TG, DTA, IR and X-ray diffraction. The SBET values and texture of the solid catalysts were investigated. The catalytic dehydration-dehydrogenation of isopropanol was carried out at 200 °C using a flow system. The results obtained showed an observable decrease in the activity of V2O5 on the addition of Fe3+ ions. Moreover, Fe2V4O13 is the more active and selective catalyst than FeVO4 spinels. The results were correlated with the active sites created on the catalyst surface.

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.

Lewis and Brönsted basic active sites on solid catalysts and their role in the synthesis of monoglycerides

2005 ◽  
Vol 234 (2) ◽  
pp. 340-347 ◽  
Author(s):  
A CORMA ◽  
S HAMID ◽  
S IBORRA ◽  
A VELTY
Keyword(s):  
Active Sites ◽  
Solid Catalysts

scholarly journals Designing effective solid catalysts for biomass conversion: aerobic oxidation of ethyl lactate to ethyl pyruvate

2018 ◽  
Vol 20 (8) ◽  
pp. 1866-1873 ◽  
Author(s):  
Wei Zhang ◽  
Bernd Ensing ◽  
Gadi Rothenberg ◽  
N. Raveendran Shiju
Keyword(s):  
Ethyl Pyruvate ◽  
Biomass Conversion ◽  
Aerobic Oxidation ◽  
Ethyl Lactate ◽  
Solid Catalyst ◽  
Solid Catalysts ◽  
Highly Efficient

A novel highly efficient solid catalyst in which vanadia is supported on pyridine-rich carbon is designed for the oxidation of ethyl lactate to ethyl pyruvate.

scholarly journals Metal-Catalyzed Degradation of Cellulose in Ionic Liquid Media

Inorganics ◽  
2018 ◽  
Vol 6 (3) ◽  
pp. 78 ◽  
Author(s):  
Tiina Aid ◽  
Mihkel Koel ◽  
Margus Lopp ◽  
Merike Vaher
Keyword(s):  
Ionic Liquid ◽  
Ionic Liquids ◽  
Molybdenum Oxide ◽  
Cellulose Degradation ◽  
Biomass Conversion ◽  
Reaction Medium ◽  
Good Activity ◽  
Industrial Chemicals ◽  
Liquid Media ◽  
Metal Catalyzed

Biomass conversion to 5-hydroxymethylfurfural (HMF) has been widely investigated as a sustainable alternative to petroleum-based feedstock, since it can be efficiently converted to fuel, plastic, polyester, and other industrial chemicals. In this report, the degradation of commercial cellulose, the isomerization of glucose to fructose, and the conversion of glucose to HMF in 1-butyl-3-methylimidazolium chloride ([BMIM]Cl]) using metal catalysts (CrCl3, ZnCl2, MgCl2) as well as tungsten and molybdenum oxide-based polyoxometalates (POM) were investigated. Tungsten and molybdenum oxide-based POMs in ionic liquids (IL) were able to degrade cellulose to majority glucose and epimerize glucose to mannose (in the case of the molybdenum oxide-based POM). A certain amount of glucose was also converted to HMF. The tungsten oxide-based POM in IL showed good activity for cellulose degradation but the overall products yield remained 28.6% lower than those obtained using CrCl3 as a catalyst. Lowering the cellulose loading did not significantly influence the results and the addition of water to the reaction medium decreased the product yields remarkably.

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