
Most commercial methoxide mixing tanks are made from stainless steel. There is a good reason why - the chemicals are corrosive as well as toxic and flammable.
What is Methoxide?Methoxide is the chemical that is made by mixing methanol with either Potassium Hydroxide (KOH) or Sodium Hydroxide. Actually the are properly known as Potassium Methylate or Sodium Methylate. Mixing the Methoxide is an intermediate step in biodiesel production. The methylate is mixed and then added to the vegetable oil. The methylate reacts with the oil and converts it into glycerine and biodiesel. |
A 304 or better grade stainless steel is rated for use with methanol and caustic soda, it is a good, safe choice for dealing with them.
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Biodiesel plant with methoxide tank in the middle |
Most home biodiesel plants use a plastic methoxide mixing tank, a carbouy is often used (the typical 25 litre methanol container is a carbouy). This is not necessarily a bad thing but you need to be aware of the issues that you can have.
These plastic tanks can be used safely, be aware of the methanol and caustic chemicals and work safely.
When using a carbouy or a non sealed tank for methoxide mixing:
Whenever mixing methoxide have a fire extinguisher close by, also running water. Remember you can put out a methanol fire with water.
The methoxide should be sucked into the processor through the pump. In our processor it gets sucked in via valve 2. Leaving valve 4 partially open sucks the oil from the bottom of the processor at the same time and mixes the methanol into it.
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