摘要
研究了以四氢化萘为溶剂 ,蔗渣分别在铁系催化剂和无催化剂作用下的液化反应。在无催化剂作用时 ,4 0 0℃下无论是反应 10min或是 1h ,残渣率和产油率都分别保持在 18%和 30 %左右不变 ;在 5 0 0℃下将反应时间由 10min延长到 1h ,残渣率升高 1倍 ,产油率略有降低。在 4 0 0℃下 ,蔗渣催化液化与相同温度下无催化剂液化残渣率相差不大 ,而产油率明显提高 ;而 5 0 0℃下无论使用催化剂与否 ,产油率和残渣率都变化不大。其原因是 ,在 4 0 0℃下 ,铁系催化剂促使氢自由基从四氢化萘转移到热解自由基和缩合的自由基碎片上 ,形成稳定的化合物 ,从而降低了自由基碎片分解汽化的几率 ,所以产油率明显提高。低温阶段蔗渣液化实质是热溶解过程 。
The liquefaction of bagasse in tetralin with and without iron-based catalyst is studied in this paper.The (residue) rate and oil yield are approximately 18% and 30% respectively at 400 ℃ whether the reaction are conducted for 5 min or 1 h.The residue rate is doubled when reaction time varies from 5 min to 1 h at 500 ℃ while oil yield was reduced.At 400 ℃ oil yield is enhanced and residue rate does not change when FeOOH and Fe_2S_3 are impregnated into bagasse.However,the catalysts do not enhance oil yield at 500 ℃.The reason why iron-based catalyst enhanced oil yield is that iron-based catalyst promotes the transfer of hydrogen free radicals from tetralin onto the free radicals from thermodecomposition of free radical fragments from condensation,which results in the formation of stable compounds that are not easily decomposed or gasified.It is concluded that bagasse is dissolved mainly by tetralin at low temperature and that the decomposition of bagasse is followed by the dissolution of fragments at high temperature.
出处
《林产化学与工业》
EI
CAS
CSCD
2004年第3期52-56,共5页
Chemistry and Industry of Forest Products
基金
国家自然科学基金资助项目 (2 0 2 74 0 5 4 )
华南理工大学制浆造纸国家重点实验室基金资助课题 (无编号 )
关键词
液化
蔗渣
纤维素
铁系催化剂
liquefaction
bagasse
cellulose
iron-based catalyst
