Researchers devise cheaper, faster way to continuously produce amines
Date:
May 4, 2022
Source:
North Carolina State University
Summary:
Chemical engineering researchers have developed a faster, less
expensive technique for producing hindered amines -- a class
of chemicals used as building blocks in products ranging from
pharmaceuticals and agrochemicals to detergents and organic light
emitting diodes.
FULL STORY ========================================================================== Researchers at North Carolina State University have developed a faster,
less expensive technique for producing hindered amines -- a class of
chemicals used as building blocks in products ranging from pharmaceuticals
and agrochemicals to detergents and organic light emitting diodes.
========================================================================== "Hindered amines are used in a tremendous variety of products, but all
of the existing techniques for producing these amines are complicated
and expensive," says Milad Abolhasani, corresponding author of a paper on
the new technique and an associate professor of chemical and biomolecular engineering at NC State.
"We set out to develop a better method for synthesizing these hindered
amines, and we were successful." One of the less expensive techniques
for producing hindered amines is hydroaminomethylation, or HAM. However,
the chemical industry has largely avoided using HAM, because there are
too many ways things can go wrong - - leaving producers with undesirable chemicals instead of the functionalized amines they were trying to
make. Researchers have improved the HAM process over the years. But
all of the techniques for avoiding undesirable byproducts have meant
extending the timeframe of the HAM process, so that it takes hours to
perform all of the necessary reactions. Until now.
"We've developed a HAM technique that makes use of continuous flow
reactor technologies to produce hindered amines more efficiently,"
Abolhasani says.
"Our HAM process takes less than 30 minutes in most cases. The only
products are hindered amines and water. And we are able to recycle the
primary catalyst, rhodium/N-Xantphos, which further drives down costs."
The success of the new technique is made possible by two things. First,
by using a continuous flow reactor that allows for continuous flow of
both gases and liquids in a segmented flow format, the researchers were
able to make the kinetics of the reaction far more efficient. Second,
the new technique makes use of a co-catalyst -- fluorinated benzoic
acid -- which reduces the amount of energy needed to perform some of
the necessary reactions in the HAM process.
Ultimately, this technique drives down the cost of producing hindered
amines using inexpensive feedstock, allowing users to produce them more
quickly and with no toxic byproducts.
"By designing a cooperative catalyst system, we've demonstrated that
the rate of the HAM reactions in our system can be 70 times higher
than the existing state-of-the-art processes," says Malek Ibrahim,
first author of the paper and a former postdoctoral researcher at
NC State. "This process is also a good example for how flow chemistry
platforms can improve catalyst turnover frequency, which is increasingly important as the price of rhodium catalysts goes up." The new technique
is particularly attractive for decentralized manufacturing operations,
since the small footprint of the necessary equipment and its scalability
allows users to efficiently produce hindered amines on site and on demand.
"What's more, the same technique can also be used to produce enamines --
which are other chemical building blocks -- on demand, simply by tuning
the solvents we use in the flow reactor," Ibrahim says. "You can literally switch back and forth between producing amines and enamines without having
to stop the production process, since the only thing you're changing is
the solvent mixture." The researchers have filed a provisional patent
on the new technique and are now looking for industrial partners to put
the technique into widespread use.
The work was done with start-up funding from NC State.
========================================================================== Story Source: Materials provided by
North_Carolina_State_University. Original written by Matt Shipman. Note: Content may be edited for style and length.
========================================================================== Journal Reference:
1. Malek Y. S. Ibrahim, Milad Abolhasani. Recyclable cooperative
catalyst
for accelerated hydroaminomethylation of hindered amines in a
continuous segmented flow reactor. Nature Communications, 2022;
13 (1) DOI: 10.1038/ s41467-022-30175-0 ==========================================================================
Link to news story:
https://www.sciencedaily.com/releases/2022/05/220504082615.htm
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