Thermodynamic and environmental impact assessment of steam methane reforming and magnesium-chlorine cycle-based multigeneration systems

Abstract

Summary In this study, thermodynamic analyses and environmental impact assessments of two integrated systems are comparatively performed for multigenerational applications. The first system consists of a heliostat solar heat and power generation field as energy source, a magnesium–chlorine (Mg–Cl) hybrid thermochemical cycle for hydrogen production, a steam Rankine cycle for power production, and a LiBr–water absorption chiller cycle for space cooling application. The second system is same as the first system except that the steam methane reforming (SMR) which considered for hydrogen production instead of Mg–Cl cycle. The SMR method is commonly used to produce hydrogen; however, it has disadvantages such as releasing CO2 emissions and utilizing fossil fuels for reforming. Mg–Cl cycle can be considered as a promising thermoelectrochemical cycle for water splitting because of its simplicity and applicability as well as possessing higher energy and exergy efficiencies and stability of chemical reactions throughout the cycle. Comparative energy and exergy performance assessments of both integrated systems are performed, and their assessment results are presented and discussed. In addition to the performance evaluation, environmental impact and sustainability assessments of both integrated systems are performed. Furthermore, the study compares two hydrogen production systems in terms of their performances and environmental impacts at varying conditions. Energy and exergy efficiencies of the present systems are found to be 28.4–18.4% for the system I and 43.2–27.4% for the system II, respectively. Exergetic sustainability of SMR‐based system is higher than that of Mg–Cl‐based system. However, Mg–Cl system does not emit greenhouse gases during production and is more environmentally benign in terms of greenhouse gas emissions. Copyright © 2015 John Wiley & Sons, Ltd.

Thermodynamic assessment of a new solar power-based multigeneration energy plant with thermochemical cycle

“…It was stated that parameters such as the solar energy intensity, condenser temperature, collector length and width, collector input air mass flow rate and evaporator pinch point temperature difference were significantly effective on the plant exergetic efficiency. Ozcan and Dincer (2015) have investigated two solar energy combined multigeneration systems and compared them exergetically by performing their thermodynamic analysis. The first system consisted of the SPT, absorption cooling chiller, Rankine cycle, and Mg-Cl thermochemical process.…”

Modeling and experimental assessment of the novel HI‐I 2 ‐H 2 O electrolysis for hydrogen generation in the sulfur‐iodine cycle

“…5,6 Among them, the sulfur-iodine (SI or IS) cycle, which was originally proposed by General Atomics, 7 gained extensive attention because of its marked advantages compared with other thermochemical cycles (copper-chlorine, magnesium-chlorine, etc. ), 5,[8][9][10] including the mild operating conditions, the high thermal efficiency up to 60%, no requirement for the separation of hydrogen and oxygen, the environmentally friendly without CO 2 emission, the ease to match the energy supply of solar, wind and nuclear, and the potential for large-scale utilization. [11][12][13][14] To date, the Japan Atomic Energy Agency has completed continuous 150 hours of SI cycle with the H 2 production rate of 30 L/h.…”