Effect of Fuel Properties on the Bottom Ash Generation Rate by a Laboratory Fluidized Bed Combustor

2006 ◽  
Vol 129 (2) ◽  
pp. 144-151 ◽  
Author(s):  
Peter L. Rozelle ◽  
Sarma V. Pisupati ◽  
Alan W. Scaroni

The fluidized bed combustion (FBC) process, used in power generation, can handle a variety of fuels. However, the range of fuels that can be accommodated by an FBC boiler system is affected by the ability of the fuel, sorbent, and ash-handling equipment to move the required solids through the boiler. Of specific interest is the bottom ash handling equipment, which must have sufficient capacity to remove ash from the system in order to maintain a constant bed inventory level, and must have sufficient capability to cool the ash well below the bed temperature. Quantification of a fuel’s bottom ash removal requirements can be useful for plant design. The effect of fuel properties, on the rate of bottom ash production in a laboratory FBC test system was examined. The work used coal products ranging in ash content from 20to40+wt.%. The system’s classification of solids by particle size into flyash and bottom ash was characterized using a partition curve. Fuel sizing was compared to the partition curve, and fuels were fractionated by particle size. Fuel fractions in the size range characteristic of bottom ash were further analyzed for distributions of ash content with respect to specific gravity, using float sink tests. The fuel fractions were then ashed in a fixed bed. In each case, the highest ash content fraction produced ash with the coarsest size consist (characteristic of bottom ash). The lower ash content fractions were found to produce ash in the size range characteristic of flyash, suggesting that the high ash content fractions were largely responsible for the production of bottom ash. The contributions of the specific gravity fractions to the composite ash in the fuels were quantified. The fuels were fired in the laboratory test system. Fuels with higher amounts of high specific gravity particles, in the size ranges characteristic of bottom ash, were found to produce more bottom ash, indicating the potential utility of float sink methods in the prediction of bottom ash removal requirements.

Author(s):  
Nevin Selc¸uk ◽  
Yusuf Gogebakan ◽  
Zuhal Gogebakan

The behavior of 20 trace elements (As, B, Ba, Cd, Co, Cr, Cu, Hg, Li, Mn, Mo, Ni, P, Pb, Sb, Se, Sn, Tl, V, Zn) and 8 major and minor elements (Al, Ca, Fe, K, Mg, Na, Si, Ti) during the combustion of high ash content lignite with and without limestone addition have been investigated in the 0.3 MWt Middle East Technical University (METU) Atmospheric Bubbling Fluidized Bed Combustor (ABFBC) Test Rig. Experiments were performed without fines recycle. Inert bed material utilized in the experiments was bed ash obtained previously from the combustion of the same lignite without limestone addition in the same test rig. Concentrations of trace elements in coal, limestone, bottom ash, cyclone ash and filter ash were determined by Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES). Measurements show that the distribution of major and minor elements follows the ash split between the bottom ash and fly ash and that the major proportion of most of the trace elements (As, Ba, Cr, Hg, Li, Mo, Ni, Sn, V, Zn) are recovered in fly ash. Comparisons between the trace element partitioning of the runs with and without limestone addition reveal that addition of limestone shifts the partitioning of Ba, Cr, Hg, Mo, Ni, Sn, V, Zn from bottom ash to fly ash.


2018 ◽  
Vol 5 (3) ◽  
pp. 9290-9297 ◽  
Author(s):  
Jarupat Panich ◽  
Chiraporn Auechalitanukul ◽  
Ryan McCuiston

2006 ◽  
Vol 129 (2) ◽  
pp. 565-571 ◽  
Author(s):  
Peter L. Rozelle ◽  
Sarma V. Pisupati ◽  
Alan W. Scaroni

A method for prediction of sorbent consumption is presented here and has been developed based on plant operating data for a boiler in which several limestone and dolostone products were tested under similar firing conditions. The method considers the characteristic partitioning of calcium and sulfur between the flyash and bottom ash stream for the boiler, the feed particle size distribution of the sorbent, and petrographic properties of the sorbents. The predictions of sorbent usage were compared to plant operating data for five sorbents, of two distinct petrographic types. The plant operating data used featured full load operation. The five sorbents tested were all from Pennsylvania, and each contained greater than 40wt.% CaO. In four of the five cases, the predicted sorbent usage was within 10wt.% of the average full load sorbent usage by the boiler.


2020 ◽  
Vol 4 (1) ◽  
pp. 19-26
Author(s):  
Ninis Hadi Haryanti, Henry Wardhana, Suryajaya

Abstrak – Pada umumnya ukuran partikel yang digunakan dalam pembuatan briket bervariasi antara 12 -100 mesh. Pada penelitian ini, ukuran partikel yang digunakan adalah 250 mesh (59,4 µm). Dilakukan kajian analisis proksimat briket terhadap variasi tekanan pencetakan. Briket dibuat dari campuran limbah industri arang kayu alaban dan abu dasar batubara. Kedua bahan dalam bentuk serbuk yang lolos pada saringan 250 mesh.Ukuran partikel yang lebih kecil diharapkan menghasilkan briket yang lebih baik dan tidak  rapuh serta dapat digunakan sebagai bahan bakar alternatif untuk rumah tangga maupun industri dan penggunaan bahan limbah diharapkan membantu pemecahan permasalahan lingkungan. Variasi tekanan yang digunakan adalah 150, 200, 250, 300, dan 350 kg/cm2. Komposisi campuran limbah arang kayu alaban dan abu dasar batubara dengan rasio 90%:10%, sedangkan perekat tepung kanji 5%. Briket dibuat dalam bentuk silinder berukuran 2 × 2 cm. Briket yang sudah dicetak dikeringkan dalam oven pada suhu 120°C selama 4 jam dan didinginkan pada suhu ruang selama 24 jam. Dari hasil uji didapatkan Kadar Air (3,831-5,892) %; Kadar Abu (7,178-10,507) %; Nilai Kalori (5607,467-5732,033) cal/g; Densitas (0,688-0,769) g/cm3; dan Porositas (46,025-47,592) %. Berdasarkan hasil uji, dapat disimpulkan bahwa semakin tinggi nilai tekanan, kadar air, kadar abu, dan porositas akan menurun, sedangkan nilai kalori mencapai nilai tertinggi pada tekanan 200 kg/cm2 kemudian cenderung mengalami penurunan. Direkomendasikan tekanan yang diberikan pada saat pembuatan briket adalah 200 kg/cm2.Kata kunci: abu dasar batubara, arang kayu alaban, briket, tekanan pencetakan, ukuran partikelAbstract – In general, the particle size used in making briquettes were varied in the range of 12 -100 mesh. In this study, the particle size used was 250 meshs (59.4 µm). The effect of press variations to proximate analysis of briquette will be conducted. Briquette was made from a mixture of alaban wood charcoal industrial waste and coal bottom ash. Both materials were crushed in the form of powder passing 250 meshs sieve. The smaller particle size is expected to produce better and less brittle briquettes and could be used as alternative fuels for households and industries, while the use of waste materials is expected to help solve environmental problems. Pressure variations used were 150, 200, 250, 300, and 350 kg/cm2. The composition of the mixture of alaban wood charcoal waste and coal bottom ash wasin ratio 90%: 10%, while starch adhesive of 5% was added. Briquettes were made in the form of cylinders (2 × 2 cm in size). Briquettes were dried in an oven at 120°C for 4 hours and cooled at room temperature for 24 hours. The results obtained were Moisture Content (3,831-5,892)%; Ash Content (7,178-10,507)%; Heating Value (5607,467-5732,033) cal / g; Density (0.688-0.769) g/cm3; and Porosity (46,025-47,592)%. Based on the results, it could be concluded that as the pressure increased, water content, ash content, and porosity were decreased. The calorie value reaches the highest value at a pressure of 200 kg/cm2 then tends to decrease. It is recommended that the pressure applied at the time of briquette making is 200 kg/cm2.Key words: coal bottom ash, alaban charcoal, briquettes, pressure, particle size


2001 ◽  
Author(s):  
V. Aizenberg ◽  
P. Baron ◽  
K. Choe ◽  
S. Grinshpun ◽  
K. Willeke

2020 ◽  
Vol 71 (1) ◽  
pp. 1-12
Author(s):  
Salman H. Abbas ◽  
Younis M. Younis ◽  
Mohammed K. Hussain ◽  
Firas Hashim Kamar ◽  
Gheorghe Nechifor ◽  
...  

The biosorption performance of both batch and liquid-solid fluidized bed operations of dead fungal biomass type (Agaricusbisporus ) for removal of methylene blue from aqueous solution was investigated. In batch system, the adsorption capacity and removal efficiency of dead fungal biomass were evaluated. In fluidized bed system, the experiments were conducted to study the effects of important parameters such as particle size (701-1400�m), initial dye concentration(10-100 mg/L), bed depth (5-15 cm) and solution flow rate (5-20 ml/min) on breakthrough curves. In batch method, the experimental data was modeled using several models (Langmuir,Freundlich, Temkin and Dubinin-Radushkviechmodels) to study equilibrium isotherms, the experimental data followed Langmuir model and the results showed that the maximum adsorption capacity obtained was (28.90, 24.15, 21.23 mg/g) at mean particle size (0.786, 0.935, 1.280 mm) respectively. In Fluidized-bed method, the results show that the total ion uptake and the overall capacity will be decreased with increasing flow rate and increased with increasing initial concentrations, bed depth and decreasing particle size.


Sign in / Sign up

Export Citation Format

Share Document