木質生質焙燒物表面色差之研究

Abstract

本研究以黑雲杉、白雲杉、杉木、桃花心木、婆羅洲鐵木和巴杜柳桉等6種木質生質物進行焙燒，並檢測焙燒後木質生質物的色差及熱值，比較經不同溫度焙燒後生質物的顏色改變與熱值差間有無直接關係，目的是為了驗證以色差作為木質生質物焙燒品管之可行性。此外，木質生質焙燒物之可磨性也為影響其應用的一個重要的性質，因此另外測量了其中2種生質物經不同焙燒溫度處理後生質物的可磨性，探討經不同溫度焙燒後，生質焙燒物之可磨性與L*、a*、b*之間之相關性。 本研究的結果顯示，不論經箱型焙燒爐或管狀加熱爐焙燒後的木質生質物，其顏色變化（ΔL*值、Δb*值和色差值）與熱值差間均呈現顯著或極顯著的相關。其中杉木以及巴杜柳桉之ΔL*值、Δb*值和色差值與熱值差間均呈現顯著或極顯著的指數性相關，而將上述結果以250 ℃為分界改成雙直線迴歸後，在260-300 ℃的操作條件下之杉木以及巴杜柳桉其ΔL*值、Δb*值和色差值與熱值差間更是一致呈現極顯著線性相關，迴歸方程式的R2均高於0.88。這顯示經過焙燒後的杉木及巴杜柳桉其顏色變化（ΔL*值、Δb*值和色差值）用以作為預測熱質時具有很高的參考價值，而進一步將溫度條件設定在對於焙燒而言較重要的260-300 ºC時，其參考價值以及迴歸線的可信度都更為提升(相較於使用210-300 ℃的指數迴歸結果而言)。 可磨性試驗的結果顯示，經箱型焙燒爐於溫度260-300 ℃焙燒後的杉木以及巴杜柳桉的L*、a*、b*及色差值與哈氏可磨性指數（HGI）間沒有明顯相關，但所有組別的HGI值皆高於40，達到煤炭的最低HGI值標準。然而此部分結果與諸多前人研究之結果有明顯出入，推測原因可能為試驗過程的誤差所致。因此無法斷言生質焙燒物的HGI值與顏色改變間沒有相關性存在。

The purposes of this study was to predict heating value and grindability of torrefied wooden biomass by investigated its colorimetric difference. At the first part, color of wooden biomass (Cunninghamia lanceolata, Shorea spp., Picea glauca, Picea mariana, Eusideroxylon zwageri and Swietenia macrophylla King) and their torrefied biomass at different torrefied temperature were measured by a hand-held color meter according to CIELab system. Then, the relationship between colorimetric difference and torrified biomass heating value were studied. At the second part, grindability of wooden biomass (Cunninghamia lanceolata and Shorea spp.) were investigated and also compared with colorimetric difference to find out whether the relationship exist. The results showed there is significant relationship between heating values and colorimetric difference of torrefied biomass (Cunninghamia lanceolata, Shorea spp., Picea glauca, Picea mariana, Eusideroxylon zwageri and Swietenia macrophylla King). Besides, biomass after 260ºC-300ºC torrefied procedure has higher significant linear relationship between heating values and colorimetric difference than that of exponential relationship. Futher, there is no relationship between grindability (HGI) and colorimetric difference of torrefied biomass (Cunninghamia lanceolata, Shorea spp.).Howerer, it’s Inconsistent with previous literature,and there might be some deviation during the process of grindability test. So the results of this part is undetermined.