乙醇制浆木素解聚历程中甲氧基副解聚反应诱导酚类单体种类调控和重聚行为研究

How to take advantage of lignin in black liquor of ethanol-water pulping has already been one of the critical problems to be solved in the process of ethanol-water pulping industrialization. Lignin, as the only natural reproducible polymer with a large amount of benzene rings in nature, has almost become the ideal alternative to petroleum based feedstock to produce aromatic fuel oil or aromatic molecular platform compounds through depolymerization. However, in its own structure, except aryl aryl ether bond, other chemical bonds are not perfect in the process of lignin depolymerization to regulate the type of the product and the mechanism of its influence on the whole reaction process. In this paper, ethanol-water pulping lignin that containing different methoxyl groups was used as raw material, and the yield and repolymerization of phenolic monomers induced by methoxy depolymerization in the products of lignin depolymerization are the focus of research. And the subject is to clear and definite the relationship between methoxy structure evolution and methoxy depolymerization pathway during the process of lignin depolymerization, as well as the generative mechanism of reunion of methoxy side depolymerization reaction induced by phenol and lignin oligomers / polymers . In the process of lignin depolymerization, a complete response mechanism of "methoxy—— route of secondary depolymerization —— induction of phenolic monomer products —— identification and suppression of reunion behavior" merization is constructed. Making a contribution to the establishment of the total chemical reaction path of lignin depolymerization, and "the regulation and repolymerization behavior of the products initiated by the methoxy side-depolymerization reaction" is an important theory.

如何利用乙醇制浆黑液中的木质素，已成为乙醇制浆工业化进程中亟待解决的关键问题之一。木质素作为自然界中唯一大量含苯环的可再生资源几乎成为替代石油原料通过解聚反应生产芳烃类燃油或芳香族平台化合物最理想的原料，但其自身结构中除芳基醚键外其他化学键在木质素解聚历程中对产物调控及整体反应影响机制构建尚不完善。本课题以含不同甲氧基的乙醇制浆木质素为原料，以调控木质素解聚产物中由甲氧基副解聚反应诱导产生的酚类单体得率及其引发的重聚行为为研究重点，拟明确木质素解聚历程中甲氧基结构演化与甲氧基副解聚反应路径相互关系和甲氧基副解聚反应诱导产生的酚类与木质素寡聚体/高聚体之间重聚行为发生机制，构建木质素解聚历程中“甲氧基—副解聚反应路径—诱导酚类单体产物调控—引发重聚行为”完整应答机制，为木质素解聚全化学反应路径的建立贡献由“甲氧基副解聚反应引发产物调控与重聚行为”这一重要历程。

《可再生能源发展“十三五”规划》明确提出“2020 年和 2030 年非化石能源分别占一次能源消费比重 15%和 20%”的总目标。近年来，利用可再生植物能源造纸后产生的木质素进行生物质精炼（Biorefining）制备生物燃油和芳香族平台化合物成为全球化研究热点，木质素几乎成为合成工业有机燃料的最有希望的原料。本项目基于木质素解聚历程中甲氧基副解聚反应诱导酚类单体产物种类调控与其所引发的重聚行为研究为导向，围绕相关的基础理论问题展开研究。以乙醇制浆木质素为原料，从木质素解聚历程各反应阶段连接键和官能团变化角度出发，以调控木质素解聚产物中由甲氧基副解聚反应诱导产生的苯酚、苯二酚、甲酚等特征结构酚类单体得率及其引发的重聚反应程度为目标，确立了木质素解聚历程中甲氧基副解聚反应特殊路径，确立了由选择性发生甲氧基副解聚反应诱导的产物种类分布与得率调控机制，识别与调控由甲氧基副解聚反应所引发的高活性酚类单体与木质素活性寡聚体/高聚体重聚反应从而形成的特征结构。开发了一系列催化剂，可有效部分打破木质素三维空间网状结构，减少木质素天然大分子空间叠层造成的基团彼此相邻而引发的空间位阻效应，同时抑制碎片化木质素之间的缩合反应，释放以β-O-4、α-O-4等醚键方式“囚困”的潜在羟基（-OH），并可选择性调控木质素结构单元端位甲基芳基醚键二次重整解封潜在酚羟基（Ar-OH），进一步提高碎片化木质素羟基活性位点基数，为后续木质素作为能源分子和材料平台分子应用提供基础研究数据，对木质素高值化利用工业进程大目标打下坚实基础。项目执行期间，基础理论研究方面主要集中在木质素结构分析、木质素催化解聚催化剂设计和产物分析、木质素解聚产物应用拓展等三方面，累计发表高质量论文22篇；成果应用方面，累计签署工业木质素提取和木质素高值化利用等技术开发合同2项；校企合作方面，累计签署产学研合作协议2项。