Reaction Kinetics of Chlorine Corrosion to Heating Surfaces during Coal and Biomass Cofiring

Table 5

Model functions of reaction kinetics.

Model functions	Symbol	f(α)	G(α)
One-dimensional diffusion model	D1	(1/2)α^−1	α ^2
Two-dimensional diffusion model	D2	[−ln (1 − α)]^−1	α + (1 − α)ln (1 − α)
Three-dimensional diffusion model (Jander)	D3	(3/2)(1 − α)^2/3[1 − (1 − α)^1/3]^−1	[1 − (1 − α)^1/3]^2
Three-dimensional diffusion model (Ginstling–Brounstein)	D4	(3/2)[(1 − α)^−1/3 –1]^−1	1 − (2/3)α − (1 − α)^2/3
Secondary nucleation and growth reaction	A2	2(1 − α)[−ln (1 − α)]^1/2	[−ln (1 − α)]^1/2
Secondary phase interface reaction	R2	2(1 − α)^1/2	1 − (1 − α)^1/2