Adsorption isotherm and kinetics of water vapor adsorption using novel super-porous hydrogel composites

Hemant Mittal, Ali Al-Alili, Saeed M. Alhassan

Research output: Chapter in Book/Report/Conference proceedingConference contributionpeer-review

6 Scopus citations

Abstract

Deliquescent salts have high water vapor adsorption capacity, but they dissolve in water by forming crystalline hydrates. That restricts their use in different water vapor adsorption applications. However, this limitation can be overcome by incorporating deliquescent salts within a polymer matrix which will keep the salt solution in place. Furthermore, if the polymer matrix used is also capable of adsorbing water vapor, it will further improve the overall performance of desiccant system. Therefore, in this work, we are proposing the synthesis and use of a highly effective new solid polymer desiccant material, i.e. superporous hydrogel (SPHs) of poly(sodium acrylate-co-acrylic acid (P(SA-co-AA)), and subsequently its composite with deliquescent salt, i.e. calcium chloride (CaCl2), to adsorb water vapors from humid air without the dissolution of the salt in the adsorbed water. Parental PAA-SPHs matrix alone exhibited an adsorption capacity of 1.02 gw/gads which increased to 3.35 gw/gads after incorporating CaCl2 salt in the polymer matrix. Both materials exhibited type-III adsorption isotherm and the experimental isotherm data fitted to the Guggenheim, Anderson and Boer (GAB) isotherm model. However, the adsorption kinetics followed linear driving force model which suggested that this extremely high adsorption capacity was due to the diffusion of water molecules into the interconnected pores of SPHs via capillary channels followed by the attachment of adsorbed water molecules to the CaCl2 salt present in the polymer matrix. Furthermore, the adsorbents were used successively for six cycles of adsorption with a very little loss in adsorption capacity. Therefore, the proposed polymer desiccant material overcomes the problem of dissolution of deliquescent salts and opens the doors for a new class of highly effective solid desiccant material.

Original languageBritish English
Title of host publicationASME 2020 14th International Conference on Energy Sustainability, ES 2020
ISBN (Electronic)9780791883631
DOIs
StatePublished - 2020
EventASME 2020 14th International Conference on Energy Sustainability, ES 2020 - Virtual, Online
Duration: 17 Jun 202018 Jun 2020

Publication series

NameASME 2020 14th International Conference on Energy Sustainability, ES 2020

Conference

ConferenceASME 2020 14th International Conference on Energy Sustainability, ES 2020
CityVirtual, Online
Period17/06/2018/06/20

Keywords

  • Adsorption isotherm
  • Superporous hydrogels
  • Water vapor adsorption

Fingerprint

Dive into the research topics of 'Adsorption isotherm and kinetics of water vapor adsorption using novel super-porous hydrogel composites'. Together they form a unique fingerprint.

Cite this