水滑石中镁、镍比对木素解聚产物分布的影响

Effect of mole ratio of Mg and Ni in hydrotalcite catalysts on lignin pyrolyzation

采用化学共沉淀法,制备了不同镁、镍、铝摩尔比的水滑石,并用XRD、FT-IR和SEM对460℃焙烧后的样品进行表征,并以制得的水滑石为催化剂对杨木乙醇制浆木素进行超临界解聚。用GC-MS对木素解聚产物进行分析,探索不同镁、镍摩尔比(0、4、8、16)的催化剂对木素超临界催化解聚产物分布的影响。GC-MS检测结果表明,解聚产物可分为芳香烃类、酯类、醇类、醛类、酚类和少量的其他产物,当镁、镍摩尔比为8时,芳香烃类、醛类和酯类产物含量最高;镁、镍摩尔比为0时,酚类产物含量最高。

Hydrotalcite catalysts were prepared with different mole ratio of Ni,Mg and Al by chemical co-precipitation roasting at 460 ℃,and characterized by XRD, FT-IR and SEM. The catalytic depolymerization of aspen lignin was in the supercritical ethanol with hydrotalcite as catalyst.The pyrolyzed products were characterized by GC-MS,and the effects of mole ratio of Mg and Ni（0,4,8,16）on lignin pyrolyzing were also evaluated.GC-MS confirmed that the pyrolyzed products of lignin were mainly composed of aromatic hydrocarbons,esters,alcohols,aldehydes,phenols and other compounds.The yields of aromatic hydrocarbons,aldehydes and esters reached highest when the mole ratio of Mg and Ni was 8,while the maximum yield of phenolic was obtained when the mole ratio of Mg and Ni was zero.