Development of Carburization-based Chemical Looping Reforming for Hydrogen Production
Date
2024-05-17
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Abstract
Chemical looping reforming technology is among the most promising technologies for syngas and hydrogen production. The results from the assessments in this thesis has presented strong evidence that hydrogen could be produced at lower carbon emissions (18.6% to 53.4% less CO2(eq) emissions) and less expensive cost of production (33.1% less than SMR 85%CCS). In order to solve problems faced by conventional looping reforming, this thesis investigates the introduction of a new reaction pathway – carburization reactions, redefining the conventional system. Firstly, a proof-of-concept provides the insights into the main concept for the introduction of carburization reactions into a chemical looping reforming system. Showcasing a thermodynamic assessment for nine possible metal carbides highlighting the best evaluated metals as tungsten carbide and zirconium carbide with a possibility of generating a syngas quality (H2/CO ratio) of 9 and 16 respectively, however the zirconium required higher temperatures and could produce nitrides during oxidation stage when using air as oxidation agent. Then, a second study was performed to have a better understanding of the reaction. The outcomes showed the carburization reaction is described as a two-step mechanism. The first is a nucleation Avrami Erofe’ev second order and the second a nucleation power law fourth order. Furthermore, the application of the process requires it to be investigated in a simulated environment by the application of AspenPlus. The focus was to evaluate the system in three different cases each with different up and downstream units. The inputs and outputs were used for a life cycle assessment to evaluate the systems environmental burdens. This study presented a decrease in greenhouse gas emissions by at least 25% and up to 57% when compared to current steam methane technologies, proving that this is a promising technology for future hydrogen applications and energy transition pathway. Lastly, the results from the simulation were used in a techno-economic assessment. The outcomes of the economic analysis showed that, in general, the proposed carburization-based chemical looping reforming leads to a lower capital cost (at least 42.25% reduction to steam methane reforming) and hydrogen production costs that could achieve up to 45.93% cost reduction.
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Keywords
Hydrogen Production, Reforming, Carburization, Chemical Looping, Kinetics, Life Cycle Assessment, Technoeconomic Assessment
Citation
Gomes Camacho, F. (2024). Development of carburization-based chemical looping reforming for hydrogen production (Doctoral thesis, University of Calgary, Calgary, Canada). Retrieved from https://prism.ucalgary.ca.