材料尺寸對木質材料慢速熱解產物基本性質之影響

Effects of Feedstock Size on the Fundamental Properties of Slow Pyrolysis Products'

本研究係利用慢速熱解法（slow pyrolysis method）將國產柳杉（Cryptomeria japonica）與相思樹（Acacia confuse）依不同尺寸（2×2×5立方公分、2×2X×10立方公分、2×2×15立方公分）以固定床式機械窯，在升溫速率100℃／hr下，將試料加熱至700℃並持溫1hr，探討材料尺寸對熱解產物木炭與木醋液基本性質之影響。試驗結果發現，柳杉及相思樹均以2×2×10立方公分者有最高之木炭及木醋液收率；在相同條件下，柳杉之木炭熱值、木醋液之收率及溶解焦油含量均高於相思樹者，而木炭之收率、木醋液之酸鹼值、比重及有機酸含量則均以相思樹高於柳杉者。各種木醋液有機成分之酸性物質（acidic compounds）均以醋酸為主，酚類物質（phenolic compounds）在柳杉木醋液以2-甲氧基酚（2-methoxy-phenol）為主，相思樹則以2, 6-二甲氧基酚（2, 6-dimethoxy-phenol）為主，各種木醋液中性物質（neutral compounds）均以1, 2-benzenediol及其衍生物含量最多。整體而言，以材料尺寸2×2×10立方公分者有最優良及均衡的木炭與木醋液基本性質。 In this study, the influence of feedstock size (2×2×5 cm^3、2×2×10 cm^3、2×2×15 cm^3) on the fundamental physical and chemical properties of slow pyrolysis products, e. g. wood charcoals and vinegars were examined. The slow pyrolysis was conducted by using steel kiln at the heating rate of 100℃/hr, pyrolysis temperature of 700℃, and holding time of 1 hr and the feedstock were Cryptomeria japonica and Acacia confusa. The result indicated that both woods of feedstock size of 2×2×10 cm^3 had the highest yields of wood charcoals and vinegars. At the same pyrolytic conditions, the C. japonica had higher heating value of charcoal, yield and soluble tar content of wood vinegar than A. confusa. While, the yield of charcoal, pH value, specific gravity, and organic acid content of wood vinegar of A. confusa were higher than those of C. japonica. Among the organic components of wood vinegar, the acetic acid of acidic fraction, 2-methoxy-phenol of phenolic fraction for C. japonica and 2,6-dimethoxy-phenol for A. confusa, and 1,2-benzenediol and its derivatives of natural fraction were the main compound of each fraction. Generally speaking, the feedstock size of 2×2×10 cm^3 had an excellent and balance between the fundamental properties of wood charcoals and vinegars.

In this study, the influence of feedstock size (2×2×5 cm^3、2×2×10 cm^3、2×2×15 cm^3) on the fundamental physical and chemical properties of slow pyrolysis products, e. g. wood charcoals and vinegars were examined. The slow pyrolysis was conducted by using steel kiln at the heating rate of 100℃/hr, pyrolysis temperature of 700℃, and holding time of 1 hr and the feedstock were Cryptomeria japonica and Acacia confusa. The result indicated that both woods of feedstock size of 2×2×10 cm^3 had the highest yields of wood charcoals and vinegars. At the same pyrolytic conditions, the C. japonica had higher heating value of charcoal, yield and soluble tar content of wood vinegar than A. confusa. While, the yield of charcoal, pH value, specific gravity, and organic acid content of wood vinegar of A. confusa were higher than those of C. japonica. Among the organic components of wood vinegar, the acetic acid of acidic fraction, 2-methoxy-phenol of phenolic fraction for C. japonica and 2,6-dimethoxy-phenol for A. confusa, and 1,2-benzenediol and its derivatives of natural fraction were the main compound of each fraction. Generally speaking, the feedstock size of 2×2×10 cm^3 had an excellent and balance between the fundamental properties of wood charcoals and vinegars.