Seawater desalination device that extracts magnesium from seawater

There are 1800 trillion tons of magnesium (100,000 years worth of oil equivalent) in seawater around the world. How to get this out was a big issue. Previously, an electrolysis method was proposed, but it requires a huge amount of energy, so magnesium made in this way cannot be used in a decarbonized society. In addition, there are seawater desalination devices such as RO (reverse osmosis membrane) membranes, but these are for making drinking water from seawater, and are designed so that salt and magnesium are discarded as unnecessary. increase.

Professor Emeritus of Tokyo Institute of Technology Yabe proposed the world's first seawater desalination device specializing in magnesium sampling. Here's what this looks like.

大気圧での蒸発

　沸騰と蒸発の違いを誤解している人が多いのですが、沸騰は沸騰温度（水の場合は、大気圧で100度C）に達したときに、水の内部から気泡が発生する現象です。一方、蒸発はコーヒーの湯気のように、沸点に達していなくても、表面から水分子が飛び出してくる現象です。

　汗をかいても、体温30度くらいでも汗は乾きます。すなわち汗が蒸発しているのです。

　　ただ汗が乾くには数十分以上かかります。この速度を上げるには、表面積を増やす必要があります。左図のように、水を微細な球形にすれば表面積は格段の増加します。水を微粒子にするには、超音波などの振動を与えたり、微細なノズルから水を吹き出す方法など多数ありますが、あとで述べる熱回収と組み合わせるためには、より簡単な方法が必要です。
　　これには、矢部が1975年に提案した、魚の養殖のための微細気泡発生装置が最適です。これは高速で回転する水車に水を当てるだけのものです。
　　この方法により、大気圧で蒸発できる装置ができました。このメリットは大きく、装置がプラスティックでも作れ、軽量で安価な装置となりました。

Experiment at a sewage treatment plant in Taizhou City, Zhejiang Province, China

December 10, 2019

A portable sewage treatment device capable of producing 1 liter per hour was carried by baggage from Japan, and the experiment

Sewage (left) becomes purified water (right)

Support for existing equipment (remora plan)

Existing seawater desalination equipment such as reverse osmosis membranes dump seawater containing high concentrations of salt and impurities into the ocean.

Use Yabe's freshwater equipment to solve this problem. We will call this the remora project. This is because I don't have to do anything just by sticking to a huge shark called the reverse osmosis membrane method. In the reverse osmosis membrane method, 1 fresh water is produced and 2 high-concentration seawater is released with 3 seawater inputs. This is the cause of the problem, so if you put Yabe's device there, you can generate 2 fresh water from this 2 high-concentration seawater, and solve the pollution problem. This plan will solve the pollution problem of existing equipment and triple the amount of fresh water produced.

3 billion people will be short of water in 2025

Nikkei Science May 2001 issue

The RO (reverse osmosis membrane) method requires new electricity

MSP Corporation
M agnesium S aves our planet

A company aiming for a magnesium recycling society

汗をかいても、体温30度くらいでも汗は乾きます。すなわち汗が蒸発しているのです。