scholarly journals Simulasi pengeringan batu bara muda dengan metode rangkaian pori pada kondisi isotermal

2018 ◽  
Vol 8 (3) ◽  
pp. 80
Author(s):  
Anton Irawan ◽  
Indar Kustiningsih
Keyword(s):  
Moisture Content ◽  
Fluid Velocity ◽  
Pore Network ◽  
Low Rank ◽  
Low Rank Coal ◽  
High Moisture Content ◽  
High Moisture ◽  
Drying Kinetic ◽  
Small Pore ◽  
Coal Drying

Simulation of low rank coal drying with pore network method in isothermal condition.Indonesia has large coal reserve with most of them are low rank coal. Low rank coal has low energy content (< 4,800 kcal/kg) and high moisture content (> 25%). High moisture content of coal will make a problem for coal conversion processing to be a main energy source such as power plant  so that the moisture of coal must be removed from inside of coal. The moisture content in the coal can be removed by drying based on drying kinetic (drying rate). Drying kinetic is influenced by several variables such as hot fluid velocity and temperature, size and pore structure of material. In this model, sample of low rank coal are analyzed to obtain the data of pore size distribution. The size of pore were used 40 and 100 nm, the pore length was 100 nm. Four different pore structures were simulated by pore network modelling. From pore network simulation, the structure with large pore had long time for drying constant period, but the structure with small pore had short time for drying constant period.Keywords: coal, drying, pore network, moisture, vapour diffusion. AbstrakIndonesia merupakan negara yang memiliki cadangan  batubara yang besar yang dapat digunakan sebagai sumber energi utama untuk industri, tetapi batubara yang dimiliki oleh Indonesia sebagian besar merupakan batubara muda yang memiliki kandungan energi yang rendah (< 4.800 kcal/kg) serta kandungan air yang tinggi (> 25%). Kandungan air batubara yang tinggi menyulitkan dalam proses konversi batubara untuk dijadikan sebagai sumber energi utama seperti pada sistem tenaga. Kandungan air dalam batubara dapat dikurangi dengan pengeringan dengan mengamati data kinetika pengeringan berupa laju pengeringan. Laju pengeringan batubara dipengaruhi oleh beberapa variabel antara lain kecepatan fluida panas, temperatur fluida panas, ukuran partikel yang dikeringkan serta struktur pori-pori dari partikel yang dikeringkan. Beberapa sampel batubara muda dianalisis strukturnya untuk mendapatkan data distribusi pori. Ukuran pori yang digunakan terdiri atas 2 macam yaitu 40 dan 100 nm serta panjang pori 500 nm.  Empat macam struktur pori disimulasikan dengan metode rangkaian pori. Dari simulasi rangkaian pori memperlihatkan bahwa ukuran pori yang besar akan memberikan waktu yang lebih lama untuk laju pengeringan tetap sedangkan struktur pori dengan  ukuran pori  kecil akan memberikan laju pengeringan tetap yang lebih pendek waktunya.Kata Kunci: batubara, pengeringan, rangkaian pori, kandungan air, difusi uap.

Drying kinetics of processed natural coffee with high moisture content

2017 ◽  
Vol 12 (3) ◽  
pp. 400 ◽  
Author(s):  
Valdiney Cambuy Siqueira ◽  
Flávio Meira Borém ◽  
Guilherme Euripedes Alves ◽  
Eder Pedroza Isquierdo ◽  
Afonso Celso Ferreira Pinto ◽  
...  
Keyword(s):  
Moisture Content ◽  
Drying Kinetics ◽  
High Moisture Content ◽  
High Moisture ◽  
Kinetics Of

Objetivou-se, com o presente trabalho, propor um novo método de processamento e secagem, assim como avaliar o comportamento dos grãos submetidos a este processo, por meio da taxa de redução de água e do ajuste de diferentes modelos matemáticos aos dados experimentais da secagem. Os frutos colhidos no estágio maduro foram divididos em três lotes. O primeiro foi seco continuamente à temperatura de 40±1 °C. O segundo consiste na secagem do café natural até os teores de água de 0,56±0,02, 0,41±0,02, 0,28±0,02 e 0,20±0,02 decimal (base seca, b.s.), seguido de beneficiamento e secagem contínua nas temperaturas de 35±1 ºC e 40±1 ºC. O terceiro lote correspondeu à secagem contínua do café descascado e desmucilado na temperatura de 40±1 °C. Em todos os lotes, a secagem foi encerrada quando os grãos atingiram o teor de água de 0,12±0,05 (b.s.). Aos dados experimentais da secagem foram ajustados dez modelos matemáticos utilizados para representação da secagem dos produtos agrícolas. Além da representação da cinética de secagem foi avaliada a taxa de redução de água dos grãos. Conclui-se que a taxa de redução de água é maior para a temperatura de secagem de 40±1 °C, especialmente para maiores teores de água. O tempo total de secagem do café beneficiado com alto teor de água é expressivamente reduzido, quando comparado ao tempo de secagem completa do café natural. O modelo de Midilli descreve satisfatoriamente a cinética de secagem do café beneficiado.

Optimization of drying of low-grade coal with high moisture content using a disc dryer

2014 ◽  
Vol 124 ◽  
pp. 267-274 ◽  
Author(s):  
Seung-Hyun Moon ◽  
In-Soo Ryu ◽  
Seung-Jae Lee ◽  
Tae-In Ohm
Keyword(s):  
Moisture Content ◽  
Low Grade ◽  
High Moisture Content ◽  
High Moisture

scholarly journals Key Metallurgical Parameters of Fe-Ni Production During 1984–1997 and 2007–2017 at the Ferronickel Smelter in Drenas

2020 ◽  
Vol 67 (2) ◽  
pp. 73-77
Author(s):  
Zarife Bajraktari-Gashi ◽  
Muharrem Zabeli ◽  
Behram Halilaj
Keyword(s):  
Moisture Content ◽  
Casting Process ◽  
The Philippines ◽  
High Moisture Content ◽  
High Moisture ◽  
Nickel Ores ◽  
Iron Nickel ◽  
Rotary Kilns ◽  
The Republic ◽  
Laterite Ore

AbstractDuring 1984–1997, the ferronickel plant in Drenas used iron-nickel ore from the mines of the Republic of Kosovo: Glavica and Çikatove (Dushkaje and Suke) mines. However, during the years 2007–2017, when the plant started operating from the cessation of production, which was from 1998 to 2007, some types of iron-nickel ores from different countries began to be used, starting from iron-nickel ores from Kosovo, iron-nickel ores from Albania, ores from Indonesia, ores from the Philippines, ores from Guatemala, ores from Turkey and ores from Macedonia. The ore composition, however, is mainly oxide-laterite ore. Iron-nickel ores in the plant are characterised by high moisture content, a very important factor influencing the process of scraping the charge in rotary kilns and presenting in general. Among the iron-nickel ore used in the ferronickel plant, the ores from Albania are characterised due to their low moisture content when compared with the other ores as well as the high content of iron oxides, which affect the temperature rise inside the furnaces, as the iron ores play an important role in the pre-casting process in rotary kilns.

scholarly journals Mycoflora of sawn timbers in Benin City

2014 ◽  
Vol 23 (2) ◽  
pp. 89-95
Author(s):  
J. A. Okhuoya ◽  
S. O. Itaman
Keyword(s):  
Moisture Content ◽  
Pleurotus Ostreatus ◽  
Fungal Species ◽  
High Moisture Content ◽  
High Moisture ◽  
Benin City ◽  
The Poor ◽  
High Incidence

In a fungal suryey of sawn timbers in scattared localities in Benin City, fungal species isolated were mainly members of <i>Hyphomycetes</i>, with few <i>Ascomycetes</i> and<i> Basidiomycetes</i>. Cellulolytic abilities of isolates were determined and found to be highest in a basidiomycete, <i>Pleurotus ostreatus</i>. The high incidence of these isolates was traced to the poor ventillation in the shades where the timbers arę sold and the high moisture content of timber before display for sale.

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