Goswami, Nitesh and Bose, Ankita and Das, Nandini and Achary, S N and Sahu, A K and Karki, V and Bindal, R C and Kar, Soumitra (2017) DDR zeolite membrane reactor for enhanced HI decomposition in IS thermochemical process. International Journal of Hydrogen Energy, 42 (16). pp. 10867-10879. ISSN 0360-3199

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Abstract

The third section of closed loop Iodine Sulphur (IS) thermochemical cycle, dealing with HI. processing, suffers from low equilibrium decomposition of HI to hydrogen with a conversion value of only similar to 22% at 700 K. Here, we report a significant enhancement in conversion of HI into hydrogen (up to similar to 95%) using a zeolite membrane reactor for the first time. The all silica DDR (deca dodecasil rhombohedral) zeolite membrane with dense, interlocked structure was synthesized on the seeded clay alumina substrate by sonication mediated hydrothermal process. The synthesized membranes along with seed crystals were characterized by X-ray diffraction (XRD), field emission scanning electron microscope (FESEM) and energy dispersive X-ray spectroscopy (EDX). Corrosion studies were carried out by exposing the membrane samples to simulated HI decomposition reaction environment (at 450 degrees C) for different durations of time upto 200 h. The FESEM, EDX and XRD analyses indicated that no significant changes occurred in the morphology, composition and structure of the membranes. Iodine adsorption on to the membrane surface was observed which got increased with the exposure duration as confirmed by secondary ion mass spectrometry studies. A packed bed membrane reactor (PBMR) assembly was fabricated with integration of in-house synthesized zeolite membrane and Pt-alumina catalyst for carrying out HI decomposition studies. The tube side was chosen as reaction zone and the shell side as the permeation zone. The HI decomposition experiments were carried out for different values of temperature and feed flow rates. DDR zeolite based PBMR was found to enhance the single-pass conversion of HI up to similar to 95%. The results indicate that for achieving optimal performance of PBMR, it should be operated with space velocities of 0.2 -0.3 s(-1) and temperature in the range of 650 K-700 K with permeate side vacuum of 0.12 kg/cm(2). It is believed that the in-house developed zeolite PBMR shall be a potential technology augmentation in making the IS thermochemical cycle energy efficient. (C) 2017 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

Item Type:	Article
Subjects:	Structural Clay Products
Divisions:	Ceramic Membrane
Depositing User:	Bidhan Chaudhuri
Date Deposited:	24 Jan 2018 10:43
Last Modified:	24 Jan 2018 10:43
URI:	http://cgcri.csircentral.net/id/eprint/4034

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