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

The duck eggshell waste was developed to the novel desiccant that is friendly to human and environment.The calcium oxide (Ca O) and calcium chloride (Ca Cl2) as the calcium-based desiccants were prepared from eggshell waste.The Ca O desiccant derived from the eggshell waste sintering at 1 300℃,while the Ca Cl2desiccant was extracted from eggshell waste with the hydrochloric (HCl) solution at difierent concentrations from 5 to 30 wt%.The yield percentage of Ca Cl2desiccant 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 Ca Cl2desiccant has the highest hydration rate.The porous host from the kaolin was sintered at different temperatures from 200 to 1 000℃and incorporated with 30%w/v concentrations of Ca Cl2.The physical properties and the humid-adsorption capacity of all porous host conditions were investigated.The porous host at sintering temperature 800℃has the highest specific surface area.Moreover,the porous host at sintering temperature 800℃with the 30%w/v concentration of Ca Cl2desiccant has the highest humid-adsorption capacity.