Ammonium Sulfate: Turning an FGD By-Product into a Valuable Nitrogen-Sulfur Fertilizer

Ammonium sulfate is gaining attention as a valuable agricultural product, offering both nitrogen and sulfur to support crop growth. As sulfur deficiencies affect agricultural soils in many regions, demand for effective sulfur fertilizers creates new opportunities for industries that produce ammonium sulfate through flue gas treatment.

Unlike sulfur sources that require oxidation before plants can absorb them, ammonium sulfate supplies sulfur in the form of sulfate, which is directly available for plant uptake. It also provides nitrogen, making it a practical option for crops with high sulfur requirements, including rapeseed, legumes, onions, garlic, and certain vegetable crops.

This agricultural demand is particularly relevant to ammonia desulfurization. In an ammonia-based flue gas desulfurization (FGD) system, ammonia reacts with sulfur dioxide to produce ammonium sulfate. The recovered product can be used as a fertilizer or as a raw material for compound fertilizer production, provided it meets the applicable quality standards.

For industrial operators, this creates a different approach to by-product management. Instead of focusing solely on the disposal of desulfurization residues, plants can evaluate opportunities to recover a marketable product and integrate it into an established fertilizer supply chain.

HaoTian Environmental Protection’s calcium-to-ammonia conversion solutions apply this resource-recovery approach to industrial flue gas treatment. The company reports sulfur dioxide removal efficiency of more than 99.5% and ammonia recovery of at least 99% under its stated process conditions.

The value of ammonium sulfate lies in connecting environmental protection with agricultural demand. With suitable process control, product quality management, and access to downstream markets, ammonia desulfurization can help turn sulfur removal into a resource-recovery opportunity.