Abstract This study investigated the effects of the acidity/alkalinity of seven oxides (Al2O3, SiO2, ZnO, K2O, MgO, CaO, La2O3) on the pyrolysis of poplar, cellulose and lignin. The results showed that the basic supports such as CaO and MgO promoted the formation of gaseous products. CO, CO2, and CH4 were the main gaseous products in the pyrolysis of poplar, cellulose and lignin, and CO was formed first, followed by CO2 and CH4. Some H2 was also formed from the dehydrogenation reactions over CaO with cellulose as the feedstock. The acidic oxides promoted the tar formation, while the basic oxides suppressed tar formation. The oxides like CaO could remarkably suppress the production of phenolic compounds. The coke formation over the basic oxides were also much more significant than that over the acidic oxides, and the tar from cellulose contributed more towards coking. The heating of the coke in inert gas released CO2, CO, H2, CH4 via probably decarboxylation/decarbonylation, dehydrogenation and etc. The coke from the pyrolysis of lignin was much more stable. CaO and La2O3 reacted with the CO2 produced in pyrolysis and form the carbonates, while MgO could not. The TPO–MS characterization showed that the coke species were multiple types over CaO, and a single type over MgO. The cellulose–derivatives and the lignin–derivatives have distinct effects on the structural configuration of the coke.

中文翻译：

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杨树、纤维素和木质素的热解：金属氧化物催化剂酸碱度的影响

摘要 本研究研究了七种氧化物（Al2O3、SiO2、ZnO、K2O、MgO、CaO、La2O3）的酸碱度对杨树、纤维素和木质素热解的影响。结果表明，CaO和MgO等碱性载体促进了气态产物的形成。CO、CO2 和 CH4 是杨树、纤维素和木质素热解过程中的主要气态产物，首先形成 CO，其次是 CO2 和 CH4。一些 H2 也由在 CaO 上以纤维素为原料的脱氢反应形成。酸性氧化物促进焦油形成，而碱性氧化物抑制焦油形成。CaO等氧化物可以显着抑制酚类化合物的产生。碱性氧化物上的焦炭形成也比酸性氧化物上的焦炭形成显着得多，来自纤维素的焦油对焦化的贡献更大。焦炭在惰性气体中加热，可能通过脱羧/脱羰、脱氢等反应释放出CO2、CO、H2、CH4。木质素热解得到的焦炭更加稳定。CaO 和 La2O3 与热解中产生的 CO2 反应形成碳酸盐，而 MgO 则不能。TPO-MS 表征表明，焦炭种类在 CaO 上是多种类型，在 MgO 上是单一类型。纤维素衍生物和木质素衍生物对焦炭的结构构型有不同的影响。CaO 和 La2O3 与热解中产生的 CO2 反应形成碳酸盐，而 MgO 则不能。TPO-MS 表征表明，焦炭种类在 CaO 上是多种类型，在 MgO 上是单一类型。纤维素衍生物和木质素衍生物对焦炭的结构构型有不同的影响。CaO 和 La2O3 与热解中产生的 CO2 反应形成碳酸盐，而 MgO 则不能。TPO-MS 表征表明，焦炭种类在 CaO 上是多种类型，在 MgO 上是单一类型。纤维素衍生物和木质素衍生物对焦炭的结构构型有不同的影响。