【JST-011】CPL, NONE, NOL One-on-One Mutual Assistance Office
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This post was last edited by Firefly on 2015-4-10 08:18. Discussant: zhcc422078. Major: Chemical Engineering and Technology. Specializations: Process theory and production of cyclohexanol (NOL), ** (NONE), and caprolactam (CPL). I have been involved in the upstream production of caprolactam for many years, and I am also experienced in PX, continuous reforming, project planning, etc. If there are any questions, everyone can discuss them together to improve themselves; we welcome active participation and communication from all! I am proficient in CAD, and the following are all my genuine works:
Could you explain the principle of benzene desulfurization during hydration?
The sulfides present in benzene cause severe damage to the catalysts used in the subsequent hydrogenation reactions; it constitutes a permanent form of poisoning. Therefore, it is necessary to remove these sulfides from the benzene and hydrogen before they enter the reaction process. Benzene contains both organic and inorganic sulfur compounds, and the desulfurization reactor operates through adsorption. The catalysts used are aluminum balls and palladium balls, which, at temperatures between 120 and 200 degrees Celsius and under pressures higher than the saturated vapor pressure at those temperatures, absorb the sulfides present in benzene. The desired level of sulfide removal is such that none are detected (less than 0.1 PPb). The amount of catalyst to be used is determined by the sulfur content in benzene
What if it’s adsorbed sulfur? What is the principle of adsorption here? Should there be organic sulfur in benzene here?
It is mainly chemical adsorption; you are right – it’s primarily organic sulfur, with a small amount of inorganic sulfur as well. The aluminum catalyst mainly adsorbs the inorganic sulfur, thereby reducing the burden on the palladium catalyst. Palladium can adsorb both organic sulfur and inorganic sulfur, whereas aluminum catalysts have little effect on organic sulfur. Since palladium catalysts are expensive, two types of catalysts were used here.
First of all, thank you to the original poster. I would like to ask whether the hydroformylation process of cyclohexene has an adverse effect on the production of caprolactam? Does the oxidation method have less impact?
First of all, thank you to the original poster. I would like to ask whether the hydroformylation process of cyclohexene has an adverse effect on the production of caprolactam? Does the oxidation method have less impact?
First of all, thank you to the original poster. I would like to ask whether the hydroformylation process of cyclohexene has an adverse effect on the production of caprolactam? Does the oxidation method have less impact?
One thing that is certain is that cyclohexene, produced through the hydrogenation process, **can be used entirely in the production of caprolactam without any impact on quality. There are examples of this in China: the Shijiazhuang Coking Plant supplied it to petrochemical fiber manufacturers, it was also supplied to Yuehua, as well as to DSM in Nanjing. Additionally, Haili Chemical produces it itself for use in its own caprolactam production. The purity of the product obtained through the hydration method has far fewer impurities compared to the traditional oxidation method, and there are also fewer types of impurities. It requires less energy and is less costly than the oxidation method; moreover, it is environmentally friendly.