钾盐对纤维素热解特性的影响

The influence of potassium salts on the pyrolysis of cellulose

利用微型热解系统,研究500℃终温条件下,钾盐(K2SO4,KNO3,K2HPO4,KOH)对纤维素热解特性的影响。收集炭、焦、重油、轻油、气5种产物,计算各产物产率,分析结果表明,钾盐添加作用下,钾对热解存在主要影响,盐本身理化特性存在次要影响。利用气质联用仪(GC-MS)对重油和轻油进行分析,发现糖、苯类物质主要集中于重油,而醛、酮类物质主要集中于轻油,钾盐显著降低了糖类产物产率,增加了酮类、环烷烃类物质产率。利用X射线光电子能谱仪(XPS)对浸渍样、热解炭、焦含碳官能团进行分析,结果表明,热解后,热解炭与热解焦具有类似的含碳官能团分布,但热解炭中以芳香环中的C=C官能团为主,含氧官能团主要为羰基-CO-而热解焦中另外含有-COO-官能团。

The main aim of the study was to investigate the influence of potassium salts （K2SO4, KNO3, K2HPO4,KOH） on the pyrolysis of cellulose at the temperature of 500 ℃ in a micro- pyrolysis reactor. Collected the products of bio-char, coke, heavy oil （HO）, light oil（LO）, bio-gas and calculated their yields. The results showed that the influence of potassium salts on the pyrolysis of cellulose mainly caused by the potassium ion instead of the physicochemical properties of the salts themselves. Compared the chemical compostion of HO and LO by using the GC-MS. It could be found that phenyl and saeeharide were mainly contained in HO, and naphthenic hydrocarbons, ketons were mainly contained in LO.Potassium salts greatly reduced the yield of saecharides, and increased the yield of ketons and naphthenic hydrocarbon. Compared and analyzed the carbon functional group in cellulose, bio-ehar, coke, similar functional group could be found in bio-char and coke.