Barekati-Goudarzi Mohamad, Khachatryan Lavrent, Asatryan Rubik, Boldor Dorin, Lynn Bert C
Department of Chemistry, Louisiana State University, Baton Rouge, LA 70803, USA.
Department of Chemical and Biological Engineering, University at Buffalo, The State University of New York, Buffalo, NY 14260, USA.
Molecules. 2025 May 19;30(10):2215. doi: 10.3390/molecules30102215.
The gas-phase delivery of lignin into the hot zone of cw-CO laser-powered homogeneous pyrolysis (LPHP) reactor under "wall-less" conditions led to the breakdown of lignin macromolecules into neutral oligomers and paramagnetic fragments deposited onto the reactor cell walls. The formation of PAHs was observed during the defragmentation of lignin, accelerated with increased laser power. Remarkably, no phenolic compounds were detected among lignin fragments-intermediate radicals and neutral oligomers. It is concluded that the PAH and soot-like conjugated particulates are formed in the hot zone of the LPHP reactor, resembling the high-temperature combustion processes. The key role of the resonantly stabilized radicals in the formation of low-molecular-weight PAHs is outlined. An alternative pathway is proposed for the generation of PAH involving the formation of cyclopentadienyl radical precursors (CPDa) that are adsorbed onto or trapped within lignin macromolecules.
在“无壁”条件下，将木质素气相输送到连续波二氧化碳激光驱动的均相热解（LPHP）反应器的热区，导致木质素大分子分解为中性低聚物和顺磁性碎片，并沉积在反应器壁上。在木质素解聚过程中观察到多环芳烃（PAHs）的形成，随着激光功率的增加而加速。值得注意的是，在木质素碎片（中间自由基和中性低聚物）中未检测到酚类化合物。得出的结论是，PAHs和类烟炱共轭颗粒在LPHP反应器的热区形成，类似于高温燃烧过程。概述了共振稳定自由基在低分子量PAHs形成中的关键作用。提出了一种生成PAH的替代途径，涉及形成吸附在木质素大分子上或被困在其中的环戊二烯基自由基前体（CPDa）。
