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題名 | 速生樹種雲南石梓(Gmelina arborea)之研究(第三報):硫酸鹽法製漿動力學之研究 |
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作者 | 蘇裕昌; 郭晏桐; 游漢明; | 書刊名 | 林業試驗所研究報告季刊 |
卷期 | 10:4 1995.12[民84.12] |
頁次 | 頁525-534 |
分類號 | 436.188 |
關鍵詞 | 速生樹種; 雲南石梓; 硫酸鹽法製漿; 製漿動力學; Fast-grown species; Gmelina arborea; Kraft pulping; Pulping kinetics; |
語文 | 中文(Chinese) |
中文摘要 | 進行雲南石梓之硫酸法批式製漿工程動力學研究,探討對各影響因子的反應級數、脫木質素反應的活化能和頻率因子導出脫木質素反應動力學方程式,期能了解製漿反應中之各種過程之影響因子,做為製漿製程控制之合理化和蒸解釜設計之依據。 雲南石梓木材在傳統批式蒸煮過程中,可分為初始相、主體相。在初始相脫木質素 反應速率與蒸解液中活性鹼的濃度及硫化度均為零次反應,而對蒸解溫度具有依存性,初始相的主要反應為擴散作用,其活化能為 14.589 kcal/mole,頻率因子為4.86X10^5。初始相脫木質素反應動力學方程式以式(1)表示之。 -dL/dt=4.860X10^5˙e^14589/RT˙L (1) 在主體相脫木質素速率與蒸解液中鹼的濃度有相當密切的關係,雲南石梓的[NaOH]和[Na2S]的反應級數分別為0.7389和0.6073,顯示其木質素對藥品的依存性高,其活化能為22.044 kcal/mole,頻率因子為4.777x10^8 。主體相脫木質素反應動力學方程式為以式(2)表示之。 -dL/dt=4.777X10^8˙e^20336/RT˙[OH^-]^0.7389[HS^-]^0.6073˙L (2) 雲南石梓為一低木質素含量的速生樹種,初始相的反應較其他樹種為高,脫木質素反應速率低,藥液對試材的攻擊的選擇性低,蒸煮時可以利用提高升溫速度及提高硫化度來改善之。主體相的脫木質素反應較一般的闊葉樹材有較快的脫木質素速率,低活化能及高藥品反應級數顯示此試材具有相當優良之蒸煮性,較一般針闊葉樹種在蒸煮時有較低之能量及用藥量之需求。 |
英文摘要 | This study investigated the kraft pulping kinetics of wood of the fast-grown Gmelina arborea. Excellent process control and pulping optimization can be obtained. The process of kraft pulping of G. arborea wood can be divided into initial bulk delignification phase and an indistinct final phase. Results showed that in the initial phase, the activation energy and frequency factor are 14.589 kcal/mole and 4.860 X 10^5, respectively. The kinetic equation of the initial phase is shown as equation I. -dL/dt=4.860 X 10^5˙e^14589/RT˙L (I) In the bulk delignification phase, the reaction order of [NaOH] and [Na2S] are 0.7389 and 0.6073 respectively. The activation energy and frequency factor are 20.336 kcal/mole and 4.777 X 10^8, respectively. The overall bulk delignification phase kinetic equation is shown as equation II. -dL/dt=4.777 X 10^8˙e^20336/RT˙[OH^-]^0.7389[HS^-]^0.6073˙L (II) In the initial phase of kraft pulping of G. arborea wood showed a higher activation energy, lower delignification rates and lower selectivity than those of other wood species. These parameters can be improved by increasing the heating rate, with cooking temperatures goes up faster than those of the ordinary cooking schedule, and increasing the sulfidity of the cooking liquor. In the bulk delignification phase, the lower activation energy and higher reaction order of the chemicals than those of other wood species revealed that the material possesses good cooking characteristics, ie., lower energy and lower chemical requirements than those of the average hardwood species. |
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