Calcium Oxide Derived from Waste Shells of Mussel, Cockle, and Scallop as the Heterogeneous Catalyst for Biodiesel Production

Table 1

Chemical compositions of waste shell-derived catalyst.

Compound	Concentration (wt.%)
	Mussel shell	Cockle shell	Scallop shell
CaO	98.367	99.170	97.529
Na2O	0.937	0.438	0.565
SO3	0.293	0.117	1.568
P2O5	0.163	0.096	0.204
SrO	0.158	0.132	0.107
ZrO2	0.046	—	0.027
Cl	0.037	—	—
Fe2O3	—	0.026	—