Abstract An understanding of the catalytic effect of potassium on lignin pyrolysis is crucial for the industrialized application of biomass. In this paper, the catalytic effect of potassium additives (KCl, KOH and K2CO3) on lignin pyrolysis was studied using two Cβ-O type lignin related polymers with a carbonyl group (C O polymer) and a hydroxyl group (OH polymer), respectively, on Cα. With or without potassium additives, the two polymers were injected into a thermogravimetric analyser coupled to a Fourier transform infrared spectrometer (TG-FTIR) and a CDS pyrolyser equipped with a gas chromatography and a mass spectrometer (Py-GC/MS). The results show that the catalytic effect of potassium additives is greatly affected by the associated anion. KOH and K2CO3 strongly reduced the thermal stability of the two polymers and increased the char yield of their pyrolysis, while limited effect of KCl was observed. A promoting effect of KOH and K2CO3 was also observed on the removal of side chains such as methoxy, acetyl and hydroxyethyl groups leading to the formation of CO2 and making phenol the main product. Furthermore, the depolymerization of C O polymers through Cβ-O bond cleavage were promoted by KOH and K2CO3. Finally, the catalytic mechanism of potassium and the overall pathway of pyrolysis of the two polymers were elucidated in this study.

中文翻译：

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KCl、KOH和K2CO3对Cβ-O型木质素相关聚合物热解的影响

摘要 了解钾对木质素热解的催化作用对于生物质的工业化应用至关重要。在本文中，使用两种分别具有羰基（CO 聚合物）和羟基（OH 聚合物）的 Cβ-O 型木质素相关聚合物，研究了钾添加剂（KCl、KOH 和 K2CO3）对木质素热解的催化作用，在 Cα 上。在有或没有钾添加剂的情况下，将两种聚合物注入到与傅立叶变换红外光谱仪 (TG-FTIR) 和配备气相色谱和质谱仪 (Py-GC/MS) 的 CDS 热解仪耦合的热重分析仪中。结果表明，钾添加剂的催化效果受缔合阴离子的影响很大。KOH 和 K2CO3 强烈降低了两种聚合物的热稳定性并增加了它们热解的焦炭产率，而观察到 KCl 的影响有限。还观察到 KOH 和 K2CO3 对去除侧链如甲氧基、乙酰基和羟乙基的促进作用，导致 CO2 的形成并使苯酚成为主要产物。此外，KOH 和 K2CO3 促进了 CO 聚合物通过 Cβ-O 键断裂的解聚。最后，本研究阐明了钾的催化机理和两种聚合物热解的总体途径。乙酰基和羟乙基导致 CO2 的形成并使苯酚成为主要产物。此外，KOH 和 K2CO3 促进了 CO 聚合物通过 Cβ-O 键断裂的解聚。最后，本研究阐明了钾的催化机理和两种聚合物热解的总体途径。乙酰基和羟乙基导致 CO2 的形成并使苯酚成为主要产物。此外，KOH 和 K2CO3 促进了 CO 聚合物通过 Cβ-O 键断裂的解聚。最后，本研究阐明了钾的催化机理和两种聚合物热解的总体途径。