A multi-generation system for hydrogen production through the high-temperature solid oxide electrolyzer integrated to 150 MW coal-fired steam boiler

Abstract

A multi-generation system including power generation, domestic hot water, and H2 production was designed for the waste recovery of a 150 MW coal-fired power plant. A high-temperature electrolyzer was integrated into the present system to produce H-2. The second product of O-2 from the electrolyzer was used to enrich the combustion process. The required power for the electmlyzer was obtained from a bottoming organic Rankine cycle (ORC). In this regard, a supercritical ORC was designed in which cyclopentane was used as the working fluid. The required heat of the electrolyzer was obtained by a heat exchanger located in the combustion chamber to reach the required temperature level. The designed system was analyzed by the energy and exergy method for different temperatures and current densities. It is determined that it is available to produce H-2 in an amount of 0.0739 to 0.0762 kmol/s for the optimal current densities at every single handled temperature. The energy efficiency of the overall system was determined in the range of 27.19% and 27.36%. The exergy efficiency of the overall system was determined in the range of 35.05% and 35.25%. An increase of 15.78-16.53% in energy efficiency was achieved. This increase was achieved as 20.43-21.16% in the exergy efficiency.