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Subcritical H2O and Supercritical Methanol Processing

Subcritical H2O and Supercritical Methanol Processing

Subcritical H2O and Supercritical Methanol Processing

(OP)
Greetings Everyone!

I am new to these forums and I am impressed by the information I have seen so far!

I have been kicking this idea around since I first learned of the Saka Dadan Process to produce biodiesel from yellow grease.

A quick primer:
http://www.ecs.energy.kyoto-u.ac.jp/english/kenkyu/kenkyu-1.html

From what I understand, the best application of process is something like this:

Step 1: 1 part Yellow grease and 9 parts water are combined and heated to 270 Celsius and 10-20 MPa (approx 520 F and 1500-3000#) for 45 minutes, producing Free fatty acids, glycerol, and water.  The FFA are decanted and made ready for step two.

Step 2: 1 part FFA and 9 parts Methanol are heated to 270 Celsius and 10-20 MPa for 60 minutes, producing Fatty Acid Methyl Esters - biodiesel.

The reason for the over abundance of water and methanol above the molar ratio in each step is to ensure complete reaction.

My idea is for a continuous flow processor consisting of the following:

This is essentially the same for both steps, save a few changes in pumping rate and coil length.

Main reactor:

Bath of tetra ethylene glycol at 270 Celsius maintained by boiler.

Immersed in the bath is a coil of 3/4" stainless steel tubing that will serve as the reaction vessel.  In the coils will be the majority of the water or methanol, kept at 270 Celsius. At the proper ratio, the reactants are preheated and then injected into the reactor coils at a rate that ensures the reactants are in the vessel for the prescribed length of the reaction.  At the end of the reactor, the products are cooled, decompressed, and seperated for use.  The methanol or water will be recycled back into the beginning of the process.

My questions are:

How much tetra ethylene glycol per volume of processed material will I need to maintain continuous reaction temperature?

How many BTU's/volume of glycol does it take to keep it at the process temperature?

How big should a heat exchanger between the preheat and cooling steps be per volume?

Thanks for your patience and (hopefully) responses!

Dan



If I have not been clear enough or detailed enough for you to answer my questions, please feel free to say so.  I am more than happy to discuss my idea further.

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