| In the late ten years, Near Infrared spectrometry (NIS) has been widely used in many aspects in petrochemical field since its' quick analysis, high efficiency, lower cost, good reproducibility, without sample pretreatment and no pollution in analysis process. In this work, Near Infrared spectrum technique was used to measure the Caprolactam content in water system, the lactam content in benzene system and water content in ammonia oximate system, in the production process of Caprolactam. The good results were reached in the practical application. The relative error is -2.58~2.90%, the determination coefficient is 0.9737, the relative standard error is 0.50%, and the variation coefficient less than 0.8% for the analysis of water content in ammonia oximate system by NIS. This shows that NIS has higher accuracy, good reproducibility, and satisfying the water content analysis and control requirement in the ammonia oximate process.Nylon 6 is the most practical, the highest yield engineering plastic raw material at present. It has good wearability, good toughness and good impact resistance, thereby widely used in many aspects. The slice of Nylon 6 is polymerized from Caprolactam. The characterization appaoch at present is relative viscosity method—the Ubbelchde viscometer method, this method is complicated and taking time in operation. Furthermore, the 96% sulfuric acid used can make serious harm to body while misoperation. NIS was used to determine the relative viscosity of Nylon slice in this study, the result shows that it is an effective and quick analysis approach. The standard error is 0.05, repeat error is less than 0.02.In the caprolactam production by HPO process, the IPL inorganic solution is the main material of inorganic circulating system of hydroxylamine oximate setup. Since hydroxylamine phosphate is prepared by reducing nitrate salt with hydrogen and catalyst of active cabborn carried platinum and palladium.The reaction is carried out in an inorganic buffer solution, in order to prevent the loss of catalyst, the Pt, Pd content analysis of the inorganic solution is very important. The Pt and Pd coexisting disturb is elimilated by double-wave spectrophotography, adopting dithizone as the extraction agent. This method overcomes the shortage of single wave method, without miscellaneous extraction separation operation.The colorimetric determination of Pt and Pd is carried out by using the same dithizone solution. This method has good selectivity and high level in technique at home. This method has been successfully used to measure micro-content of Pd, Pt in the hydroxylamine oxminate solution, showing easy operation, quickness, good precision and accuracy to the requirement of production. It is one ideal method to determine the content of Pt, Pd at present. The determination of oil and some organic material in the liquid ammonia was also studied by Infrared spectrophotometry, violet spectrophotometry and Non-dispersive Infrared spectrometry. It is found that Non-dispersive Infrared spectrometry is a quick and simple method directly to determine oil and organic material in liquid ammonia, the result is in accordance with that of gravimetric method, the precision and accuracy satisfy the production requirement.Moreover, the determination of the content of dissociate cyclohexanone-omine in the mixture of rearrangement process in caprolactam production was also studied. The rearrangement mixture is a complicated and difficult system to directly analyze, containing great volume of sulfuric acid and some amount of sulphur trioxide, with higher viscosity and strong corrosivity. However, by a neutralization treatment, the dissociate oxime is hydrolyzed as hydroxylamine, thus a diazotation-coupling reaction method to determine the dissociate oxime is established with simplicity, quickness, accuracy, satisfying the requirement of production control. |
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