【作者】 余武斌；

【导师】 高建荣； 李郁锦；

【作者基本信息】 浙江工业大学 ， 应用化学， 2013， 博士

【摘要】 安全、清洁、高效、节能和可持续等清洁生产是21世纪化学工业发展的一个趋势。采用微米级反应器进行化工反应的技术,简称微化工技术(Microchemical Technology),它是一门通过过程强化来实现绿色合成的新技术。相对于传统的批次反应工艺,其具有快速混合、高效传热、窄的停留时间分布、重复性好、系统响应迅速、便于自动化控制、几乎无放大效应及高安全性能等优势,已成为科研院校和企业界共同的研究热点之一。论文以微化工技术在精细有机合成中应用为目标,设计聚四氟乙烯、玻璃、不锈钢等材质的微通道反应器,研究了偶合、氧化溴化、硝化等典型的精细有机合成反应及微尺度下的物料微混合规律。以C.I.酸性红54为模型化合物,研究聚四氟乙烯毛细管式微通道反应器内合成偶氮染料的偶合反应过程,考察反应物流速、停留时间、管道内径和反应温度等对反应的影响,得到较优工艺条件为：在室温下进行(20℃)下,n(重氮组份)：n(偶合组份)=1：1,流速v=0.18m/s,停留时间τ=11.1ls,管道内径D=1.0mm,产率达96.80%。同时,参考C.I.酸性红54较优工艺条件,固定流速v=0.18m/s,管道内径D=1.0mm,研究微通道反应器中C.I.酸性黄23、C.I.酸性紫1、C.I.活性红35、C.I.活性黄16等不同色系的酸性偶氮染料和活性偶氮染料的合成,其中酸性系列染料产率达95%以上,活性染料产率达80%以上。以甲苯为模型化合物,H202-HBr为溴化体系,研究聚四氟乙烯毛细管和玻璃管式微通道反应器中氧化溴化反应,考察物料配比、停留时间、光照强度等对反应的影响,在聚四氟乙烯毛细管微通道反应系统内,较优工艺条件为n甲苯：nH202:nHBr=2：1.5：1,100W白炽灯光照,停留时间5min,溴原子利用率达66.5%,苄溴的选择性达93.1%；在玻璃微通道反应器中,较优工艺条件为n甲苯：nH202；nHBr=2：1.5：1,150W白炽灯光照,停留时间5min,溴原子利用率达93.6%,苄溴的选择性达94.0%。同时,参考甲苯氧化溴化较优工艺,对均三甲苯、间二甲苯、间氯甲苯、间硝基甲苯、3,4-二氯甲苯等其它取代甲苯的氧化溴化进行探索性研究,结果均取得较好溴原子利用率和选择性,表明HBr-H2O2体系的氧化溴化反应具潜在的应用价值。以氯苯为模型化合物,硝硫混酸为硝化体系,研究不锈钢模块式微通道反应器中硝化反应过程,考察氯苯与硝酸摩尔比、体积流速、反应温度等对反应的影响,得到较优工艺条件为：n氯苯：n硝酸=1：1.3,n硝酸：n硫酸=1：3,反应温度80℃,物料氯苯体积流速0.5mL/min,转化率达74.8%,n(邻硝基氯苯)：n(对硝基氯苯)=0.56：1。同时,参考氯苯硝化较优工艺,对其它芳烃的硝化反应进行了研究,结果表明与常规反应器相比,邻对比有明显提高,且副产物相对较少,同时微通道反应器的时空转化率比常规反应器约高4个数量级。以C.I.酸性红54为模型化合物,Reynolds数Re和离集指数Xs为数学模型,研究物料在聚四氟乙烯毛细管式微通道反应器的微混合规律,考察流速、内径等对微观混合的影响,结果表明流速对Reynolds数Re和离集指数Xs的影响存在一个临界值,超过这个值后,流速影响不再显著；同时,流速在最优条件下,以及内径在一定范围内,内径对离集指数Xs的影响较小,并趋于稳定值,而Reynolds数Re均大于临界数Rec。通过对微通道反应器内偶合、氧化溴化、硝化等典型精细有机合成反应及混合规律的研究,表明微反应技术不仅可以强化过程,大大提高生产效率,还可以提高工艺的稳定性、安全性、操作性及环境友好性等。由此,微反应技术是实现精细有机合成过程高效、节能、安全、清洁的有效手段,可为精细化工产业的绿色化可持续发展提供重要的技术基础。更多还原

【Abstract】 Safe, clean, efficient, energy-saving and continuous production will be the trend of the development of chemical industry in the21st Century. Microchemical technology is a novel technology using microreactor in chemical reactions, to realize green synthesis through strengthening process. Compared with traditional batch reactor, microchemical technology has many advantages, such as high speed mixing, efficient heat transfer, short residence time, good repeatability, quick response, facilitate automation, almost no amplification effect and high safety performance, which makes it becomes one of the research hotspots in Chemical Engineering. The PTFE microreactor, glass microreactor and stainless steel microreactor were design and made. The reactions for synthesis of fine chemicals and mixing law of process in microreactor were studied in the dissertation.A model study was initiated with C.I. acid red54as substrate. The coupling reaction for synthesis of azo dyes was studied in a microchannel reactor. The effects of the reaction flow rate, the residence time, the pipe inner diameter and the reaction temperature on the single-pass conversion and selectivity were evaluated. The optimum process parameters were selected as follows:at room temperature, molar ratio of diazo components to coupling components1:1, flow rate0.18m/s, residence time11.11s, tube diameter1.0mm. The yield reached to96.80%. These conditions also applied in the synthesis of C.I. Acid Yellow23, C.I. Acid purple1, C.I. reactive red35, C.I. Reactive yellow16. The products yield of acidic series is up to95%, and up to80%for reactive dyes.A model study was initiated with toluene as substrate. The oxidative bromination of toluene derivatives with HBr-H2O2as brominating agent was studied in PTFE tube and glass tube microchannel reactors. The effects of molar ratio, residence time, and light intensity on the single-pass conversion and selectivity were evaluated. The optimum process parameters in PTFE-microreactor were selected as follows:molar ratio of toluene to H2O2to HBr2:1.5:1, incandescent light100W, residence time5minutes. The utilization rate of bromine atom reached to66.5%, target product’s selectivity reached to93.1%. For glass-microreactor, the optimum conditions were selected as follows:molar ratio of toluene to H2O2to HBr2:1.5:1, incandescent light150W, residence time5minutes. The utilization rate of bromine atom reached to93.6%, target product’s selectivity reached to94.0%. The optimum reaction conditions were also applied to oxidative bromination of other alkylbenzenes with getting a better utilization rate of bromine atom and selectivity. The result showed that this process and HBr-H2O2system has a great value of usage.A model study was initiated with chlorobenzene as substrate. The nitration of aromatics with nitrate-sulfuric acid as nitrating agent as nitrating agent was studied in stainless steel microchannel reactor. The effects of molar ratio, volume flow rate, reaction temperature on the single-pass conversion and selectivity were evaluated. The optimum process parameters in PTFE-microreactor were selected as follows:the molar ratio of chlorobenzene to nitric acid1:1.3, the ratio of nitric acid to sulfuric acid1:3, reaction temperature80℃, chlorobenzene’s volume flow rate0.5mL/min. The single batch conversion rate of chlorobenzene reached to74.8%. The ratio of o-nitrocholobenzene to p-nitrocholobenzene was about0.56. The optimum reaction conditions were also applied in other aromatic compounds. The results showed that it was significantly improved for the ratio of o-nitrocholobenzene to p-nitrocholobenzene and decreased for byproducts. The space-time conversion (STC) in microreactor was about3.08×104times than that in conventional reactor.A model study was initiated with C.I. acid red54as substrate. Reynolds (Re) and Segregation index (Xs) as mathematical model, the micro-mixing was studied. The effects of flow rate, inside diameter on the micro-mixing were evaluated. The results showed that the flow rate effecting on Re and Xs existed a critical value, when the number exceeded this value, the flow rate effect was no longer significant. Under the optimum flow rate, inside diameter had little influence on Xs and tends to a stable value. At the same time, any one of Reynolds (Re) was greater than critical Reynolds (Rec).In summary, though the study of typical fine organic reaction, such as coupling, oxidative bromination, nitration reaction and its mixing law, it was get a conclusion that micro-technology could not only improved the production efficiency greatly, but also increased the stability, safety, operability of the process. The microreactor technology is an effective method to realize safe, clean, efficient, energy-saving and continuous production for fine organic synthesis. Thus, the research of application basis for microreactor technology can lay a theoretical basis for industrialized efficient and green production.更多还原