Energy Efficiency in the Hydrogen Value Chain for Ammonia Synthesis
(2025) In Department of Process and Life Science Engineering KETM05 20251Chemical Engineering (M.Sc.Eng.)
- Abstract
- Green ammonia, produced from renewable hydrogen, is emerging as an important energy carrier and decarbonized fertilizer alternative. However, its production is highly energy-intensive, making process efficiency critical to its commercial viability. This study investigates how targeted heat integration can enhance the energy and cost efficiency of green ammonia production based on a 200 MW PEM electrolyzer. Three design configurations were developed and simulated using Aspen Plus: The Base Design without advanced heat integration representing a conventional green ammonia plant including freshwater generation, electrolysis, Haber-Bosch synthesis and cooling. The Alfa Laval Design, incorporating Alfa Laval’s multi-effect evaporation... (More)
- Green ammonia, produced from renewable hydrogen, is emerging as an important energy carrier and decarbonized fertilizer alternative. However, its production is highly energy-intensive, making process efficiency critical to its commercial viability. This study investigates how targeted heat integration can enhance the energy and cost efficiency of green ammonia production based on a 200 MW PEM electrolyzer. Three design configurations were developed and simulated using Aspen Plus: The Base Design without advanced heat integration representing a conventional green ammonia plant including freshwater generation, electrolysis, Haber-Bosch synthesis and cooling. The Alfa Laval Design, incorporating Alfa Laval’s multi-effect evaporation technology for freshwater generation using electrolyzer waste heat into the process, and a Suggested Design further optimized with absorption refrigeration and steam turbine enhancements. The designs were evaluated based on electricity, heating, and cooling demands, and compared with literature in terms of total energy intensity and the levelized cost of ammonia.
Results proved that strategic heat recovery significantly improved process performance. The Suggested Design reduced electricity consumption by 1.1%, heating by over 60%, and cooling demand by 16% compared to the Base Design. These reductions translated into a total annual utility savings of 85.4MSEK and lowered the levelized cost of ammonia by 380 SEK/ton ammonia. With a payback period of approximately 1.5 years, the optimizations demonstrated strong economic viability. The study concludes that heat integration offers a powerful pathway to reduce both energy use and production cost in green ammonia systems.
The findings demonstrate that strategic process integration can significantly improve the energy efficiency and cost-effectiveness of green ammonia production. This methodological framework can be used to support industrial-scale design decisions, provide a foundation for further research, and contribute to the global transition toward utilizing green hydrogen for sustainable ammonia. (Less) - Popular Abstract (Swedish)
- I omställningen till fossilfria lösningar har grön vätgas och ammoniak visat på att vara lovande energibärande bränsle. Att tillverka ammoniak med vätgas från förnybara energikällor kräver däremot stora mängder energi, och det är just därför denna studie är relevant. Genom att designa och simulera en ammoniakproduktion baserat på en 200MW elektrolysör med fokus på värmeintegration, har stora vinster i energi såväl som kostnad identifierats. Första steget i processen är att rena havsvatten till färskvatten, som sedan används i en elektrolysör som spjälkar vatten till vätgas och syrgas. Det här steget kräver mycket elektricitet, men producerar också mycket spillvärme. Vätgasen används sedan för att producera ammoniak, som även det producerar... (More)
- I omställningen till fossilfria lösningar har grön vätgas och ammoniak visat på att vara lovande energibärande bränsle. Att tillverka ammoniak med vätgas från förnybara energikällor kräver däremot stora mängder energi, och det är just därför denna studie är relevant. Genom att designa och simulera en ammoniakproduktion baserat på en 200MW elektrolysör med fokus på värmeintegration, har stora vinster i energi såväl som kostnad identifierats. Första steget i processen är att rena havsvatten till färskvatten, som sedan används i en elektrolysör som spjälkar vatten till vätgas och syrgas. Det här steget kräver mycket elektricitet, men producerar också mycket spillvärme. Vätgasen används sedan för att producera ammoniak, som även det producerar mycket värme. Ammoniaken behöver sedan kylas för att kunna separeras från processen.
Tre olika designförslag har modellerats: Basdesignen, som är en konventionell grön ammoniakprocess utan någon avancerad värmeåtervinning. Alfa Laval-designen, där spillvärme från elektrolysören används för att producera färskvatten. Den optimerade designen, där processen slutligen optimeras med förbättring av ångturbinen samt absorptionskylning i kylsystemen. Genom att analysera de olika designscenarierna med programvaran Aspen Plus, kunde elektricitets-, värme och kylbehovet i processen minskas. Minskade energibehov leder inte bara till hållbarhetsvinster, utan även lägre kostnad. Den optimerade designen sänkte kostnaden per ton ammoniak med ungefär 380SEK i förhållande till bas-designen, medan den extra investering som krävs betalar tillbaka sig på ungefär 1.5år, vilket gör lösningen hållbar och lönsam.
Sammantaget visar studien att det finns potential att förbättra energieffektiviteten i framtidens gröna ammoniakfabriker genom smart processintegration. Studiens resultat kan användas som beslutsunderlag för industriaktörer eller som modell för vidare forskning. Med rätt teknik och metodik kan grön vätgas och ammoniak spela en viktig roll i den gröna omställningen – både som drivkraft i jordbruket och som effektivt energilager. (Less)
Please use this url to cite or link to this publication:
http://lup.lub.lu.se/student-papers/record/9197935
- author
- Lindström, Sofia LU and Norman, Vilma LU
- supervisor
-
- Ola Wallberg LU
- organization
- course
- KETM05 20251
- year
- 2025
- type
- H2 - Master's Degree (Two Years)
- subject
- keywords
- Green hydrogen, Ammonia, Green ammonia, Optimization, Process, Integration, Energy efficiency, Chemical engineering
- publication/series
- Department of Process and Life Science Engineering
- language
- English
- id
- 9197935
- date added to LUP
- 2025-06-16 14:57:08
- date last changed
- 2025-06-16 14:57:08
@misc{9197935,
abstract = {{Green ammonia, produced from renewable hydrogen, is emerging as an important energy carrier and decarbonized fertilizer alternative. However, its production is highly energy-intensive, making process efficiency critical to its commercial viability. This study investigates how targeted heat integration can enhance the energy and cost efficiency of green ammonia production based on a 200 MW PEM electrolyzer. Three design configurations were developed and simulated using Aspen Plus: The Base Design without advanced heat integration representing a conventional green ammonia plant including freshwater generation, electrolysis, Haber-Bosch synthesis and cooling. The Alfa Laval Design, incorporating Alfa Laval’s multi-effect evaporation technology for freshwater generation using electrolyzer waste heat into the process, and a Suggested Design further optimized with absorption refrigeration and steam turbine enhancements. The designs were evaluated based on electricity, heating, and cooling demands, and compared with literature in terms of total energy intensity and the levelized cost of ammonia.
Results proved that strategic heat recovery significantly improved process performance. The Suggested Design reduced electricity consumption by 1.1%, heating by over 60%, and cooling demand by 16% compared to the Base Design. These reductions translated into a total annual utility savings of 85.4MSEK and lowered the levelized cost of ammonia by 380 SEK/ton ammonia. With a payback period of approximately 1.5 years, the optimizations demonstrated strong economic viability. The study concludes that heat integration offers a powerful pathway to reduce both energy use and production cost in green ammonia systems.
The findings demonstrate that strategic process integration can significantly improve the energy efficiency and cost-effectiveness of green ammonia production. This methodological framework can be used to support industrial-scale design decisions, provide a foundation for further research, and contribute to the global transition toward utilizing green hydrogen for sustainable ammonia.}},
author = {{Lindström, Sofia and Norman, Vilma}},
language = {{eng}},
note = {{Student Paper}},
series = {{Department of Process and Life Science Engineering}},
title = {{Energy Efficiency in the Hydrogen Value Chain for Ammonia Synthesis}},
year = {{2025}},
}