so I'm really quite excited today
because we've had a paper published
about our
research to understand the paper you
need to appreciate that I'm a very bad
chemist in making
molecules my skills in the lab in
preparing things have always been poor
so I have always been fascinated by
machines in which you pump in the
chemicals that're going to react and out
comes product
these days my group uses a reactor which
is just a piece of metal
tube which if you look through it is
empty and we fill it with a
catalyst which turns reactants into
products so the actual reactor looks
like this with tubes to pump things in
and one to pump them out we pump our
reactants in with high press carbon
dioxide so-called super critical fluid
removes the need to have other solvents
you can see there's some kit B behind me
here which I use for demonstrating
supercritical fluids to visitors to my
office now the problem with reactors
like this is that there are all sorts of
different reaction conditions that you
have to alter to get the best result you
have to change the temperature so you
get the best temperature you have to
alter the flow rates of of the chemicals
through it and in the case of carbon
dioxide you can vary the pressure and
this is quite a slow process it takes a
long time and to be honest it's really
boring or can be changing the
temperature just a tiny bit looking at
the results changing it again and so on
now we made it easier some time ago by
putting a machine on the um outflow of
the reactor which analyzes the products
automatically a gas chromatograph which
will tell you how much of the different
products you've got so this brings me to
our new paper you can see it's here it
was published online today so you can
see it already still says these are not
the final page numbers so it's really
hot it's called self-optimizing
continuous reactions in supercritical
carbon dioxide the point about this EXP
experiment the the thing that's really
important is the first word of the title
self optimizing so what we've done is to
use the signals from the gas
chromatograph to adjust the conditions
of the reaction so you begin by telling
the reactor which product you want you
give it a few starting conditions so it
knows approximately the right
temperatures and pressures and then you
let it get on with it it analyzes the
first
four different sets of conditions and
then the computer attached to the
machine calculates what it thinks is a
better condition and it goes on
gradually improving things till it gets
the highest possible yield of the
product and you don't need to do
anything you can be lying in bed and the
Machine is working away and the thing
that's exciting is that it takes away
all the boring bits and lets you think
about the science
but let's go to the lab and have a look
so you can see it for yourself this is
one of my other students Ryan who's Now
using the machine to go on to do other
reactions beyond what we've already
published because it takes quite a long
time between writing the paper and
getting it published in this reaction
and the one we used to prove the idea
we're reacting an alcohol not ethanol
but pentanol that has five carbon atoms
with a molecule called dimethy carbonate
which makes an ether the mixture of the
two starting materials pentol and DMC
are in this bottle here and they're bit
going through this pipe and into a pump
and the pump pumps the reaction solution
into the
reactor and at the same time we have a
second pump that pumps in the carbon
dioxide the cylinder that holds the
carbon dioxide is in the cupboard behind
me the reactants and the carbon dioxide
are mixed here one comes in this side
one that side and this measures the
temperature here there is So-Cal
preheater which warms things up and then
it goes through the reactor which is
exactly like the one in my office but it
has a metal block around it to heat it
up then the product comes out of this
pipe up to here this is a valve which
takes small samples into this machine
that analyzes it the gas chromatograph
and the rest of the flow which we
haven't analyzed continues on into this
valve that releases the pressure and the
product goes into the bottle here the
important thing is really the signals
that go to the computer then over there
to where the results are anal now we
calculated in the paper that in the old
way we used to do it where we change the
temperature and look at that effect and
then rais the pressure a bit change the
temperature and so on the experiment
that we published would have taken 84
days to do it under computer control it
only took 36 hours so it's a huge saving
in time so some people might question is
this really chemistry I think it
definitely is it's on the borders of
chemistry and chemical engineering but
if you're interested like I am in
Greener ways of making chemicals you
can't just make tiny amounts in the lab
you have to be able to do it on a larger
scale eventually to build whole
factories to do this so I'm very excited
because I believe this is the way of
doing chemistry far more cleanly than
many of the chemical reactions are done
now so here you could see how the
computer is changing the conditions and
homing in around here in the best
possible yield for that particular
product so like all bits of science done
now it's not the professor who does the
experiments but there's a whole team and
everybody makes their contribution which
is why there are so many authors on the
paper and apart from that there are
acknowledgements on the paper to those
that have helped us particularly in this
case the technicians who made some of
the reactors and the other things that
we use so we're really proud the whole
team