Beijing: Chinese experts have developed an advanced system for separating hydrogen and lithium from seawater, which has been successfully tested.
Experts from Nanjing Tech University have created an advanced electrolyzer that can separate hydrogen and lithium from salt water instead of fresh water. Earlier, only fresh water was required for this task and a lot of energy was consumed.
According to a report published in the weekly Nature, the electrolyte used consists of concentrated potassium hydroxide. In a generator-like system, there is a difference in vapor pressure between the salt water and the electrolyte itself, and the seawater begins to turn into a gas.
The main role of the suitcase equivalent of an electrolyzer is a membrane called polytetrafluoroethylene (PTFE). When seawater vapor passes through this membrane, it is absorbed there. 11 such electrolysers were installed off the coast of Shenzhen and operated continuously for 133 days. During this time 386 liters of hydrogen was produced but its quantity is very small which is hardly 31 grams. If it is put into a hydrogen vehicle, it can hardly run up to three hundred kilometers.
An electrolyzer consumes five kilowatt-hours of energy and operates at 71 percent efficiency. Most importantly, however, it was operated continuously throughout this period and did not corrode from the salt water or develop any system failures.
Another important thing is that there is some amount of lithium in the sea which can be present in the form of lithium phosphate. It should be noted that lithium is the backbone of battery making.
