作为一种新兴的环境友好化学品,甲缩醛在绿色化学工艺中发挥着重要作用,甲缩醛生产过程产生的高浓度难生物降解有机废水的处理工艺目前鲜有报道。为探索臭氧催化氧化工艺对该废水的预处理效果,提高废水可生化性(B/C),为后续生化处理提...作为一种新兴的环境友好化学品,甲缩醛在绿色化学工艺中发挥着重要作用,甲缩醛生产过程产生的高浓度难生物降解有机废水的处理工艺目前鲜有报道。为探索臭氧催化氧化工艺对该废水的预处理效果,提高废水可生化性(B/C),为后续生化处理提供便利条件。采用浸渍法制备了以活性炭(AC)为载体的双金属复合催化剂Fe-Mn-AC,并与外购的2种催化剂进行了对比试验,对催化效果最优的催化剂进行表征分析微观结构,进行了工艺优化试验以确定最佳工艺参数。实验结果表明:催化剂选用Fe-Mn-AC、催化剂用量为25 g/L、废水初始pH值为8.3、反应温度为25℃、臭氧流量为1.5 L/min;臭氧浓度为102 mg/L条件下,废水COD的去除率达到74.32%,B/C比由初始的0.120提升到0.472,为后续生化处理创造了有利条件。Methylal is a new environmentally friendly chemical, which plays an important role in green chemical processes. A large amount of wastewater produced in the process of methal production and research and development belongs to high-concentration organic wastewater that is difficult to biodegrade. At present, there are few reports on the treatment technology of methyl acetal wastewater. In order to explore the efficiency of catalytic ozone oxidation process for pretreatment of methylal production wastewater and improve the biodegradability (B/C) of wastewater, and provide favorable conditions for subsequent biochemical treatment. Fe-Mn-AC ozone catalyst was prepared by impregnation method, and compared with two purchased catalysts, the microstructure of the catalyst with the best catalytic effect was characterized and analyzed, and then the process optimization test was carried out to determine the best process parameters. It was determined that Fe-Mn-AC was selected as catalyst, the amount of catalyst was 25 g/L, the initial pH of wastewater was 8.3, the reaction temperature was 25˚C, and ozone flow rate 1.5 L/min. When the ozone concentration is 102 mg/L, the removal rates of COD and UV254 in wastewater reach 74.32% and 66.84%, respectively, and the B/C ratio increases from the original 0.120 to 0.472, indicating better biodegradability.展开更多
通过调控铝源合成了四种HZSM-5分子筛,并将其应用于催化甲缩醛(DMM)气相羰基化合成甲氧基乙酸甲脂(MMAc)反应。结果表明,改变合成凝胶体系中的铝源种类,可以制备出织构性质、酸性特征相近,但骨架铝分布不同、催化羰基化性能迥异的HZSM-...通过调控铝源合成了四种HZSM-5分子筛,并将其应用于催化甲缩醛(DMM)气相羰基化合成甲氧基乙酸甲脂(MMAc)反应。结果表明,改变合成凝胶体系中的铝源种类,可以制备出织构性质、酸性特征相近,但骨架铝分布不同、催化羰基化性能迥异的HZSM-5分子筛。其中,使用硝酸铝与硫酸铝作为铝源制备的分子筛HZ-N与HZ-S表现出更为优异的催化活性,HZ-N对应的DMM转化率与MMAc选择性分别为25.3%与58.9%,HZ-S对应的DMM转化率与MMAc选择性分别为28.7%与64.6%。采用Co-ZSM-5的UV-vis-DRS与27 Al MAS NMR等表征手段详细分析证实,硝酸铝与硫酸铝作为铝源时,更多的骨架铝优先落位于HZSM-5分子筛交叉孔道,其在催化DMM羰基化反应过程中起主导作用,落位比例高,更有利于反应的进行,反之可能导致较低的DMM转化率以及更高的副产物选择性。展开更多
变压精馏工艺虽然是生产高浓度甲缩醛的主要方法,但该工艺存在能耗高的缺点。本文基于变压精馏分离甲缩醛和甲醇共沸物的工艺方法,利用Aspen plus软件对10万t/a高浓度甲缩醛生产过程进行模拟,基于模拟数据和Aspen Energy analyzer软件...变压精馏工艺虽然是生产高浓度甲缩醛的主要方法,但该工艺存在能耗高的缺点。本文基于变压精馏分离甲缩醛和甲醇共沸物的工艺方法,利用Aspen plus软件对10万t/a高浓度甲缩醛生产过程进行模拟,基于模拟数据和Aspen Energy analyzer软件对该过程换热网络进行分析和优化。结果表明:在最小传热温差为10℃时,常规变压精馏工艺夹点温度为84.03℃(热物流)和74.03℃(冷物流),充分利用甲缩醛加压精馏塔塔顶物流潜热及塔底物流显热的换热网络节能效果显著,优化后的换热网络可节省热公用工程3.732 MW、冷公用工程3.701 MW,热节能率为33.68%。展开更多
文摘作为一种新兴的环境友好化学品,甲缩醛在绿色化学工艺中发挥着重要作用,甲缩醛生产过程产生的高浓度难生物降解有机废水的处理工艺目前鲜有报道。为探索臭氧催化氧化工艺对该废水的预处理效果,提高废水可生化性(B/C),为后续生化处理提供便利条件。采用浸渍法制备了以活性炭(AC)为载体的双金属复合催化剂Fe-Mn-AC,并与外购的2种催化剂进行了对比试验,对催化效果最优的催化剂进行表征分析微观结构,进行了工艺优化试验以确定最佳工艺参数。实验结果表明:催化剂选用Fe-Mn-AC、催化剂用量为25 g/L、废水初始pH值为8.3、反应温度为25℃、臭氧流量为1.5 L/min;臭氧浓度为102 mg/L条件下,废水COD的去除率达到74.32%,B/C比由初始的0.120提升到0.472,为后续生化处理创造了有利条件。Methylal is a new environmentally friendly chemical, which plays an important role in green chemical processes. A large amount of wastewater produced in the process of methal production and research and development belongs to high-concentration organic wastewater that is difficult to biodegrade. At present, there are few reports on the treatment technology of methyl acetal wastewater. In order to explore the efficiency of catalytic ozone oxidation process for pretreatment of methylal production wastewater and improve the biodegradability (B/C) of wastewater, and provide favorable conditions for subsequent biochemical treatment. Fe-Mn-AC ozone catalyst was prepared by impregnation method, and compared with two purchased catalysts, the microstructure of the catalyst with the best catalytic effect was characterized and analyzed, and then the process optimization test was carried out to determine the best process parameters. It was determined that Fe-Mn-AC was selected as catalyst, the amount of catalyst was 25 g/L, the initial pH of wastewater was 8.3, the reaction temperature was 25˚C, and ozone flow rate 1.5 L/min. When the ozone concentration is 102 mg/L, the removal rates of COD and UV254 in wastewater reach 74.32% and 66.84%, respectively, and the B/C ratio increases from the original 0.120 to 0.472, indicating better biodegradability.
文摘通过调控铝源合成了四种HZSM-5分子筛,并将其应用于催化甲缩醛(DMM)气相羰基化合成甲氧基乙酸甲脂(MMAc)反应。结果表明,改变合成凝胶体系中的铝源种类,可以制备出织构性质、酸性特征相近,但骨架铝分布不同、催化羰基化性能迥异的HZSM-5分子筛。其中,使用硝酸铝与硫酸铝作为铝源制备的分子筛HZ-N与HZ-S表现出更为优异的催化活性,HZ-N对应的DMM转化率与MMAc选择性分别为25.3%与58.9%,HZ-S对应的DMM转化率与MMAc选择性分别为28.7%与64.6%。采用Co-ZSM-5的UV-vis-DRS与27 Al MAS NMR等表征手段详细分析证实,硝酸铝与硫酸铝作为铝源时,更多的骨架铝优先落位于HZSM-5分子筛交叉孔道,其在催化DMM羰基化反应过程中起主导作用,落位比例高,更有利于反应的进行,反之可能导致较低的DMM转化率以及更高的副产物选择性。
