Metal Catalyst and Hydrogen Gas-Free Selective Reduction of Biomass-Derived Substituted Furfuraldehyde to Alkyl Furan as a Key Biofuel Additive

2021 ◽  
Author(s):  
Arvind Singh Chauhan ◽  
Ajay Kumar ◽  
Pralay Das
Keyword(s):  
Selective Reduction ◽  
Hydrogen Gas ◽  
Metal Catalyst

A Study on Spirituous Liquor Efficiency Using Direct Alcohol Fuel Cell

2015 ◽  
Vol 658 ◽  
pp. 129-132
Author(s):  
Nutthapon Wongyao ◽  
Apichai Therdthianwong ◽  
Supaporn Therdthianwong
Keyword(s):  
Fuel Cell ◽  
Electrical Power ◽  
Open Circuit ◽  
Ethanol Solution ◽  
Hydrogen Gas ◽  
Initial Time ◽  
Metal Catalyst ◽  
Pure Ethanol ◽  
Direct Alcohol Fuel Cell ◽  
Alcohol Fuel

The electro-oxidation of 40 degree of alcohol as a local-commercial of spirituous liquor in Thailand compared with pure ethanol solution on the metal catalyst of PtSn/C was carried out. With using the 5 cm2 anode electrode of PtSn/C catalyst, the direct alcohol fuel cell was employed and then fed with 1 M of spirituous liquor at flow rate of 1 ml/min under operating condition of atmospheric pressure. The results from an output electrical power of 40 degree liquor fed into direct alcohol fuel cell (celled 40DFC) indicated that, at the initial time, the spirituous liquor provided the higher power density of 6 mW/cm2 compared with ethanol solution (celled DEFC) at the same concentration. For the cell open circuit voltage (OCV) using the spirituous liquor as fuel, it was 0.63 V which slightly lower than ethanol solution one. Nevertheless, 15 minutes left after applying the liquor, the cell performance was dramatic dropped due to the poisoned species of sulfur contained in liquor. The anode catalyst performance loss was also proved by using hydrogen gas for rechecking of the permanent degradation of fuel cell caused by feeding liquor onto the PtSn catalyst surface.

scholarly journals General and selective deoxygenation by hydrogen using a reusable earth-abundant metal catalyst

2019 ◽  
Vol 5 (11) ◽  
pp. eaav3680 ◽  
Author(s):  
T. Schwob ◽  
P. Kunnas ◽  
N. de Jonge ◽  
C. Papp ◽  
H.-P. Steinrück ◽  
...  
Keyword(s):  
Natural Products ◽  
Hydrogen Gas ◽  
Metal Catalyst ◽  
Tertiary Alcohols ◽  
Aryl Ketones ◽  
Earth Abundant ◽  
Fuels And Chemicals ◽  
Cost Efficient ◽  
Economic Upgrading ◽  
Selective Deoxygenation

Chemoselective deoxygenation by hydrogen is particularly challenging but crucial for an efficient late-stage modification of functionality-laden fine chemicals, natural products, or pharmaceuticals and the economic upgrading of biomass-derived molecules into fuels and chemicals. We report here on a reusable earth-abundant metal catalyst that permits highly chemoselective deoxygenation using inexpensive hydrogen gas. Primary, secondary, and tertiary alcohols as well as alkyl and aryl ketones and aldehydes can be selectively deoxygenated, even when part of complex natural products, pharmaceuticals, or biomass-derived platform molecules. The catalyst tolerates many functional groups including hydrogenation-sensitive examples. It is efficient, easy to handle, and conveniently synthesized from a specific bimetallic coordination compound and commercially available charcoal. Selective, sustainable, and cost-efficient deoxygenation under industrially viable conditions seems feasible.

The Synthesis and Characteristics of Homogenously Dispersed CNT-Al2O3 Nanocomposites by the Thermal CVD Method and Pulsed Electric Current Sintering Process

2007 ◽  
Vol 121-123 ◽  
pp. 295-298 ◽  
Author(s):  
S.H. Yoo ◽  
J.K. Yang ◽  
Sung Tag Oh ◽  
Kae Myung Kang ◽  
Sung Goon Kang ◽  
...  
Keyword(s):  
Electric Current ◽  
Selective Reduction ◽  
Chemical Vapor ◽  
Metal Catalyst ◽  
Sintering Process ◽  
Composite Powders ◽  
Reduction Processes ◽  
Pulsed Electric Current ◽  
Nanocomposite Powders ◽  
Pulse Electric

An optimum route to synthesize Al2O3-based composite powders with a homogeneous dispersion of carbon nanotubes (CNTs) was investigated. CNT/Metal/Al2O3 nanocomposite powders were fabricated by thermal chemical vapor deposition (CVD) over a metal catalyst homogeneously dispersed into an Al2O3 matrix by the means of chemical and selective reduction processes. The nanocomposite powders were densified by Pulse Electric Current Sintering (PECS). The experimental results show that the CNT/Metal/Al2O3 nanocomposites have unique electrical properties.

Influences of Hydrogen Gas on Carbon Nanotube Growth

2008 ◽  
Vol 1081 ◽  
Author(s):  
Fumitaka Ohashi ◽  
Guan Yow Chen ◽  
Vlad Stolojan ◽  
S. Ravi P. Silva
Keyword(s):  
Carbon Nanotube ◽  
Growth Temperature ◽  
Gas Flow ◽  
Chemical Vapour ◽  
Hydrogen Gas ◽  
Metal Catalyst ◽  
Growth Stages ◽  
Carbon Nanofibres ◽  
Carbon Nanotube Growth ◽  
Nanotube Growth

AbstractFor practical deployment of carbon nanotubes, an understanding of their growth mechanism is required in order to obtain better control over their crystallinity, chirality and other structural properties. In this study, we focus on the influences of gas species on carbon nanotube synthesis using thermal chemical vapour deposition. The influence of methane, hydrogen, and helium gases was investigated from the viewpoint of gas chemistry in relation to the nanotube structural change, by varying the growth pressure, the gas-flow ratio and the growth temperature. Simple changes in the hydrogen gas concentration during different growth stages have been found to induce surprising changes to the nanotube formation. The structure of the tubular carbon growth changed from amorphous to graphitic as the growth temperature and the concentration of hydrogen in the initial periods of growth decreases. The excess hydrogen tends to give rise to poor crystalline carbon nanofibres but has the effect of increasing the yields. Hydrogen gas is typically used in reducing metal catalyst particles during the pre-treatment and the carbon nanotube growth periods. We show that while hydrogen species can improve yield, it can also result in the degradation of the nanotube's crystallinity. The use of hydrogen in the growth process is one of the key parameters for enhanced control of carbon nanotube/nanofibre growth and their resulting crystallinity.

scholarly journals Kinetic study on Fermentation of xylose for The Xylitol Production

2017 ◽  
Vol 1 (1) ◽  
pp. 1
Author(s):  
Efri Mardawati ◽  
Andi Trirakhmadi ◽  
MTAP Kresnowati ◽  
Tjandra Setiadi
Keyword(s):  
Kinetic Study ◽  
High Pressures ◽  
Scale Up ◽  
Reduction Process ◽  
Hydrogen Gas ◽  
Raw Material ◽  
Metal Catalyst ◽  
Xylitol Production ◽  
Monod Kinetics ◽  
Formation Kinetic

Xylitol is a natural sugar that has the sweetness level similar to sucrose, but has lower calorie. It is an important sugar alternate for diabetics people. Reduction of xylose is a normally method to produce the xylitol. It Conducted via chemical hydrogenation of xylose at high pressures and temperatures by reacting pure xylose with hydrogen gas using a metal catalyst. This process requires pure xylose as the raw material. Alternatively, the reduction process can be carried out via fermentation. This process does not require high purity of xylose as the raw material, and thus the oil palm empty fruit bunch (EFB) hydrolysate, without any prior pretreatment, can be used.  In order to scale up the xylitol production via fermentation, kinetic study of xylitol fermentation including growth and xylitol formation kinetic using the synthetic xylose as substrate will be required.  Data used in the kinetic model development were obtained from series of batch fermentations of Debaryomycess hansenii ITB CCR85 varying the initial xylose and glucose concentrations. Yeast growth could be sufficiently modeled using the Monod kinetics, whereas xylitol production could be reasonably well modelled by Luedeking Piret kinetics.

Perbandingan aktivitas katalis nikel dan katalis tembaga pada reaksi hidrogenasi metil ester untuk pembuatan surfaktan

2018 ◽  
Vol 8 (2) ◽  
pp. 63
Author(s):  
Tania S Utami ◽  
Rita Arbianti ◽  
Heri Hermansyah ◽  
Wiwik Handayani ◽  
Desti Andani
Keyword(s):  
Surface Tension ◽  
Flow Rate ◽  
Gas Flow ◽  
Hydrogen Gas ◽  
Operating Conditions ◽  
Optimum Operating ◽  
Metal Catalyst ◽  
Ni Catalyst ◽  
Gas Flow Rate ◽  
Cu Catalyst

Surfactant has ability in decreasing surface tension, interfacial surface tension, and increasing stability of emulsion systems. Surfactant is used in several industry such as soap and detergent industry, healthcare and cosmetics industry. One major advantage of oleochemical surfactant is its renewable and degradable properties regarding environmental issue. This surfactant is made using methyl esther from coconut oil through hydrogenation of methyl esther (methyl laurate) by using metal catalyst, sulfatation reaction by adding H2SO4, and neutralization by using NaOH. The goal of this research is to obtain the optimum reaction condition in aspects of several variables, such as temperature, hydrogen gas flow rate, and percent weight of catalyst in the hydrogenation reaction using Ni dan Cu catalyst. This research showed that the optimum operating conditions are 270 oC of temperature, 1 mL/s of H2 gas flow rate, and 30 %-wt of catalyst. Ni catalyst has better activity. After adding 25 %-wt of surfactants, it had surface tension of 26.4 mN/m and it could stabilize emulsion for 839 seconds. Keywords : hydrogenation, Cu catalyst, Ni catalyst, methyl esther, surfactant. Abstrak Surfaktan memiliki kemampuan menurunkan tegangan permukaan, tegangan antarmuka, dan meningkatkan kestabilan sistem emulsi. Hal ini membuat surfaktan banyak digunakan pada berbagai bidang industri seperti industri sabun, detergen, produk perawatan diri, dan kosmetika. Surfaktan berbahan baku oleokimia memiliki beberapa keunggulan, diantaranya bersifat terbarukan (renewable resources) dan secara alami mudah terdegradasi. Surfaktan ini dapat dibuat dengan menggunakan bahan baku metil ester dari minyak kelapa melalui reaksi hidrogenasi metil ester (metil laurat) dengan katalis logam, reaksi sulfatasi dengan menambahkan H2SO4, dan netralisasi dengan NaOH. Tujuan dari penelitian ini adalah mendapatkan kondisi optimum yang meliputi suhu reaksi, laju alir gas hidrogen, dan persentase berat katalis pada reaksi hidrogenasi metil laurat menggunakan katalis Ni dan Cu. Hasil penelitian menunjukkan kondisi operasi optimum yang sama dari kedua katalis, yaitu pada suhu 270 oC, laju alir gas H2 1 mL/s, dan 30 %-berat katalis. Aktivitas katalis yang lebih baik diberikan oleh katalis Ni, dengan nilai penurunan tegangan permukaan air setelah ditambahkan surfaktan sebesar 26,4 mN/m dan stabilitas emulsi minyak-air setelah ditambahkan surfaktan sebesar 839 detik. Kata Kunci : hidrogenasi, katalis Cu, katalis Ni, metil ester, surfaktan.

Synthesis of CNTs/Metal/Al2O3 Nanocomposite Powders by Chemical Vapor Deposition

2004 ◽  
Vol 449-452 ◽  
pp. 797-800 ◽  
Author(s):  
C.D. Park ◽  
Hyung Jun Jeon ◽  
H.J. Wang ◽  
Yong Ho Choa ◽  
Sung Tag Oh ◽  
...  
Keyword(s):  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Selective Reduction ◽  
Chemical Vapor ◽  
Metal Catalyst ◽  
Composite Catalyst ◽  
Phase Identification ◽  
Multi Walled Carbon Nanotubes ◽  
Nanocomposite Catalysts ◽  
Nanocomposite Powders

CNTs/metal/Al2O3 nanocomposite powders were fabricated by thermal chemical vapor deposition (CVD) of C2H2 gas over metal/Al2O3 nanocomposite catalysts prepared by the selective reduction of oxide/Al2O3 powders. The yield and diameter of CNTs significantly depended on the kind of metal catalyst and catalyst size. X-ray diffraction (XRD) was used for phase identification. The morphology of CNTs was determined using field emission scanning electron microscopy (FESEM). FT-Raman spectroscopy revealed that the CNTs have single- and multi-walled carbon nanotubes structure. The relationship between the CNT yield/diameter and the characteristics of the composite catalyst was systematically investigated.

Homogeneous Palladium-Catalyzed Selective Reduction of 2,2’-Biphenols Using HCO2H as Hydrogen Source

Synthesis ◽  
2020 ◽  
Author(s):  
Ruoling Li ◽  
Chenchen Li ◽  
Wen Yang ◽  
Wanxiang Zhao
Keyword(s):  
Selective Reduction ◽  
Current Method ◽  
Catalytic Synthesis ◽  
Hydrogen Gas ◽  
Palladium Catalyzed ◽  
Selective Deoxygenation

An efficient homogeneous palladium-catalyzed selective deoxygenation of 2,2’-biphenols by reduction of aryl triflates with HCO2H as the hydrogen source is reported. This protocol complements the current method based on heterogeneous Pd/C-catalyzed hydrogenation with hydrogen gas. This process provided the reduction products in good to excellent yields, which could be readily converted to various synthetically useful molecules, especially ligands for catalytic synthesis.

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