Combined supercritical water gasification of algae and hydrogenation for hydrogen production and storage

Combined system for converting algae to hydrogen is developed based on principles of enhanced process integration technology to achieve high total energy efficiency. The system mainly consists of supercritical water gasification, hydrogen separation, hydrogenation, and combined cycle. Enhanced process integration combines both exergy recovery and process integration technologies, therefore, exergy destruction throughout the combined system can be minimized leading to high energy efficiency. Algae are converted initially to hydrogen-rich syngas through supercritical water gasification. Hydrogen separation is performed to produce hydrogen which is hydrogenated to achieve more convenient storage and transport. The remaining gas is combusted for power generation using combined cycle. Process modeling and evaluation regarding the effect of some operating parameters to total energy efficiency are performed. The combined system can achieve high total energy efficiency, higher than 60%.