煤炭與木顆粒燃料混燒之燃燒性能與污染物排放特性研究

Study on the Combustion Performance and Pollutant Emission Characteristics of Co-firing with Coal and Wood Pellets

張文振(W.C. Chang) ； 黃緯程(W.C. Huang) ； 王派毅(P.Y. Wang) ； 李泰成(T.C. Li) ； 徐恆文(H.W. Hsu)

《鑛冶：中國鑛冶工程學會會刊》 66卷4期 (2022/12) Pp. 9-20

https://doi.org/10.30069/MM.202212_66(4).01

摘要

以生質燃料取代部分煤炭於鍋爐中混燒，可有效降低鍋爐的SO_2、NO_x與CO_2等燃燒污染物排放，因此，在國際上生質燃料已被廣泛利用作為取代煤炭和石油等化石燃料的低碳燃料。本研究利用一300 kW_(th)垂直下火式燃燒實驗爐來探討煤炭與木顆粒混燒時，對於燃燒性能以及SO_2和NO_x污染物排放量的影響。以高熱值高灰份的澳洲煙煤和低灰的印尼亞煙煤為對象，分別以1:4與2:3兩種重量比例混合成為混煤後再與木顆粒進行直接混燒。由實驗結果得知，混煤（2:3）於實驗爐垂直輻射段所測得之爐溫分布普遍高過於混煤（1:4），而通過水平對流段的煙氣溫度則以混煤（2:3）為最高。由於本研究所使用的亞煙煤含硫量較高，因此，其SO_2排放量以混煤（1:4）要略高於混煤（2:3），當混燒5 wt.%木顆粒時，由實驗數據顯示，混煤（1:4）的SO_2平均排放值由398 ppm降低為389 ppm，其降低率約為2.3%。

關鍵字

混燒（co-firing） ； 煤炭（coal） ； 木顆粒（wood pellet） ； 燃燒（combustion）

並列摘要

Using biomass fuel to replace part of coal in the boiler for co-firing can effectively reduce the SO_2, NO_x, CO_2, and other combustion pollutants emissions of the boiler. Therefore, biomass fuels have been widely used as low-carbon fuels to replace fossil fuels such as coal and other fossil fuels. In this study, a 300 kW_(th) vertical down-fired furnace was used to investigate the combustion performance and the emissions of pollutants of co-firing with coal and wood pellets. The Australian bituminous coal and the Indonesian sub-bituminous coal were mixed with two weight ratios of 1:4 and 2:3 to form blended coal and then the wood pellets were directly added into the blend coals, individually, for co-firing. Experimental results show the temperature distributions of the blended coal (2:3) are generally higher than that of the blended coal (1:4) measured in the vertical radiation section of the furnace wall; while the flue gas temperature in the horizontal convection section of blended coal (2:3) is the highest. As the sulfur content of the Indonesian sub-bituminous coal is higher than that of the Australian bituminous coal, the SO_2 emission of blended coal (1:4) is slightly higher than that of blended coal (2:3). When these blended coals mixed with 5% of wood pellets, experimental data shows that the average SO_2 emissions of blended coal (1:4) reduced from 398 ppm to 389 ppm. The reduction rate is about 2.3%.

並列關鍵字

co-firing ； coal ； wood pellet ； combustion

參考文獻

Kati Veijonen, Pasi Vainikka, Timo Järvinen, Eija Alakangas, “Biomass co-firing-an efficient way to reduce greenhouse gas emissions”, European Bioenergy Networks. VTT Processes, Espoo, Finland (2003).

B.M. Jenkins, L.L. Baxter, Jr. T.R. Miles, T.R. Miles, “Combustion properties of biomass”, Fuel Processing Technology, (1998), 54(1-3), 17-46.

Peter McKendry, “Energy production from biomass (part 1): overview of biomass”, Bioresource Technology, (2002), 83(1), 37-46.

Mischa Theis, Bengt-Johan Skrifvars, Maria Zevenhoven, Mikko Hupa, Honghi Tran, “Fouling tendency of ash resulting from burning mixtures of biofuels. Part 2: Deposit chemistry”, Fuel, (2006), 85(14-15), 1992-2001.

D.L. Granatstein, “Gasification vs Combustion of Waste-Biomass in Fluidized Bed Reactors. Natural Resources Canada, CANMET Energy Technology Centre-Ottawa. (CETC-O), 1 Haanel Drive, Ottawa, Ontario, Canada K1A 1M1 (2004).