Design and Simulations of Solar-Based Hydrogen Production System via Methane Decomposition

Abstract

A solar-based hydrogen production system is analyzed and studied with the intention of optimizing the parameters involved in oil refining industry and the environment of the United Arab Emirates. Methane decomposition in molten salt media using a concentrated solar power system was adopted, since the temperature range required in the system design is achievable with this method. The System Advisor Model software was used in this study with three cases to optimize the system using the levelized cost of heat concept. In Case 1, a levelized cost of heat of 9.32 ¢/kWh was achieved using an optimized system with a CSP-RTUVR-2014 receiver and a Luz LS-3 collector. The design of Cases 1 and 2 exhibited pressure drops along the system of just 10 bar, significantly lower than the 50 bar of Case 3. Similarly, designs of Cases 1 and 2 resulted in maximum receiver thermal losses of around 7 MW, whereas Case 3 yielded 14 MW loss. Analysis of the best-suited molten salt option showed that HITEC solar salt was better than HITEC XL and standard HITEC. A regression analysis was carried out to examine the pressure drop responses since it is a key variable affecting the integrity of the solar system. It was observed that the receiver mass flow rate is the main contributing cause of pressure drop. Through careful operator control of receiver mass flow rate, premature failures of the solar system caused by the pressure drop can be avoided.