Support–Activity Relationship in Heterogeneous Catalysis for Biomass Valorization and Fine-Chemicals Production

Heterogeneous catalysts are progressively expanding their field of application, from high-throughput reactions for traditional industrial chemistry with production volumes reaching millions of tons per year, a sector in which they are key players, to more niche applications for the production of fine chemicals. These novel applications require a progressive utilization reduction of fossil feedstocks, in favor of renewable ones. Biomasses are the most accessible source of organic precursors, having as advantage their low cost and even distribution across the globe. Unfortunately, they are intrinsically inhomogeneous in nature and their efficient exploitation requires novel catalysts. In this process, an accurate design of the active phase performing the reaction is important; nevertheless, we are often neglecting the importance of the support in guaranteeing stable performances and improving catalytic activity. This review has the goal of gathering and highlighting the cases in which the supports (either derived or not from biomass wastes) share the worth of performing the catalysis with the active phase, for those reactions involving the synthesis of fine chemicals starting from biomasses as feedstocks.

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Efficient Catalytic Upgrade of Fructose to Alkyl Levulinates with Phenylpyridine- phosphotungstate Solid Hybrids

Current Green Chemistry ◽

10.2174/2213346105666181112112330 ◽

2019 ◽

Vol 6 (1) ◽

pp. 44-52 ◽

Cited By ~ 6

Author(s):

Chengjiang Fang ◽

Yan Li ◽

Zhaozhuo Yu ◽

Hu Li ◽

Song Yang

Keyword(s):

Heterogeneous Catalysts ◽

Phosphotungstic Acid ◽

Solvothermal Method ◽

Low Cost ◽

Value Added ◽

Catalytic Performance ◽

Biomass Valorization ◽

Methyl Levulinate ◽

Alkyl Levulinates ◽

Facile Solvothermal Method

Biomass, as the most abundant and renewable organic carbon source, can be upgraded into various value-added platform molecules. To implement more sustainable and economic catalytic biomass valorization, reusable heterogeneous catalysts would be one of the preferable choices. In this work, a series of phosphotungstic acid-based solid hybrids were produced by assembly of phosphotungstic acid with different pyridines using a facile solvothermal method. The obtained 3- phenylpyridine-phosphotungstate hybrid displayed superior catalytic performance in the upgrade of fructose to methyl levulinate with 71.2% yield and 83.2% fructose conversion at 140 ºC for 8 h in methanol, a bio-based and environmentally friendly solvent, which was probably due to its relatively large pore size and high hydrophobicity. This low-cost and eco-friendly catalytic process could be simply operated in a single pot without cumbersome separation steps. In addition, the 3- phenylpyridine-phosphotungstate catalyst was able to be reused for four times with little deactivation.

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What catalysis needs from the electron microscopist

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100105539 ◽

1988 ◽

Vol 46 ◽

pp. 694-695

Author(s):

Alexis T. Bell

Keyword(s):

Active Sites ◽

Heterogeneous Catalysts ◽

Catalyst Deactivation ◽

Surface Composition ◽

Internal Surface ◽

Active Phase ◽

Atomic Scale ◽

Metal Catalyst ◽

Internal Surface Area ◽

Porous Support

Heterogeneous catalysts, used in industry for the production of fuels and chemicals, are microporous solids characterized by a high internal surface area. The catalyticly active sites may occur at the surface of the bulk solid or of small crystallites deposited on a porous support. An example of the former case would be a zeolite, and of the latter, a supported metal catalyst. Since the activity and selectivity of a catalyst are known to be a function of surface composition and structure, it is highly desirable to characterize catalyst surfaces with atomic scale resolution. Where the active phase is dispersed on a support, it is also important to know the dispersion of the deposited phase, as well as its structural and compositional uniformity, the latter characteristics being particularly important in the case of multicomponent catalysts. Knowledge of the pore size and shape is also important, since these can influence the transport of reactants and products through a catalyst and the dynamics of catalyst deactivation.

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An Overview of Biodiesel Production via Calcium Oxide Based Catalysts: Current State and Perspective

Energies ◽

10.3390/en14133950 ◽

2021 ◽

Vol 14 (13) ◽

pp. 3950

Author(s):

Hoora Mazaheri ◽

Hwai Chyuan Ong ◽

Zeynab Amini ◽

Haji Hassan Masjuki ◽

M. Mofijur ◽

...

Keyword(s):

Heterogeneous Catalysis ◽

Calcium Oxide ◽

Heterogeneous Catalysts ◽

Low Cost ◽

Biodiesel Production ◽

Catalyst Synthesis ◽

Process Improvements ◽

Current State ◽

The Common ◽

Activity Mechanism

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 candidates for the synthesis of heterogeneous catalysts. However, process improvements are required to design productive calcium oxide-based catalysts at an industrial scale. The current work presents an overview of the biodiesel production advancements using calcium oxide-based catalysts (e.g., pure, supported, and mixed with metal oxides). The review discusses different factors involved in the synthesis of calcium oxide-based catalysts, and the effect of reaction parameters on the biodiesel yield of calcium oxide-based catalysis are studied. Further, the common reactor designs used for the heterogeneous catalysis using calcium oxide-based catalysts are explained. Moreover, the catalytic activity mechanism, challenges and prospects of the application of calcium oxide-based catalysts in biodiesel generation are discussed. The study of calcium oxide-based catalyst should continue to be evaluated for the potential of their application in the commercial sector as they remain the pivotal goal of these studies.

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Screening of low-cost materials as heterogeneous catalysts for olive mill wastewater Fenton’s peroxidation

Energy Reports ◽

10.1016/j.egyr.2020.11.095 ◽

2020 ◽

Vol 6 ◽

pp. 161-167

Author(s):

E. Domingues ◽

F. Rodrigues ◽

J. Gomes ◽

M.J. Quina ◽

S. Castro-Silva ◽

...

Keyword(s):

Heterogeneous Catalysts ◽

Low Cost ◽

Olive Mill Wastewater ◽

Olive Mill

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A brief review on the reaction mechanisms of CO2 hydrogenation into methanol

International Journal of Innovative Research and Scientific Studies ◽

10.53894/ijirss.v3i2.31 ◽

2020 ◽

Vol 3 (2) ◽

pp. 33-40

Author(s):

Jawed Qaderi

Keyword(s):

Catalytic Hydrogenation ◽

Density Functional ◽

Heterogeneous Catalysts ◽

Catalytic Reduction ◽

Kinetic Monte Carlo ◽

Low Cost ◽

Hydrogenation Of Co2 ◽

Fuel Prices ◽

Metal Metal ◽

Reduction Of Co2

The catalytic reduction of CO2 to methanol is an appealing option to reduce greenhouse gas concentration as well as renewable energy production. In addition, the exhaustion of fossil fuel, increase in earth temperature and sharp increases in fuel prices are the main driving factor for exploring the synthesis of methanol by hydrogenating CO2. Many studies on the catalytic hydrogenation of CO2 to methanol were published in the literature over the last few decades. Many of the studies have presented different catalysts having high stability, higher performance, low cost, and are immediately required to promote conversion. Understanding the mechanisms involved in the conversion of CO2 is essential as the first step towards creating these catalysts. This review briefly summarizes recent theoretical developments in mechanistic studies focused on using density functional theory, kinetic Monte Carlo simulations, and microkinetics modeling. Based on these simulation techniques on different transition metals, metal/metal oxide, and other heterogeneous catalysts surfaces, mainly, three important mechanisms that have been recommended are the formate (HCOO), reverse water–gas shift (RWGS), and trans-COOH mechanisms. Recent experimental and theoretical efforts appear to demonstrate that the formate route in which the main intermediate species is H2CO* in the reaction route, is more favorable in catalytic hydrogenation of CO2 to chemical fuels in various temperature and pressure conditions.

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Trends in Widely Used Catalysts for Fatty Acid Methyl Esters (FAME) Production: A Review

Catalysts ◽

10.3390/catal11091085 ◽

2021 ◽

Vol 11 (9) ◽

pp. 1085

Author(s):

Shafaq Nisar ◽

Muhammad Asif Hanif ◽

Umer Rashid ◽

Asma Hanif ◽

Muhammad Nadeem Akhtar ◽

...

Keyword(s):

Fatty Acid ◽

Large Scale ◽

Heterogeneous Catalysts ◽

Fatty Acid Methyl Esters ◽

Low Cost ◽

Methyl Esters ◽

Acid Catalyst ◽

Product Formation ◽

Biodiesel Production ◽

Acid Methyl

The effective transesterification process to produce fatty acid methyl esters (FAME) requires the use of low-cost, less corrosive, environmentally friendly and effective catalysts. Currently, worldwide biodiesel production revolves around the use of alkaline and acidic catalysts employed in heterogeneous and homogeneous phases. Homogeneous catalysts (soluble catalysts) for FAME production have been widespread for a while, but solid catalysts (heterogeneous catalysts) are a newer development for FAME production. The rate of reaction is much increased when homogeneous basic catalysts are used, but the main drawback is the cost of the process which arises due to the separation of catalysts from the reaction media after product formation. A promising field for catalytic biodiesel production is the use of heteropoly acids (HPAs) and polyoxometalate compounds. The flexibility of their structures and super acidic properties can be enhanced by incorporation of polyoxometalate anions into the complex proton acids. This pseudo liquid phase makes it possible for nearly all mobile protons to take part in the catalysis process. Carbonaceous materials which are obtained after sulfonation show promising catalytic activity towards the transesterification process. Another promising heterogeneous acid catalyst used for FAME production is vanadium phosphate. Furthermore, biocatalysts are receiving attention for large-scale FAME production in which lipase is the most common one used successfully This review critically describes the most important homogeneous and heterogeneous catalysts used in the current FAME production, with future directions for their use.

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Patient Monitoring System Using Internet of Things

Advances in Data Mining and Database Management - Challenges and Applications of Data Analytics in Social Perspectives ◽

10.4018/978-1-7998-2566-1.ch015 ◽

2021 ◽

pp. 275-289

Author(s):

Bollipelly PruthviRaj Goud ◽

A. Prasanth Rao ◽

Sravan kumar S. ◽

Sathiyamoorthi V.

Keyword(s):

Heart Rate ◽

Linear Accelerator ◽

Low Cost ◽

The Internet ◽

Sensor Platforms ◽

Critical Issues ◽

Patient Monitoring System ◽

Healthcare Application ◽

Iot Platforms ◽

Novel Applications

IoT comprises billions of devices that can sense, communicate, compute, and potentially actuate. The data generated by the IoTs are valuable and have the potential to drive innovative and novel applications. IoT allows people and things to be connected anytime, anyplace and to anyone with the internet using tiny sensor. One of the best advantages of the IoT is the increasing number of low-cost sensors available along with its functionalities. A few standard sensors include linear accelerator, compass, light sensors, camera, and microphone, moisture, location, heart rate, and heart rate variability. The trend is multi-sensor platforms that incorporate several sensing elements. In such environment, discovering, identifying, connecting, and configuring sensor hardware are critical issues. The cloud-based IoT platforms can retrieve data from sensors IoT is an inter-disciplinary technology, encompassing multiple areas such as RTS, embedded systems. This chapter detailed investigation and presents highly innovative and revolutionary ideas in healthcare application are available.

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Application of Low-Cost Sensors for the Development of a Methodology to Design Front-End Loaders for Tractors

Journal of Sensors ◽

10.1155/2020/3504389 ◽

2020 ◽

Vol 2020 ◽

pp. 1-13

Author(s):

H. Malon ◽

A. Ayuda ◽

F. J. Garcia-Ramos ◽

M. Vidal ◽

J. Cuartero

Keyword(s):

Finite Element Method ◽

Low Cost ◽

Strain Gauges ◽

Second Phase ◽

The Finite Element Method ◽

Structural Behaviour ◽

Experimental Phase ◽

Front End ◽

Accurate Design ◽

Two Phases

Tractor front-end loaders are an essential part of the equipment used on farms. At present, there are an important number of small- and medium-sized companies involved in the manufacturing of this equipment. These companies rely heavily on experience for innovative designs, as in the vast majority of cases they lack access to adequate methodology for the optimal design of new front-end loaders. The study conducted has developed a methodology to design tractor front-end loaders with a view of obtaining their accurate design during the bucket loading process. The methodology comprises two phases: the first phase involves a numerical analysis of the structural behaviour of the front-end loader components by means of the Finite Element Method; the second phase, the experimental phase, makes use of low-cost sensors, in particular, strain gauges, to analyse existing strains at selected points in the front-end loader structure. The experimental results obtained by means of low-cost sensors fitted onto the front-end loader allow analysing the existing strains at the points measured, as well as validate the numerical model developed. This methodology is validated by applying it to a commercial front-end loader, more specifically to model 430E2 of the company Maquinaria Agrícola El León S.A (Spain).

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Application of Heterogeneous Catalysts for Biodiesel Production from Microalgal Oil—A Review

Catalysts ◽

10.3390/catal10091025 ◽

2020 ◽

Vol 10 (9) ◽

pp. 1025

Author(s):

Mohammed O. Faruque ◽

Shaikh A. Razzak ◽

Mohammad M. Hossain

Keyword(s):

Heterogeneous Catalysts ◽

Reaction Rate ◽

Fossil Fuel ◽

Solid Phase ◽

Low Cost ◽

Biodiesel Production ◽

Terrestrial Plants ◽

Homogeneous Catalysts ◽

Microalgal Oil ◽

Solid Catalysts

The depletion of fossil fuel reserves and increased environmental concerns related to fossil fuel production and combustion has forced the global communities to search for renewable fuels. In this regard, microalgae-based biodiesel has been considered as one of the interesting alternatives. Biodiesel production from the cultivation of microalgae is eco-friendly and sustainable. Moreover, microalgae have several advantages over other bioenergy sources, including their good photosynthetic capacity and faster growth rates. The productivity of microalgae per unit land area is also significantly higher than that of terrestrial plants. The produced microalgae biomass is rich with high quality lipids, which can be converted into biodiesel by transesterification reactions. Generally, the transesterification reactions are carried out in the presence of a homogeneous or heterogeneous catalyst. The homogeneous catalysts have many disadvantages, including their single use, slow reaction rate and saponification issues due to the presence of fatty acids in the feedstock. The acidic nature of the homogeneous catalysts also causes equipment corrosion. On the other hand, the heterogeneous catalysts offer several advantages, including their reusability, higher reaction rate and selectivity, easy product/catalyst separation and low cost. Due to these facts, the development of solid phase transesterification catalysts have been receiving growing interest. The present review is focused on the use of heterogeneous catalysts for biodiesel production from microalgal oil as a reliable feedstock with a comparison to other available feedstocks. It also highlights optimal reaction conditions for maximum biodiesel yields, reusability of the solid catalysts, cost, and environmental impact. The superior lipid content of microalgae and the efficient concurrent esterification and transesterification of the solid acid−base catalysts can offer new advancements in biodiesel production.

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