|摘要: ||本研究選用柳杉、桉樹、桉樹顆粒以及棕櫚顆粒四種農林廢棄物之生質材料，進行焙燒試驗，試驗之反應溫度為250、300、350、400、450及500oC；持溫時間為30、60、90以及120 min。焙燒後所產生之產物，包括固體焙燒物、液體及氣體。固體產物部分，進行近似分析、元素分析、質量收率、能源收率、熱值、哈氏可磨性指數及傅立葉紅外線光譜之分析，而液體及氣體部分則分別量測其收率與組成。|
In this study, Cryptomeria japonica and Eucalyptus globules chips, and the wood pellets of Eucalyptus globules and Trachycarpus fortunei were employed to carry out the torrefaction experiments. The operating conditions for the torrefaction temperature and residence time were set as 250, 300, 350, 400, 450 and 500℃ , and 30, 60, 90, 120 minutes, respectively. Torrefaction products can be classified into solid, liquid and gas based on the room temperature. The characteristics of torrefied biomass such as ultimate, proximate, mass yield, energy yield, heating value, Fourier transform infrared spectroscopy and Hardgrove Grindability Index (HGI) analyses were be assessed. Furthermore, the yield and composition of torrefaction liquid and gas were also investigated.
The results show that the heating value, ash content, fixed carbon and carbon content of torrefied biomass increased with increasing the temperature and residence time, but the moisture content, oxygen and hydrogen content show the contrary results. In addition, HGI of biomass increased significantly after torrefaction. According to the van Krevelen’s diagram, it shows that the characteristics of torrefied biomass are similar to the coal with increasing the temperature and residence time. Therefore, the torrefied biomass will be more suitable as alternative fuels for PC boilers.
In addition, the organic components can be found in the torrified liquid, and increased with increasing the torrefaction temperature. Acetic acid was found at 250℃. Phenol, 2-methoxy-phenol and 2,6-dimethoxy-phenol were the major compounds of phenolic components at 350oC treatments and they also increased with increasing the torrefaction temperature. Moreover, the major torrefaction gas products were CO2、CO、CH4 and CnHm. CH4 and CO contents increased with increasing the temperature. On the other hand, CO2 increased with increasing the temperature, but decreased over 400℃.