Chemical Composition Monitoring in a Batch Distillation Process Using Raman Spectroscopy

Abstract

Raman spectroscopy was used to monitor the batch distillation of an ethanol/water mixture in a sieve-plate column. The chemical composition of the top product was determined as a function of process time. Four different experimental runs with systematically varied heating and reflux strategies were studied. The results show that the reflux ratio influences the process timing as well as the product quality, whereas the heating strategy impacts the timing only. In the second part of this work, we demonstrate that the Raman technique can also be applied to hydrocarbon systems that are relevant in the oil and gas industries. For this purpose, hexane isomers and their mixtures were studied. The results show that, even though they exhibit very similar structure, the individual compounds can be identified and, moreover, quantified in a mixture. In conclusion, Raman spectroscopy is a useful and versatile tool for monitoring practical distillation processes.

Molecular Solution Behaviour of an Intermediate Biofuel Feedstock: Acetone–Butanol–Ethanol (ABE)

“…[11n, 16] The alcohols, on the other hand, show ad istinct broad vibrational band between 3000 cm À1 and 3600 cm À1 associated with the stretching vibration of the hydroxyl group. [11n, 16,19] These bands are associated with those functional groups most likely involved in interspeciesh ydrogen bonding, that is, acetone-alcohol interactions. As the molecules in pure acetonea re predominantly interacting via dipole-dipole interactions, [20] the carbonyl stretching peak, n(C=O), is strongly influenced by dipolari nteractions between acetonem olecules.…”

Recent Advances in the Characterization of Gaseous and Liquid Fuels by Vibrational Spectroscopy

“…Therefore, the method is mainly used in gases [37] and simple liquid mixtures [38]. For our example, the mixture spectrum and the weighted pure components spectra are illustrated in Figure 6.…”

“…These results demonstrate how good and reliable spectroscopic techniques can be for the analysis of real-world fluids. Another study of ethanol-water solutions was carried out by Struthers et al [38], who monitored the ethanol concentration in the top product of a distillation column using Raman spectroscopy. The spectra were evaluated using the intensity ratio method.…”

Fiberoptic-Coupled Spectrofluorometer with Array Detection as a Process Analytical Chemistry Tool for Continuous Flow Monitoring of Fluoroquinolone Antibiotics

“…e Process Analytical Technology (PAT) [10,11] was defined in 2004 by the Food and Drug Administration (FDA) to support innovation in the industry quality control. PAT has many applications in the pharmaceutical and antibiotics manufacturing [12][13][14][15][16][17][18][19][20][21][22][23][24][25], chemical [26,27], petrochemical [28], and food industries [29][30][31][32][33]. In addition, there are many recent progress in realtime monitoring of cultivations in bioreactors and cell culture process [34][35][36][37][38][39][40][41], fermentation [42,43] and biological process [44], and electrochemical [45,46] and protein purification [47].…”