Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
8954927 | International Journal of Hydrogen Energy | 2018 | 14 Pages |
Abstract
A concentrating solar plant is proposed for a thermochemical water-splitting process with excess heat used for electricity generation in an organic Rankine cycle. The quasi-steady state thermodynamic model consisting of 23 components and 45 states uses adjustable design parameters to optimize hydrogen production and system efficiency. The plant design and associated thermodynamic model demonstrate that cerium oxide is suitable for thermochemical water-splitting cycles involving the co-production of hydrogen and electricity. Design point analyses at 900Â W/m2 DNI indicate that a single tower with solar radiation input of 27.74Â MW and an aperture area of 9.424Â m2 yields 10.96Â MW total output comprised of 5.55Â MW hydrogen (Gibbs free energy) and 5.41Â MW net electricity after subtracting off 22.0% of total power generation for auxiliary loads. Pure hydrogen output amounts to 522 tonne/year at 20.73Â GWh/year (HHV) or 17.20Â GWh/year (Gibbs free energy) with net electricity generation at 14.52Â GWh/year using TMY3 data from Daggett, California, USA. Annual average system efficiency is 38.2% with the constituent hydrogen fraction and electrical fraction being 54.2% and 45.8%, respectively. Sensitivity analyses illustrate that increases in particle loop recuperator effectiveness create an increase in hydrogen production and a decrease in electricity generation. Further, recuperator effectiveness has a measurable effect on hydrogen production, but has limited impact on total system efficiency given that 81.1% of excess heat is recuperated within the system for electricity generation.
Related Topics
Physical Sciences and Engineering
Chemistry
Electrochemistry
Authors
Vishnu Kumar Budama, Nathan G. Johnson, Anthony McDaniel, Ivan Ermanoski, Ellen B. Stechel,