Combustion and NOx emissions in deep-air-staging combustion of char in a circulating fluidized bed

Combustion behavior and SO2, NOx emissions of anthracite coal in a circulating fluidized bed are reported in this paper. Experimental researches were done on a 1 MWt circulating fluidized bed facility with a 0.31 m × 0.31 m cross section and 11.2 m height combustor. The anthracite coal with 6.28% volatile and 3.76% sulfur content burns steadily during the test. The bed was operated under different temperature, Ca/S ratio and excess air. A limestone containing 75% CaCO3 and 15% MgCO3 was used as the sulfur sorbent. Results show that the SO2 emission varies with operating bed temperature and more than 90% sulfur capture efficiency can be reached while Ca/S is about 3. With Rosemount Analytical NGA2000, N2O, NO and NO2 were also measured in the test. It was found the majority content of NOx was NO and the least was NO2. Those NOx emissions change highly with the excess air number.

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Combustion of wood-chips in circulating fluidized bed boilers — NO and CO emissions as functions of temperature and air-staging

Fuel ◽

10.1016/s0016-2361(99)00006-x ◽

1999 ◽

Vol 78 (9) ◽

pp. 1065-1072 ◽

Cited By ~ 38

Author(s):

A. Lyngfelt ◽

B. Leckner

Keyword(s):

Fluidized Bed ◽

Circulating Fluidized Bed ◽

Wood Chips ◽

Fluidized Bed Boilers ◽

Air Staging

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Circulating fluidized bed hydrodynamics with air staging: an experimental study

Powder Technology ◽

10.1016/j.powtec.2004.05.008 ◽

2004 ◽

Vol 145 (1) ◽

pp. 25-33 ◽

Cited By ~ 35

Author(s):

L.E Ersoy ◽

M.R Golriz ◽

M Koksal ◽

F Hamdullahpur

Keyword(s):

Experimental Study ◽

Fluidized Bed ◽

Circulating Fluidized Bed ◽

Air Staging

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NOx EMISSIONS FROM BUBBLING FLUIDIZED BED COMBUSTION OF LIGNITE COAL

Acta Polytechnica ◽

10.14311/ap.2015.55.0275 ◽

2015 ◽

Vol 55 (4) ◽

pp. 275 ◽

Cited By ~ 2

Author(s):

Pavel Skopec ◽

Jan Hrdlička ◽

Jan Opatřil ◽

Jiří Štefanica

Keyword(s):

Nitrogen Content ◽

Fluidized Bed ◽

Oxygen Concentration ◽

Brown Coal ◽

Conversion Factor ◽

Nox Emissions ◽

Fluidization Velocity ◽

Bed Temperature ◽

Bubbling Fluidized Bed ◽

Air Staging

This paper presents experimental results of NOx emission measurements for combustion of two kinds of coal in a bubbling fluidized bed combustor. The tested fuels were Czech brown coal (CBC) and German young brown coal (GYC). These fuels have different nitrogen contents. The experiments were performed in the pilot scale BFB experimental unit with power output of 500 kW. The influence of several parameters on NOx formation are investigated in this paper. The parameters studied here include the effect of the nitrogen content in the fuel, the effect of the oxygen concentration in the bed, the effect of bed temperature, the effect of air staging, and the effect of fluidization velocity. Significantly different behaviour of the fuels was found. Although GYC has a lower nitrogen content than CBC, it is more reactive and produces higher NOx emissions. The biggest dependence of NOx production for CBC was found for the effects of air staging and fluidization velocity. As the fluidization velocity increases and the amount of secondary air decreases, there is an increase in NOx emissions. The oxygen concentration in the bed has the strongest effect on the NOx production of GYCs. With increasing oxygen concentration, the production of NOx also increases. On the basis of the NOx measurements, the N-NO conversion factor was calculated and the effect of the operating parameters on this conversion factor was investigated.

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Pengurangan Pelepasan Emisi dari Pembakar Lapisan Terbendalir Menggunakan Tempurung Kelapa Sawit Sebagai Bahan Api

Jurnal Teknologi ◽

10.11113/jt.v59.1261 ◽

2012 ◽

pp. 07-11

Author(s):

Mohammad Nazri Mohd Jaafar ◽

Rosyida Permatasari ◽

Mohd Nazar Yakin Mohd Sobree

Keyword(s):

Fluidized Bed ◽

Fuel Oil ◽

Silica Sand ◽

Nox Emissions ◽

Fuel Feed ◽

Bed Height ◽

Excess Air ◽

Axial Temperature ◽

Fluidized Bed Combustor ◽

Air Staging

Emissions released from fluidized bed combustor (FBC) are highly dependent on several operating parameters, for example, temperature, staged air, excess air, fuel feed rate, and fuel properties. This paper presents results of experiments conducted using air staging technique on a laboratory scale fluidized bed rig, using palm shells as fuel oil and silica sand as an inert medium. Silica sand was used to ensure a sustainable fuel ignition and stable combustion occurs in the FBC. Emission of CO and NOx emissions, and temperatures along the height of the bed and flue were measured. The experimental results show that the axial temperature profile along the height was proportionally reduced with bed height of FBC. CO and NOx emissions obtained exhibit lower values for the air staged combustion. Pelepasan emisi dari pembakar lapisan terbendalir (FBC) adalah sangat bergantung kepada beberapa parameter kendalian sebagai contoh: suhu, udara berperingkat, udara berlebihan, kadar suapan bahan api, dan sifat bahan api. Kertas kerja ini mempersembahkan keputusan eksperimen yang dilaksanakan menggunakan teknik pemeringkatan udara ke atas rig lapisan terbendalir skala makmal, menggunakan tempurung kelapa sawit sebagai bahan api dan pasir silika sebagai bahan perantara lengai. Pasir silica telah digunakan untuk memastikan pencucuhan bahan api mampan dan pembakaran stabil berlaku di dalam FBC. Pelepasan gas emisi CO dan NOx serta suhu sepanjang ketinggian pembakar dan juga dalam serombong diukur. Keputusan ujikaji menunjukkan bahawa profil suhu paksi berkurangan secara berkadaran sepanjang ketinggian FBC. Pelepasan CO dan NOx yang diperolehi mempamerkan nilai yang lebih rendah untuk keadaan pembakaran dengan pemeringkatan udara.

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