Efficient Hydrogen Production via Methanol Steam Reforming by Preventing Back-permeation of Hydrogen in a Palladium Membrane Reactor

Modification of Electrospun CeO2 Nanofibers with CuCrO2 Particles Applied to Hydrogen Harvest from Steam Reforming of Methanol

Hydrogen is the alternative renewable energy source for addressing the energy crisis, global warming, and climate change. Hydrogen is mostly obtained in the industrial process by steam reforming of natural gas. In the present work, CuCrO₂ particles were attached to the surfaces of electrospun CeO₂ nanofibers to form CeO₂-CuCrO₂ nanofibers. However, the CuCrO₂ particles did not readily adhere to the surfaces of the CeO₂ nanofibers, so a trace amount of SiO₂ was added to the surfaces to make them hydrophilic. After the SiO₂ modification, the CeO₂ nanofibers were immersed in Cu-Cr-O precursor and annealed in a vacuum atmosphere to form CeO₂-CuCrO₂ nanofibers. The CuCrO₂, CeO₂, and CeO₂-CuCrO₂ nanofibers were examined by X-ray diffraction analysis, transmission electron microscopy, field emission scanning electron microscopy, scanning transmission electron microscope, thermogravimetric analysis, and Brunauer-Emmett-Teller studies (BET). The BET surface area of the CeO₂-CuCrO₂ nanofibers was 15.06 m²/g. The CeO₂-CuCrO₂ nanofibers exhibited hydrogen generation rates of up to 1335.16 mL min^-1 g-cat^-1 at 773 K. Furthermore, the CeO₂-CuCrO₂ nanofibers produced more hydrogen at lower temperatures. The hydrogen generation performance of these CeO₂-CuCrO₂ nanofibers could be of great importance in industry and have an economic impact.

Hydrothermal synthesis of high surface area CuCrO2 for H2 production by methanol steam reforming

Hydrogen (H₂) is viewed as an alternative source of renewable energy in response to the worldwide energy crisis and climate change. In industry, hydrogen production is mainly achieved through steam reforming of fossil fuels. In this research, hydrothermally-synthesized delafossite CuCrO₂ nanopowder were applied in methanol steam reforming. Reducing the size of the CuCrO₂ nanopowder significantly improved the efficiency of hydrogen production. The prepared CuCrO₂ nanopowder were characterized by X-ray diffraction, Brunauer-Emmett-Teller (BET) analysis, field emission scanning electron microscopy, and transmission electron microscopy. The calculated BET surface area of the hydrothermally synthesized CuCrO₂ nanopowder was 148.44 m² g^-1. The CuCrO₂ nanopowder displayed high catalytic activity, and the production rate was 2525 mL STP per min per g-cat at 400 °C and a flow rate of 30 sccm. The high specific area and steam reforming mechanism of the CuCrO₂ nanopowder catalyst could have vital industrial and economic effects.

Advances in Methanol Production and Utilization, with Particular Emphasis toward Hydrogen Generation via Membrane Reactor Technology

Methanol is currently considered one of the most useful chemical products and is a promising building block for obtaining more complex chemical compounds, such as acetic acid, methyl tertiary butyl ether, dimethyl ether, methylamine, etc. Methanol is the simplest alcohol, appearing as a colorless liquid and with a distinctive smell, and can be produced by converting CO₂ and H₂, with the further benefit of significantly reducing CO₂ emissions in the atmosphere. Indeed, methanol synthesis currently represents the second largest source of hydrogen consumption after ammonia production. Furthermore, a wide range of literature is focused on methanol utilization as a convenient energy carrier for hydrogen production via steam and autothermal reforming, partial oxidation, methanol decomposition, or methanol⁻water electrolysis reactions. Last but not least, methanol supply for direct methanol fuel cells is a well-established technology for power production. The aim of this work is to propose an overview on the commonly used feedstocks (natural gas, CO₂, or char/biomass) and methanol production processes (from BASF-Badische Anilin und Soda Fabrik, to ICI-Imperial Chemical Industries process), as well as on membrane reactor technology utilization for generating high grade hydrogen from the catalytic conversion of methanol, reviewing the most updated state of the art in this field.

Progress in Methanol Steam Reforming Modelling via Membrane Reactors Technology

Hydrogen has attracted growing attention for various uses, and, particularly, for polymer electrolyte membrane fuel cells (PEMFCs) supply. However, PEMFCs need high grade hydrogen, which is difficult in storing and transportation. To solve these issues, hydrogen generation from alcohols and hydrocarbons steam reforming reaction has gained great consideration. Among the various renewable fuels, methanol is an interesting hydrogen source because at room temperature it is liquid, and then, easy to handle and to store. Furthermore, it shows a relatively high H/C ratio and low reforming temperature, ranging from 200 to 300 °C. In the field of hydrogen generation from methanol steam reforming reaction, a consistent literature is noticeable. Despite various reviews that are more devoted to describe from an experimental point of view the state of the art about methanol steam reforming reaction carried in conventional and membrane reactors, this work describes the progress in the last two decades about the modelling studies on the same reaction in membrane reactors.