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Adsorption characteristics of 2,4-Dichlorophenoxyacetic acid (2,4-D) and 2,4-Dinitrophenol (2,4-DNP) onto granular activated
carbon (GAC) were studied to obtain basic information on their removal from aqueous solution. Single component adsorption
equilibria of 2,4-D and 2,4-DNP dissolved in water have been measured for three kinds of GACs (F400, SLS103, and WWL). In
case of 2,4-D, the magnitude of adsorption capacity was in the order of F400> SLS103>WWL, and that for 2,4-DNP was SLS103>
F400> WWL. The influence of temperature and initial pH of aqueous solution on adsorption has been discussed in detail by using
the Sips equation. 相似文献
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2,4-二氯苯乙酮ω-位选择性单溴化反应研究 总被引:2,自引:0,他引:2
研究了2,4 二氯苯乙酮ω 位单溴化反应及其影响ω 溴 2,4 二氯苯乙酮(即单溴物)收率的各种因素。结果表明,以苯、二氯甲烷、四氯化碳与1,2 二氯乙烷等作为反应介质时,单溴物的收率为84%~86%,而以乙醚、三氯甲烷、甲醇、乙醇及冰醋酸等作为反应介质,单溴物的收率只有69%~77%,但在甲醇、乙醇或三氯甲烷等溶剂中,增加溴的用量收率增加,如在乙醇中收率可升至89 23%。脱去溶剂前是否用水或碱溶液洗涤,对单溴物的收率没有明显影响。以苯为反应介质时,温度在-10~10℃对单溴化的影响不大,但在加入水时,收率下降,且需要加热反应才能正常进行。在1,2 二氯乙烷、甲醇、乙醇等溶剂中,或以络合态溴作为溴化剂时,反应也需要加热。溴与二氧六环形成络合物后,不能减少ω,ω 二溴 2,4 二氯苯乙酮(即二溴物)的产生。反应过程中吹入N2排除HBr,或用H2O2吸收并利用HBr,可使单溴物收率分别上升到89 40%和89 74%。 相似文献
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采用尿素法合成甲苯-2,4-二氨基甲酸甲酯(TDC)是一条绿色的工艺路线.其反应路径之一是以1-甲基-2,4-苯二脲(TBU)为中间产物,即2,4-二氨基甲苯(TDA)与尿素反应生成TBU,TBU再与甲醇反应得到TDC.首先对该路径进行了热力学分析,然后分别对两步反应进行了研究.对于TBU合成反应,适宜溶剂和催化剂分别为环丁砜(CBS)和乙酸锌;适宜反应条件为:反应温度130℃,反应时间7 h,n(TDA):n(Zn(OAc)2):n(Urea):n(CBS)=1:0.05:3.5:10.此时TDA转化率为54.3%,TBU选择性为73.3%.对于TDC合成反应,基于液相色谱-质谱和气相色谱分析结果,确定了反应组分.适宜的反应条件为:反应温度140℃,反应时间5 h,反应压力1.1 MPa,甲醇与TBU摩尔比为110:1.在该反应条件下,TBU转化率为100%,TDC选择性为60.4%. 相似文献
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Sung Yong Cho Sook Jin Kim Tae Young Kim Hee Moon Seung Jai Kim 《Korean Journal of Chemical Engineering》2003,20(2):365-374
The influence of temperature and initial pH of aqueous solution on adsorption has been discussed in detail using the Sips
equation. Single-component adsorption equilibria of 2,4-D and 2,4-DNP dissolved in water have been measured for three kinds
of GACs (F400, SLS103, and WWL). For 2,4-D, the magnitude of adsorption capacity was in the order of F400>SLS103>WWL, and
that for 2,4-DNP was SLS103>F400>WWL. These results may come from the effects of the pore size distribution, surface area,
surface properties, and difference in adsorption affinity. Kinetic parameters were measured in a batch adsorber to analyze
the adsorption rates of 2,4-D and 2,4-DNP. The internal diffusion coefficients were determined by comparing the experimental
concentration curves with those predicted from surface diffusion model (SDM) and pore diffusion model (PDM). The linear driving
force approximation (LDFA) model was used to simulate isothermal adsorption behavior in a fixed bed adsorber and successfully
simulated experimental adsorption breakthrough behavior under various operation conditions. Efficiency of desorption for 2,4-D
and 2,4-DNP was about 80% using distilled water at pH of 6. 相似文献
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甲苯-2,4-二氨基甲酸甲酯(TDC)是非光气合成甲苯二异氰酸酯(TDI)的重要中间体,2,4-二氨基甲苯(TDA)、尿素和甲醇一步合成TDC是一条绿色的反应工艺。今在反应精馏装置上研宄了操作条件对非催化合成TDC反应的影响,得出适宜操作条件为:反应温度190°C,压力0.7~0.75 MPa,反应原料分为两股进料,其中一股进料为TDA,尿素和甲醇的混合液(nTDA:/nUrea:nMeOH=1:5:80),进料位置为反应段上方,速率为0.3 m L·min-1,另一股为纯甲醇,进料位置在反应段下方,速率为5.0m L·min-1,塔顶回流比0.75,塔釜釆出比90:2。在该条件下,TDA的转化率62%,TDC的收率和选择性分别为36%和58%。与高压釜上所得结果相比,TDC的选择性提高了17%。 相似文献
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采用间二甲苯和CO为原料、粉状无水AlCl3为催化剂,利用羰基化反应在反应温度-20℃,CO压力1.5MPa,反应时间50分钟,n(AlCl3):n(间二甲苯)=1.0:3.0的较佳工艺条件下,合成的羰基化中间δ-络合物经水解、干燥、减压蒸馏可以得到2,4-二甲基苯甲醛,产率(相对催化剂AlCl3的摩尔数)≥83.0%。 相似文献
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相转移催化合成2,4-二氯苯氧乙酸新工艺研究 总被引:1,自引:0,他引:1
以2,4-二氯苯酚和氯乙酸为原料,在碳酸钾作用下筛选相转移催化剂(四丁基溴化铵、四乙基溴化铵和PEG-600)进行醚化反应,制备2,4-二氯苯氧乙酸。所获得的最佳工艺条件是:催化剂选PEG-600/KI为最佳,二氯苯酚和氯乙酸原料物质的量比1∶2,相转移催化剂PEG-600用量为二氯苯酚的6%,KI用量为二氯苯酚量的10%。在此合成条件下,2,4-二氯苯氧乙酸收率达94.2%。 相似文献
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建立一种采用高效液相色谱法测定2,4-二氯苯酚的定量分析方法,选用甲醇+水作流动相,RP-18色谱柱,检测波长254nm,外标法定量。本方法的回收率在98.1%-101.8%,标准偏差0.225,变异系数1.98%。2,4-二氯苯酚得到较好分离,操作简便、实用,本方法定量分析结果准确、稳定。 相似文献
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Ilyas S. Nizamov Yevgeniy N. Nikitin Ilnar D. Nizamov Rafael A. Cherkasov 《Journal of Sulfur Chemistry》2016,37(2):189-195
Bis(trimethylsilyl) esters of bisaryldithiophosphonic acids were obtained in 70–81% yields by the reactions of 2,4-diaryl 1,3,2,4-dithiadiphospheta ne-2,4-disulfides with 1,3-bis(trimethylsilyloxy)benzene and 2-methyl 1,3-bis(trimethylsilyloxy)benzene. 相似文献
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采用2,4-二氯硝基苯为原料,以硝硫混酸为硝化试剂,经硝化反应得到2,4-二氯-1,3,5-三硝基苯。研究了硝化体系的比例、反应温度和反应时间对硝化反应的影响,确定了合成工艺条件为:发烟硫酸与发烟硝酸的体积比为5∶1、反应温度为150℃,反应时间为8 h,产品得率达64%以上。对产物样品进行熔点测定,熔点为127~128℃。用薄层色谱和高效液相色谱分析了样品的纯度,用红外和核磁共振表征了样品的结构。 相似文献
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以2,4-二氯苯氧乙酸与正丁醇为原料,三氟甲磺酸为催化剂,催化合成2,4-滴丁酯,考察了醇酸摩尔比、反应时间及催化剂用量等对反应的影响。结果表明,合成2,4-滴丁酯的最佳反应条件是:正丁醇与2,4-二氯苯氧乙酸的摩尔比为3∶1,催化剂用量为0.2%(占2,4-二氯苯氧乙酸摩尔量),回流反应8 h,在此条件下,酯化率达97.1%。 相似文献
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Kinetic analysis for decomposition of 2,4-dichlorophenol by supercritical water oxidation 总被引:1,自引:0,他引:1
Hyeon-Cheol Lee Jung-Hyun In Jong-Hwa Kim Kyung-Yub Hwang Chang-Ha Lee 《Korean Journal of Chemical Engineering》2005,22(6):882-888
2,4-Dichlorophenol (2,4-DCP), as a halogenated model pollutant, was decomposed by using supercritical water oxidation (SCWO)
in a batch reactor made of Hastelloy C-276. SCWO experiments for 2,4-DCP decomposition were performed in the range of 380–420
°C, 230–280 bar and 0.074-0.221 mol/L H2O2. The effect of oxidant concentration on decomposition rate and efficiency was significant near the critical temperature of
380 °C. However, the role of the oxidant concentration in the SCWO process decreased with an increase in temperature; also,
excess oxidant played a key role in quite significantly decreasing the activation energy of 2,4-DCP oxidation. Variation of
the reaction rate by the change of pressure was negligible even at a near critical temperature. The kinetic rate for the decomposition
of 2,4-DCP in the SCWO process was well described by a simple first-order kinetic and global reaction rate model. From the
SCWO experiments, the various intermediates identified with a GC/MS implied that the first reaction pathway for 2,4-DCP decomposition
led to dimers such as dichlorophenoxyphenols, and the second led to single-ring and ring-opening products. 相似文献