Iterative method for fast estimation of convective drying characteristics of biomass

TL;DR

This paper introduces an iterative, fully predictive method to quickly estimate the convective drying characteristics of biomass, aiding in equipment design and experimental verification.

Contribution

The paper presents a novel iterative approach that accurately predicts drying rates of biomass during the constant-rate period, independent of initial moisture content.

Findings

Drying rate is a linear function of inlet air mass flow rate.

Drying rate is independent of initial water and dry material masses.

Method estimates the maximum possible drying rate for given inlet air conditions.

Abstract

Convective drying of biomass is an important technological solution required to increase the quality of biomass for efficient biomass conversion in heat and power generation sector. We propose a fully predictive method based on iteratively solving heat power conservation equation, which evaluates the convective drying rate for deep fixed porous material bed containing any type of evaporating liquid during a constant-rate drying period with given inlet air parameters. The analysis of the heat power conservation equation during the constant-rate period showed that the drying rate of deep fixed moist porous material bed is a linear function of the inlet air mass flow rate and is independent of the initial masses of water and dry material inside the bed when inlet air absolute humidity is constant. Furthermore, the proposed method estimates the theoretical maximum possible drying rate for a drying system with given inlet air conditions and; therefore, it can be used as an important tool for designing industrial equipment and verifying the correctness of drying experiments.