scholarly journals "PALLADIUM ON COAL" CATALYST OBTAINED BY PYROLYSIS OF POWDER CELLULOSE GRANULES IM-PREGNATED WITH PALLADIUM NITRATE

2021 ◽  
pp. 333-342
Author(s):  
Andrey Borisovich Shishmakov ◽  
Yuliya Vladimirovna Mikushina ◽  
Ol'ga Vasil'yevna Koryakova
Keyword(s):  
Palladium Catalysts ◽  
Total Porosity ◽  
Carbon Matrix ◽  
Ash Content ◽  
Spherical Particles ◽  
Powdered Cellulose ◽  
Powder Cellulose ◽  
Palladium Nitrate ◽  
Water Seal ◽  
Pyrolysis Gases

By pyrolysis of powdered cellulose granules impregnated with palladium nitrate, catalysts of 1–8% Pd / C were obtained. Pyrolysis was carried out in a reactor with a water seal at 600 ° C. Metal reduction was carried out with pyrolysis gases and matrix carbon. It was found that the ash content of powdered cellulose granules is ~ 40 times less than the ash content of sulfate cellulose, from which they were made. It was shown by X-ray phase analysis and electron microscopy that palladium in the catalysts is present in the form of Pd (0) nanoparticles uniformly covering carbon fibers and shapeless massive metal precipitates up to 20 μm in diameter. In catalysts 1–3% Pd / С, nanoparticles 10–40 nm dominate (> 95%), in 8% Pd / С, 20–70 nm. The share of massive metal formations in Pd (1%) / C, Pd (3%) / C and Pd (8%) / C is: ~ 2%, ~ 5% and ~ 60%, respectively. They consist of aggregated spherical particles 0.05–0.15 µm in diameter. XRD palladium oxide was not detected in the catalysts. The presence of palladium nitrate in powdered cellulose during its carbonization has a significant effect on the formation of the carbon matrix. With an increase in the content of palladium nitrate in powdered cellulose, the yield of carbon material decreases and its total porosity increases. Infrared spectroscopy revealed the presence of oxygen-containing ether groups in the carbon matrix of palladium catalysts. The activity of catalysts in the model process of decomposition of hydrogen peroxide increases with increasing dispersion of palladium nanoparticles.

scholarly journals Structural, morphological and catalytic characteristics of nanostructured palladium catalysts

2021 ◽  
Vol 2086 (1) ◽  
pp. 012203
Author(s):  
P D Pushankina ◽  
I S Lutsenko ◽  
I S Glazkova ◽  
T I Malkov ◽  
M A Mukhanov
Keyword(s):  
Palladium Catalysts ◽  
Active Sites ◽  
High Efficiency ◽  
Active Surface ◽  
Spherical Particles ◽  
Methanol Oxidation Reaction ◽  
Catalyst Synthesis ◽  
Long Term Stability ◽  
Highly Active

Abstract A new method for the highly active palladium catalyst synthesis on the surface of a Pd-23%Ag film has been developed to increase the material activity with respect to reactions involving hydrogen. Comparison of the electrochemical experiments data of classical palladium black and a new developed nanocatalyst demonstrated a significant increase in catalytic activity in the methanol oxidation reaction (up to 17.09 μA cm−2) for electrodes modified with the latter catalyst. The reason for that is an increase in the number of localized potentially more active surface regions due to the creation of a larger number of active sites in comparison with spherical particles. Estimation of resistance to CO poisoning showed high efficiency of nanocatalysts. Chronoamperometric experiment established the long-term stability and activity of the developed catalyst and confirmed the possibility of its practical use.

scholarly journals Studies on Carbon-Fly Ash Composites with Chopped PANOX Fibers

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Rakesh V. Patel ◽  
S. Manocha
Keyword(s):  
Thermal Stability ◽  
Fly Ash ◽  
Polymer Matrix ◽  
Chemical Constituents ◽  
Carbon Matrix ◽  
Processing Parameters ◽  
Spherical Particles ◽  
Particulate Composites ◽  
Morphological Studies ◽  
Silica Alumina

Chemical analysis and morphological studies of fly ash reveals the complex chemical constituents present as spherical particles with diameter of less than 25 μm. The constituents of fly ash are silica, alumina, iron oxide, titanium dioxide, calcium and magnesium oxide, and other trace elements. The use of thermosetting as well thermoplastic polymer matrix has been made by several workers to develop polymer matrix fly ash particulate composites by using the hard and abrasive properties of fly ash and lightweight of polymers. Such composites have poor mechanical strength, fracture toughness, and thermal stability. To overcome these shortcomings, in carbonaceous matrix, the carbon fibers were added as additional reinforcement along with the fly ash. The composites were developed with two different methods known as Dry method and Wet method. The processing parameters such as temperature and pressure were optimized in establishing the carbon matrix. Physical, thermal, and mechanical characteristics were studied. The microstructures of composites show good compatibility between fly ash and fibers with the carbon matrix. These composites have higher strength, thermal stability, and toughness as compared to polymer matrix fly ash particulate composites.

scholarly journals THE INFLUENCE OF THE KNIFE METHOD OF GRINDING PULP ON THE PROCESS OF OBTAINING POWDERED CELLULOSE

2020 ◽  
pp. 493-499
Author(s):  
Yuriy Davidovich Alashkevich ◽  
Larisa Vladimirovna Yurtaeva ◽  
Наталья Сергеевна Reshetova ◽  
Roman Aleksandrovich Marchenko
Keyword(s):  
Cellulose Fiber ◽  
Degree Of Polymerization ◽  
Water Retention Capacity ◽  
Technological Parameters ◽  
Retention Capacity ◽  
Powdered Cellulose ◽  
Cellulose Material ◽  
Powder Cellulose ◽  
Hydrolysis Process ◽  
Hardwood Pulp

This article presents the classification of the resulting types of powdered cellulosic materials, their scope, as well as the problems arising during production. The main properties of powder cellulose materials are considered. Analyzed the quality indicators of the pulp, previously ground in a disc mill. The main technological parameters of the experimental setup and the comparative characteristics of the used knife grinding sets are presented. In the course of the experimental research, knife grinding sets with straight and curved knives were used. The data obtained confirmed the previously put forward hypothesis about the predominant fibrillation of cellulose fiber milled using a grinding set with a curved blade shape. This feature of the headset design is especially important when grinding hardwood pulp, which has a lower initial value, compared to softwood pulp. The data obtained in determining the degree of grinding, water retention capacity, fiber length of softwood and hardwood cellulose after knife grinding and the degree of polymerization after hydrolysis are presented. A method for producing powdered cellulose material with characteristics similar to microcrystalline cellulose is considered. The regulated parameters of the hydrolysis process are set and a comparison is made of the degree of polymerization of the considered samples of powdered cellulose.

scholarly journals INFLUENCE OF THE FIBROUS MASS GRINDING METHOD ON THE PROCESS OF POWDER CELLULOSE PRODUCTION

2020 ◽  
Author(s):  
L.V. Yurtaeva ◽  
Yuri Alashkevich ◽  
N.S. Reshetova ◽  
Roman Marchenko
Keyword(s):  
Microcrystalline Cellulose ◽  
Experimental Studies ◽  
Cellulose Production ◽  
Powdered Cellulose ◽  
Cellulose Material ◽  
Grinding Method ◽  
Powder Cellulose ◽  
Disk Mill

The article presents results of experimental studies of cellulose properties depending on different shaped knife tooling of the disk mill used for grinding. A method for production of powdered cellulose material with characteristics close to microcrystalline cellulose is considered.

HYDROPHILIC RUBBER BASED ON BUTADIENE-NITRILE RUBBER AND POWDER CELLULOSE OF PLANT ORIGIN

2021 ◽  
pp. 33-37
Author(s):  
E.N. Cherezova ◽  
◽  
Yu.S. Karaseva ◽  
K.S. Momzyakova ◽  
◽  
...  
Keyword(s):  
Tensile Strength ◽  
Aqueous Medium ◽  
Nitrile Rubber ◽  
Plant Origin ◽  
Mechanical Destruction ◽  
Powdered Cellulose ◽  
Powder Cellulose ◽  
Degree Of Swelling ◽  
Oat Straw ◽  
Butadiene Nitrile Rubber

It has been established that the introduction of powdered cellulose, obtained by chemo-mechanical destruction from oat straw, into the composition of rubbers as a hydrosorption filler increases the conditional tensile strength of vulcanizates in comparison with samples without this filler. It was revealed that the degree of swelling of rubbers containing powdered cellulose from oat straw, the pH of the aqueous medium and the degree of mineralization have little effect.

STEM Study of Surface Plasmon Excitation in Small Spherical Particles

1990 ◽  
Vol 48 (2) ◽  
pp. 42-43
Author(s):  
Daniel UGARTE
Keyword(s):  
Energy Loss ◽  
Spherical Particles ◽  
Small Particles ◽  
Bulk Materials ◽  
Low Loss ◽  
Plasmon Excitation ◽  
Surface Modes ◽  
Surface Plasmon Excitation ◽  
Analytical Electron ◽  
Analytical Electron Microscope

Small particles exhibit chemical and physical behaviors substantially different from bulk materials. This is due to the fact that boundary conditions can induce specific constraints on the observed properties. As an example, energy loss experiments carried out in an analytical electron microscope, constitute a powerful technique to investigate the excitation of collective surface modes (plasmons), which are modified in a limited size medium. In this work a STEM VG HB501 has been used to study the low energy loss spectrum (1-40 eV) of silicon spherical particles [1], and the spatial localization of the different modes has been analyzed through digitally acquired energy filtered images. This material and its oxides have been extensively studied and are very well characterized, because of their applications in microelectronics. These particles are thus ideal objects to test the validity of theories developed up to now.Typical EELS spectra in the low loss region are shown in fig. 2 and energy filtered images for the main spectral features in fig. 3.

A novel method for the determination of linting propensity of paper

TAPPI Journal ◽  
2012 ◽  
Vol 11 (10) ◽  
pp. 9-17
Author(s):  
ALESSANDRA GERLI ◽  
LEENDERT C. EIGENBROOD
Keyword(s):  
Ash Content ◽  
The Novel ◽  
Offset Printing ◽  
Excellent Correlation ◽  
End Conditions ◽  
Bottom Side ◽  
Novel Method ◽  
Total Fraction

A novel method was developed for the determination of linting propensity of paper based on printing with an IGT printability tester and image analysis of the printed strips. On average, the total fraction of the surface removed as lint during printing is 0.01%-0.1%. This value is lower than those reported in most laboratory printing tests, and more representative of commercial offset printing applications. Newsprint paper produced on a roll/blade former machine was evaluated for linting propensity using the novel method and also printed on a commercial coldset offset press. Laboratory and commercial printing results matched well, showing that linting was higher for the bottom side of paper than for the top side, and that linting could be reduced on both sides by application of a dry-strength additive. In a second case study, varying wet-end conditions were used on a hybrid former machine to produce four paper reels, with the goal of matching the low linting propensity of the paper produced on a machine with gap former configuration. We found that the retention program, by improving fiber fines retention, substantially reduced the linting propensity of the paper produced on the hybrid former machine. The papers were also printed on a commercial coldset offset press. An excellent correlation was found between the total lint area removed from the bottom side of the paper samples during laboratory printing and lint collected on halftone areas of the first upper printing unit after 45000 copies. Finally, the method was applied to determine the linting propensity of highly filled supercalendered paper produced on a hybrid former machine. In this case, the linting propensity of the bottom side of paper correlated with its ash content.

Facile preparation of nanofiller-paper using mixed office paper without deinking

TAPPI Journal ◽  
2015 ◽  
Vol 14 (3) ◽  
pp. 167-174 ◽  
Author(s):  
QIANQIAN WANG ◽  
J.Y. ZHU
Keyword(s):  
Cellulose Nanofibrils ◽  
Ash Content ◽  
Raw Material ◽  
Mechanical Grinding ◽  
Microscope Imaging ◽  
Facile Preparation ◽  
Electron Microscope Imaging ◽  
Thermal Stability Of ◽  
Scanning Electron ◽  
Office Paper

Mixed office paper (MOP) pulp without deinking with an ash content of 18.1 ± 1.5% was used as raw material to produce nanofiller-paper. The MOP pulp with filler was mechanically fibrillated using a laboratory stone grinder. Scanning electron microscope imaging revealed that the ground filler particles were wrapped by cellulose nanofibrils (CNFs), which substantially improved the incorporation of filler into the CNF matrix. Sheets made of this CNF matrix were densified due to improved bonding. Specific tensile strength and modulus of the nanofiller-paper with 60-min grinding reached 48.4 kN·m/kg and 8.1 MN·m/kg, respectively, approximately 250% and 200% of the respective values of the paper made of unground MOP pulp. Mechanical grinding duration did not affect the thermal stability of the nanofiller-paper.

PENGARUH VIRGIN COCONUT OIL (VCO) TERHADAP KARAKTERISTIK DAN UMUR SIMPAN ROTI MANIS

2020 ◽  
Vol 5 (1) ◽  
Author(s):  
Aulia Alfi
Keyword(s):  
Moisture Content ◽  
Shelf Life ◽  
Coconut Oil ◽  
Temperature Treatment ◽  
Ash Content ◽  
Virgin Coconut Oil ◽  
Food Ingredients ◽  
Life Analysis ◽  
Antibacterial And Antifungal ◽  
Physical And Chemical

Virgin Coconut Oil (VCO) adalah bahan alami yang memiliki sifat antimikroba (antivirus, antibakteri, dan antijamur). Sehingga VCO dapat memberikan efek pengawet pada bahan makanan, salah satunya adalah roti manis. Penelitian ini dilakukan untuk mengevaluasi pengaruh VCO terhadap karakteristik (fisik dan kimia) dan umur simpan roti manis. Roti manis dianalisis secara fisik (tekstur dan porositas) dan kimia (kadar air, kadar abu, kadar lemak, kadar protein, dan kandungan karbohidrat), dan analisis umur simpan dengan FFA, uji organoleptik dan jamur setiap dua hari selama delapan hari penyimpanan di suhu ruang. Variasi perlakuan roti manis adalah dari rasio konsentrasi VCO: margarin: mentega, K (0%: 8%: 8%); A (4%: 6%: 6%); B (8%: 4%: 4%), C (12%: 2%: 2%); D (16%: 0%: 0%). Hasil penelitian menunjukkan bahwa VCO tidak memiliki pengaruh yang signifikan terhadap karakteristik fisik dan karakteristik kimia roti manis. Namun, VCO berpengaruh signifikan terhadap kadar air roti manis yang dihasilkan, roti manis K memiliki kadar air tertinggi (22,36%) dan berbeda dengan sampel roti manis lainnya. VCO secara efektif menghambat pertumbuhan jamur di roti manis pada konsentrasi 8%, 12%, dan 16%. Roti manis K dan A memiliki masa simpan 4 hari, sedangkan roti manis B, C, dan D memiliki masa simpan 6 hari.Kata kunci: VCO, roti manis, karakteristik, umur simpanABSTRACTVirgin Coconut Oil (VCO) is a natural ingredient that has antimicrobial (antiviral, antibacterial, and antifungal) properties. So that VCO can provide a preservative effect on food ingredients, one of which is sweet bread. This research was conducted to evaluate the effect of VCO on characteristics (physical and chemical) and shelf life of sweet bread. Sweet bread was analyzed physically (texture and porosity) and chemistry (moisture content, ash content, fat content, protein content, and carbohydrate content), and shelf life analysis with FFA, organoleptic and mold tests every two days for eight days of storage at ambient temperature. Treatment variations of sweet breads is from the ratio of the concentration of VCO: margarine: butter, K (0%: 8%: 8%); A (4%: 6%: 6%); B (8%: 4%: 4%), C (12%: 2%: 2%); D (16%: 0%: 0%). The results showed that VCO did not have a significant effect on the physical characteristics and chemical characteristics of sweet bread. However, the VCO has a significant effect on the water content of the sweet bread produced, sweet bread K has the highest moisture content (22,36%) and it is different from other sweet bread samples. VCO effectively inhibits the growth of sweet bread mold at concentrations of 8%, 12%, and 16%. K and A sweet bread has a shelf life of 4 days, while sweet breads B, C, and D have a shelf life of 6 days.Keywords: VCO, sweet bread, characteristics, shelf life

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