汽爆－超细秸秆的分级分离及转化
文献类型：学位论文
| 作者 | 靳胜英 |
| 学位类别 | 博士 |
| 答辩日期 | 2007-09-02 |
| 授予单位 | 中国科学院过程工程研究所 |
| 授予地点 | 过程工程研究所 |
| 导师 | 陈洪章 |
| 关键词 | 汽爆 气流超细粉碎 分级分离 稻草 乙醇 乙酰丙酸 固体超强酸催化 |
| 其他题名 | Fractionation and transformation of steam-exploded and superfine-ground straw |
| 学位专业 | 生物化工 |
| 中文摘要 | 充分认识秸秆结构的不均一性并进行分级分离和转化是实现其高值化的基础。本文以稻草为原料，在深入研究其不均一结构的基础上，采用汽爆－气流粉碎技术分级分离稻草，并探索固体酸催化稻草制备乙酰丙酸的可能性。 首先，从器官、组织、细胞、分子水平研究稻草的不均一结构，以及汽爆－气流粉碎处理对稻草分级分离和转化性能的影响。研究表明：(1)稻草的纤维特征、组成细胞相对含量、化学成分等结构特征在器官水平上不均一；各器官的酶解性能、产乙醇性能和制浆性能均存在明显差异。证明了稻草结构的不均一性是导致转化性能差异的物质基础。(2)首次用汽爆－气流粉碎技术分级分离稻草，实现粉碎的同时，从汽爆稻草分级分离出78%易酶解转化的粉体，平均纤维长度0.060mm，留下难酶解转化的残渣。粉体与残渣的结构特征和转化性能均存在明显差异，粉体酶解率接近理论值，发酵12h的乙醇得率达到7.1%，比残渣高42.3%。(3)以获得秸秆长纤维为目的，首次采用汽爆－湿法气流粉碎技术，从汽爆稻草分级分离出70.4%的纤维组织部分，平均纤维长度0.97mm，比原稻草平均纤维长度(0.93mm)略长。与原稻草相比，纤维组织部分具有较高的纤维细胞和纤维素含量、较强的产乙醇性能和制浆造纸性能，其发酵12h的乙醇得率达到6.5%，比原稻草高41.3%；其粗纸浆得率达到61.4%，比原稻草高91.3%。稻草分级分离能够提高稻草作为纤维原料的利用价值。 针对传统乙酰丙酸制备使用液体无机酸催化存在污染环境和腐蚀设备等问题，首次采用固体超强酸为催化剂，探索稻草制备乙酰丙酸的可能性。结果表明：在反应釜中，以固体超强酸S2O82-/ZrO2-SiO2-Sm2O3为催化剂，汽爆稻草超细粉体和汽爆稻草纤维组织部分的乙酰丙酸得率分别达到71.7％和65.9%，接近理论值，为利用秸秆生产乙酰丙酸提供了新思路。 |
| 英文摘要 | High-valuable transformation of straw is based on its fractionation for its heterogeneity. Rice straw, one of the main abundant and renewable lignocellulosics, was used as the representative straw to study its heterogeneous structure and fractionation by efficient techniques such as steam explosion and airflow superfine grinding. As to the straw-based chemical products, levulinic acid, one of the most important platform chemical, was prepared from the straw by the reaction catalyzed with clean solid superacid catalyst. Fractionation of rice straw based on its organ, tissue, cell and molecule levels was investigated by steam explosion and airflow superfine grinding techniques. Then, the structural characteristics and conversion properties on the above levels were studied. The following results were obtained. First, rice straw of different organ levels presented different structural properties such as fiber characteristics, composed cell proportion, chemical composition, and conversion performance, which proved that the diversity of conversion performance was resulted from the structural heterogeneity. Secondly, steam explosion and airflow superfine grinding pretreatment were used to fractionate rice straw on cell level, and then the easy-hydrolytic product (78%) and difficult-hydrolytic residue were obtained. These two parts had different fiber characteristics, chemical compositions, composed cells and fermentable bioethanol productivity. The ethanol yield was 7.1% for 12h-fermentation of superfine ground product, which was 42.3% higher than that of the residue. Finally, in order to obtain the raw fibers, 70.4% fibrous fraction was separated by steam explosion-wet airflow superfine grinding, the fibrous tissue had higher fiber and cellulose content and it took on a better bioethanol and pulp productivity than those using untreated rice straws. The ethanol yield was 6.5% for 12h-fermentation of the fibrous fraction, which was 41.3% higher than that of untreated rice straw. The pulp yield of fibrous fraction was 61.4%，which was 91.3% higher than that of untreated rice straw. The steam explosion-wet airflow superfine grinding method separated fibrous fraction by removing the non-fibrous tissue. Fractionation of fibrous fraction from rice straw could enhance its value as a fibrous material. With respect to the polluting and corrosive status of mineral acid catalyzed production of levulinic acid, exploring a clean production technique of levulinic acid from straw by catalysis of solid acid is becoming very important. A solid superacid catalyst was first explored to convert rice straw into levulinic acid. The results showed that 71.1% and 65.9% levulinic acid were obtained from the steam exploded-superfine ground rice straw and the fibrous fraction of steam exploded rice straw, respectively, in the pressured reactor when S2O82-/ZrO2-SiO2-Sm2O3, a kind solid superacid was used as the catalyzer. The solid acid catalyzed reaction from rice straw to levulinic acid brought forward a new way to convert straw into levulinic acid. |
| 语种 | 中文 |
| 公开日期 | 2013-09-13 |
| 页码 | 141 |
| 源URL | [http://ir.ipe.ac.cn/handle/122111/1116]  |
| 专题 | 过程工程研究所_研究所（批量导入） |
| 推荐引用方式 GB/T 7714 | 靳胜英. 汽爆－超细秸秆的分级分离及转化[D]. 过程工程研究所. 中国科学院过程工程研究所. 2007. |
入库方式： OAI收割
来源：过程工程研究所
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