scholarly journals Experimental Investigations of the Ignitability of Several Coal Dust Qualities

Energies ◽  
2021 ◽  
Vol 14 (19) ◽  
pp. 6323
Author(s):  
Reyhane Youssefi ◽  
Tom Segers ◽  
Frederik Norman ◽  
Jörg Maier ◽  
Günter Scheffknecht
Keyword(s):  
Moisture Content ◽  
Coal Dust ◽  
Characteristic Number ◽  
Ash Content ◽  
Hard Coal ◽  
Volatile Content ◽  
Explosion Pressure ◽  
Maximum Explosion Pressure ◽  
Deflagration Index ◽  
Ignition Characteristics

The ignition characteristics of coal dust is of high importance for the flame stability in coal-fired power plants. We investigate the ignitability of six lignite dust qualities and one hard coal using dust explosion tests and an ignitability characteristic number. The paper aims to identify the degree of impact of the properties of coals, such as the moisture content, the ash content etc., on the ignition characteristics and ultimately to compare the identified relevant ignition parameters to the ignition performance of the dust qualities in an industrially relevant environment. The minimum cloud ignition temperature (MCIT), the maximum rate of pressure rise ((dp/dt)max), the maximum explosion pressure (pmax), the deflagration index (Kst-value) and the modified ignitability characteristic number (ZWZmod.) were determined and were attributed to the moisture content, the ash content and the median particle size. The MCIT was largely influenced by the volatile content, whereas the variations of moisture and ash contents within the range of 10% to 20% did not have a significant impact on the MCIT. The maximum explosion pressure did not differ considerably and stayed in a narrow range among the tested dust qualities. The deflagration index showed a higher sensitivity to the dust properties. The deflagration index and the modified ignitability characteristics number dropped as the moisture content increased and the volatile content reduced. The Kst and ZWZmod. values showed the highest susceptibility to the coal dust properties. Hence, they were used as representative parameters for further comparison with the ignition performance of coal dust in a pilot-scale testing. The results showed that both parameters predicted the ignition performance relatively well and can be used as indicators for the prediction of the ignition performance.

Making Charcoal Briquettes from Corncobs Organic Waste Using Variation of Type and Percentage of Adhesives

2017 ◽  
Vol 2 (1) ◽  
pp. 43 ◽  
Author(s):  
Lilih Sulistyaningkarti ◽  
Budi Utami
Keyword(s):  
Moisture Content ◽  
Carbon Content ◽  
Wheat Flour ◽  
Alternative Energy ◽  
Organic Waste ◽  
Calorific Value ◽  
Ash Content ◽  
Volatile Content ◽  
Biomass Waste ◽  
Tapioca Flour

This study aimed to (1) make charcoal briquettes from corncobs organic waste; (2) determine the right type of adhesive to make a corncobs charcoal briquette to produce good quality briquettes; (3) determine the appropriate percentage of adhesive to produce corncobs briquettes to produce good quality briquettes; and (4) know the best characteristics of corncobs charcoal briquettes which include moisture content, volatile content, ash content, carbon content and caloric value. The sample used was corncob obtained from a corn farmer in Pasekan Village, Wonogiri regency. This research used experimental method in laboratory with several stages, namely: (1) preparation of materials; (2) carbonization; (3) crushing and sifting of charcoal (4) mixing charcoal with adhesive and water; (5) briquetting; (6) briquette drying; And (7) analysis of briquette quality. This adhesive types used in this research were tapioca flour and wheat flour and the percentage of adhesive material were 5%, 10% and 15% from total weight of charcoal powder. The result of the research were: (1) charcoal briquettes as alternative energy source can be made from biomass waste (corncobs organic waste); (2) charcoal briquettes from organic corncobs wastes using tapioca flour adhesives have better quality than using wheat flour adhesives; (3) the both charcoal briquettes using 5% of tapioca flour adhesive and 5% wheat flour adhesives have better quality than 10% and 15% in terms of moisture content, volatile content, ash content, carbon content and calorific value; and (4) the best characteristics obtained are for the charcoal briquettes using 5% of tapioca flour adhesive, which have water content of 3,665%; volatile matter amounting of 11.005%; ash content of 4.825%; fixed carbon content of 80.515%; and high heat value of 5661,071%.

scholarly journals Pemanfaatan Limbah Kulit Kakao Menjadi Briket Arang sebagai Bahan Bakar Alternatif dengan Penambahan Ampas Buah Merah

2019 ◽  
Vol 13 (1) ◽  
pp. 57
Author(s):  
Syarifhidayahtullah Syarif ◽  
Rochim Bakti Cahyono ◽  
Muslikhin Hidayat
Keyword(s):  
Moisture Content ◽  
Carbon Content ◽  
Calorific Value ◽  
Ash Content ◽  
Fruit Pulp ◽  
Volatile Content ◽  
Fixed Carbon ◽  
Shell Waste ◽  
Cocoa Shell ◽  
Fixed Carbon Content

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.

scholarly journals Variation and Prediction Methods of the Explosion Characteristic Parameters of Coal Dust/Gas Mixtures

Energies ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 264
Author(s):  
Yingquan Qi ◽  
Xiangyang Gan ◽  
Zhong Li ◽  
Lu Li ◽  
Yan Wang ◽  
...  
Keyword(s):  
Coal Dust ◽  
Dust Cloud ◽  
Prediction Method ◽  
Gas Mixtures ◽  
Gas Mixture ◽  
Characteristic Parameters ◽  
Explosion Pressure ◽  
Maximum Explosion Pressure ◽  
Spherical Explosion ◽  
Explosion Limit

In order to investigate the change law of the explosion characteristic parameters of hybrid mixture of coal dust and gas, and then establish an effective prediction method of these parameters, the maximum explosion pressure, explosion index, and lower explosion limit of coal dust and gas mixtures were measured in a standard 20 L spherical explosion system. Four different kinds of hybrid mixture were selected in this study and they are composed of coal dust with different components and gas respectively. According to the measured results, the change law of the explosion characteristic parameters of hybrid mixture of coal dust and gas was analyzed, and the prediction method of these parameters was discussed. The results show that the addition of gas to a coal dust cloud can obviously increase its maximum explosion pressure and explosion index and notably reduce its minimum explosion concentration. On increasing the gas equivalent ratio, the maximum explosion pressure of coal dust and gas mixture increases linearly and the explosion index increases quadratically, while the decrease curve of the lower explosion limit is nonlinear. Based on these change laws, the methods for predicting the maximum explosion pressure and the explosion index of hybrid mixture of coal dust and gas were established respectively. The applicability of the existing methods for predicting the lower explosion limit of hybrid mixture to coal dust and gas mixture was demonstrated.

scholarly journals ANALISIS POTENSI REFUSE DERIVED FUEL (RDF) DARI SAMPAH PADA TEMPAT PEMBUANGAN AKHIR (TPA) DI KABUPATEN TEGAL SEBAGAI BAHAN BAKAR INCINERATOR PIROLISIS

2019 ◽  
Vol 13 (1) ◽  
pp. 51
Author(s):  
Mutiara Fadila Rania ◽  
I Gede Eka Lesmana ◽  
Eka Maulana
Keyword(s):  
Power Generation ◽  
Moisture Content ◽  
Laboratory Testing ◽  
Laboratory Tests ◽  
Calorific Value ◽  
Ash Content ◽  
Plastic Waste ◽  
Volatile Content ◽  
Know How ◽  
Refuse Derived Fuel

The garbage dumping in Tegal Regency has reached 989.8 m3/day and increasing every year. The percentage of waste in Murareja landfill is dominated by plastic waste which is 40.15%. The plastic waste will be processed by pyrolysis by utilizing Refuse Derived Fuel (RDF) as its fuel. The percentage of garbage in Murareja TPA that can be used as RDF is quite high, which is 28.7%, consisting of 15.35% paper waste, 2.35% rubber / leather waste, 2% garbage cloth, 1% wood waste, and 8% plastic waste. The waste is considered potentially to be produced into RDF. The production of RDF aims to convert the combustible waste fraction from 4K1P waste (Paper, Wood, Fabrics, Rubber / Leather and Plastics) to be fueled. Therefore it is important to know how much potential of 4K1P waste to be processed into RDF, and how optimal calorific value of RDF is to be used as fuel of pyrolysis incinerator on Waste Power Generation at Murareja TPA, Tegal regency. Based on the result of the research that has been done, the theoretical value of the theoretical value of 4K1P RDF briquette is 3677.0945 - 5507.114 [kcal / kg]. From the actual data obtained with laboratory testing the value of RDF beverage caloric waste 4K1P RDF amounted to 3973.45 [kCal / kg]. The optimal calorific value of RDF required as a pyrolysis incinerator fuel is 3248.809 [kcal / kg]. Based on the results of laboratory tests, the percentage of moisture content, ash content, volatile content and carbon content are 4.68%, 11.64%, 7.81% and 75.87% respectively.

scholarly journals Utilization of soybean dregs for solid fuel production through hydrothermal carbonization

2020 ◽  
pp. 292-292
Author(s):  
Nugroho Pambudi ◽  
Panji Ardiyansyah ◽  
Riina Syivarulli ◽  
Muhammad Biddinika ◽  
Mochamad Syamsiro ◽  
...  
Keyword(s):  
Moisture Content ◽  
Carbon Content ◽  
Saturation Pressure ◽  
Calorific Value ◽  
Hydrothermal Carbonization ◽  
Ash Content ◽  
Holding Time ◽  
Soy Sauce ◽  
Volatile Content ◽  
Water Ratio

Hydrothermal carbonization (HTC) is a thermochemical process used in converting biomass into a coal-like substance known as hydrochar. This is usually carried out at high temperature with water below the saturation pressure for a certain period known as holding time. The biomass used was soybean dregs, which is the residue obtained from processing soy sauce with low economic value. The aim of this study therefore was to determine the calorific value of the hydrochar produced from soybean dregs at hydrothermal carbonization temperatures of 160?C, 190?C, and 220?C and at holding times of 30 and 60 minutes, also at a temperature of 190?C with the biomass and water ratio at 1:4 and 1:5. The results showed that the highest calorific value was produced a temperature of 220?C and a holding time of 60 minutes, which was 3,866 Kcal/Kg, the highest carbon content was 26.49%, the lowest moisture content was at 1.77%, the lowest volatile content was at 62.98%, while the lowest ash content was8.64%. Considering biomass to water ratio with the holding time, the highest calorific value was at 3,546 Kcal/Kg, the highest carbon content was 20.32%, the lowest moisture content at 1.71%, the lowest volatile content was 68.58%, while the lowest ash content was at 8.37%. The highest calorific value of the hydrochar produced was similar to the calorific value standard of lignite coal which is around 3,511-4,611 Kcal/Kg according to the American Standard Testing and Mineral (ASTM).

scholarly journals Comparative study of the explosion pressure characteristics of micro- and nano-sized coal dust and methane–coal dust mixtures in a pipe

2020 ◽  
Vol 7 (1) ◽  
pp. 68-78 ◽  
Author(s):  
Bo Tan ◽  
Huilin Liu ◽  
Bin Xu ◽  
Tian Wang
Keyword(s):  
Coal Dust ◽  
Pressure Rise ◽  
Dust Explosion ◽  
Nano Particle ◽  
Explosion Pressure ◽  
Deflagration Index ◽  
Pressure Maximum ◽  
Explosion Accidents ◽  
The Impact ◽  
Pressure Characteristics

AbstractCoal dust explosion accidents often cause substantial property damage and casualties and frequently involve nano-sized coal dust. In order to study the impact of nano-sized coal on coal dust and methane–coal dust explosions, a pipe test apparatus was used to analyze the explosion pressure characteristics of five types of micro-nano particle dusts (800 nm, 1200 nm, 45 μm, 60 μm, and 75 μm) at five concentrations (100 g/m3, 250 g/m3, 500 g/m3, 750 g/m3, and 1000 g/m3). The explosion pressure characteristics were closely related to the coal dust particle size and concentration. The maximum explosion pressure, maximum rate of pressure rise, and deflagration index for nano-sized coal dust were larger than for its micro-sized counterpart, indicating that a nano-sized coal dust explosion is more dangerous. The highest deflagration index Kst for coal dust was 13.97 MPa/(m·s), indicating weak explosibility. When 7% methane was added to the air, the maximum deflagration index Kst for methane–coal dust was 42.62  MPa/(m·s), indicating very strong explosibility. This indicates that adding methane to the coal dust mixture substantially increased the hazard grade.

scholarly journals The Maximum Explosion Pressure of Lignite in Dependence on Particle Size

2019 ◽  
Vol 27 (44) ◽  
pp. 57-64
Author(s):  
Richard Kuracina ◽  
Zuzana Szabová
Keyword(s):  
Particle Size ◽  
Coal Dust ◽  
Underground Mines ◽  
Explosion Pressure ◽  
Maximum Explosion Pressure ◽  
Dust Clouds ◽  
Potential Safety ◽  
Fire Properties ◽  
Explosion Accidents

Abstract Floating coal dusts are always produced during coal mining process in the underground mines. In a coal mine and other coal processing or utilizing industries, there are always some potential safety problems, such as coal dust explosion accidents.[1,2] During lignite mining and processing, flammable coal dust is produced. Fire properties of coal dust depend on the particle size. The article deals with the measurement of explosion characteristics of lignite in dependence of particle size at three various concentrations. The measurements were carried out according to EN 14034-1+A1:2011 Determination of explosion characteristics of dust clouds. Part 1: Determination of the maximum explosion pressure pmax of dust clouds. Tests of the lignite dust clouds explosions showed that the maximum value of the pressure was reached at the concentrations of 500 g.m−3 and the particle size between 0 – 56 µm. At this concentration, the highest explosion pressure of 8.25 bar was reached.

scholarly journals Principal component analysis of the effect of coal quality indexes on the maximum explosion pressure of coal dust

2021 ◽  
pp. 104-104
Author(s):  
Tao Ban ◽  
Wen-Ling Li ◽  
Guo-Xun Jing ◽  
Lei Cheng ◽  
Chuang Liu ◽  
...  
Keyword(s):  
Principal Component Analysis ◽  
Coal Dust ◽  
Principal Component ◽  
Calorific Value ◽  
Component Analysis ◽  
Multivariate Statistical ◽  
Coal Quality ◽  
Explosion Pressure ◽  
Maximum Explosion Pressure ◽  
Quality Indexes

It is well-known that the calorific value and heat transfer speed of coal are closely related to the coal quality index, and affect the explosion intensity and the maximum explosion pressure of coal dust explosion. In this paper, the pressure for different coal quality indexes is studied experimentally, and the main parameters affecting the pressure are elucidated by the principal component analysis of multivariate statistical analysis.

scholarly journals Thermal Analyses of Briquette Fuels Produced from Coal Dust and Groundnut Husk

2020 ◽  
Vol 4 (1) ◽  
pp. 24-27
Author(s):  
Ikelle I. Ikelle ◽  
Nworu J. Sunday ◽  
Nworie F. Sunday ◽  
Jedidiah John ◽  
Ogbuagu J. Okechukwu ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Thermal Properties ◽  
Moisture Content ◽  
Burning Rate ◽  
Coal Dust ◽  
Ignition Time ◽  
Calorific Value ◽  
Ash Content ◽  
Fixed Carbon ◽  
Water Boiling Test

AbstractThis work involved the production and thermal characterization of biomass briquettes produced by blending a major agricultural waste with coal dust. In the work, nine different compositions of coal dust/groundnut husk briquettes were produced using starch as the binder while Ca(OH2) was incorporated as the de-sulphurizing agent. The ash content, volatile matter, fixed carbon, moisture content, compressive strength, ignition time, calorific value, water boiling test and burning rate were carried out to determine the physical, mechanical and thermal properties of the briquettes produced. The results showed that moisture content values are in the range 2.43 - 6.44%, for compressive strength 7.72 - 10.85 N/mm3, for ash content 24.18 - 29.15 %, for calorific value 21714.17 - 25027.18 kJ/kg, for fixed carbon 16.77-53.22 %, for ignition time 22.23-45.20 s, for water boiling test 1.50-4.99 min and burning rate 16.10-28.32 g/min. These are appreciable values for the thermal properties of the bio-briquettes. Therefore, the agro-wastes briquettes are beneficial for heating purposes rather than open incineration of the wastes.

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