煤加氘液化反应特性及产物中氘的分布组成特征

Direct coal deuterium liquefaction characteristics and distribution of deuterium in the products

研究液化反应过程中氢的迁移与传递对于深化认识煤的加氢转化、提升氢气利用效率均非常重要,虽目前已采用同位素示踪技术从氢的来源、氢的活化和氢的传递等方面探讨煤直接液化过程中氢转移反应的相互作用和影响,但还需对煤直接液化加氢过程中氢的分布、参与反应的煤的分子结构等信息从分子层面进行详细阐述。针对新疆淖毛湖煤在四氢萘为溶剂条件下的加氘液化反应行为进行研究,探究动力学氘同位素效应对液化过程的影响规律,并借助ESI-FT-ICR MS表征手段以分析煤液化液固产物杂原子化合物中氘原子的分布特征与结构组成。研究结果表明:淖毛湖煤是液化的优良煤种,动力学氘同位素效应导致淖毛湖煤加氘液化性能偏低,加氘产物分子量分布范围缩小,O_(2)、N_(1)O_(1-2)化合物类型相对丰度较高,停留时间缩短,动力学氘同位素效应的干扰减弱;O_(2)类化合物以D3、D4相对丰度最高,碳数分布C13~C23,推测可能是苯并呋喃醇、二苯并吡喃酮、芳二酚类化合物;与O_(2)类化合物相比,高DBE值的N_(1)O_(1-2)类化合物更容易与氘反应。

It was very important to study the migration and transfer of hydrogen during liquefaction reaction for deep understanding of coal hydrogenated conversion and improvement of hydrogen utilization efficiency.At present,isotope tracer technology had been used to explore the interaction and influence of hydrogen transfer reaction in coal direct liquefaction from the aspects of hydrogen source,hydrogen activation and hydrogen transfer.It was also necessary to elaborate the distribution of hydrogen in the process of direct liquefaction and the molecular structure of coal from the molecular level.Reaction behavior of Nao Maohu(NMH)coal in tetralin was carried out under the atmosphere of deuterium(D2).Kinetic deuterium isotope effect on the liquefaction reaction was discussed.Distribution and composition characteristics of deuterium in the heteroatomic compound from coal liquefaction with deuterium had been analyzed using ESI FT-ICR MS.The results show that NMH coal presents good liquefaction performance.Deuteriation reactivity becomes low caused by kinetic deuterium isotope effect.The distribution range of molecular weight of products from NMH coal liquefaction with deuterium is reduced.The relative abundance of O_(2),N_(1)O_(1-2)compound is high.The interference of kinetic deuterium isotope effect becomes weak with short residence time.The relative abundance of D3,D4compound is the highest in the O_(2)class species compound.O_(2)class species compound is supposed to be benzofuranol,dibenzopyranone and aromatic binary phenols by C13-C23distribution.Compared with O_(2)class species compound,N_(1)O_(1-2)class species with high DBE value tend to be easier to react with deuterium.