共查询到20条相似文献,搜索用时 125 毫秒
1.
2.
3.
常压催化加氢制备间三氟甲基本胺的方法研究 总被引:1,自引:0,他引:1
在对文献报道的间三氟甲基苯胺的合成方法进行对比的基础上,以自制d/C为催化剂,建立了常压催化加氢制备高纯度间三氟甲基苯胺的方法,确定了以底物比为2%,溶剂用量为100mL无水乙醇/0.10mol间三氟甲基硝基苯,氢化温度为45℃,搅拌速度为240r/min的最佳氢化条件,氢化反应收率为98.5%,纯度为99.3%。 相似文献
4.
5.
6.
7.
以2,3,4-三氟硝基苯作起始原料,用Raney镍作催化剂,常温常压加氢合成2,3,4-三氟苯胺,收率高达96%。 相似文献
8.
9.
10.
11.
以超临界二氧化碳为介质,3%Pd/C为加氢催化剂,在流动的固定床反应器中对法呢基丙酮进行催化加氢研究。当二氧化碳压力超过临界压力后,加氢转化率急剧上升,表明超临界条件对法呢基丙酮的催化加氢反应具有巨大的促进作用。在温度为42℃、二氧化碳压力为10.5MPa、空速为1.2m?min?1、氢气浓度为1.0mol?L?1的条件下,转化率可达到99.5%,选择性达到98.8%。与液相加氢反应比较,其加氢反应速度提高646倍。法呢基丙酮超临界加氢反应的较佳反应温度区间为35~50℃,在此温度下可以达到较佳的转化率。超临界加氢反应可以提高加氢速率与选择性,具有很大的优越性。 相似文献
12.
Fengyu Zhao Rong Zhang Maya Chatterjee Yutaka Ikushima Masahiko Arai 《Advanced Synthesis \u0026amp; Catalysis》2004,346(6):661-668
Transition metal catalysts such as Pd, Pt, Ru, and Rh supported on carbon, silica and alumina have been examined for the hydrogenation of nitrobenzene (NB) in supercritical carbon dioxide (scCO2) and in ethanol. The order of hydrogenation activity is Pt>Pd>Ru, Rh in scCO2 and in ethanol. The effectiveness of the support is C>Al2O3, SiO2 for either Pt or Pd in scCO2. For all the catalysts, higher selectivity to aniline has been obtained in scCO2 compared with ethanol. Hydrogenation of nitrobenzene catalyzed with Pd/C and Pt/C catalysts was successfully conducted in scCO2 with a 100% yield to aniline at a lower reaction temperature of 35 °C. The product aniline (organic phase) can be easily separated from the side‐product water (aqueous phase), solvent (scCO2), and catalyst (solid) by a simple phase separation process. The hydrogenation of NB is a structure‐sensitive reaction in ethanol as well as in scCO2 except for a few Pt/C catalysts in which the degree of metal dispersion is small (<0.08). 相似文献
13.
14.
In supercritical carbon dioxide medium, a platinum-containing cubic mesoporous molecular sieve was shown to promote markedly the selective hydrogenation of trans-cinnamaldehyde, giving an excellent selectivity for cinnamyl alcohol. In contrast to the other platinum-containing conventional catalysts, Pt-MCM-48 can be recycled a number of times without showing any deactivation in the studied reaction condition. The selectivity mainly depends on the pressure of carbon dioxide, while the conversion depends on the pressure of carbon dioxide as well as hydrogen pressure. 相似文献
15.
16.
17.
18.
19.
萃取八角茴香精油的研究 总被引:4,自引:0,他引:4
用超临界CO2萃取八角茴香精油。采用4因素4水平的正交试验,得出超临界CO2萃取八角茴香精油的最佳工艺条件为:压力16 MPa、温度35℃、时间2 h、CO2流量30 L/h。在此条件下,八角茴香萃取物得率为10.5%。采用水蒸气蒸馏提取精油,得率为7.5%。对两种不同提取方法得到的精油的品质和得率进行了比较。超临界CO2萃取方法得到的八角茴香精油产品得率比水蒸气法高出40%,并且香气更全面。 相似文献
20.
超临界CO_2萃取芹菜籽油研究 总被引:14,自引:2,他引:14
用超临界CO2萃取技术对广东白芹菜籽进行了萃取研究。结果表明,萃取压力低于15MPa时,较重的油树脂等成分难以被萃取出来;萃取温度为308K时对萃取最有利;解析温度对萃取效率影响较小;CO2流量对萃取效率的影响比床层高度引起的扩散阻力的影响大得多。超临界CO2萃取所得芹菜籽油品质优越,且其中的药用有效成分(3-正丁基-4,5-二氢苯并呋喃酮)含量比水汽法所得芹菜籽油的高五倍多。 相似文献