Green Nitrates, development of new nitric acid process for cost competitive and GHG emission free production of fertilizers.

The project will develop a new nitric acid production process for integration in a profitable new zero emission fertilizer production process, a key enabler for Yara?s target to become carbon neutral by 2050. The shift from fossil to electrical energy based production implies a shift from heat to electrical energy integration. The vast amounts of heat generated in the nitric acid production will be converted to electrical energy, reducing the net energy consumption of the full fertilizer plant. At the core of the novel electrical fertilizer plant is an electrolyser producing hydrogen from water. Normally, the oxygen by-product is vented, but the novel nitric acid process will use the oxygen to achieve a range of improvements. Firstly, researchers at Yara have identified opportunities for increased energy recovery and power export by optimal integration of oxygen. Secondly, intensification with oxygen appears to offer the potential of significant CAPEX savings by tailoring reactor design and materials. Thirdly, the pure oxygen stream implies an additional degree of freedom that can be translated to new optimum process conditions giving lower OPEX and resource consumption. The improved process will be obtained through process development and modelling, obtaining new experimental data for chemical reactions and novel materials under non-standard conditions, and development of models predicting the performance of reactors with novel design operated with unconventional process conditions. Achievement of the project targets will be an instrumental contribution to future profitable green fertilizer production, giving Yara a competitive position in a future sustainable fertilizer and food market.

The purpose of the project is to develop and qualify an improved novel process for production of nitric acid and electrical energy, tailored for integration in a plant complex converting renewable energy to green fertilizer. By utilizing oxygen available from other units of the plant complex, major benefits will be sought related to increased energy recovery and product efficiency, and reduced CAPEX and resource consumption. The recovered energy will be converted to electrical power reducing the net power consumption of the green fertilizer plant concept. Achievement of the project targets will be an instrumental contribution to future profitable green fertilizer production, giving Yara a competitive position in a future sustainable fertilizer and food market. The con-conventional process conditions represented by the increased oxygen content implies challenges and opportunities. By optimisation of the general process design and heat recovery system, Yara has developed process concepts allowing significantly increased electrical power production. This development will continue in the current project. The extra oxygen requires reassessment of optimal process conditions for the ammonia oxidation unit, converting ammonia to NO. This is a complex problem, requiring detailed knowledge of the dependence of catalyst activity, selectivity and lifetime on gas composition, pressure, temperature and catalyst composition and geometry. To some extent the project needs to measure new data for this purpose. Early indications are that substantial value can be realised by such optimisation. The increased oxygen concentration allows for intensified NO oxidation and NOx absorption to nitric acid. For the realisation of a compact low cost absorber, the project must and will experimentally determine new data related to acid-NOx reaction kinetics and material stability and performance. Based on this, models will be developed and used for the design of a new low cost compact absorber.