Effect of CaO and Fe2O3 on Partitioning of As and S within Ash Fractions from Fluidised-Bed Co-Combustion of Coal and Wastes

Possible interaction of volatilized As and S with CaO and Fe2O3 (creating solid product) could efficiently improve coal combustion flue gas cleaning. For this reason, S-CaO, As-CaO, S- Fe2O3 and As- Fe2O3 relationships were evaluated in bottom ash and fly ash fractions from fluidised-bed co-combustion of coal and wastes (and limestone as desulphurization additive) through calculation of correlation coefficients and composition of magnetic concentrates. It was concluded that S exhibited a dominant association with CaO while As exhibited affinity to both CaO and Fe2O3 - the significance differed a little in bottom ash and fly ash. In the bottom ash, the affinity of As to CaO was more significant, while in the fly ash the association to Fe2O3 slightly prevailed.

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Desulfurisasi dan Penyerapan Merkuri secara Simultan dari Batubara Peringkat Rendah (Aceh Barat) untuk Aplikasi Power Plant dengan Adsorben Zeolit

Jurnal Teknologi Kimia Unimal ◽

10.29103/jtku.v7i1.1171 ◽

2019 ◽

Vol 7 (1) ◽

pp. 73

Author(s):

Yuanda Wattimena ◽

Asri Gani ◽

Medyan Riza

Keyword(s):

Stainless Steel ◽

Fly Ash ◽

Power Plant ◽

Fluidized Bed ◽

Flue Gas ◽

Coal Combustion ◽

Bottom Ash ◽

Tube Furnace ◽

Fluidized Bed Combustion ◽

Gas Combustion

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

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Effect of fly ash composition on the retention of mercury in coal-combustion flue gas

Fuel Processing Technology ◽

10.1016/j.fuproc.2015.09.023 ◽

2016 ◽

Vol 142 ◽

pp. 6-12 ◽

Cited By ~ 23

Author(s):

Ping He ◽

Xianbing Zhang ◽

Xiaolong Peng ◽

Jiang Wu ◽

Xiuming Jiang

Keyword(s):

Fly Ash ◽

Flue Gas ◽

Coal Combustion ◽

Ash Composition

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Use of fly ash, bottom ash and zeolite as additives for enhancing lime reactivity towards flue gas desulfurization

Environmental Progress & Sustainable Energy ◽

10.1002/ep.10608 ◽

2011 ◽

Vol 32 (1) ◽

pp. 75-83 ◽

Cited By ~ 4

Author(s):

Paul Maina ◽

Makame Mbarawa

Keyword(s):

Fly Ash ◽

Flue Gas ◽

Bottom Ash ◽

Flue Gas Desulfurization ◽

Lime Reactivity

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Removal of elemental mercury in flue gas by Cu-Fe modified magnetosphere from coal combustion fly ash

Fuel ◽

10.1016/j.fuel.2020.117668 ◽

2020 ◽

Vol 271 ◽

pp. 117668 ◽

Cited By ~ 2

Author(s):

Yang Li ◽

Lixin Dang ◽

He Yang ◽

Jie Li ◽

Haoquan Hu

Keyword(s):

Fly Ash ◽

Flue Gas ◽

Coal Combustion ◽

Elemental Mercury

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Ammonia in Fly Ashes from Flue Gas Denitrification Process and its Impact on the Properties of Cement Composites

Buildings ◽

10.3390/buildings9110225 ◽

2019 ◽

Vol 9 (11) ◽

pp. 225 ◽

Cited By ~ 2

Author(s):

Agnieszka Michalik ◽

Joanna Babińska ◽

Filip Chyliński ◽

Artur Piekarczuk

Keyword(s):

Fly Ash ◽

Flue Gas ◽

Coal Combustion ◽

Catalytic Reduction ◽

Structural Features ◽

Cement Composites ◽

Fly Ashes ◽

Ammonia Content ◽

Denitrification Process ◽

Flue Gas Denitrification

The paper presents the results of research on the properties of fly ashes from the process of flue gas denitrification by selective non-catalytic reduction (SNCR), consisting of dosing urea into the coal combustion chamber. The research was carried out on two types of fly ash: Silica fly ash from flue gas denitrification and ash from a traditional boiler without the flue gas denitrification process. The scope of comparative studies included physicochemical and structural features of ashes, as well as slurries and mortars with the addition of ashes. Fly ash from denitrification, whose ammonia content at the time of sampling was 75 mg/kg at the maximum, was examined. Our own research has shown that fly ash from flue gas denitrification is characterized by a higher value of losses on ignition and ammonia content in comparison to ashes without denitrification. It was shown that the ammonia content in the analyzed range does not limit the use of fly ash as an additive to cement and concrete.

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Partitioning of Cr, Cu, Pb and Zn in sewage sludge incineration by rotary kiln and fluidized bed furnaces

Water Science & Technology ◽

10.2166/wst.2000.0143 ◽

2000 ◽

Vol 41 (8) ◽

pp. 61-68 ◽

Cited By ~ 8

Author(s):

G. Mininni ◽

C. M. Braguglia ◽

D. Marani

Keyword(s):

Fly Ash ◽

Sewage Sludge ◽

Rotary Kiln ◽

Bottom Ash ◽

Point Of View ◽

Fluidised Bed ◽

Chlorinated Organic Compounds ◽

Sludge Incineration ◽

Significant Enrichment ◽

The One

The behaviour of four metals (Cr, Cu, Pb, Zn) during sewage sludge incineration was studied in eight pilot plant tests performed with a rotary kiln (RK) and a fluidised bed (FB) furnace. To simulate sludge co-incineration with hazardous wastes, in three FB tests feed sludge was mixed with chlorinated organic compounds. Chromium and copper showed similar concentrations both in bottom or cyclone ash and in fly ash, even at high chlorine input and high combustion temperature. In contrast, zinc and lead concentrations in fly ash produced in RK tests are one or two orders of magnitude higher than those in bottom ash. However, not even these two metals showed significant enrichment in FB tests carried out at high chlorine input. The predictive capability of a thermodynamic model was checked by comparing predicted metal volatilisation in the combustion chamber with experimental metal enrichment in the fly ash. Large discrepancies were observed in FB tests carried out at high chlorine content, where Pb, Zn, and Cu are predicted to volatilise in great extent, andin RK tests where zinc volatilisation is not predicted. Likely explanations of these discrepancies are the very short solid residence times in the FB furnace (non equilibrium conditions) and the incomplete mixing conditions in the RK furnace (pyrolysis pockets). From the environmental impact point of view, the pilot tests suggest that sludge incineration with fluidised bed furnace is safer than the one using rotary kiln furnace.

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Mercury Removal From Coal Combustion Flue Gas by Pyrite-Modified Fly Ash Adsorbent

10.21203/rs.3.rs-934628/v1 ◽

2021 ◽

Author(s):

Liqiang QI ◽

Xu WANG ◽

Wen WANG ◽

Jingxin LI ◽

Yan HUANG

Keyword(s):

Fly Ash ◽

Flue Gas ◽

Coal Combustion ◽

Gas Flow ◽

Active Component ◽

Mercury Removal ◽

Gas Flow Rate ◽

Mercury Adsorption ◽

Mass Proportion ◽

Modified Fly Ash

Abstract Pyrite and fly ash have certain advantages in adsorption and mercury oxidation. The pyrite-modified fly ash (PY+AC-FA) mercury adsorbent was prepared by mixing pyrite (PY) with acid-modified fly ash (AC-FA), which has better mercury removal effect than AC-FA. The experimental results of mercury adsorption show: when the reaction temperature is 50°C, the best doping proportion of modified fly ash is 20wt%, the mass proportion of pyrite to acid modified fly ash is 4:1, and the flue gas flow rate is 1.0L/min, the adsorbent has the best performance, and the adsorption rate of mercury reaches 91.92%. BET, XRD, SEM, TG-DSG and XRF were used to characterize these adsorbents. And the mechanism of mercury removal of pyrite-modified fly ash adsorbent is inferred: Hg0 is first adsorbed on the surface of the adsorbent, and then oxidized to HgS by the active component FeS2 in pyrite-modified fly ash.

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Mercury Migration Behavior from Flue Gas to Fly Ashes in a Commercial Coal-Fired CFB Power Plant

Energies ◽

10.3390/en13051040 ◽

2020 ◽

Vol 13 (5) ◽

pp. 1040 ◽

Cited By ~ 1

Author(s):

Xiaohang Li ◽

Yang Teng ◽

Kai Zhang ◽

Hao Peng ◽

Fangqin Cheng ◽

...

Keyword(s):

Fly Ash ◽

Specific Surface ◽

Surface Area ◽

Specific Surface Area ◽

Flue Gas ◽

Power Plants ◽

Bottom Ash ◽

Migration Behavior ◽

Boiler Unit ◽

Cfb Boiler

Mercury (Hg) emissions from coal-fired power plants are of increasing concern around the world. In this study, field tests were carried out to understand the Hg emission characteristics and its migration behaviors in a commercial CFB boiler unit with the electricity generation capacity of 25 MW. This boiler is equipped with one electrostatic precipitator (ESP) and two fabric filters (FFs) in series for removing particulates from the flue gas. The EPA 30B method was used for simultaneous flue gas Hg sampling at the inlet of the ESP and the outlet of the second FF. The Hg mass balance in the range of 104.07% to 112.87% was obtained throughout the CFB unit by measuring the Hg contents in the feed fuel, the fly ash and the bottom ash, as well as in the flue gas at the outlet of the particulate control device (PCD) system. More than 99% of Hg contained in the feed fuel was captured by the fly ash, whilst less than 1% of Hg was remained in the bottom ash or the flue gas after passing the PCD system. The gaseous Hg obviously migrated from the flue gas to the fly ash in the air pre-heater, where the flue gas temperature decreased from 250 °C at the inlet to 120 °C at the outlet. Other gaseous Hg migrated from the flue gas to the fly ash in the PCD system, as the Hg concentrations in the flue gas ranged from 3.14 to 4.14 μg/m3 at the inlet of the ESP and ranged from 0.30 to 0.36 μg/m3 at the outlet of the second FF. The average Hg contents in the fly ash samples collected from the ESP, the first FF and the second FF were 912.3, 1313.6 and 1464.9 ng/g, respectively, while the mean particle diameters of these fly ash samples tend to decrease along the flow pass in the PCD system. Compared to large fly ash particles, smaller fly ash particles exhibit higher Hg capture performance due to their high unburned carbon (UBC) content and large specific surface area. The migration of gaseous Hg from the flue gas to the fly ash downstream of the CFB boiler unit was easier than that downstream of the PC boiler unit due to high UBC content and specific surface area.

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