Production of Bio-Calcium Oxide Derived from Hatchery Eggshell Waste Using an Industrial-Scale Car Bottom Furnace

Abstract

The valorization of eggshell waste as bio-calcium oxide is crucial for pollution prevention and supporting sustainable development. There are several reports on the thermal conversion of eggshell waste to calcium oxide for the partial or complete substitution of natural lime applications. However, this paper reports the thermal decomposition of large amounts of hatchery eggshell waste on an industrial-scale car bottom furnace for the first time. The hatchery eggshell waste was sundried and placed into five stacked trays in the car bottom furnace. The calcination of the eggshell waste was conducted at 900°C for 3 and 4 h under an atmosphere of air. Both the physical and chemical properties of the eggshell samples and the bio-quicklime products were carefully examined by TGA, SEM, XRD, FTIR, and XRF. The results demonstrate that the purity of calcium oxide in the quicklime products increased from 79% to 87% upon increasing the calcination time from 3 to 4 h. However, the color of the calcined eggshell samples at the surface of the pile was white while the color of the product beneath the surface was black or dark gray. The purity of the calcium oxide of both the black and white calcined samples was 76.4% and 91.5%, respectively. These results indicate the limited efficacy of the car bottom furnace for thermal decomposition of the large amount of eggshell waste to calcium oxide. Additionally, the production cost of bio-calcium oxide is approximately twice the cost of industrial grade lime. For further industrial applications, the furnace should contain the mixing equipment for improving the thermal decomposition of the large pile of eggshell waste. Furthermore, the oil burner system may be used in order to reduce fuel costs.

Combined Potential of Quarry Waste Fines and Eggshells for the Hydrothermal Synthesis of Tobermorite at Varying Cement Content

“…However, XRF does not show carbonates; thus, CaO (calcium oxide) is reported. The oxide, CaO, is the product of the thermal decomposition of the eggshell [56][57][58]. In normal cases, calcium carbonate (CaCO 3 ) makes up approximately 95% of the composition of eggshells [56,59].…”

“…The oxide, CaO, is the product of the thermal decomposition of the eggshell [56][57][58]. In normal cases, calcium carbonate (CaCO 3 ) makes up approximately 95% of the composition of eggshells [56,59]. It is in the XRD result that the true structure of the material is shown as CaCO 3 .…”

Biomimetic Use of Food-Waste Sources of Calcium Carbonate and Phosphate for Sustainable Materials—A Review

“…Biological calcium carbonate has already received a considerable amount of attention, striving, in particular, to improve the sustainability of the materials' production with inexpensive secondary raw materials, hence not affecting resource depletion [15]. Potential was also demonstrated in several applications, including, e.g., energy storage in batteries, considering its electrochemical stability [16]; water treatment and antibacterial action with silver nanoparticles [17]; the synthesis of hydroxyapatite for non-biomedical purposes, such as dye absorption [18]; and the production of bio-calcium oxide into industrial furnaces [19], or carbon-derived catalysts [20].…”

Combined Potential of Quarry Waste Fines and Eggshells for the Hydrothermal Synthesis of Tobermorite at Varying Cement Content

“…On the other hand, ESP has a high calcium oxide content (CaO) of up to 97.8%. However, the oxide, CaO, is the product of the thermal decomposition of the eggshell [50][51][52]. Eggshells are almost entirely composed of calcium carbonate (CaCO3) up to about 95% in normal cases [50,53].…”

“…However, the oxide, CaO, is the product of the thermal decomposition of the eggshell [50][51][52]. Eggshells are almost entirely composed of calcium carbonate (CaCO3) up to about 95% in normal cases [50,53]. This compound, however, cannot be determined in the XRF analysis.…”