生質燃料炭化後燃燒性研究

A Study on Combustibility of Carbonized Biomass Materials

陳君驛(Chen Chun-Yi)

指導教授 ： 蔡建雄

國立屏東科技大學/工學院/車輛工程系所/碩士(2012年)

https://doi.org/10.6346/NPUST.2012.00231

摘要

本研究之目的在於探討生質物經炭化後，燃燒行為是否符合高爐PCI之規範。藉由沉降管高溫反應爐(Drop Tube Furnace，DTF)與著火試驗設備，評估五種生質物(竹子、油棕果短纖、稻殼、蔗渣與小葉欖仁)之燃燒性與著火性，並與動力廠所使用之Adaro煤作比較，以作為替代燃煤之參考依據。
生質物分別在400、450與500°C炭化反應下，持溫1小時。本研究利用DTF模擬高爐與鍋爐快速加熱之環境，試驗溫度為1000°C，樣品粒徑大小為100~200msh。結果顯示，當生質物經炭化後，生質物之外觀顏色轉變為黑色。主要是因碳元素含量隨著溫度提高而增加，導致外觀顏色從原料之黃色加深至咖啡色，最後則為黑色。近似分析方面，將生質物經炭化後之特性與Adaro煤相互比較，生質物經炭化後之揮發分含量較低，灰分與固定炭含量較高，換句話說，生質物經炭化後之碳元素含量較Adaro煤多，氫元素與氧元素含量較低。因此，熱值會隨著溫度提高而增加，有利於應用在高爐燃燒，減少風徑區所產生之未燃煤。至於生質物之著火性評估，生質物經炭化反應後之著火性均高於Adaro煤，且著火性會因炭化溫度提高而增加，即炭化溫度越高，著火溫度越高，導致較不易燃燒。因此，著火性過低之生質物，在儲存與運輸時，宜避免與高溫火源接觸，防止生質物瞬間燃燒。此外，為能維持高燃料利用率，生質物燃燒性之評估是本研究重點之一。生質物經炭化反應後之燃燒性會隨著溫度提高而減少，主要是因生質物持續在高溫環境下，釋出較多之易燃氣體，使揮發分含量減少，導致燃燒性較Adaro煤低。然而，生質物經炭化反應後，碳元素含量提高，熱值因而提高，但燃燒性會受到影響。因此，必須慎選炭化操作條件來提高生質物之燃料利用率。

關鍵字

生質物 ； 炭化 ； 沉降管反應爐 ； 燃燒性 ； 著火性

並列摘要

The purpose of this study was to investigate the combustion behavior whether conform to the blast furnace PCI specification by carbonized biomass. To investigate the combustion efficiency and ignitability of Five woods(bamboo, oil palm shell, rice husk, bagasse and Terminalia boivinii Tul) before/after carbonization, a drop tube furnace (DTF) and ignition eauipment were adopted in this study. The result com[ared with Adaro coal for power plant was also tested as a reference base case for altermative to coal-fired.
The tested woods were carbonized by 400, 450 and 500°C respectively for 1 hour. A drop tube furnace (DTF) was adopted in this study to simulate the rapid heating environment of blast furnace and boiler with 1000°C. The particle size of tested samples was controlled between 100 to 200 mesh. The experimental results indicate that the woods of carbonized appearance color are dark color with the increase of carbonization temperature. It can be explained by the carbon content increase as the temperature increase, the coloe of raw biomass is yello conversion to brown and finally is black. In the approximate, the characteristics of carbonized biomass compare with Adaro coal each other, it is shown that volatile material of carbonized biomass is low and ash is high as well as fixed carbon. In other words, carbon of carbonized biomass is higher than Adaro coal and hydrogen is lower as well as oxygen. Hence, calorific values is increase with increase of carbonization temperature, the application of combustion in the blast furnace is benesifical to reduce the raceway generated unburned. In the case of ignitability assessment of carbonized biomass, ignitability of carbonized biomass is higher than that in Adaro coal and ignitability will increase, that is, the higher the carbonization temperature, the higher the ignition temperature, results in the more difficult to burn. Therefore, the low ignitability for biomass should avoid contact with higher temperature in the storage and transportation, prevent the instantaneous combustion of biomass. In order to maintain high fuel efficiency, the assessment of biomass combustion efficiency is one of the focus of this dtudy, combustion efficiency of carbonized biomass is reduce with increase of the carbonization temperature. It can be explained by the biomass in higher temperature environment at all time, the volatile materials is decrease with the more release of flammable gas, it makes combustion efficiency is lower than that in Adaro coal. At the same time, carbon of carbonized biomass is high as well as calorific values, but combustion efficiency will be affected. Hence, it is must carefully choose the carbonization operating conditions to increase the utilization of biomass fuel.
Keywords:Biomass, Carbonized, Drop Tube Furnace, Combustion Efficiency, Ignitability

並列關鍵字

Biomass ； Carbonized ； Drop Tube Furnace ； Combustion Efficiency ； Ignitability

參考文獻

26.吳志鴻，吳東霖，陳永龍，趙瑩瑩，2010，「竹材加工廢料應用在生物可分解型塑膠複合材製備之研究」，行政院農業委員會林務局委託研究計畫系列。

1.International Energy Agency, 2011, Key World Energy Statistics.

2.BP, 2011, Statistical Review of World Energy.

3.Almeida G., Brito J. O., Perre P., 2010, “Alterations in energy properties of eucalyptus wood and bark subjected to torrefaction: The potential of mass loss as a synthetic indicator,” Bioresource Technology, vol. 101, pp. 9778–84.

5.Guerrero M., Ruiz M. P., Alzueta M. U., Bilbao R., Millera A., 2005, “Pyrolysis of eucalyptus at different heating rates: studies of char characterization and oxidative reactivity, ” Journal of Analytical and Applied Pyrolysis, Vol. 88, pp. 307-314.