Abstract
Determination of the mass diffusion coefficient for dried, inhomogeneous material is difficult as it depends on the drying agent temperature and the moisture content and physical structure of the material. The paper presents a method for efficient determination of the water diffusion coefficient for wood solid cuboids dried using convective drying methods. In this work, the authors define a theoretical dependence of the Fourier number on reduced water content in a convectively dried cuboidal solid, based on a simplified theoretical solution of the diffusion equation for such a body. The material for drying included shoots of common osier, robinia (false acacia), multiflora rose, and energy poplar, dried at temperatures of 40, 50, 60, 70, and 80 °C, in free convection. The obtained results differ from the theoretically anticipated changes of the coefficient.
Highlights
(5), rapidly converges to 0, the calculations were limited to a limited interval, Fourier number (Fom) є< 0; 4.9>
As an algorithm for the determination of the mass diffusion coefficient (5) requires a function inverse to the dependence described by Equation (6), such a function, a spline, was obtained by approximation of segments of a set of analytically determined points [Ui, Fomi ]
The determination of the water diffusion coefficient in moist wood biomass during convective drying is an important issue that describes the process of water transport in the material
Summary
Lignocellulosic biomass is a highly available renewable fuel that is considered to not contribute to the greenhouse effect. In this context, it is expected that biomass and biowaste conversion will play a major role in the global energy transition [8,9]. The most important parameters of biomass for energy purposes are the heat of combustion and heat value [11]. These parameters are predominantly related to the chemical composition of the material as well as moisture content
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have