Development of Eggshell Waste Incorporated with a Porous Host as a Humidity Adsorption Material

Abstract

The duck eggshell waste was developed to the novel desiccant that is friendly to human and environment. The calcium oxide (CaO) and calcium chloride (CaCl₂) as the calcium-based desiccants were prepared from eggshell waste. The CaO desiccant derived from the eggshell waste sintering at 1 300 °C, while the CaCl₂ desiccant was extracted from eggshell waste with the hydrochloric (HCl) solution at different concentrations from 5 to 30 wt%. The yield percentage of CaCl₂ desiccant increased with increasing the HCl concentration to 25 wt%. The humidity adsorption behavior were investigated in the range of 75%–5% relative humidity. The results show the CaCl₂ desiccant has the highest hydration rate. The porous host from the kaolin was sintered at different temperatures from 200 to 1 000 C and incorporated with 30%w/v concentrations of CaCl₂. The physical properties and the humid-adsorption capacity of all porous host conditions were investigated. The porous host at sintering temperature 800 °C has the highest specific surface area. Moreover. the porous host at sintering temperature 800 °C with the 30%w/v concentration of CaCl₂ desiccant has the highest humid-adsorption capacity.

Keywords

eggshell waste / calcium chloride / desiccant / kaolin / porous materials