Zeolite for efficient drying

Efficient drying is still an important issue in industry. This work concerns the potential of adsorption drying using zeolite to enhance the energy efficiency of drying. Zeolite is used to dehumidify air before drying and increases the air temperature by releasing heat of vapour adsorption. As a result, the capacity of air to evaporate water from wet product in a dryer increases which makes the process more efficient. However, after taking into account the energy for regenerating of used zeolite, the efficiency improvement is marginal. This situation can be solved by applying multistage adsorption dryers with a energy recovery system. The steady-state calculation study showed that the energy efficiency of a multistage adsorption dryer with 2-3 stages and 4 additional heat exchangers for energy recovery, is 20-30% better than that of conventional dryers