Calculating Moisture Content in Dry Solid Basis

Understanding Moisture Content in Dry Solid Basis

The activity A wet solid is to be dried from 82% to 6% moisture content (wet solid basis). What are the beginning and end moisture content expressed in a dry solid basis?

If you aim to get 1150 kg of dry product (with the permissible 6% kg water/ kg wet solid), the initial and final moisture contents on a dry solid basis are 455.5% and 6.4% respectively. To achieve 1150 kg of dry product with a final moisture content of 6%, one would need 1223.4 kg of the wet solid.

Explanation

The beginning and end moisture contents on a dry solid basis are calculated differently than on a wet basis. For the initial 82%, it means there's 82kg water / 100kg wet solid. The total weight of dry solid is (100-82) kg, thus the moisture on a dry basis is 82 / (100-82) = 455.5%. For the final 6%, from a similar calculation, the moisture on a dry basis is 6 / (100-6) = 6.4%. To get 1150 kg of the dry product, you'll need to consider the final 6% moisture, which means in total you'll need 1150 kg / (1 - 0.06) = 1223.4 kg of the wet solid.