Potassium sulfate (K₂SO₄) can be generated as a byproduct during biodiesel production when potassium-based catalysts (like potassium hydroxide) are used. The recovery and use of Potassium Sulphate contribute to sustainable agricultural practices and help in minimizing environmental impact. Potassium sulfate is commonly used as a fertilizer due to its ability to supply plants with essential potassium and sulfur without adding chlorine, making it ideal for chloride-sensitive crops like tobacco, potatoes, and certain fruits.

Potassium carbonate (K₂CO₃) can be produced as a byproduct in biodiesel production when potassium hydroxide (KOH) is used as a catalyst. During the biodiesel purification process, glycerol and water-soluble salts are formed, including potassium carbonate. This compound has a variety of applications: it is commonly used in the production of glass, soaps, and detergents. In agriculture, potassium carbonate serves as a fertilizer, providing potassium essential for plant growth.