Nitric acid belongs to the main inorganic products in the chemical industry. 50-65% nitric acid, also called ‘weak acid’, is besides ammonia the main raw material for the production of nitrogen fertilizers. The technological process of ‘weak nitric acid’ production is based on two methods, depending on the pressure configuration:
- mono-pressure method
- dual-pressure method
Plants using the mono-pressure method are characterized by lower investment costs, but operating costs (consumption / conversion of ammonia and Pt-catalyst loss) are slightly higher to the dual-pressure method. Mono-pressure method is typically implemented to plants producing up to 900 MTPD (based on 100% acid concentration).
Plants using the dual-pressure method are more demanding on the turbo train and are suitable for a higher production capacity, which follows the current trend of nitrogen fertilizer producer requirements. Investment costs are higher to mono-pressure plants, but the cost of raw material consumption is significantly lower. Plants using the dual-pressure method are designed for capacities up to 1500 MTPD (based on 100% acid concentration).
The choice of method depends on the requirements of product end-users, on the requirement for production capacity, on the cost of input raw materials, catalyst, utilities and the specific requirements resulting from local conditions, legislation or customer wishes. The acid production capacity range is typically 70-110% of the nominal plant performance.
Nitric acid plants offered by CASALE PROJECT are based on a process provided by its affiliate company CASALE SA
- High flexibility of plant, 70–110% of nominal load
- Plant capacity: 600–1500 MTPD
- Low consumption of raw materials: up to 284 kg of ammonia per ton of 100% acid
- Export of steam: 600-700 kg per ton of 100% acid depending on the energy arrangement of the plant