I want to convert cellulose to another form (crystalline => amorphous). Cellulose requires a temperature of 320 °C and pressure of 25 MPa to become amorphous in water.(Is the pressure achievable in the lab?)

Is this doable in the lab and how should I begin on reproducing that situation (which tools would I need) ?

I'm guessing that a bunsen burner would produce high enough temperatures (but I'm not quite sure about the pressure)

EDIT to my question, following up the advice of bobthechemist...

Crystalline substance to amorphous - Other ways? You can convert crystalline cellulose to the amorphous, more reactive form by heating it to a temperature of around 320°C under a pressure of 25MPa.

But are there other, less extreme ways, to achieve that amorphous form of the compound? So because I can't achieve these high temperatures, how can I achieve it in another way?

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    $\begingroup$ That kind of pressure can be achieved in commercial high pressure reactors as far as I know. So if you have access to such equipment and know how to handle it safely, this should be possible. $\endgroup$ – Mad Scientist Sep 3 '13 at 18:24
  • $\begingroup$ and without being able to use high pressure reactors? would I stand a chance? $\endgroup$ – user2117 Sep 3 '13 at 18:25
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    $\begingroup$ A pretty good chance at injuring yourself, I'd say. I wouldn't dare to try such pressures with any improvised equipment, you're very likely to just blow the whole thing up. $\endgroup$ – Mad Scientist Sep 3 '13 at 18:26
  • $\begingroup$ ok - so there is no possibility what so ever to do that? $\endgroup$ – user2117 Sep 3 '13 at 18:28
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    $\begingroup$ That's about 250 times atmospheric pressure. A quick back of the envelope calculation suggests that a 160 pound person standing on a block that is 0.5x0.5 cm could generate 25 MPa of pressure. You'd need to be a very good acrobat to do that over a bunsen burner. $\endgroup$ – bobthechemist Sep 3 '13 at 19:25

25MPa is just north of 3600psi for those of us that haven't converted to SI units; 320*C ~= 608*F. Your average lecture bottle is rated to about 3000psi, while compressed gas cylinders can go as high as 6000psi. Trouble is, most of them don't stand up well to being heated by an open flame. Temperature is another beast; your Bunsen burner can easily achieve a flame temperature well in excess of 600*F (and a simple variation, the Meker burner, can hit more than twice that), but your Pyrex glassware is only rated to 500*F, and that for short periods. Bunsen burners are often used for glassworking on the lab bench, creating custom tubing rigs by softening straight tubing and then bending or stretching to create bends and bottlenecks. If the glass can be molded over a Bunsen burner, it's not going to be able to sustain the temperatures you're talking about.

The short of it is that both the temperature and pressure are possible, but neither are achievable with a benchtop apparatus in a fume hood; you'll need an HTHP reactor vessel rated for your experimental conditions. They exist, but whether you can get access to one is another question only your superior can answer. If you were planning on visually studying the change in the cellulose, you'll need a sapphire viewport, and these get very expensive very quickly.

Once you have the right tool for the job, it becomes a rather academic task of calculating how much volume of reactants are required to achieve the desired pressure in the vessel when heated to temperature, then filling the vessel and evenly heating it. Only two of the vessels in the linked column hold any appreciable amount of material at the proper temp and pressure, and one of them will just barely meet your needs; if you unevenly heat any of these vessels, by the time the far end reaches the proper temperature the spot being heated will have failed.

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