Investigation of integrated systems for clean ammonia synthesis

Hydrogen is essential to modern life, as it is primarily used to synthesize ammonia for fertilizer, which plays an indispensable role in feeding the world’s 7.5 billion people. Ammonia is among the most utilized chemicals all over the world owing to the numerous applications namely; fertilizer sector, cooling, fuel cells and also for the formation of different chemicals. Conventionally, the Haber-Bosch process is most widely used for the synthesis of ammonia that involves very high operating pressures and temperatures and undergoes low conversion rates and the natural gas reforming process is employed to produce hydrogen. This thesis study develops five different integrated systems for hydrogen and cascaded ammonia synthesis. Each developed system includes different route of hydrogen production which is further converted into ammonia and each system considers different energy sources such as solar heliostat-assisted natural gas reforming, biomass gasification, industrial thermal management solar PV and wind energy-assisted and solar heliostat field-driven integrated energy systems. An experimental cascaded ammonia synthesis system is also designed and tested under different operating conditions. The solar heliostat assisted natural gas reforming system offers the overall energy and exergy efficiencies of 66.83% and 68.55%. The efficiencies of the biomass gasification based integrated system for cascaded ammonia synthesis are found to 44.2% and 42.4%. The industrial waste heat recovery based cascaded ammonia synthesis system offers the overall efficiencies of 28.7% and 40.8%. The solar PV and wind energy-assisted integrated system offers the maximum energy and exergy efficiencies of 24.42% and 26.06% and the maximum energy and exergy efficiencies of the solar heliostat assisted cascaded ammonia synthesis system are found to be 25.4% and 28.6% respectively. The results of the experimentally developed cascaded ammonia synthesis system reveal that the ammonia conversion efficiencies that range from 4.58-7.88% using the single reactor with pressure rise from 6-12 bar at the temperature of 370℃, increase to the conversion efficiencies of 5.42-9.16% by employing cascaded ammonia synthesis design. The experimental investigations reveal the improved conversion efficiencies and validation of the simulation data with experimental results shows a difference of 1.62-6.61% between the simulation and the experimental results.

Name thesis:degree_name

Doctor of Philosophy (PhD)

Discipline thesis:degree_discipline

Mechanical Engineering

Grantor

University of Ontario Institute of Technology

Year dc:date.issued

2020

Author dc:creator

• Ishaq, Haris

Advisor dc:contributor.advisor

• Dincer, Ibrahim

Language dc:language.iso

en

Handle dc:identifier.uri

https://hdl.handle.net/10155/1888

OAI identifier oai:identifier

oai:ontariotechu.scholaris.ca:10155/1888