Partitioning of Trace Elements During Fluidized Bed Combustion of High Ash Content Lignite

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.

2019 ◽  
Vol 7 (1) ◽  
pp. 73
Author(s):  
Yuanda Wattimena ◽  
Asri Gani ◽  
Medyan Riza

Adsorpsi emisi pembakaran batubara dengan menggunakan adsorben zeolit pada jenis briket dan pulverized telah dilakukan. Penelitian ini bertujuan untuk mengurangi emisi gas SO2 dan logam Hg yang berbahaya apabila rilis di udara bebas dengan cara menggunakan adsorben zeolit untuk kecendrungan emisi menjadi bottom ash yang lebih terkendali. Pengujian ini fokus mengevaluasi rasio optimal rasio adsorben terhadap jumlah batubara terhadap performa penyerapan, sehingga penggunaannya tidak mengurangi nilai bakar batubara. Prosedur pembakaran ekspremintal awal dimulai dari pencampuran batubara dan zeolit dengan rasio 4%, 6%, 8%, 10%  dan 12%  yang dibagi dalam bentuk briket dan pulverized. Kedua jenis sampel dibakar secara berurutan pada electrical stainless steel reaction tube furnace pada kondisi temperatur pembakaran Fludized Bed Coal Combustion yaitu 600oC, 700oC, dan 800oC dengan laju alir udara disesuaikan. Flue gas hasil pembakaran yang keluar dari outlet dianalisa menggunakan Gas Combustion and Emission Analyzer (E4400, E-Instrument). Logam Hg yang yang diserap oleh zeolit pada Bottom Ash dianalisa menggunakan NIC Mercury SP Anlayzer. Hasil pengujian menunjukan kinerja zeolit terhadap kapasitas penyerapan logam Hg untuk pembakaran batubara pulverized pada temperatur pembakaran  600oC, 700oC dan 800oC masing-masing didapat pada angka 33,6, 19,25 dan 9,97 ppb/gr serta pada pembakaran briket batubara  masing-masing didapat sebesar 59,83, 37,8 dan 24,22 ppb/gr. Secara simultan untuk mengurangi emisi SO2 dan logam berat Hg pada fly ash untuk temperatur pembakaran Fludized Bed Coal Combustion rasio optimum berkisar antara 6%-8% adsoben zeolit dari jumlah massa batubara Kaway XVI Kabupaten Aceh Barat. Kata kunci:adsorpsi,  fluidized bed combustion, zeolit, briket, pulverized


2018 ◽  
Vol 16 (1) ◽  
Author(s):  
Yuanda Wattimena

Penelitian ini bertujuan untuk mengurangi emisi gas SO2 dan logam Hg dengan menggunakan adsorben zeolit. Pengujian ini fokus mengevaluasi rasio optimal adsorben terhadap jumlah batubara dan performa penyerapan serta tidak mengurangi nilai bakar batubara. Ekspremintal awal dimulai dari pencampuran batubara dan zeolit dengan rasio 4%, 6%, 8%, 10% dan 12% yang dibagi dalam bentuk briket dan pulverized. Kedua jenis sampel dibakar secara berurutan pada electrical stainless steel reaction tube furnace pada temperatur pembakaran Fluidized Bed Combustion yaitu 600oC , 700oC dan 800oC dengan laju alir udara disesuaikan. Flue gas hasil pembakaran dianalisa menggunakan Gas Combustion and Emission Analyzer (E4400, E-Instrument). Logam Hg yang diserap oleh zeolit pada bottom ash dianalisa menggunakan NIC Mercury SP Anlayzer. Hasil pengujian menunjukan kinerja zeolit terhadap kapasitas penyerapan logam Hg untuk pembakaran batubara pulverized pada temperatur pembakaran 600oC, 700oC dan 800oC masing-masing didapat pada angka 33,6, 19,25 dan 9,97 ppb/gr serta pada pembakaran briket batubara masing-masing sebesar 59,83, 37,8 dan 24,22 ppb/gr. Secara simultan untuk mengurangi emisi SO2 dan logam berat Hg pada fly ash untuk temperatur pembakaran Fluidized Bed Combustion rasio optimum berkisar antara 6%-8% adsoben zeolit dari jumlah massa Batubara Kaway XVI Kabupaten Aceh Barat.


Author(s):  
Yinghai Wu ◽  
Edward J. Anthony ◽  
Lufei Jia

The hydration of partially sulphated fluidized bed combustion (FBC) ash with saturated steam was carried out in the laboratory. The ash samples were obtained from a commercial-scale 165 MWe circulating fluidized bed combustor (CFBC) firing a petroleum coke and coal blend. Both bottom ash and fly ash were tested, and in addition the bottom ash was also separated into five size fractions and tested. These solid streams and the “as-received” fly ashes were hydrated by steam produced in a pressure bomb for different lengths of time at different saturated temperatures. Samples of the ashes were analyzed for free lime and calcium hydroxide content before and after the hydration process. Scanning electron microscopy (SEM) with an energy dispersive X-ray system (EDX) was employed to determine physical characteristics of the samples. X-ray diffractograms (XRD) were also used to determine the phase composition. These results show that after hydration treatment with saturated steam at elevated pressures, the unreacted CaO in the partially sulphated material can be quantitatively converted to Ca(OH)2. However, the free lime content is also observed to change throughout the hydration process, which indicates that the hydration of CaO is not the only reaction occurring in this system. It is also clear that for fines, i.e., fly ash and <75 μm size fraction bottom ash, the effectiveness of the hydration depends much more strongly on hydration time and temperature than for coarser ashes and it is also clear that the behaviour of each particle size fraction is different.


Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3106
Author(s):  
Tomasz Kalak ◽  
Kinga Marciszewicz ◽  
Joanna Piepiórka-Stepuk

Recently, more and more attention has been paid to the removal of nickel ions due to their negative effects on the environment and human health. In this research, fly ash obtained as a result of incineration of municipal sewage sludge with the use of circulating fluidized bed combustion (CFBC) technology was used to analyze the possibility of removing Ni(II) ions in adsorption processes. The properties of the material were determined using analytical methods, such as SEM-EDS, XRD, BET, BJH, thermogravimetry, zeta potential, SEM, and FT-IR. Several factors were analyzed, such as adsorbent dose, initial pH, initial concentration, and contact time. As a result of the conducted research, the maximum sorption efficiency was obtained at the level of 99.9%. The kinetics analysis and isotherms showed that the pseudo-second order equation model and the Freundlich isotherm model best suited this process. In conclusion, sewage sludge fly ash may be a suitable material for the effective removal of nickel from wastewater and the improvement of water quality. This research is in line with current trends in the concepts of circular economy and sustainable development.


2014 ◽  
Vol 629-630 ◽  
pp. 306-313 ◽  
Author(s):  
Mao Chieh Chi ◽  
Ran Huang ◽  
Te Hsien Wu ◽  
Toun Chun Fou

Circulating fluidized bed combustion (CFBC) fly ash is a promising admixture for construction and building materials due to its pozzolanic activity and self-cementitious property. In this study, CFBC fly ash and coal-fired fly ash were used in Portland cement to investigate the pozzolanic and cementitious characteristics of CFBC fly ash and the properties of cement-based composites. Tests show that CFBC fly ash has the potential instead of cementing materials and as an alternative of pozzolan. In fresh specimens, the initial setting time of mortars increases with the increasing amount of cement replacement by CFBC fly ash and coal-fire fly ash. In harden specimens, adding CFBC fly ash to replace OPC reduces the compressive strength. Meanwhile, CFBC fly ash would results in a higher length change when adding over 30%. Based on the results, the amount of CFBC fly ash replacement cement was recommended to be limited below 20%.


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