题名 | Co-Mn-Br体系催化甲基萘液相氧化合成萘甲酸研究 |
作者 | 高红艳 |
学位类别 | 博士 |
答辩日期 | 2012-05 |
授予单位 | 中国科学院研究生院 |
授予地点 | 北京 |
导师 | 吾满江 |
关键词 | 甲基萘 Co/Mn/Br 催化氧化 萘甲酸 反应机理 |
学位专业 | 有机化学 |
中文摘要 | 本文以工业级甲基萘为原料,以氧气为氧化剂进行甲基萘的氧化反应;提出了氧化α-甲基萘,β-甲基萘的最佳工艺条件;考察了不同催化体系对甲基萘氧化反应的影响,得出了甲基萘氧化反应的规律;给出了甲基萘氧化的可能的机理。主要研究内容和结果如下: 1.在甲基萘氧化反应中,选择了甲基萘油和纯度不同的工业级甲基萘分别进行了初探,根据反应进行的情况,选择纯度不同的工业级甲基萘作为以后实验的原料。 2.考察了氧气、臭氧和双氧水等氧化剂对甲基萘的氧化,综合考虑实验结果,最终选择氧气作为对甲基萘氧化的氧化剂。 3. 以Co-Mn-Br为催化剂,对β-甲基萘液相催化氧化制取β-萘甲酸进行了研究,考察了操作方式、催化剂用量、溶剂用量、反应压力、反应温度等因素的影响。结果表明甲基萘催化氧化体系存在明显的诱导期,时间长短与反应条件有关。当反应温度超过120 °C,压力超过0.6 MPa,产物的颜色变深。最后的工艺条件确定为以Co-Mn-Br 1:1:2为催化剂,β-甲基萘与HAc之比为1:6,,适宜的反应条件是催化剂用量1 %,120 °C,0.6 MPa。在此反应条件下,得到β-萘甲酸收率达93.7 % 。 4. 在Co-Mn-Br催化体系中,任何一个单组分或Co-Mn组合都没有催化活性,Co-Mn-Br、Co-Br或Mn-Br对甲基萘的氧化有催化作用。分别以Co-Br和Mn-Br为催化剂,对β-甲基萘液相催化氧化制取β-萘甲酸进行了研究,结果表明,相同条件下耗氧量基本一致,达到理论耗氧值的120%左右。与Co-Mn-Br催化体系相比,Co- Br诱导时间较长,催化氧化产物的颜色深、收率低;而Mn-Br诱导时间较短,氧化产物的颜色浅、收率高。诱导期过后反应开始,从整个氧化反应的温升看,Co-Br催化的反应剧烈,Mn-Br温和。 5. 以Co-Mn-Br为催化剂,对α-甲基萘液相催化氧化制取α-萘甲酸进行了研究,考察了压力、温度等反应条件的影响。结果表明,α-甲基萘在较低温度(90 °C)和较低压力(0.3 MPa)下得到了α-萘甲酸,收率93.9%。 6.为了能得到甲基萘的氧化机理,本文考察了催化剂组成、水含量、产物萘甲酸、Cu离子等对氧化反应的影响。提出了适宜的反应机理。 |
英文摘要 | The process for preparing naphthoic acid by oxidation of methylnaphthalene over Co-Mn-Br catalyst was studied aiming at obtaining high yield of naphthoic acid. The main results of this thesis are summarized as following: 1. In the process of oxidation, the source of methylnaphthalenes and the contribution of oxidation with oxidant were investigated according to the reaction results. Different purity industrial methylnaphthalenes were choosed in the following experiments. 2. In the process of oxidation, the source of oxidants such as oxygen, ozone and hydrogen peroxide were investigated. Oxygen was chosen as the oxidant of methylnaphthalene oxidation according to the experimental results. 3.The effects of reaction parameters such as operation mode, catalyst loading, amount of solvent, temperature and pressure on the liquid phase catalytic oxidation of β-methylnaphthalene to β-naphthoic acid over Co-Mn-Br catalyst have been investigated in a high-pressure reactor. The results showed that the pressure-constant operation mode was better than stepwise pressure rise operation mode. It has been demonstrated that oxidation process existed an induction period. Using a Co-Mn-Br catalyst of 1:1:2 ratio and with the pressure-constant operation mode, the appropriate reaction parameters were 1 % catalyst loading, 120°C and 0.6 MPa. Under that condition, a β-naphthoic acid yield of about 93.7 % was realized. 4. It has been demonstrated that each single component of Co, Mn or Br and Co-Mn had little catalytic oxidation activity, while the oxidation was catalyzed by Co-Br, Mn-Br and Co-Mn-Br. Compared with that of Co-Br, the oxidation went smoothly with Mn-Br and higher yield was obtained but with longer reaction time. 5. The Effects of reaction pressure and temperature on the liquid phase catalytic oxidation of α-methylnaphthalene to α-naphthoic acid over Co-Mn-Br catalyst have also been investigated in a high-pressure reactor. The results showed that the oxidation of α-methylnaphthalene could be performed at both lower pressure (0.3 MPa) and lower temperaturet ( 90°C). Under that condition, a α-naphthoic acid yield of about 93.9 % was realized. 6. In order to get the methylnaphthalene oxidation mechanism, the effects of catalyst composition, water addition, product as well as Cu2+ on the liquid phase catalytic oxidation of methylnaphthalene over Co-Mn-Br catalyst have been investigated in a high-pressure reactor. |
内容类型 | 学位论文 |
源URL | [http://ir.xjipc.cas.cn/handle/365002/4408] ![]() |
专题 | 新疆理化技术研究所_新疆维吾尔自治区精细化工工程技术研究中心 |
作者单位 | 中国科学院新疆理化技术研究所 |
推荐引用方式 GB/T 7714 | 高红艳. Co-Mn-Br体系催化甲基萘液相氧化合成萘甲酸研究[D]. 北京. 中国科学院研究生院. 2012. |
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