Differing kinds of desiccant dehumidifiers do the job in various ways, but the main process they use to extract moisture from the air is either absorption or adsorption. Absorption occurs when the desiccant compound dissolves as it's going to take humidity within the air, as is the situation with humidity https://dstdehumidifiers.co.uk/case-studies/desiccant-dehumidifiers-in-cold-stores/