Catalytic aspects of industrial hydrogenations of nitriles

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F60461373%3A22310%2F18%3A43916865" target="_blank" >RIV/60461373:22310/18:43916865 - isvavai.cz</a>

Result on the web

<a href="https://www.icct.cz/predchozi-konference/2018" target="_blank" >https://www.icct.cz/predchozi-konference/2018</a>

DOI - Digital Object Identifier

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Result language

angličtina

Original language name

Catalytic aspects of industrial hydrogenations of nitriles

Original language description

Part: The possibilities of producing lower aliphatic dialkylamines and trialkylamines by nitrile hydrogenation in CSTR. The possibilities of producing lower aliphatic trialkylamines &amp; dialkylamines by nitrile hydrogenation are discussed and potential problems of such a production method are described and summarized. The paper is focused mainly on the possibility of manufacturing in continuous slurry stirred-tank reactors. Lower aliphatic dialkylamines can be produced commercially by hydrogenation of nitriles in these reactors, but it is not possible to produce trialkylamines, if sponge metal catalysts (Raney catalysts), incl. the modified types, are used. Trialkylamines are formed in significant quantities only if supported palladium catalysts are used. Nevertheless, this reaction path is unsuitable and inscrutable for the trialkylamine industrial production. In addition, the CSTR mode cannot be applicable for the nitrile hydrogenation catalyzed with Pd. Opposite to Raney-Ni, where nitrile hydrogenation follows the zero-order kinetics respect to the nitrile conversion, the kinetics of hydrogenation of nitriles on Pd is of an order higher than one. The reaction rate decreases progressively with the nitrile concentration in the reaction mixture and at nitrile concentrations lower than 1% it is in principle at zero. In many cases, the reaction stops before the 100% nitrile conversion is achieved. The steep decrease in the reaction rate along the nitrile conversion is caused by strong chemisorption of hydrogenation products to the Pd catalyst surface. This sorption is so strong that it causes complete deactivation of the catalyst. The loss of activity is not permanent, by washing the catalyst with a suitable solvent, it is possible to remove the strongly absorbed amines from its surface and renew partially its hydrogenation activity. Although the supported Pd catalysts are highly active for hydrogenation of unsaturated hydrocarbons at low temperatures already, their specific activity to nitrile hydrogenation is, by contrast, very low. In the nitrile hydrogenation, Pd is far less active than Ni.

Czech name

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Czech description

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Type

D - Article in proceedings

CEP classification

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OECD FORD branch

20402 - Chemical process engineering

Project

<a href="/en/project/LO1613" target="_blank" >LO1613: Future materials</a><br>

Continuities

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Publication year

2018

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Article name in the collection

PROCEEDINGS of the 6th International Conference on Chemical Technology

ISBN

978-80-86238-77-7

ISSN

2336-8128

e-ISSN

neuvedeno

Number of pages

5

Pages from-to

314-318

Publisher name

Česká společnost průmyslové chemie (ČSPCH)

Place of publication

Praha

Event location

Mikulov

Event date

Apr 16, 2018

Type of event by nationality

WRD - Celosvětová akce

UT code for WoS article

000461293800058