Full Scale Plant Testing of a Process that Uses Sewage Sludge to Produce an Organically-Enhanced Granular Nitrogen Fertilizer

A full scale granulation testing facility was utilized to confirm process chemical and physical operating parameters and product fertilizer composition for the production of an inorganic/organic (sewage sludge) granulated nitrogen fertilizer. This technology was developed and commercialized in 1996 and continued through 2004. Dewatered sewage sludge was used as a replacement for water as the granulator pipe-cross reactor cooling agent. Pipe-cross reactor raw materials included sulfuric acid, anhydrous ammonia, and conditioned sludge. Granulator raw materials included anhydrous ammonia, aluminum sulfate, granulated ferric sulfate, and recycled product. Final fertilizer product met EPA Part 503 standards and fertilizer industry standards end point conditions of hardness, critical relative humidity and moisture including 17–18% nitrogen with 7.5% organic matter, 4% total carbon, 3% amino acids and micronutrients. This is a true beneficial reuse technology with value added components important to prevent nutrient mining of farmed soils and nutrient loss to the environment.