Cyan Hydrogen Process: A New Route for Simultaneous Hydrogen Production and Carbon Valorization

ACS Omega. 2024 Feb 8;9(7):7793-7805. doi: 10.1021/acsomega.3c07277. eCollection 2024 Feb 20.

Abstract

Hydrogen is expected to largely contribute to the near-future circular economy. Today, most hydrogen is still produced from fossil fuels or renewable pathways with low efficiency and high cost. Herein, a proof of concept for a novel hydrogen production process is proposed, here named cyan hydrogen, inspired by a combination of the green and blue processes, due to the key role played by water and the low carbon content in the gas phase, respectively. The developed novel process, recently patented and demonstrated at the lab scale, is based on successive steps in which ethanol (5.0 mL) and water (10.0 mL) are alternately fed, with a fixed initial amount of sodium metaborate (2.0 g), in a batch reactor at 300 °C. Preliminary results showed the simultaneous production of a 95% v/v hydrogen stream, a polymeric byproduct with a repetitive carbon pattern -CH2-CH2-, and a liquid phase rich in oxygenated chemicals at temperatures lower than conventional hydrogen production processes.