氢氧化钠固态预处理对稻草中木素结构特性的影响

为探明这种NaOH固态预处理对稻草产气量影响的内在机理,采用傅立叶变换红外光谱(FTIR)、氢质子核磁共振波谱(1HNMR)、凝胶渗透色谱(GPC)等方法,对NaOH固态处理前后稻草中木素结构的变化进行了多方位研究.结果表明,NaOH固态预处理使稻草中木素内部结构、木素-碳水化合物复合体的形态结构发生了明显的变化,使得纤维素从木素的包裹中释放出来,木素成分也由难降解的三维网状大分子转变成了易降解的直链结构的小分子,从而使得厌氧微生物能够接触到更多的纤维素并对其进行更有效的消化.这些木素形态结构的变化是导致稻草厌氧消化产气量提高的内在原因.

Effect of solid-state pretreatment with sodium hydroxide on the lignin structure of rice straw

The biogas yield of rice straw during anaerobic digestion can be increased through solid-state pretreatment with sodium hydroxide. This study was conducted to investigate the mechanism of biogas yield improvement of the pretreated rice straw. Fourier Transform Infrared Spectroscopy (FTIR), proton Nuclear Magnetic Resonance Spectroscopy (1H-NMR), and Gas Permeation Chromatography (GPC) were used to analyze changes of the lignin structure of pretreated rice straw from different angles. The results showed that the internal structures of the lignin and lignin-carbohydrate complex (LCC) were greatly altered after NaOH pretreatment, resulting in the separation of cellulose from lignin and the decomposition of lignin from large molecules with three-dimensional network structures to small molecules with linear structures. The changes mean the pretreated rice straw is more available to and more easily digested by anaerobic micro-organisms than raw rice straw, leading to the improved biodegradability and the increased biogas yield of the pretreated rice straw.