scholarly journals Effect of Particle Size on the HDS Activity of Molybdenum Sulfide

2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Carola Contreras ◽  
Fernanda Isquierdo ◽  
Pedro Pereira-Almao ◽  
Carlos E. Scott
Keyword(s):  
Particle Size ◽  
Heavy Oil ◽  
Molybdenum Sulfide ◽  
Vacuum Gas Oil ◽  
Particle Sizes ◽  
Heavy Oils ◽  
Gas Oil ◽  
Oil Reserves ◽  
Effect Of Particle Size

More than half of the total world oil reserves are heavy oil, extra heavy oil, and bitumen; however their catalytic conversion to more valuable products is challenging. The use of submicronic particles or nanoparticles of catalysts suspended in the feedstock may be a viable alternative to the conversion of heavy oils at refinery level or downhole (in situ upgrading). In the present work, molybdenum sulfide (MoS2) particles with varying diameters (10000–10 nm) were prepared using polyvinylpyrrolidone as capping agent. The prepared particles were characterized by DLS, TEM, XRD, and XPS and tested in the hydrodesulfurization (HDS) of a vacuum gas oil (VGO). A correlation between particle size and activity is presented. It was found that particles with diameters around 13 nm show double the HDS activity compared with the material with micrometric particle sizes (diameter ≈ 10,000 nm).

Effect of particle size on in-situ desulfurization for oxy-fuel CFBC

Fuel ◽  
2021 ◽  
Vol 291 ◽  
pp. 120270
Author(s):  
Seo Yeong Kang ◽  
Su Been Seo ◽  
Eun Sol Go ◽  
Hyung Woo Kim ◽  
Sang In Keel ◽  
...  
Keyword(s):  
Particle Size ◽  
Effect Of Particle Size

Effect of Particle Size on the Oil Yield and Catechin Compound Using Accelerated Solvent Extraction

2013 ◽  
Vol 60 (1) ◽  
Author(s):  
Mohd Azizi Che Yunus ◽  
Manzurudin Hasan ◽  
Norasikin Othman ◽  
Siti Hamidah Mohd-Setapar ◽  
Liza Md.-Salleh ◽  
...  
Keyword(s):  
Particle Size ◽  
Solvent Extraction ◽  
Accelerated Solvent Extraction ◽  
Extraction Time ◽  
Oil Yield ◽  
Particle Sizes ◽  
Experimental Range ◽  
Areca Catechu ◽  
Effect Of Particle Size ◽  
Extraction Cycle

Kajian ini bertujuan untuk mengkaji kesan saiz zarah ke atas pengekstrakan sebatian catechin daripada biji Areca catechu L. dengan menggunakan Pengekstrakan Pelarut Terpecut (PPT). Saiz zarah biji Areca catechu dipelbagaikan dari 75 μm sehingga 500 μm. Pengekstrakan telah dijalankan padaparameter tetap iaitu suhu (140oC), tekanan (1500 psi), masa (10 minit), isipadu semburan (60%) dan satu kitaran pengekstrakan, masing-masing. Hasil minyak peratusan yang lebih tinggi adalah 300 mg minyak / gram sampel (30.00% pati minyak) ditemui pada 125 μm. Walaubagaimanapun, kandungan catechin dalam pati minyak hanya 0.0375 mg catechin / gram sampel. Saiz zarah yang terbaik dalam julat uji kaji ini telah dikenal pasti pada 500 μm yang memberikan kandungan catechin yang tinggi iaitu 0.0515 mg catechin / gram sampel dari 247.5 mg minyak / gram sampel (24.75% pati minyak). Kata kunci: Saiz zarah; catechin; LC-MS-TOF; pengekstrakan pelarut terpecut The purpose of this work is to investigate the effects of particle size on the extraction of catechincompound from Areca catechu L. seeds by using Accelerated Solvent Extraction (ASE). The particle sizes of Areca catechu L. seeds are varied from 75 µm until 500 µm. The extraction is conducted at fixed parameters which are temperature (140oC), pressure (1500 psi), extraction time (10 minutes), flush volume (60%) and the static cycle is done for 1 extraction cycle respectively. Higher percentage oil yield of 300mg oil/gram of sample (30.00% oil yield) is found at 125 µm. However, the amount of catechin in oil yields is only 0.0375 mg of catechin/gram of sample. The best of particle size within the experimental range has been identified at 500 µm which gives a high content of catechin with 0.0515 mg Catechin/gram of sample from 247.5 mg oil/gram of sample (24.75% oil yield). Keywords: Particle size; catechin; LC-MS-TOF; accelerated solvent extraction

The use of hollow sphere pigments as strength additives in paper and paperboard coatings—Part 1: The predictive nature of packing models on coating properties

TAPPI Journal ◽  
2020 ◽  
Vol 19 (11) ◽  
pp. 585-593
Author(s):  
ETHAN GLOR ◽  
BRIAN EINSLA ◽  
JOHN ROPER ◽  
JIAN YANG ◽  
VALERIY GINZBURG
Keyword(s):  
Particle Size ◽  
Hollow Sphere ◽  
Particle Packing ◽  
Particle Sizes ◽  
Coating Properties ◽  
Ideal System ◽  
Thermal Paper ◽  
Effect Of Particle Size ◽  
Low Levels ◽  
Better Than

Hollow sphere pigments (HSPs) are widely used at low levels in coated paper to increase coating bulk and to provide gloss to the final sheet. However, HSPs also provide an ideal system through which one can examine the effect of pigment size and particle packing within a coating due to their unimodal and tunable particle sizes. The work presented in Part 1 and Part 2 of this study will discuss the use of blends of traditional inorganic pigments and HSPs in coating formulations across a variety of applications for improved coating strength. Part 1 of this study focuses on the theory of bimodal spherical packing and demonstrates the predictive nature of packing models on the properties of coating systems containing HSPs of two different sizes. This study also examines conditions where the model fails by examining the effect of particle size on coating strength in sytems like thermal paper basecoats where the non-HSP component has a broad particle size distribution, and how these surprising trends can be used to generate better-than-expected thermal printing performance in systems with low HSP/clay ratios. Part 2 of this study focuses on the incorporation of HSPs of different particle sizes into paperboard formulations to affect coating strength and opacity.

Effect of Particle Size upon Pt/SiO2Catalytic Cracking ofn-Dodecane under Supercritical Conditions: In situ SAXS and XANES Studies

ChemCatChem ◽  
2016 ◽  
Vol 9 (1) ◽  
pp. 99-102 ◽  
Author(s):  
Sungwon Lee ◽  
Sungsik Lee ◽  
Mrunmayi D. Kumbhalkar ◽  
Kamila M. Wiaderek ◽  
James Dumesic ◽  
...  
Keyword(s):  
Particle Size ◽  
Supercritical Conditions ◽  
Effect Of Particle Size

In situ cracking of silica beads in the SEM and TEM — Effect of particle size on structure–property correlations

2015 ◽  
Vol 270 ◽  
pp. 337-347 ◽  
Author(s):  
J. Paul ◽  
S. Romeis ◽  
M. Mačković ◽  
V.R.R. Marthala ◽  
P. Herre ◽  
...  
Keyword(s):  
Particle Size ◽  
Structure Property ◽  
Sem And Tem ◽  
Silica Beads ◽  
Effect Of Particle Size ◽  
Property Correlations

scholarly journals EFFECT OF PARTICLE SIZE OF GROSSMAN'S CEMENT POWDER ON SETTING TIME

1998 ◽  
Vol 12 (1) ◽  
pp. 1-4 ◽  
Author(s):  
Jesus Djalma PÉCORA ◽  
Ricardo Gariba SILVA ◽  
Ricardo Novak SAVIOLI ◽  
Luis Pascoal VANSAN
Keyword(s):  
Particle Size ◽  
Powder Particle ◽  
Setting Time ◽  
Particle Sizes ◽  
Cement Powder ◽  
Effect Of Particle Size

A study was conducted on the hardening time of three Grossman's cements with different powder particle sizes (60, 100 and 150 mesh) using Specification n. 57 of the AMERICAN DENTAL ASSOCIATION1 (1983). The cement obtained from mesh 150 particles showed the longest hardening time (22 minutes), which was different when compared to mesh 60 (17 minutes) and 100 (17 minutes) particles.

scholarly journals Investigation of the Effect of Particle Size on Groundnut-Oil Solvent Extraction

2008 ◽  
Vol 31 (2) ◽  
pp. 1-13
Author(s):  
S.V. Manyele ◽  
I.F. Kahemel
Keyword(s):  
Particle Size ◽  
Solvent Extraction ◽  
Oil Recovery ◽  
Volatile Matter ◽  
Particle Sizes ◽  
Total Volatile ◽  
Groundnut Oil ◽  
Time Intervals ◽  
Effect Of Particle Size ◽  
Rate Of Extraction

An investigation of the effect of particle size on the performance of vegetable oil recovery by solvent extraction is reported. Experiments were conducted using soxhlet extractor, groundnuts and n-hexane. Samples were grouped into mean particle sizes of 0.25, 0.75, 1.3, 3.3, and 7.5 mm using standard sieves. The effect of particle size was studied for extraction time intervals of 1, 2, 3, 4, 5 and 8 hours. The oil yield, oil recovered per kg solvent used, kg solvent lost per unit time, and the rate of extraction (kg oil recovered per hour) decreased with increasing particle size. Meanwhile, the percent of solvent recovered, the ratio of oilrecovered to the total volatile matter driven off and the kg solvent lost per kg oil recovered, increased with increasing particle size. Based on the normalization of averaged extraction-parameters, a mean particle size of 3.3 mm was observed to be the optimum size.

EXPERIMENTAL AND NUMERICAL EVALUATION OF THE EFFECT OF PARTICLE SIZE ON SLURRY EROSION PREDICTION

2020 ◽  
pp. 1-19
Author(s):  
Qiuchen Wang ◽  
Qiyu Huang ◽  
Xu Sun ◽  
Jun Zhang ◽  
Soroor Karimi ◽  
...  
Keyword(s):  
Particle Size ◽  
Exclusion Process ◽  
Local Maximum ◽  
Particle Sizes ◽  
Slurry Erosion ◽  
Carrier Fluid ◽  
Erosion Damage ◽  
Erosion Models ◽  
Effect Of Particle Size ◽  
Erosion Profiles

Abstract During petroleum production, sand particles can be entrained with the transported carrier fluid despite of any sand exclusion process and erode the inner walls of pipelines. This erosion process may even cause pipe leakage and oil spill. Therefore, investigate the regularities of erosion damage changing with particle sizes and predict erosion behavior under different sizes particles are important to pipeline safety. In this study, slurry erosion experiments are conducted using quartz particles with similar shapes and different sizes ranging from 25 micrometers to 600 micrometers to investigate the effect of particle size on erosion profiles and provide the database for evaluating models. Computational Fluid Dynamics (CFD) is used to simulate the fluid flow and track particles to obtain impact information. Erosion equations then connect the particles' impact information with erosion rate. Finally, the available mechanistic and empirical equations erosion models are evaluated by comparing predicted erosion profile with experimental data. It was found that the local maximum erosion damage increases with particle sizes although the total erosion ratio is not increasing. These changes of erosion profiles can be predicted with acceptable accuracy by available empirical erosion models when particle sizes are no less than 75 micrometers.

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