On-line monitoring and quantification of a process reaction by near-infrared spectroscopy. Catalysed esterification of butan-1-ol by acetic acid

被引:15
作者
Blanco, M [1 ]
Serrano, D [1 ]
机构
[1] Univ Autonoma Barcelona, Fac Sci, Dept Chem, Analyt Chem Unit, E-08193 Barcelona, Spain
关键词
D O I
10.1039/b005038p
中图分类号
O65 [分析化学];
学科分类号
070302 ; 081704 ;
摘要
The acid-catalysed esterification of butan-1-ol by acetic acid was monitored and quantified using near-infrared spectroscopy (NIRS). Partial least-squares regression (PLSR) was used to construct calibration models based on synthetic mixtures of the esterification components (viz. butan-1-ol, acetic acid, n-butyl acetate and water) with a view to determining all of them simultaneously. The constructed models were used to monitor a set of esterification reactions based on a factorial design using initial composition and temperature as factors; the results thus obtained were consistent with those provided by the GC reference method, even for reactions performed at higher temperatures than those used for calibration, with relative standard error of prediction (RSEP) values less than 3.5% in all cases. The kinetics of the reaction were calculated and it was shown that the reaction follows theoretical second-order kinetics, which is expected for this esterification. The proposed method allows one to determine quantitatively rate constants, end-points, yields and equilibrium constants, and also the influence of initial water on the performance of the reaction. A statistical study of these variables, based on the characteristics of the used experimental design, proved that the studied factors and their interaction were significant, and that higher temperatures and an excess of acetic acid were the best conditions. The proposed NIR method is thus an effective alternative to traditional methods and is suitable for the on-line quantitative control of batch processes.
引用
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页码:2059 / 2064
页数:6
相关论文
共 16 条
[11]  
Heise HM, 1998, JOURNAL OF NEAR INFRARED SPECTROSCOPY, VOL 6 1998, P349
[12]   A DEMONSTRATION OF TRULY REMOTE IN-LINE NEAR-INFRARED PROCESS ANALYSIS [J].
MACKISON, R ;
BRINKWORTH, SJ ;
BELCHAMBER, RM ;
ARIES, RE ;
CUTLER, DJ ;
DEELEY, C ;
MOULD, HM .
APPLIED SPECTROSCOPY, 1992, 46 (06) :1020-1024
[13]  
Osborne B.G., 1986, Near infrared spectroscopy in food analysis
[14]   SPECTROPHOTOMETRIC MULTICOMPONENT ANALYSIS APPLIED TO TRACE-METAL DETERMINATIONS [J].
OTTO, M ;
WEGSCHEIDER, W .
ANALYTICAL CHEMISTRY, 1985, 57 (01) :63-69
[15]  
Swarin S.J., 1992, SPECTROSCOPY-US, V7, P42
[16]   Modelling and diagnostics of batch processes and analogous kinetic experiments [J].
Wold, S ;
Kettaneh, N ;
Fridén, H ;
Holmberg, A .
CHEMOMETRICS AND INTELLIGENT LABORATORY SYSTEMS, 1998, 44 (1-2) :331-340