walruslover69
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Subcritical Water Reactor (asking for experience)
I am very interested recently in green chemistry, specifically replacing organic solvents with subcritical water for extraction and reactions.
I have read a multitude of papers that carry out reactions in sub critical water such as
"Dehydration of lactic acid to acrylic acid in high temperature water at high pressures"
Subcritical Water Extraction of Natural Products
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8271798/
I am not attached to any specific target molecule but more interested in building a setup where I can experiment and better understand the process of
using sub critical water as a replacement for organic solvents.
An apparatus compatible with subcritical water extraction needs to be able to withstand
1) High temperatures. I would like to be able to reach 175-200C, but could settle for 150C .
2) High pressures. Goal of 150 Psi working pressure
3) Resistance to Hot water. Water at these temperatures can become significantly more corrosive.
I am reaching out to any forum members who have experience building an apparatus like this, or working with sub critical water.
I want to get an understanding of what building an apparatus would involve and how feasible a project like this is.
If this is successful I want to make it a priority to take suggestions from people on application of this apparatus, so feel free to leave ideas for
future projects as well.
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BlenderS4m
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The simplest way to construct pressurized apparatus is to use standard piping, fittings, and valves which are rated to the design pressures and
temperatures. You would likely use threaded fittings in the construction of your apparatus. I will suggest a book to you which should familiarize
yourself with the language of piping and the different components available:
Pipe Drafting and Design by Roy A Parisher Chapter 3, 5, and 6. Read up on threaded fittings, valves (ball, globe, butterfly, needle, pressure relief
valve/safety valve, and check valve), and pumps.
Be aware that with metals the yield strength decreases with temperatures. Therefore, the pressure rating of piping components is dependent on
temperature. Resources such as engineeringtoolbox.com are useful for finding information on the pressure rating of different piping components.
However, it is not so much an official source. The official source for information would be to refer to the ASME standards, which are unfortunately
not freely available. Relevant standards for your application are: ASME Boiler Pressure Vessel Code (BPVC) Part VIII, and ASME B31.3, Process Piping.
In the US any pressure vessels which operates at >15 psig is required to conform to these codes.
Since your pressures and temperatures are relatively mild (in terms of pressure vessel design) you could probably get away with threading standard/Sch
40 piping and fittings together.
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EF2000
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Pipe Drafting and Design, Fourth Edition: https://annas-archive.org/md5/7770886e1c18cf76b2ecfbdf67379c...
ASME Boiler Pressure Vessel Code (BPVC) Section VIII Division 1: https://annas-archive.org/md5/728272a798ff8ceede8c3216cdeed3... (Divisions 2 and 3 are about much higher pressures)
And ASME B31.3 (2018): https://annas-archive.org/md5/9e99580b503dff52781ba61f351af1...
By the way, our GOST standards are always freely available, be it dairy products conservation or rocket fuel. Take it,
ISO.
Wroom wroom
"The practice of pouring yourself alcohol from a rocket fuel tank is to be strongly condemned encouraged"
-R-1 User's Guide
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Sulaiman
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No experience but....
For 220C, PTFE
https://www.ebay.co.uk/itm/275450449104?_nkw=hydrothermal&am...
For 280C, PPL
https://www.ebay.co.uk/itm/364974548765?_trkparms=amclksrc%3...
CAUTION : Hobby Chemist, not Professional or even Amateur
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Copenhagen1968
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This sounds like an interesting project. I might build one myself.
Are you looking for a batch system or a continuous system?
If it is an option for you, I would recommend looking at swagelok.com for fittings, valves, regulators and measuring equipment. It may not be the
cheapest solution, but 150 psi (10.3 bar for SI persons) is definitely in range for swagelok. A quick look revealed they can handle up to 450
Fahrenheit (232 degC) and the pressure is 'limitless' compared to your goal ( >>1000 psi).
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bobm4360
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Your local homebrew (beer/wine) supply may have sch 40 stainless steel pipe and fittings.
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