UC Irvine

Economic sectors such as transportation, electricity, industrial, commercial, residential, and agriculture depend on a reliable and consistent supply of energy. However, a vast majority of these sectors draw most of their energy from fossil fuels which emit pollutants and greenhouse gases (GHG) when combusted or processed. The emissions, as a result, are the largest contributing factors to recent climate change and environmental challenges. To reduce the emissions using sustainable and renewable energy sources (RES) in the power generating and cement manufacturing sectors, design and integration of a concentrated solar power (CSP) plant with a solid oxide electrolysis cell (SOEC) system for hydrogen production and with a coal-fired cement plant for producing cement are analyzed. To analyze the dynamic behavior, such as temperature variations for thermal management, and system performance characteristics, a dynamic CSP-integrated SOEC system model is developed, aiming to achieve high hydrogen production efficiency and to minimize the balance of plant power consumption. The results show that the electrical efficiency of the integrated hydrogen production system is greater than 90% throughout the majority of the operating time. Particularly, the electrical efficiency between 10 AM and 1 PM is nearly 100%. Such high efficiency is achieved as a result of the SOEC stack operating in endothermic conditions while taking thermal energy provided by the CSP plant. A CSP-integrated cement plant is modeled to assess the percent solarization, reduction in carbon dioxide (CO2) emissions, and costs of CO2 avoided. Five locations have been selected across the United States providing a wide range of Direct Normal Irradiance (DNI) potentials. The results show that the plant located in Southern California (SoCal) has the best performance characteristics with the highest percent solarization and reduction of CO2 emissions, utilizing solar thermal energy more than 70% of the operating time and reducing the CO2 emissions by 15%. Economically, the western region of the United States, especially the states of California, Arizona, Nevada, and New Mexico, is found to be the best region for integrating a conventional cement plant with a CSP plant where the annual DNI exceeds 2000 kWh/m2. The costs of CO2 avoided in the region range from 70 to 100 USD per ton of CO2 which makes such integration as competitive as integration with competing carbon capture technologies.