The manufacture of ammonia is crucial to use in fertilizer as it helps to maintain food production for billions of people worldwide. Nitrogen compound in fertilizer can consider as the most effective compost because plants need it to produce proteins. Besides, phosphorus and potassium elements frequently found in fertilizer. Fertilizer also essential to keep soils productive, thus help to sustain healthy crops.
Generally, ammonia can be produced
via the Haber-Bosch process. The Haber-Bosch process is an industrial process
for manufacturing ammonia from nitrogen and hydrogen reaction, using an iron
catalyst at high temperature and pressure.
BENEFITS OF IRON CATALYST
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Figure 1: Iron Catalyst |
The significant advantage of using iron catalyst (figure 1) in the process is it readily available and plentiful, thus making the use of it on the metric ton scale feasible. The production can produce tons of ammonia per day by using a catalytic reaction. For example, 1800 tons ammonia per day requires a gas pressure of at least 130 bar, temperatures of 400 to 500 °C and a reactor volume of at least 100 m³. Iron also is an inexpensive catalyst used in the making ammonia via Haber process. Many other metals are not nearly as inexpensive. Next, iron catalyst helps to attain an acceptable yield in good time. Therefore, it produce high yield of product which is ammonia. Because of reasonably low cost, readily availability, easy handling, life cycle and activity, iron was the ultimate catalyst in the ammonia manufacturing.
DISADVANTAGES OF IRON CATALYST AND HABER PROCESS
However, pure iron catalysts are
very limited. It must include cobalt in the reaction. The disadvantage of using
an iron catalyst in the Haber-Borsch process is they can form rust from iron
oxide. Meanwhile, in the Haber process, ammonia is not compatible with the
copper element. It cannot use in systems that used copper pipes since most of
the industry used copper pipes in reactors. Next, the Haber process consists of
high energy consumptions level. According to a paper published in CellPress,
the production of ammonia via the Haber-Bosch process, is the most
energy-intensive commodity chemical, responsible for 1%–2% of global energy
consumption and 1.44% of CO2 emissions. The Haber-Bosch process
also consumes natural gas such as fossil fuel almost 3 to 5 per cent of (Yuyu
et al., 2019). Furthermore, ammonia is toxic, flammable, and poisonous at the
individual level, high concentrations. Ammonia is harmful towards human health
as they resulted in corrosive to the skin, eyes, and lungs. The exposure of
ammonia can irritate the throat and cause coughing (Diana et al., 2018).
Therefore, ammonia must be appropriately handled and implement safety
precaution. Using ammonia as fertilizer also bring disadvantages towards
human health such as causes eutrophication (Figure 2) which algae growth and cover the
surface of the water body, then giving further impact across the ecosystem. Besides,
ammonia will initiate blue baby syndrome, which affects by nitrate in drinking
water, thus disturbs the blood circulation by reducing the hemoglobin level in
human body. Lastly, ammonia is at its disadvantage by turning the soil acidic
which can trigger the crop growth.
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| Figure 2: Eutrophication Process |
