Differing types of desiccant dehumidifiers perform in different ways, but the main approach they use to extract moisture with the air is either absorption or adsorption. Absorption happens if the desiccant substance dissolves as it's going to take humidity with the air, as is the case with humidity absorbers. Even https://dstdehumidifiers.co.uk/case-studies/desiccant-dehumidifiers-in-cold-stores/