Direct production of hydrogen-rich gas and/or pure-hydrogen with high-pressure from alcohol/water/metal-powder mixture at low processing temperature. (24th January 2020)

• Record Type: Journal Article
• Authors: Deguchi, Seiichi; Kobayashi, Noriyuki; Isu, Norifumi; Ito, Mitsunori
• Is Part Of: International journal of hydrogen energy. Volume 45:Number 4(2020)
• Page Start: 2513
• Page End: 2526
• Publication Date: 2020-01-24
• Subjects: Pure-hydrogen direct production -- Single and simple operation -- High-pressure hydrogen -- Hydrogen-rich gas -- Alcohol/water/metal-powder mixture -- Low processing temperature; Hydrogen as fuel -- Periodicals; Hydrogène (Combustible) -- Périodiques; Hydrogen as fuel; Periodicals; 665.81
• DOI: 10.1016/j.ijhydene.2019.11.166
• Languages: English
• ISSNs: 0360-3199

Abstract

Abstract: High-pressure hydrogen-rich gas producing experiments from various alcohol/water/metal-powder mixtures at low processing temperatures from 473 to 723 K are carried out in a prototype airtight apparatus possessing a withstand pressure of 15 MPa in the aim of technologizing an incidentally emerged high-pressure hydrogen-rich gas production from a methanol/water/aluminum-powder mixture at 723 K. Methanol/water due to a proven track record and ethanol/water in order to make an allowance for replacing the reagent to commercially-available potable alcohols are selected as main hydrogen sources. As tested metal-powders, aluminum, cobalt, iron, magnesium and nickel are chosen, taking their ready-availabilities and costs into consideration. Among tested metal-powders, aluminum and cobalt are found optimal adding metals for the high-pressure hydrogen-rich gas productions from 60.0 wt% methanol/water and ethanol/water solutions, respectively. From 60.0 wt% methanol/water and Al-powder mixture at 723 K, pure-hydrogen with 10.0 MPa is produced at a great hydrogen producing rate of 24.9 LN /(dm 2 min). All carbons discharged from methanol are fixed as a wide variety of solid higher hydrocarbons and organic liquid residues of benzyl alcohol and toluene. Almost all oxygens from methanol/water solution are fixed as aluminum-compounds of aluminum oxide hydroxide and aluminum hydroxide. From 60.0 wt% ethanol/water and Co-powder mixture, pure-hydrogen with pretty high pressure over 15 MPa can be produced at 723 K with simultaneous fixations of all the carbons and oxygens from the main hydrogen source as solid/liquid residues of wide variety of solid higher hydrocarbons, benzyl alcohol, toluene, cobalt oxide, cobalt hydroxide, tricobalt tetroxide and cobalt carbonate. Responding to the outcome from 60.0 wt% ethanol/water and Co-powder mixture, a certain rice-wine having an alcohol degree 60 with Co-powder at 723 K is experimented, and provides high-pressure hydrogen-rich gas with hydrogen concentration of 80 % and hydrogen partial pressure of around 8 MPa. All the produced hydrogen-rich gases are confirmed to keep a full declared potential in polymer electrolyte fuel cell for over 24 h without any exceptions. These findings speak by themselves that this developing high-pressure hydrogen-rich gas (pure-hydrogen) direct producing method is surely approaching a self-operating dispersed hydrogen producing appliance (i.e. a part of a dispersion type power source) anywhere whole the world. And, this method still leaves unlimited room for far higher pure-hydrogen pressures and hydrogen producing rates by slight changing the operating conditions, and its applicable fields are broadening for eternity. Finally, some recommended future strategies to improve this method so as to supply complete solutions to any global-scale issues are also proposed in every part through this paper. Highlights: Pure-hydrogen with 10.0 MPa is produced from methanol/water/Al-powder at 723 K. Maximum pure-hydrogen producing rate is 24.9 LN /(dm 2 min). Pure-hydrogen with above 15 MPa is produced from ethanol/water/Co-powder at 723 K. Hydrogen-rich gas with around 8 MPa is produced from rice-wine/Co-powder at 723 K. All produced hydrogen-rich gases keep a full potential in PEFC for over 24 h.