Latest Buzz...


Thursday, November 11, 2021

Hydrogen from Renewable Energy

 It may be surprisingly simple to make hydrogen commercially viable with renewable energy. 

In a renewable energy powered electrolyzer 91 tonnes of water can be decomposed into 80 tonnes of oxygen and 10 tonnes of hydrogen leaving a residue of 1 tonne of water. 

See for example "Alkaline Water Electrolysis Powered by Renewable Energy: A Review" by Jörn Brauns and Thomas Turek, Institute of Chemical and Electrochemical Process Engineering, Clausthal University of Technology, Leibnizstr. 17, 38678 Clausthal-Zellerfeld, Germany. 

A schematic flow diagram of an alkaline water electrolyzer.

At the target price of $2 per kilogram, the 10 tonnes of hydrogen has a sale value of $20,000.

The residue of 1 tonne of water contains a little over 7 kilograms of deuterium oxide. 

At $1,500 per kilogram, the 7 kilograms of deuterium oxide has a sale value of $10,500. 

The 80 tonnes of oxygen has a number of potential uses. 

One use is to generate electricity in a gas turbine while partially oxidising 80 tonnes of biomethane into 20 tonnes of hydrogen and 140 tonnes of carbon monoxide. 

See for example "Integrated Coproduction of Power and Syngas from Natural Gas to Abate Greenhouse Gas Emissions without Economic Penalties" by Mikhail Granovskiy, Southern Research, Laboratory of Sustainable Chemistry and Catalysis, Birmingham, Alabama, USA. 

Schematic diagram of syngas utilization to manufacture formic acid.

At the top-left of the above schematic diagram, the "Air Separation Unit" is replaced with an alkaline water electrolyzer that produces oxygen, doing away with the need for an "Air Separation Unit".

At the target price of $2 per kilogram, this 20 tonnes of hydrogen has a sale value of $40,000.  

The power generated may be sold or used in powering the electrolyzer. 

The 140 tonnes of carbon monoxide can be combined with 90 tonnes of water to produce 230 tonnes of formic acid. Formic acid can be used in various industrial processes. 

At a price of $500 a tonne, the formic acid has a sale value of $115,000

Note that there are no carbon dioxide emissions. 

There is no carbon capture and storage required.