Tesfaw Andinet Alemayehu, Tizazu Belachew Zegale
Department of Chemical Engineering, Addis Ababa Science and Technology University, Addis Ababa, Ethiopia.
Int J Biomater. 2021 Nov 2;2021:2857764. doi: 10.1155/2021/2857764. eCollection 2021.
The present study evaluated first the characterization of straw and then Box-Behnken design (BBD), and response surface methodology was adopted to optimize the parameters (hydrolysis temperature, dilute sulfuric acid concentration, solid to liquid ratio, and hydrolysis time) of dilute sulfuric acid hydrolysis of straw in order to get a maximum yield of total reducing sugar (TRS). The chemical analysis of straw revealed high amounts of cellulose (41.8 wt%), hemicellulose (38 wt%), and lignin (17 wt%). The morphological analysis using SEM showed that hydrolyzed straw with dilute sulfuric acid has more pores and distorted bundles than those of raw straw. XRD analysis also indicated that hydrolyzed straw has higher crystallinity index and smaller crystallite size than raw straw, which might be due to removal of hemicellulose, amorphous cellulose, and lignin components. Under the optimized conditions for dilute sulfuric acid hydrolysis of straw (120°C, 4% v/v HSO concentration, 1 : 20 solid to liquid ratio, and 55 min hydrolysis time), we have found a total reducing sugar yield of 26.65 mg/g. The results of validation experiment under the optimum conditions agreed well with model predictions.
本研究首先评估了秸秆的特性，然后采用Box-Behnken设计（BBD），并运用响应面法对秸秆稀硫酸水解的参数（水解温度、稀硫酸浓度、固液比和水解时间）进行优化，以获得最高的总还原糖（TRS）产率。秸秆的化学分析表明其含有大量的纤维素（41.8 wt%）、半纤维素（38 wt%）和木质素（17 wt%）。使用扫描电子显微镜（SEM）进行的形态分析表明，与未处理的秸秆相比，经稀硫酸水解的秸秆具有更多的孔隙和扭曲的束状结构。X射线衍射（XRD）分析还表明，水解后的秸秆比未处理的秸秆具有更高的结晶度指数和更小的微晶尺寸，这可能是由于半纤维素、无定形纤维素和木质素成分被去除。在秸秆稀硫酸水解的优化条件下（120°C、4% v/v H₂SO₄浓度、1∶20固液比和55分钟水解时间），我们发现总还原糖产率为26.65 mg/g。在最佳条件下进行的验证实验结果与模型预测结果吻合良好。
