The application of drying technology plays
a crucial role in extending storage time and
increasing the added value of lychee products.
Currently, most processing facilities still employ
direct-firing dryers in which the drying agent
is combustion flue gas, resulting in unstable
product quality, low energy efficiency, and high
emissions. This study evaluates the current drying
technologies used in northern lychee-producing
regions and presents the experimental results of
a forced-convection drying model using indirect
heat from biomass, with a processing capacity of
over 5 tons of fresh material per batch. The results
indicate that, for a final moisture content of ≤ 15%,
fuel consumption reaches 1,345 kg of biomass per
batch, reducing energy costs by over 25% and
shortening the drying duration by 17% (down to
1
51 hours) compared to existing technologies. The
dried product exhibits high sensory quality, no
smoke contamination, and improved uniformity
due to controlled airflow distribution and 10-50%
staged exhaust recirculation. The investment cost
of the model is 40-45% of an equivalent indirect
steam drying system, with simple operation
and modular scalability, making it suitable for
household and cooperative-level processing. The
results confirm that biomass-based indirect drying
is an energy-efficient, environmentally friendly,
and seasonally appropriate solution for lychee
producing regions, with potential applicability to
other agricultural products such as longan, plum,
bamboo shoots, turmeric, and ginger.
