scholarly journals Characteristics of the Coal Fines Produced from Low-Rank Coal Reservoirs and Their Wettability and Settleability in the Binchang Area, South Ordos Basin, China

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-17
Author(s):  
Yue Chen ◽  
Zhuoyuan Ma ◽  
Dongmin Ma ◽  
Zhicang Zhang ◽  
Weibo Li ◽  
...  

By using proximate analysis, X-ray diffraction mineral analysis, scanning electron microscope, contact angle measurement, and settlement simulation experiment, the coal fines produced from the coalbed methane wells of Binchang area were used to study the characteristics including particle size distribution, composition, morphology, wettability, and settleability. The results show that the particle size of coal fines produced from coalbed methane wells are mainly >20 mesh, ranging of 1-400 μm, and the particle size distribution curve is mainly dominated by the main-secondary bimodal type, with the main peak of 30-300 μm. The particle size from large to small is drill cutting coal fines, flowback coal fines, bailing coal fines, and pipeline filter coal fines. In terms of ash content, coal fines are higher than coal seam, and drilling cuttings are higher than bailing coal fines, while the fixed carbon content of the former is lower than that of the latter. The minerals of coal fines are mainly kaolinite, illite, quartz, and other 6 minerals, and the mineral types of drilling coal fines are the most abundant, while the bailing coal fines only contain illite and quartz. The roundness of coal fine particles ranges from excellent to poor in the order of bailing coal fines, pipeline filter coal fines, flowback coal fines, and drilling cuttings. However, the sorting of drilling cuttings is excellent, and the particle edges are straight, neat, and smooth, while the sorting of bailing coal fines is poor, and the particle edges are curved, uneven, and rough. The contact angles of coal fines are 40.25°-69.5°, indicating hydrophilous. The wettability of bailing coal fines is better than that of drilling cuttings. The particle size has a negative correlation with the wettability effect. The more obvious the modification effect of positive wetting agent is, the worse the modification effect of negative wetting agent is. The modification of surfactant has nothing to do with the particle size of the coal fines, but is closely related to organic components and minerals. The larger the coal particle size, the higher the settling rate, and the higher the ash content and the lower the fixed carbon content, the faster the settling rate. With the dividing point 150 mesh, the settling rate of large particles is mainly affected by particle size, while that of small particles is affected by the composition.

2019 ◽  
Vol 20 (2) ◽  
pp. 75
Author(s):  
Deni Mustika ◽  
Sudirman Sudirman ◽  
Adel Fisli ◽  
I Made Joni ◽  
Th. Rina M.

THE POTENTIAL OF INDONESIAN GRAPHITE AS RDE FUEL MATRIX. The development plan of Ex- perimental Power Reactor (RDE) in Indonesia is non-commercial and leads to the technology type of Pebble Bed Reactor (PBR) - High Temperature Gas Cooled Reactor (HTGR). The fuel used for PBR reactors is kernel dispersed in spherical fuel elements. The matrix used in PBR nuclear fuel is graphite which functions as a neutron moderator, fuel protective material and heat conductor. Domestication of the domestic fuel matrix needs to be conducted to improve national independence. Therefore, it is necessary to do research on the potential of local graphite to be used as RDE fuel matrix. This study focused on the identification and characterization of local and commercial graphite. The results are compared with the literature, how far it is fulfilling nuclear grade graphite for PBR fuel matrix. Characterization of graphite includes phase analysis with XRD, micro- structure with SEM, surface area/porosity, impurities determination with AAS, ICP-OES and NAA, equivalent boron content, carbon content, density, particle size distribution and ash content. The characterization results show that the carbon content obtained was 87.0 ± 4.2% for local graphite and 100% for commercial graphite. Meanwhile, for the purposes of nuclear graphite it requires a carbon content of >99%. The impurity content in local and commercial graphite still does not meet the RDE fuel matrix standard. The results of XRD analysis show that the local graphite phase is the same as the commercial graphite phase, namely the 2H graphite hexagonal crystal system with the lattice group of P 63/mmc. Particle size distribution and surface area of local graphite are higher compared to nuclear graphite literature. The ash content of commercial graphite was 0.236 ± 0.029 and local graphite was 9.587 ± 0.010%. The results of this study indicate that the local graphite from the flotation still requires a further refinement process to obtain local graphite that can be used as a fuel matrix for RDE.


2018 ◽  
Vol 7 (1) ◽  
pp. 28-33
Author(s):  
Okta Bani ◽  
Iriany ◽  
Taslim ◽  
Cici Novita Sari ◽  
Cindy Carnella

Briquettes are solid fuels from organic materials with high calorific values ​​and burn duration. The composition and particle size of the raw material may affect briquette quality. This study aimed to evaluate the effect of composition and particle size on calorific value and characteristics of the resulting briquettes. In this study, briquettes were made using palm oil fronds and shells at mass ratio of 1:2, 1:4, 1:6, 1:8 and particle size of not-dertemined, 50, 70, and 100 mesh. First, raw material was carbonized at 450°C for 30 minutes then added to 20%wt. starch glue and waste oil (1:1 ratio). Resulting briquettes were analyzed for its water content, ash content, density, volatile matter content, fixed carbon content, combustion rate, calorific value, and compressive strength. Satisfying results were obtained for briquettes with a front to shell ratio of 1:8, and a particle size of 100 mesh. At this condition, the resulting briquettes have water content of 5.5%; ash content of 2.54%; density of 0.51 g/cm3; 19.58% vapor content; fixed carbon content of 72.38%; combustion rate of 0.2 g/min (3.4×10-3 g/sec); calorific value of 15.3 kcal/g; and compressive strength of 0.06 N/mm2. These results have complied with the Indonesian National Standard (SNI), Japanese, American, and English standards, except for briquette compressive strength, which have not met the industrial standard.


2019 ◽  
Vol 13 (1) ◽  
pp. 57
Author(s):  
Syarifhidayahtullah Syarif ◽  
Rochim Bakti Cahyono ◽  
Muslikhin Hidayat

A B S T R A C TThe conversion of cocoa shell waste into char briquettes has been carried out through various methods. However, the product characteristics do not meet the SNI briquettes requirements. Therefore, it is necessary to improve process engineering by mixing cocoa peel waste with red fruit pulp to get char briquettes in order to improve quality of briquette products. This research was carried out through pyrolysis process with temperthwatures up to 500 oC and held for 4 hours. The research objective was to produce char briquettes from cacao pod shell waste with the addition of red fruit pulp and its characteristic test. The study was designed with 2 variables, namely independent variables in the form of char raw material powder that passed 50 mesh sieve, weight ratio of cocoa shell char powder and red fruit pulp char powder (100:0, 70:30, 50:50, 30:70, and 0%:100%), pressure (100 kg/cm2), 10% starch adhesive from raw materials, and briquette diameter of 40 mm. Whereas the dependent variables are the moisture content (%), volatile content (%), ash content (%), fixed carbon content (%), and calorific value (cal/g). The results showed that the process of pyrolysis of char briquettes waste cocoa shell with red fruit pulp can increase its calorific value. The best characteristics of briquette were obtained from mixed briquettes (composition of 30%:70%) with moisture content of 5.63%, volatile content of 18.65%, ash content of 9.45%, fixed carbon content of 66.27%, and calorific value of 6422 cal/g.A B S T R A KPemanfaatan limbah kulit buah kakao menjadi briket arang telah banyak dilakukan melalui berbagai metode tetapi belum memenuhi persyaratan SNI briket arang. Oleh karena itu, perlu diupayakan untuk mendapatkan briket arang yang memenuhi persyaratan SNI. Salah satunya dengan cara mencampurkan limbah kulit kakao dengan ampas buah merah karena ampas buah merah memiliki nilai kalor yang cukup tinggi. Penelitian ini dilakukan melalui proses pirolisis dengan suhu sampai dengan 500 oC  dan ditahan selama 4 jam. Tujuan penelitian untuk memproduksi briket arang dari limbah kulit buah kakao dengan penambahan ampas buah merah serta uji karakteristiknya. Penelitian dirancang dengan 2 variabel, yaitu variabel bebas (independent variable) berupa ukuran serbuk bahan baku arang yang lolos saringan  50 mesh, rasio massa campuran serbuk arang kulit kakao dengan serbuk arang ampas buah merah (100:0, 70:30, 50:50, 30:70, dan 0%:100%), tekanan pengempaan (100 kg/cm2), perekat kanji 10% dari bahan baku, dan diameter briket 40 mm. Variabel terikat (dependent variable) yang diukur yaitu kadar air (%), kadar zat mudah menguap (%), kadar abu (%), kadar karbon terikat (%), dan nilai kalor (kal/g). Hasil penelitian menunjukkan bahwa, dengan melalui proses pirolisis briket arang limbah kulit kakao dengan ampas buah merah dapat meningkatkan nilai kalor-nya. Karakteristik briket terbaik diperoleh dari briket komposisi campuran (30%:70%) dengan kadar air 5,63 %, kadar zat mudah menguap 18,65 %, kadar abu 9,45 %, kadar karbon terikat 66,27 %, dan nilai kalor 6422 kal/g.


2016 ◽  
Vol 17 (4) ◽  
pp. 611-620
Author(s):  
H.O. Sirenko ◽  
L.M. Soltys ◽  
V.P. Svidersky ◽  
I.V. Sulyma

The resultsof studies of the effect of nature and parameters of particle size distribution of graphite on physical and mechanical properties of polymer composites based on aromatic polyamide fenіlon C-2. The particle size of the filler and polymer for the theoretical gamma-distribution parameters (perimeter, thickness and diameter) have different values. Found the influence of fillers (natural graphite different bands), which differed ash content (5-15% and 0,05-2,5%), moisture and grinding fineness (dispersion) on the wear resistance of the samples of the polymer composite. There is non-linear connectionbetween the intensity and parameters graphite particles distribution.


Author(s):  
Rapheal Ige ◽  
Elinge Ogala ◽  
Cosmos Moki ◽  
Abdulrahman Habeeb

The selection or choice of agro-waste briquettes for domestic and industrial cottage applications depends on the fuel properties. In this study, the briquette was produced by carbonizing the rice stalk followed by crushing and sieving, the binder was prepared by dissolving the starch in hot water, then mixed with the sieved carbonized rice stalk and then the briquette was produced using the briquetting machine. Proximate analyses, viability, characteristics and combustion were determined to know the average composition of their constituents. From the results obtained it was observed that ash content, moisture content, after glow and ignition propagation decrease as the binder ratio increase while fixed carbon content, volatile matter, calorific value, density and compressive strength increase. The results of this work indicate that briquettes produced using high concentration of the binder would make good biomass fuels. However, it has a high moisture content of 25.00%, high ash content of 23.00%, moderate volatile matter of 44.80%, low fixed carbon content of 32.20%, moderate calorific value of 13.86 MJ/Kg and high density of 0.643g/cm3. The results obtained for all the parameters showed that rice stalks briquettes produced with high concentration of the binder (starch) had a better performance based on their combustion profile.


1998 ◽  
Vol 29 ◽  
pp. S353-S354 ◽  
Author(s):  
T. A˚lander ◽  
A. Leskinen ◽  
L. Laitinen ◽  
I. Ruotsalainen ◽  
T. Raunemaa ◽  
...  

2021 ◽  
Author(s):  
Dmitriy Moskovchenko ◽  
Roman Pozhitkov ◽  
Dzhamilya Ukarkhanova

Abstract The article presents the results of studying the composition of road dust in Tyumen, a large city in Western Siberia. On roads with different traffic intensities, 50 dust samples were taken, in which the particle size distribution, pH, and organic carbon content were determined. The content of 62 major and trace elements was studied using atomic emission spectrometry (AES-MS) и inductively coupled plasma spectrometry (ICP-MS). It was revealed that the dust has an alkaline reaction pH = 7.4 - 10.2, low organic carbon content (0.07 - 2.9%). The particle size distribution is dominated by particles PM = 100-250. The content of small particles (PM <2 and PM2-10) representing the greatest environmental hazard is minimal on roads with an average traffic intensity. Studies have shown that the main road dust pollutants in Tyumen are Ni, Sb, Cr, Zn, Co. The average geoaccumulation index (Igeo) values ​​are ranked as Ni (2.2) > Sb (1.5) > Cr (1.3) > Zn (0.4) > Co (0.4) > Cu (0.2). The contamination evaluation through enrichment factor (EF) calculation showed that road dust is highly enriched in Ni and significantly in Cr and Sb. More than 80% of Zn, Co, Cu and more than 90% of Ni, Sb, Cr come from anthropogenic sources. By the content of Ni and Cr, Tyumen surpasses all cities of the Earth where similar studies were carried out. The high Ni content is associated with the composition of local soils and roadways, increased content in vehicle exhaust gases, and abrasion of metal parts. Calculations of the total pollution indices (IPI and Zc) showed that the level of road dust pollution in most of Tyumen's territory is average, moderately hazardous.


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