{"title":"Decarbonizing urea: Techno-economic and environmental analysis of a model hydroelectricity and carbon capture based green urea production","authors":"Sijan Devkota , Pratistha Karmacharya , Sherila Maharjan , Dilip Khatiwada , Bibek Uprety","doi":"10.1016/j.apenergy.2024.123789","DOIUrl":null,"url":null,"abstract":"<div><p>This study reports a comprehensive techno-economic and environmental assessment of a realistic pathway for decarbonizing the urea industry. The proposed green urea synthesis plant utilizes hydroelectricity-powered electrolysis process and carbon capture from cement flue gas to create sustainable and environmentally friendly production process. Utilizing Aspen Plus and MATLAB, this study first, models the electrolysis, air separation, ammonia synthesis, carbon capture and urea synthesis units, and then evaluates the economic and environmental parameters of the synthesis process. Furthermore, the study highlights the transformative impacts of carbon credit and the renewable energy prices on the profitability metrics of the green urea plant. For the proposed 220 kt/year urea plant, the total energy consumption is 8.18 × 10<sup>6</sup> GJ/year with the electrolysis unit accounting for half of the energy demand. The estimated total capital investment for the urea plant is 510.79 million USD, with an annual operating expenditure of 156.02 million USD. The urea synthesis unit accounted for half of the total capital expenditure, while electricity contributed to the largest proportion (73%) of the operating expenses. The levelized cost for urea (LCOU) is estimated to be 570.96 USD/t which is approximately 62.2% higher than the urea obtained from conventional process. The electrolyzer unit contributed to 34.4% of the total LCOU. Sensitivity analysis showed that 30% decrease in the electricity price from the base case could lower the LCOU by 27%. The global warming potential of the proposed green urea process is 326.11 kg CO<sub>2</sub>/t of urea. Lower hydroelectricity prices and carbon credit opportunities significantly improve the economic viability of the green urea production process.</p></div>","PeriodicalId":246,"journal":{"name":"Applied Energy","volume":null,"pages":null},"PeriodicalIF":10.1000,"publicationDate":"2024-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Applied Energy","FirstCategoryId":"5","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0306261924011723","RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"ENERGY & FUELS","Score":null,"Total":0}
引用次数: 0
Abstract
This study reports a comprehensive techno-economic and environmental assessment of a realistic pathway for decarbonizing the urea industry. The proposed green urea synthesis plant utilizes hydroelectricity-powered electrolysis process and carbon capture from cement flue gas to create sustainable and environmentally friendly production process. Utilizing Aspen Plus and MATLAB, this study first, models the electrolysis, air separation, ammonia synthesis, carbon capture and urea synthesis units, and then evaluates the economic and environmental parameters of the synthesis process. Furthermore, the study highlights the transformative impacts of carbon credit and the renewable energy prices on the profitability metrics of the green urea plant. For the proposed 220 kt/year urea plant, the total energy consumption is 8.18 × 106 GJ/year with the electrolysis unit accounting for half of the energy demand. The estimated total capital investment for the urea plant is 510.79 million USD, with an annual operating expenditure of 156.02 million USD. The urea synthesis unit accounted for half of the total capital expenditure, while electricity contributed to the largest proportion (73%) of the operating expenses. The levelized cost for urea (LCOU) is estimated to be 570.96 USD/t which is approximately 62.2% higher than the urea obtained from conventional process. The electrolyzer unit contributed to 34.4% of the total LCOU. Sensitivity analysis showed that 30% decrease in the electricity price from the base case could lower the LCOU by 27%. The global warming potential of the proposed green urea process is 326.11 kg CO2/t of urea. Lower hydroelectricity prices and carbon credit opportunities significantly improve the economic viability of the green urea production process.
期刊介绍:
Applied Energy serves as a platform for sharing innovations, research, development, and demonstrations in energy conversion, conservation, and sustainable energy systems. The journal covers topics such as optimal energy resource use, environmental pollutant mitigation, and energy process analysis. It welcomes original papers, review articles, technical notes, and letters to the editor. Authors are encouraged to submit manuscripts that bridge the gap between research, development, and implementation. The journal addresses a wide spectrum of topics, including fossil and renewable energy technologies, energy economics, and environmental impacts. Applied Energy also explores modeling and forecasting, conservation strategies, and the social and economic implications of energy policies, including climate change mitigation. It is complemented by the open-access journal Advances in Applied Energy.