Sorption based heat recovery in drying process
report
Drying is an essential operation in the chemical, agricultural, biotechnology, food, polymer, ceramics, pharmaceutical, pulp and paper, mineral processing, and wood processing industries. The removal of the liquid from the product is a very energy-intensive process: about 15% of the industrial energy use is for drying purposes. This accounts for 90 PetaJoule (25TWh) per year within the Dutch industry. Convective drying is the most commonly applied drying technology and typically use heated air to achieve drying. This process results in moist, lukewarm air that contains large amounts of latent heat in the form of water vapour, which is lost through the exhaust. Recovery of this latent heat comes with many practical challenges, such as pollution or fouling by sticky particles, and therefore the lukewarm, moist air is commonly vented to the atmosphere. By applying a sorption process, the latent heat in the humid air can be recovered while avoiding fouling and stickiness issues. The moisture is absorbed by the sorbent, resulting in dry air and the heat of adsorption will heat the air to be re-used in the drying process. The objective of the IDEA project (Industrial Drying Energy-efficiently using Absorption) is to demonstrate the technical and economic feasibility of the liquid sorption concept by demonstrating the liquid sorption technology under conditions typical for drying applications in industry. The activities performed in the IDEA project have led to an increased knowledge and operational experience, applying liquid sorption for latent heat recovery of humid air.
TNO Identifier
980393
Publisher
TNO
Collation
19 p.
Place of publication
Petten, The Netherlands