Abstract Acid-hydrolysis residual (AHR) offers significant potential for harvesting chemical energy with simultaneous reduction of environmental pollution, providing carbon neutral (or even carbon negative) sustained energy production, energy security and alleviating social concerns associated with the wastes. In this study, the different effects of intrinsic and extrinsic K and Na were compared firstly. In addition, the effect of different content of alkali metal chlorides doped into AHR and temperature on pyrolysis products were investigated, especially for the phenolic products in bio-oil, along with the grey relational analysis. The results showed that KCl and NaCl promoted the generation of char and gas at the expense of the bio-oil yield. While, addition of KCl and NaCl could increase the yields of total phenolic species. Specifically, the yields of phenols and hydroxy phenols increased, while the guaiacols and syringols content decreased. The effect of KCl on the distribution of pyrolysis products and phenolic species was somewhat greater than NaCl, especially for bio-oil yield. The increasing of pyrolysis temperature would increase gas yield and reduce the char yield. While the bio-oil yield was peaked at 650 ℃. Besides, higher temperature restrained the generation of syringols and promoted the generation of phenols and hydroxy phenols. The grey relational analysis of KCl and temperature showed that KCl content was the major factor in the generation of bio-oil in pyrolysis process, while temperature played more notable role on the yields of total phenolic species, phenols, hydroxy phenols, guaiacols and syringols. The addition of alkali metal chlorides could promote the pyrolysis process and enhance the maximum lower heating value (LHV) of pyrolysis gas, especially the addition of NaCl. The optimal value of addition amount of KCl and NaCl was found to be 2 wt.% and 0.5 wt.%, respectively. Besides, the addition of KCl and NaCl could improve pore quality and activation of AHR pyrolysis char. Based on the pyrolysis products from cellulose, it can be proposed that cellulose has two main pathway depending on the alkali metal chlorides content.

中文翻译：

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碱金属氯化物和温度对酸水解残余热解产物的影响

摘要 酸水解残渣 (AHR) 为收集化学能源提供了巨大潜力，同时减少了环境污染，提供了碳中性（甚至碳负）的持续能源生产、能源安全和缓解与废物相关的社会问题。本研究首先比较了内在和外在K和Na的不同作用。此外，还研究了不同碱金属氯化物掺入量和温度对热解产物的影响，特别是生物油中的酚类产物，并进行了灰色关联分析。结果表明，KCl 和NaCl 以牺牲生物油产量为代价促进了炭和气体的生成。同时，添加 KCl 和 NaCl 可以增加总酚类物质的产量。具体来说，酚类和羟基酚类的产量增加，而愈创木酚和丁香酚的含量下降。KCl 对热解产物和酚类物质分布的影响略大于 NaCl，尤其是对生物油产量。热解温度的升高会增加气体产率并降低焦炭产率。而生物油产率在650℃达到峰值。此外，较高的温度抑制了丁香醇的生成，促进了酚类和羟基酚类的生成。KCl与温度的灰色关联分析表明，KCl含量是热解过程中生物油生成的主要因素，而温度对总酚类、酚类、羟基酚类、愈创木酚和丁香酚的产率的影响更为显着。碱金属氯化物的添加可以促进热解过程，提高热解气的最大低热值（LHV），尤其是NaCl的添加。发现KCl和NaCl的最佳添加量分别为2wt.%和0.5wt.%。此外，KCl和NaCl的加入可以改善AHR热解炭的孔隙质量和活化。根据纤维素的热解产物，根据碱金属氯化物的含量，可以提出纤维素有两种主要途径。