Background of Haber Process

The phenomenon of catalysis can be divided into two different systems that undergoes chemical change which are homogeneous and heterogeneous (Figure 1). This phenomenon highly effected the rates of approach to equilibrium state in processes (Jennings, 1991). In agriculture sector, ammonia salts and solutions are the critical components in the manufacturing of synthetic fertilizers (Figure 2) which consume 83% of the world’s ammonia and warrant higher demands for ammonia production (Chavis, 2015). The overall process for synthesis of ammonia were from molecular nitrogen and hydrogen by feeding the reactants over iron catalyst at high pressure and temperature, requiring bulky, well-insulated reactors to house the process (Roper, 2015). The main focus of our report is about Haber process as it is known to be one of the heterogeneously catalyzed processes in industry. The reaction is in reversible and the production of ammonia is exothermic (Clark, 2013).

Figure 1: Type of Catalyst Process

  

Figure 2: Ammonia in Synthetic Fertilizer

The Haber process is the primary industrial method for ammonia synthesis which performed by German chemist Fritz Haber in 1905 by synthesizing ammonia from N₂ and H₂ in the laboratory. Next, the process is further developed by Walther Nernst. In 1906, using osmium as the catalyst, Haber was able to achieve a 6% ammonia concentration in a reactor and this has become the biggest turning point for the production of ammonia in commercial quantities. Next, Haber has proposed a recycle system, and received a patent for the concept to concentrate on space-time yield in a system (Pattabathula and Richardson, 2016). The first practical procedure for ammonia synthesis was scale-up in the industry by Carl Bosh in 1910. He is known as a great chemist and engineer under BASF and has purchased Haber’s patent to start the development of a commercial process of ammonia on a promoted iron catalyst (Figure 3).

Walther Nernst 

Figure 3: Developers for Haber-Bosch Process

This has become the most important technological advances of the 20^th century and has contribute for massive increase in growths of crops for agriculture sector across the world where in 1900, the global population had increase from 1.6 billion to over 7 billion alive today. Both of the developers of the Haber-Bosch process were each awarded Nobel prizes for their works (Figure 4&5) (Smil, 2003).

Figure 4: Haber and Bosch working together

Figure 5: Haber and Bosch received Noble's prize

This process is still used in industry today because it has been proven where sufficient amount of synthetic ammonia are able to meet demands through Haber process and the abundance of both reactants suggested as it is the most sustainable option possible. Furthermore, the performance of synthetic fertilizers from nitrogenous content has consistent from season to season making it a more reliable choice than organic fertilizers and high in nutrient content. In world's industry, the example of synthetic fertilizers produced from ammonia Haber process industry can be found operated by Yara International company and BASF.

Figure 6: Yara International

Figure 7: BASF