Researchers from Georgia Tech have figured out how to release hydrogen from even the toughest sources of biomass. This article from Chemistry World says Yulin Deng and his team at the university developed a low-temperature electrolytic technology that can crack even molecules like lignin and cellulose, eliminating the need to use fossil fuels to release clean-burning hydrogen.
The process takes place in an electrolysis cell containing a membrane that protons can pass through, sandwiched between an anode and a cathode. Water containing both powdered biomass and polyoxometalate (POM), a metal oxide catalyst, is added to the anode side of the cell. By heating the solution or exposing it to sunlight, POM molecules can grab hydrogen atoms from the biomass, becoming H-POM. Applying a voltage across the electrodes causes the H-POM molecules to dump an electron onto the positively charged anode, and a proton into the electrolyte solution. The electrons flow around a circuit to the cathode side of the cell, while the free floating protons diffuse though the membrane and combine with these electrons at the cathode, forming hydrogen atoms. The atoms then react to form stable hydrogen gas, which can be collected.
Experts in deriving hydrogen from biomass have praised the new approach. ‘This process provides an open door to using smaller quantities of biomass and different biomass varieties for renewable hydrogen production,’ comments Chris Zygarlicke, at the University of North Dakota, US. And David King from the Pacific Northwest National Laboratory, US, says, ‘this is really interesting work … the claimed Faradaic efficiency for the process is extremely high.’
Deng and his team are currently working to make the method even more efficient. ‘Our goal is to collect 100% of the hydrogen atoms from biomass. We’re also looking for an industrial collaborator to scale up the technique.’