Efficient Hydrogen Production from Algae and its Conversion to Methylcyclohexane

Abstract

Herein, the supercritical water gasification (SCWG) of microalgae combined with syngas chemical looping (SCL) for H2 production and storage employing liquid organic H2 carrier (LOHC) system have been proposed and analysed in terms of energy efficiency. Microalgae are converted to syngas in the SCWG module and then introduced into the SCL module to produce high-purity of H2 and a separated CO2 stream. H2 storage is achieved via the hydrogenation reaction using toluene to produce methylcyclohexane (MCH). The heat released from the exothermic hydrogenation reaction is exploited to generate steam for sustaining the SCWG reaction. Simulations were performed using Aspen Plus™ considering the feed concentration and SCWG temperature as the system variables. The simulation results show that the SCWG reaction can be energetically self-sustained using the proposed configuration. Based on the process modelling and calculations, the proposed integrated system exhibited of approximately 13.3 %, 42.5 %, and 55.8 % for power generation, H2 production, and total energy efficiency.