摘要
用共沉淀法和超临界流体干燥法，分别制备了Ｚｒ－Ｍｎ－Ｋ沉淀型催化剂和超细催化剂．以正十一～十三烷的混合物为超临界介质，在反应温度３６０～４１０℃、合成气压力７．５ＭＰａ、ＧＨＳＶ１７００ｈ－１及介质压力２．０８ＭＰａ的实验条件下，分别考察了超细催化剂和沉淀催化剂的气相和超临界相催化合成气制甲醇、异丁醇的性能．气相和超临界相反应的研究均表明，超细催化剂催化合成异丁醇的活性高于沉淀催化剂；在超临界条件下反应，超细催化剂上产物的异丁醇含量较高（为２３％～３２％），甲醇含量为２２％～３３％，其它醇均在１０％左右．气相与超临界相反应结果的对比显示，超临界流体促进产物的脱附与传递，提高了ＣＯ的转化率．但超临界流体对甲烷的萃取作用强于对醇的萃取，醇选择性低于气相反应．在超临界条件下合成甲醇、异丁醇仍遵循异丁醇形成的链增长机理，超临界流体改变了链增长各步骤的相对速度，致使超临界相反应的产物分布不同于气相反应的产物分布．
Precipitated and ultrafine Zr Mn K catalysts for synthesis of methanol and isobutanol from syngas were prepared by co precipitation and supercritical fluid drying technology, respectively. Experiments were carried out in gas phase and supercritical phase using a fixed bed reactor at reaction temperatures 360～410 ℃, syngas pressure 7.5 MPa, GHSV 1700 h -1 , and partial pressure of reaction medium ( n C 11 0～C 13 0 mixture) 2.08 MPa. Results show that the ultrafine catalyst has higher catalytic activity for synthesis of isobutanol than the co precipitated catalyst under both gas and supercritical conditions. The product composition over the urtrafine catalyst under supercritical condition is isobutanol 23%～32%, methanol 22%～33% and other alcohols about 10% each. Comparison of results under gas and supercritical phase conditions indicates that the mechanism of alcohols formation in supercritical phase is chain propagation mechanism and supercritical fluid makes the relative rates of individual addition steps different from those in gas phase. CO conversion is higher and ROH selectivity is lower for reaction in supercritical phase.
出处
《分子催化》
EI
CAS
CSCD
北大核心
1999年第1期15-20,共6页
Journal of Molecular Catalysis(China)
关键词
超临界相
异丁醇
甲醇
催化剂
合成气
锆
锰
钾
Supercritical phase, Isobutanol, Methanol, Zr Mn K catalyst, Syngas
