Identification of compounds adsorbed and deposited on the Ni-Mo catalysts surface of alumina and SBA-15 by DRIFTS, Raman and TPO Analyses before and after Guaiacol hydrodeoxygenation.

Abstract We studied and identified compounds adsorbed or deposited on the catalysts surface of the Ni-Mo supported on alumina and SBA-15, before and after hydrodeoxigenation of a bio-oil model (guaiacol). Marked differences were observed on both catalysts through DRIFTS and Raman spectroscopy showing that the alumina-supported catalyst contains deposits of aromatic and oxygenated organic substances, while the carbon deposits on the SBA-15 as aliphatic simple molecules. TPO analyses confirm that the carbon deposited on the NiMo/SBA-15 catalyst were light polymer types, mainly nanotubes and nano fibers, while on the alumina catalyst the mainly carbon species formed were graphite type and heavier carbons. Post reaction analysis of the catalysts showed coke formation and carbon deposition rate of 1.14 mgcoke.gcat−1 h− 1 for NiMo/SBA-15 and the deactivation was 44 % higher for the NiMo/Al2O3 with 1.65 mgcoke.gcat−1 h− 1of carbon deposition rate.

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Analysis of Precursors of Carbon Deposition in Hydrogen Preparation by Fast Pyrolysis of Bio-Oil via Catalytic Steam Reforming

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.512-515.338 ◽

2012 ◽

Vol 512-515 ◽

pp. 338-342 ◽

Cited By ~ 1

Author(s):

Ping Lan ◽

Li Hong Lan ◽

Tao Xie ◽

An Ping Liao

Keyword(s):

Steam Reforming ◽

Molecular Sieve ◽

Carbon Deposition ◽

Catalyst Activity ◽

Coke Formation ◽

Fast Pyrolysis ◽

Bio Oil ◽

Aldehydes And Ketones ◽

Pyrolysis Of Biomass ◽

Catalytic Steam Reforming

In the preparation of hydrogen, the bio-oil from pyrolysis of biomass must be further upgraded (catalytic steam reforming)SO as to improve its quality．However the catalyst used in the steam reforming reaction is easy to lose its activity due to being coked' SO that it is important to study the coke formation and its efects on the catalyst activity in the steam reforming process．Fourier Transform Infrared Spectroscopy were used to analyze the precursor of coke on the catalyst Ni/MgO-La2O3-Al2O3 used in steam reforming reaction and the mechanism of coking Was also discussed based on it．The results indicate that precursors of coke deposited inside the pore of the molecular sieve are mainly paraffin, alcohols, aldehydes and ketones, and aromatic compounds.

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Hydrodeoxygenation of Guaiacol over Pd–Co and Pd–Fe Catalysts: Deactivation and Regeneration

Processes ◽

10.3390/pr9030430 ◽

2021 ◽

Vol 9 (3) ◽

pp. 430

Author(s):

Nga Tran ◽

Yoshimitsu Uemura ◽

Thanh Trinh ◽

Anita Ramli

Keyword(s):

Coke Formation ◽

Fixed Bed ◽

Fixed Bed Reactor ◽

Regeneration Ability ◽

Co Catalyst ◽

Fe Catalyst ◽

Coke Deposit ◽

Bio Oil ◽

Before And After ◽

Fe Catalysts

In bio-oil upgrading, the activity and stability of the catalyst are of great importance for the catalytic hydrodeoxygenation (HDO) process. The vapor-phase HDO of guaiacol was investigated to clarify the activity, stability, and regeneration ability of Al-MCM-41 supported Pd, Co, and Fe catalysts in a fixed-bed reactor. The HDO experiment was conducted at 400 °C and 1 atm, while the regeneration of the catalyst was performed with an air flow at 500 °C for 240 min. TGA and XPS techniques were applied to study the coke deposit and metal oxide bond energy of the catalysts before and after HDO reaction. The Co and Pd–Co simultaneously catalyzed the CArO–CH3, CAr–OH, and multiple C–C hydrogenolyses, while the Fe and Pd–Fe principally catalyzed the CAr–OCH3 hydrogenolysis. The bimetallic Pd–Co and Pd–Fe showed a higher HDO yield and stability than monometallic Co and Fe, since the coke formation was reduced. The Pd–Fe catalyst presented a higher stability and regeneration ability than the Pd–Co catalyst, with consistent activity during three HDO cycles.

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Silica Sol-Gel Supported Nickel Nano-Catalyst for Hydrogen Production Using Microreactors

MRS Proceedings ◽

10.1557/proc-0885-a10-09 ◽

2005 ◽

Vol 885 ◽

Author(s):

Krithi Shetty ◽

Shihuai Zhao ◽

Wei Cao ◽

Naidu V. Seetala ◽

Debasish Kuila

Keyword(s):

Steam Reforming ◽

Average Pore Size ◽

Sol Gel ◽

Supported Catalyst ◽

Silica Sol ◽

Average Pore ◽

Steam Reforming Of Methanol ◽

Nano Catalyst ◽

Before And After ◽

Reforming Reactions

ABSTRACTThe goal of this research is to investigate the activities of a non-noble nano-catalyst (Ni/SiO2) using Si-microreactors for steam reforming of methanol to produce hydrogen for fuel cells. The supported catalyst was synthesized by sol-gel method using Ni (II) salts and Si(C2H5O)4 as starting materials. EDX results indicate that the actual loading of Ni (5-6%) is lower than the intended loading of 12 %. The specific surface area of the silica sol-gel encapsulated Ni nano-catalyst is 452 m2/g with an average pore size of ∼ 3 nm. Steam reforming reactions have been carried out in a microreactor with 50 µm channels in the temperature range of 180-240 °C and atmospheric pressure. Results show 53% conversion of methanol with a selectivity of 74 % to hydrogen at 5 l/min and 200 °C. The magnetic properties of the catalysts were performed using a Vibrating Sample Magnetometer (VSM) to study the activity of the catalysts before and after the steam reforming reactions. The VSM results indicate much higher activity in the microreactor compared to macro-reactor and Ni forms non-ferromagnetic species faster in the microreactor.

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Effects of temperature on the hydrotreatment behaviour of pyrolysis bio-oil and coke formation in a continuous hydrotreatment reactor

Fuel Processing Technology ◽

10.1016/j.fuproc.2016.03.002 ◽

2016 ◽

Vol 148 ◽

pp. 175-183 ◽

Cited By ~ 40

Author(s):

Mortaza Gholizadeh ◽

Richard Gunawan ◽

Xun Hu ◽

Ferran de Miguel Mercader ◽

Roel Westerhof ◽

...

Keyword(s):

Coke Formation ◽

Bio Oil ◽

Effects Of Temperature

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Energy and Resources Recovery from Gasified Screenings and Toxic Sludge

Materials Science Forum ◽

10.4028/www.scientific.net/msf.1045.194 ◽

2021 ◽

Vol 1045 ◽

pp. 194-202

Author(s):

Siviwe H. Bunge ◽

James L. Topkin ◽

Joshua Gorimbo ◽

Diakanua B. Nkazi

Keyword(s):

Liquid Fuel ◽

Energy Content ◽

Chemical Species ◽

Adsorption Properties ◽

Fuel Production ◽

Management Options ◽

High Quality ◽

Oil Resources ◽

Bio Oil ◽

Before And After

Sludge and screenings management is increasingly becoming a dilemma due its accumulating and tightening environmental regulations that limit its disposal methods. Various sludge management options have been researched, ranging from incineration, thermochemical liquefaction, to pyrolysis and gasification. This work proposes syngas, bio-oil, chemical resources and bio-char production for beneficiation through gasification of a mixture of sludge and screenings at different ratios of 25/75, 50/50 and 75/25. It also studies mass loss and toxins possible destruction by gasification temperatures and reactions. Toxicity and CHNS analysis before and after gasification were aimed at finding sludge energy content, while thermogravimetric analysis (TGA), was to find sampling and stopping temperatures during gasification. The overall best results of high syngas quality (high LHV, H2, CO and CH4 contents) and high quality bio-oil (i.e. cleanest, with high crude oil equivalent bonds such as C1 up to C36 and higher applicable bio-oil resources and chemical species obtained) was achieved by a 75/25 ratio, followed by a 50/50 ratio. The results also showed some possibility of biological and chlorinated hydrocarbon toxins (PCBs and PAHs) break down as well as the reduction of sludge and screenings to about 32% of the initial mass. These results can be further investigated for syngas application in power generation and liquid fuel production. Char toxicity can be analysed for its application in agriculture and for its adsorption properties. Char can be analysed for the presence of metals in it.

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Comparative study by GC×GC-TOFMS on the composition of crude and composite-additives bio-oil before and after accelerated aging treatment

Journal of the Energy Institute ◽

10.1016/j.joei.2020.05.010 ◽

2020 ◽

Vol 93 (6) ◽

pp. 2163-2175

Author(s):

Yichen Wang ◽

Renzhan Yin ◽

Meiyun Chai ◽

Nishu ◽

Chong Li ◽

...

Keyword(s):

Comparative Study ◽

Accelerated Aging ◽

Aging Treatment ◽

Bio Oil ◽

Before And After

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Single Wafer Amorphous Silicon Process Evaluation

MRS Proceedings ◽

10.1557/proc-467-633 ◽

1997 ◽

Vol 467 ◽

Author(s):

David O'Meara ◽

Chow Ling Chang ◽

Roc Blumenthal ◽

Rama I. Hegde ◽

Lata Prabhu ◽

...

Keyword(s):

Surface Roughness ◽

Surface Morphology ◽

Amorphous Silicon ◽

Deposition Rate ◽

Cross Sections ◽

Growth Conditions ◽

Degree Of Crystallinity ◽

Deposition Parameters ◽

Before And After ◽

Production Requirement

ABSTRACTSingle wafer amorphous silicon deposition was characterized through process modeling and film characterization for application in semiconductor production. DOE methodology was used to determine the main deposition parameters, and the responses were limited to device production requirement properties of surface roughness, deposition rate and degree of crystallinity of the as-deposited film. The data trends and models show that deposition temperature and silane flow are the main factors. Increasing either or both factor increases the deposition rate and the surface roughness. The surface morphology, evaluated by AFM, SEM and TEM, was found to be rougher at extreme growth conditions than the poly crystalline film formed after anneal. The as-deposited surface morphology was not a result of pre-anneal crystal formations as determined by TEM cross sections of samples before and after anneal. Lack of crystalinity is important for impurity diffusion considerations. Device application of the single wafer a-Si process will be a compromise between growth rate (and associated throughput) and surface roughness that can be tolerated.

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