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Records with Keyword: Catalysis
Nano-Intermediate of Magnetite Nanoparticles Supported on Activated Carbon from Spent Coffee Grounds for Treatment of Wastewater from Oil Industry and Energy Production
Laura Acosta, Dahiana Galeano-Caro, Oscar E. Medina, Farid B. Cortés, Camilo A. Franco
October 14, 2021 (v1)
Keywords: activated carbon, Adsorption, Catalysis, coffee residue, crude oil, magnetite nanoparticles
This work focused on evaluating the adsorptive removal of crude oil using a nano-intermediate based on magnetite nanoparticles supported on activated carbon synthesized from spent coffee grounds and the subsequent catalytic oil decomposition to recover by-products and regenerate the support material. The magnetite nanoparticles were synthesized by the co-precipitation method and were used as active phases on prepared activated carbon. The amount of crude oil adsorbed was determined by adsorption isotherms. In addition, dynamic tests were performed on a packed bed to evaluate the efficiency of the removal process. Thermogravimetric analysis and mass spectrometry were used to evaluate the catalytic powder and the quantification of by-products. Contrasting the results with commercial carbon, the one synthesized from the coffee residue showed a greater affinity for the oil. Likewise, the adsorption capacity increased by doping activated carbon with magnetite nanoparticles, obtaining an eff... [more]
Economic and Environmental Assessment of Catalytic and Thermal Pyrolysis Routes for Fuel Production from Lignocellulosic Biomass
Akshay D. Patel, Masoud Zabeti, K. Seshan, Martin K. Patel
July 19, 2021 (v1)
Keywords: abatement cost, biofuel, Catalysis, economics, lifecycle environmental impacts, lignocellulosic biomass, pyrolysis, Renewable and Sustainable Energy
Meeting the transport needs of a growing world population makes it imperative to develop renewable and sustainable routes to production of liquid fuels. With a market-driven economic structure and pressing environmental issues, it is essential that these new routes provide environmental benefits while being economically viable. Conversion of second-generation lignocellulosic biomass resources to fuels via pyrolysis represents an important technological route. In this article, we report comparative assessment of the economic and lifecycle environmental aspects for catalytic and thermal pyrolysis. The goal of this assessment is two-fold: one is to understand the potential of this conversion route via the catalytic and thermal processes and second is to provide feedback for further development of catalysts for various stages of this conversion. The complete assessment is interdisciplinary in nature and connects the laboratory experiments with contextual sustainability assessment. Three ca... [more]
Processing Methods Used in the Fabrication of Macrostructures Containing 1D Carbon Nanomaterials for Catalysis
João Restivo, Olívia Salomé Gonçalves Pinto Soares, Manuel Fernando Ribeiro Pereira
May 4, 2021 (v1)
Subject: Materials
Keywords: 1D carbon nanomaterials, carbon nanofibers, Catalysis, catalyst preparation, nanocatalysts, nanostructured carbon, structured catalysts
A large number of methodologies for fabrication of 1D carbon nanomaterials have been developed in the past few years and are extensively described in the literature. However, for many applications, and in particular in catalysis, a translation of the materials to a macro-structured form is often required towards their use in practical operation conditions. This review intends to describe the available methods currently used for fabrication of such macro-structures, either already applied or with potential for application in the fabrication of macro-structured catalysts containing 1D carbon nanomaterials. A review of the processing methods used in the fabrication of macrostructures containing 1D sp2 hybridized carbon nanomaterials is presented. The carbon nanomaterials here discussed include single- and multi-walled carbon nanotubes, and several types of carbon nanofibers (fishbone, platelet, stacked cup, etc.). As the processing methods used in the fabrication of the macrostructures ar... [more]
Phosphorus-Doped Carbon Supported Vanadium Phosphate Oxides for Catalytic Oxidation of 5-Hydroxymethylfurfural to 2,5-Diformylfuran
Sha Wen, Kai Liu, Yi Tian, Yanping Xiang, Xianxiang Liu, Dulin Yin
April 29, 2021 (v1)
Keywords: 2,5-diformylfuran, 5-hydroxymethylfurfural, Catalysis, selective oxidation, vanadium phosphate oxides
2,5-diformylfuran (DFF) is an important downstream product obtained by selective oxidation of the biomass-based platform compound 5-hydroxymethylfurfural (HMF). In this study, a phosphorus-doped carbon (P-C) supported vanadium phosphate oxide (VPO) catalyst was successfully prepared and showed remarkably high catalytic activity in the selective oxidation of HMF to produce DFF with air as an oxidant. The effects of the reaction temperature, reaction time, solvent, catalyst amount, and VPO loading amount were investigated. The results showed that an HMF conversion rate of 100% and a DFF yield of 97.0% were obtained under suitable conditions, and DMSO was found to be the most suitable solvent under an air atmosphere.
Study of H2S Removal Capability from Simulated Biogas by Using Waste-Derived Adsorbent Materials
Hua Lun Zhu, Davide Papurello, Marta Gandiglio, Andrea Lanzini, Isil Akpinar, Paul R. Shearing, George Manos, Dan J.L. Brett, Ye Shui Zhang
February 3, 2021 (v1)
Keywords: activated carbon, Adsorption, biochar, Catalysis, circular economy, H2S, waste
Three waste-derived adsorbent materials (wood-derived biochar, sludge-derived activated carbon and activated ash) were pre-activated at the laboratory scale to apply them for the removal of H2S from a biogas stream. The H2S removal capabilities of each material were measured by a mass spectrometer, to detect the H2S concentration after the adsorption in an ambient environment. The activated ash adsorbent has the highest removal capacity at 3.22 mgH2S g−1, while wood-derived biochar has slightly lower H2S removal capability (2.2 mgH2S g−1). The physicochemical properties of pristine and spent materials were characterized by the thermogravimetric analyzer, elemental analysis, X-ray fluorescence spectroscopy and N2 adsorption and desorption. Wood-derived biochar is a highly porous material that adsorbs H2S by physical adsorption of the mesoporous structure. Activated ash is a non-porous material which adsorbs H2S by the reaction between the alkaline compositions and H2S. This study shows... [more]
N-Tosylcarboxamide in C−H Functionalization: More than a Simple Directing Group
Benjamin Large, Vincent Terrasson, Damien Prim
December 22, 2020 (v1)
Keywords: C–H functionalization, Catalysis, directing group, tosylbenzamide
C−H activation with transition metal catalysis has become an important tool in organic synthesis for the functionalization of low reactive bonds and the preparation of complex molecules. The choice of the directing group (DG) proves to be crucial for the selectivity in this type of reaction, and several different functional groups have been used efficiently. This review describes recent advances in C−H functionalization of aromatic rings directed by a N-tosylcarboxamide group. Results regarding alkenylation, alkoxylation, halogenation, and arylation of C−H in the ortho position to the tosylcarboxamide are presented. Moreover, the advantage of this particular directing group is that it can undergo further transformation and act as CO or CON fragment reservoir to produce, in sequential fashion or one-pot sequence, various interesting (hetero)cycles such as phenanthridinones, dihydroisoquinolinones, fluorenones, or isoindolinones.
A Novel Cysteine-Functionalized MxOy Material as Support for Laccase Immobilization and a Potential Application in Decolorization of Alizarin Red S
Agnieszka Kołodziejczak-Radzimska, Teofil Jesionowski
November 11, 2020 (v1)
Subject: Biosystems
Keywords: Catalysis, decolorization, kinetic, l-cysteine, laccase, SiO2, ZrO2
Immobilization process improves the enzyme properties, like stability, activity, selectivity or specificity. In the study, a novel cysteine-functionalized MxOy (ZrO2, SiO2) material was used as a support for the immobilization of laccase from Trametes versicolor. The proposed matrix was prepared using a simple sol-gel method. The cysteine was introduced during the synthesis of a sample. Additionally, the obtained supports were modified with glutaraldehyde. The basic properties of the prepared cysteine functionalized ZrO2 and SiO2 were determined using spectroscopic, thermal, porous, electrostatic and elemental analysis. Furthermore, the obtained biocatalytic systems were used as catalysts in the oxidation of sulfonic acid. Catalytic and kinetic parameters were determined based on the proposed model reaction. Next, laccase immobilized on ZrO2- and SiO2-based materials were, for the first time, utilized in the decolorization of Alizarin Red S. In that process, the influence of duration,... [more]
A Review of Methane Activation Reactions by Halogenation: Catalysis, Mechanism, Kinetics, Modeling, and Reactors
David Bajec, Matic Grom, Damjan Lašič Jurković, Andrii Kostyniuk, Matej Huš, Miha Grilc, Blaž Likozar, Andrej Pohar
June 22, 2020 (v1)
Keywords: Catalysis, density functional theory, halogenation, kinetics, mechanism, methane
Methane is the central component of natural gas, which is globally one of the most abundant feedstocks. Due to its strong C−H bond, methane activation is difficult, and its conversion into value-added chemicals and fuels has therefore been the pot of gold in the industry and academia for many years. Industrially, halogenation of methane is one of the most promising methane conversion routes, which is why this paper presents a comprehensive review of the literature on methane activation by halogenation. Homogeneous gas phase reactions and their pertinent reaction mechanisms and kinetics are presented as well as microkinetic models for methane reaction with chlorine, bromine, and iodine. The catalysts for non-oxidative and oxidative catalytic halogenation were reviewed for their activity and selectivity as well as their catalytic action. The highly reactive products of methane halogenation reactions are often converted to other chemicals in the same process, and these multi-step processe... [more]
An Improvement in Biodiesel Production from Waste Cooking Oil by Applying Thought Multi-Response Surface Methodology Using Desirability Functions
Marina Corral Bobadilla, Rubén Lostado Lorza, Rubén Escribano García, Fátima Somovilla Gómez, Eliseo P. Vergara González
July 26, 2019 (v1)
Subject: Biosystems
Keywords: biodiesel, Catalysis, multi-response surface methodology, waste cooking oil
The exhaustion of natural resources has increased petroleum prices and the environmental impact of oil has stimulated the search for an alternative source of energy such as biodiesel. Waste cooking oil is a potential replacement for vegetable oils in the production of biodiesel. Biodiesel is synthesized by direct transesterification of vegetable oils, which is controlled by several inputs or process variables, including the dosage of catalyst, process temperature, mixing speed, mixing time, humidity and impurities of waste cooking oil that was studied in this case. Yield, turbidity, density, viscosity and higher heating value are considered as outputs. This paper used multi-response surface methodology (MRS) with desirability functions to find the best combination of input variables used in the transesterification reactions to improve the production of biodiesel. In this case, several biodiesel optimization scenarios have been proposed. They are based on a desire to improve the biodies... [more]
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