Hierarchically structured catalysts for cascade and selective steam reforming/hydrodeoxygenation reactions

2015 ◽  
Vol 51 (93) ◽  
pp. 16617-16620 ◽  
Author(s):  
Junming Sun ◽  
Ayman M. Karim ◽  
Xiaohong Shari Li ◽  
James Rainbolt ◽  
Libor Kovarik ◽  
...  
Keyword(s):  
Lignocellulosic Biomass ◽  
Steam Reforming ◽  
Active Sites ◽  
Size Exclusion ◽  
Structured Catalysts ◽  
Structured Catalyst

A hierarchically structured catalyst with combined steam reforming and hydrodeoxygenation active sites is reported to efficiently upgrade the pyrolysis vapors of lignocellulosic biomass via size-exclusion.

scholarly journals Enhanced catalytic ozonation of ibuprofen using a 3D structured catalyst with MnO2 nanosheets on carbon microfibers

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Guhankumar Ponnusamy ◽  
Hajar Farzaneh ◽  
Yongfeng Tong ◽  
Jenny Lawler ◽  
Zhaoyang Liu ◽  
...  
Keyword(s):  
Removal Efficiency ◽  
Active Sites ◽  
Low Cost ◽  
Three Dimensional ◽  
Industrial Applications ◽  
Catalytic Ozonation ◽  
Heterogeneous Catalytic ◽  
Structured Catalyst ◽  
Dimensional Network ◽  
Carbon Microfibers

AbstractHeterogeneous catalytic ozonation is an effective approach to degrade refractory organic pollutants in water. However, ozonation catalysts with combined merits of high activity, good reusability and low cost for practical industrial applications are still rare. This study aims to develop an efficient, stable and economic ozonation catalyst for the degradation of Ibuprofen, a pharmaceutical compound frequently detected as a refractory pollutant in treated wastewaters. The novel three-dimensional network-structured catalyst, comprising of δ-MnO2 nanosheets grown on woven carbon microfibers (MnO2 nanosheets/carbon microfiber), was synthesized via a facile hydrothermal approach. Catalytic ozonation performance of Ibuprofen removal in water using the new catalyst proves a significant enhancement, where Ibuprofen removal efficiency of close to 90% was achieved with a catalyst loading of 1% (w/v). In contrast, conventional ozonation was only able to achieve 65% removal efficiency under the same operating condition. The enhanced performance with the new catalyst could be attributed to its significantly increased available surface active sites and improved mass transfer of reaction media, as a result of the special surface and structure properties of this new three-dimensional network-structured catalyst. Moreover, the new catalyst displays excellent stability and reusability for ibuprofen degradation over successive reaction cycles. The facile synthesis method and low-cost materials render the new catalyst high potential for industrial scaling up. With the combined advantages of high efficiency, high stability, and low cost, this study sheds new light for industrial applications of ozonation catalysts.

scholarly journals A Short Review on Ni Based Catalysts and Related Engineering Issues for Methane Steam Reforming

Catalysts ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 352 ◽  
Author(s):  
Eugenio Meloni ◽  
Marco Martino ◽  
Vincenzo Palma
Keyword(s):  
Steam Reforming ◽  
Large Scale ◽  
Short Review ◽  
Raw Material ◽  
Methane Steam Reforming ◽  
Thermal Exchange ◽  
Structured Catalysts ◽  
Methane Steam ◽  
Load Fluctuation ◽  
Hydrogen Station

Hydrogen is an important raw material in chemical industries, and the steam reforming of light hydrocarbons (such as methane) is the most used process for its production. In this process, the use of a catalyst is mandatory and, if compared to precious metal-based catalysts, Ni-based catalysts assure an acceptable high activity and a lower cost. The aim of a distributed hydrogen production, for example, through an on-site type hydrogen station, is only reachable if a novel reforming system is developed, with some unique properties that are not present in the large-scale reforming system. These properties include, among the others, (i) daily startup and shutdown (DSS) operation ability, (ii) rapid response to load fluctuation, (iii) compactness of device, and (iv) excellent thermal exchange. In this sense, the catalyst has an important role. There is vast amount of information in the literature regarding the performance of catalysts in methane steam reforming. In this short review, an overview on the most recent advances in Ni based catalysts for methane steam reforming is given, also regarding the use of innovative structured catalysts.

scholarly journals Formation of a Pd/MgO Structured Catalyst for the Aqueous Oxidation of Silane to Silanol

Catalysts ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 834 ◽  
Author(s):  
Zhou ◽  
Cao ◽  
Wang ◽  
Li
Keyword(s):  
Catalytic Activity ◽  
Pd Nanoparticles ◽  
Structured Catalysts ◽  
Long Term Stability ◽  
Plasma Electrolyte ◽  
Structured Catalyst ◽  
Aqueous Oxidation ◽  
Plasma Electrolyte Oxidation ◽  
Fabrication Parameters

The catalytic oxidation of silanes to produce silanols using water as an oxidant at mild temperatures is a major challenge in Si-H activation. Highly efficient and easy-to-recycle catalysts based on Pd nanoparticles are in high demand. In this study, Pd nanoparticles embedded in an MgO porous overlayer on an Mg plate as a structured catalyst was prepared by the plasma electrolyte oxidation (PEO) technique. The Pd/MgO catalyst is strongly anchored to the MgO plate, building a structured catalyst. Fabrication parameters such as the temperature of the electrolyte and applied voltage significantly influenced the structure of the obtained Pd/MgO catalyst and in turn its catalytic activity. The catalytic activities of Pd/MgO were evaluated by activation of a Si-H bond for catalyzing the aqueous oxidation of silanes to silanol at mild temperatures. The catalytic activity of Pd nanoparticles is favored by their electro-deficient state due to influence from the MgO substrate. The Pd/MgO catalyst exhibits good performance stability during recycling. This work paves the way for fabricating structured catalysts with long-term stability and enhanced metal–oxide interaction.

Effect of Catalytic Distribution on the Performance of Microreactor for Hydrogen Production through Methane Steam Reforming

2010 ◽  
Vol 156-157 ◽  
pp. 873-876 ◽  
Author(s):  
Feng Wang ◽  
Zi Long An ◽  
Bo Qi ◽  
Jing Zhou
Keyword(s):  
Steam Reforming ◽  
Active Sites ◽  
Flow Direction ◽  
Space Velocity ◽  
H2 Production ◽  
Methane Steam Reforming ◽  
Reactor Performance ◽  
Methane Steam ◽  
Site Density ◽  
Availability Ratio

The effect of catalyst coating distributing on the reactor performance for methane steam reforming(MSR) was numerically investigated. In calculation, the amount catalyst loaded on the microreactor wall was fixed but the catalyst active site density was distributed according to arithmetic progression along the flow direction. Results show that it is possible to get the higher conversion of CH4 and output of H2 due to the higher availability ratio of catalyst surface active sites at this distribution. And this distribution effect is more remarkable at higher space velocity or lower reaction temperature, however, there exists an optimal distribution which can reach the highest CH4 conversion and H2 production at 900K.

Hydrogen production by ethanol steam reforming over multimetallic RhCeNi/Al2O3 structured catalyst. Pilot-scale study

2016 ◽  
Vol 41 (38) ◽  
pp. 16786-16796 ◽  
Author(s):  
R. González-Gil ◽  
C. Herrera ◽  
M.A. Larrubia ◽  
F. Mariño ◽  
M. Laborde ◽  
...  
Keyword(s):  
Hydrogen Production ◽  
Steam Reforming ◽  
Pilot Scale ◽  
Ethanol Steam Reforming ◽  
Structured Catalyst ◽  
Ethanol Steam

scholarly journals Understanding The Structure And Composition of Recalcitrant Oligosaccharides In Ammonia Treated Lignocellulosic Biomass Hydrolysate Using High-Throughput Biotin- Based Glycome Profiling And Mass Spectrometry.

2021 ◽  
Author(s):  
Saisi Xue ◽  
Sivakumar Pattathil ◽  
Leonardo Costa Sousa ◽  
Bryan Ubanwa ◽  
Bruce Dale ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Lignocellulosic Biomass ◽  
Plant Cell ◽  
High Throughput ◽  
Plant Cell Wall ◽  
Enzyme Hydrolysis ◽  
Size Exclusion ◽  
Negative Ion ◽  
Fungal Enzymes ◽  
Glycome Profiling

Abstract Novel Immunological and Mass Spectrometry Methods for Comprehensive Analysis of Recalcitrant Oligosaccharides in AFEX Pretreated Corn Stover Lignocellulosic biomass is a sustainable alternative to fossil fuel and is extensively used for developing bio-based technologies to produce products such as food, feed, fuel, and chemicals. The key to these technologies is to develop cost competitive processes to convert complex carbohydrates present in plant cell wall to simple sugars such as glucose, xylose and arabinose. Since lignocellulosic biomass is highly recalcitrant, it must undergo a combination of thermochemical treatment such as Ammonia Fiber Expansion (AFEX), dilute acid (DA), Ionic Liquid (IL) and biological treatment such as enzyme hydrolysis and microbial fermentation to produce desired products. However, when using commercial fungal enzymes during hydrolysis, only 75-85% of the soluble sugars generated are monomeric sugars, while the remaining 15-25% are soluble recalcitrant oligosaccharides that cannot be easily utilized by microorganisms. Previously, we successfully separated and purified the soluble recalcitrant oligosaccharides using a combination of charcoal and celite-based separation followed by size exclusion chromatography and studies their inhibitory properties on enzymes. We discovered that the oligosaccharides with higher degree of polymerization (DP) containing methylated uronic acid substitutions were more recalcitrant towards commercial enzyme mixtures than lower DP and neutral oligosaccharides. Here, we report the use of several complementary techniques that include glycome profiling using plant biomass glycan specific monoclonal antibodies (mAbs) to characterize sugar linkages in plant cell walls and enzymatic hydrolysate, matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF-MS) using structurally-informative diagnostic peaks offered by negative ion post-secondary decay spectra, gas chromatography followed by mass spectrometry (GC-MS) to characterize oligosaccharide sugar linkages with and without derivatization. Since oligosaccharides (DP 4-20) are small, it is challenging to immobilize these molecules for mAbs binding and characterization. To overcome this problem, we have developed a new biotin-coupling based oligosaccharide immobilization method that successfully tagged most of the low DP soluble oligosaccharides on to a micro-plate surface followed by specific linkage analysis using mAbs in a high-throughput system. This new approach will help develop more advanced versions of future high throughput glycome profiling methods that can be used to separate and characterize oligosaccharides present in biomarkers for diagnostic applications.

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