Experimental investigation and analysis of alumina/polymer/alginate composite desiccant materials.

This study developed a novel lump activated alumina-based composite material (AACM), which composed of activated alumina, polyacrylic acid, sodium polyacrylate, and sodium alginate with a mass mixing ratio of 10:1.5:1.5:1.5. The 10:1.5:1.5:1.5 AACM had the rigid and compact structure without the problems of crack and disintegration. Moreover, due to great structure strength, air channels of 10:1.5:1.5:1.5 AACM can be made by the drilling machine, which was uncomplicated and fast, and can save the mold cost. Under the same adsorption conditions, equilibrium adsorption capacities of 10:1.5:1.5:1.5 AACM were 1.3–2.7 times higher than those of activated alumina in the range of 50–90% relative humidity, and 1.1−1.4 times better than those of a silica gel-based composite material (SGCM) in the high relative humidity (80−90% RH). The calculated results by a linear driving force model showed that 10:1.5:1.5:1.5 AACM possessed greater adsorption rate coefficients compared to activated alumina and SGCM. Moreover, the energy factor of 10:1.5:1.5:1.5 AACM was comparable to that of SGCM at the regenerative conditions of 50 °C and 15% RH, and it was 53% and 27% higher than activated alumina and SGCM, respectively, when using the return air for regeneration. Thus, the proposed AACM is competitive and flexible for extensive applications. [Display omitted] • A novel lump activated alumina-based desiccant composite material was developed. • Fabrication process was uncomplicated and fast, and can save cost. • A composite had 1.3−2.7 times adsorption capacity higher than activated alumina. • A composite can increase adsorption rate coefficients and save power consumption. [ABSTRACT FROM AUTHOR]