Abstract:
Ammonia, with annual production of about 176 million tonnes, is a key component of
many fertilizers. The conventional Haber-Bosch process for ammonia production relies
on nonrenewable resources (natural gas) which are rapidly depleting. In addition, it
contributes to about 1.8% of global carbon emissions annually causing serious
environmental problems.
A significant amount of work has been done in exploring the alternatives for the
conventional process and green ammonia emerges as a prominent contender. The
purpose of this project is to address the above-mentioned challenges and develop an ecofriendly process utilizing renewable raw materials and energy resources.
The project proposes the production of 150 tonnes/day of green ammonia from green
hydrogen and nitrogen. Green hydrogen is produced via water electrolysis using a Proton
Exchange Membrane Electrolyzer. Water is split into hydrogen and oxygen gas using
electricity produced from renewable resources (solar and wind). Nitrogen is separated
from air via Pressure Swing Adsorption. Carbon molecular sieve is used as the adsorbent
that selectively absorbs oxygen from air leaving behind the pure nitrogen gas. Hydrogen
and nitrogen are then reacted in a fixed bed reactor to produce ammonia. This catalyst
driven exothermic reaction is carried out under high pressures and moderate
temperatures. The ammonia produced as the result can be stored and utilized as a fuel or
for production of different fertilizers.
Use of such sustainable methods for ammonia production can help address major
environmental problems and contribute to the net zero carbon future.
