Studying the uptake of aniline vapor by active alumina through in-line monitoring a differential adsorption bed with near-infrared diffuse reflectance spectroscopy

Abstract

Through non-invasive monitoring the uptake of aniline vapor by active alumina in a differential adsorption bed (DAB) with near-infrared diffuse reflectance spectroscopy (NIR-DRS), we have studied several features of the adsorption, including isotherm, kinetics and the chemical state of aniline molecules in aniline-alumina system. What is perhaps more important, since the information above is obtained synchronously, the proposed methodology could provide information about the type of adsorption (chemical or physical adsorption), the change of chemical state of aniline in the system during the adsorption process, whether the chemical adsorption and physical adsorption took place simultaneously, the rate of the chemical and physical adsorption, and so on.

Visualization of water vapour flow in a packed bed adsorber by near-infrared diffused transmittance tomography

“…Dispersion profiles, which show the effectiveness of heat and mass transfers inside and around the solid beads of a packed bed, are commonly measured by multiple experiments in which invasive probes are placed at different locations, leading to different residence time distributions (Coppens, 2005;Freund et al, 2005). However, recent developments in spatially-resolved techniques have allowed magnetic resonance imaging (MRI) (Rigby and Gladden, 1996), X-ray (Roels and Carmeliet, 2006) neutron (Asano et al, 2005) and laser spectroscopy (Cai et al, 2009) to measure anisotropic dispersion profiles in gas-solid and liquid-solid reactors, achieving rapid access to scalar data of chemical kinetics and associated mass transfers in a single experiment. These techniques allow three-dimensional (3D) distributions along axial, radial and circumferential directions of the bed structure, such as porosity, pore size and tortuosity, to be mapped within the macroscopic (0.01-10 mm) heterogeneity of the packing.…”

Screening wall effects of a thin fluidized bed by near-infrared imaging

“…Local dispersions in fixed beds are commonly measured by multiple experiments where invasive probes are placed at different locations to collect different residence time distributions [1][2][3][4]. Recent developments of spatially resolved techniques based on magnetic resonance imaging (MRI) [5][6][7], X-ray [8], neutron [9], and laser spectroscopy [10,11] imaging have allowed non-intrusive measurements of anisotropic flow structure, voidage, solid velocity and dispersions in liquid-solid reactors and have achieved rapid access to scalar data of chemical kinetics and associated mass transfer in a single experiment. Unfortunately, these techniques are still not sufficiently mature to be applied to gas-solid reactors due to the inherently weak signal retrieved from the gaseous phase.…”

Using near-infrared process analysis to study gas–solid adsorption process as well as its data treatment based on artificial neural network and partial least squares

“…In this way, we designed experimental setups to investigate the adsorption mechanism of aniline vapor onto active alumina [20] and the multicomponent gas (orthoxylene/isoamyl alcohol) uptake on silica gel [21]. These researches demonstrated great potentials of NIR PAC/PAT in studying the gas-solid adsorption process, but also the demand for further improvements if NIR would be developed into a reliable as well as convenient tool.…”