One of the watch words of the 21st Century is “Green Energy.” Scientists at Stanford University are working on what they are calling “Blue Energy.” The idea was first proposed by British Engineer R E Pattle in the journal Nature in 1954.
The process involves mixing fresh water with seawater. Salt is chemically a combination of sodium and chlorine and, when brought into solution, disassociate into their respective positive and negative ions. A steady current can be generated with appropriate electrodes – one made of Prussian Blue (which is used as a pigment for paints and in medicine and is the basis of the term “Blue Energy”) and the other a conducting polymer like polypyrrole (which is already found in batteries and other devices).
A prototype tested at a wastewater plant in San Francisco Bay maintained a 97% effectiveness in capturing energy to flush out effluent from the plant. Dr. Kristian Dubrawski, a civil and environmental engineer at Stanford said that “Blue energy is an immense and untapped source of renewable energy.” One cubic meter of freshwater that mixes with seawater produces 0.65 kW-hr of energy, enough to power a US house for half an hour. The mind staggers at the potential of this source of energy.
One of my hobbies is water coloring and my favorite color just happens to be Prussian Blue. If “Blue Energy” becomes as successful as it appears to be heading, then I might need to ration my Prussian Blue. In fact, maybe I need to stock up now. – Dr. Tom
Mechanical Engineers – Change Is Coming!
You Should Take the PE Exam Now.
Learn the Latest Here.
